Browsing by Subject "Cervical cancer"

Human Papillomavirus-induced cervical cancer represents one of the most significant causes of female morbidity and mortality from cancer worldwide. Detecting HPV-related cervical disease during the premalignant treatable stage of development is critical to reduce the burden of this disease. Cervical cytology has been the primary screening tool for cervical dysplasia in the United States for decades. However in Haiti, early attempts to identify cervical dysplasia were thwarted by a high incidence of obscuring inflammation on conventional Pap smears. This study seeks to determine if liquid-based cytology screening can increase the detection of cervical dysplasia over conventional Pap smears when obscuring inflammation is present. The study population was recruited in Haiti and women underwent both types of cervical dysplasia testing; those for whom it was indicated underwent follow-up cervical biopsy. The cervical dysplasia tests were compared to each other using kappa agreement statistics with cervical biopsy as the gold standard for diagnosis. Both tests showed comparable sensitivity for dysplasia with and without inflammation-containing samples. The Pap test showed superior specificity by greater agreement with the gold standard biopsy, though the sample size was small. Interpretation of these results and application to a low-resource setting for implementation of a standardized screening regimen would require a larger sample size and cost/benefit analysis.

Background: Cervical cancer is a preventable disease with a disproportionate burden in Sub-Saharan Africa. In Kenya, cervical cancer is the leading cause of cancer-related death in women. In line with WHO recommendations, Kenya is offering screening to women between the ages of 30 and 65 years old; however, rates of screening uptake are far below desired levels due to economic, logistical, and social barriers. This study is phase 2 of a two-part trial exploring implementation strategies for HPV-testing using self-collected specimens. Drawing on lessons from phase 1, we offered HPV-testing through community health campaigns (CHCs) in rural communities followed by linking HPV-positive women to facility-based treatment. Methods: Target communities were enumerated before the CHCs to identify women in the age range of 30-65 years old and who were not pregnant. Women were educated about cervical cancer by community health volunteers and told of when and where the CHC would be happening. At the CHC, participants were consented, given a brief demographics survey, and instructed on how to self-collect cervical specimens for HPV-testing. Participants were later contacted via SMS messaging, phone calls, or home visits with their results. Women who were enumerated but did not attend the fair were visited at home and offered testing. Those who tested as HPV-positive were linked to their nearest health center for preventative treatment. Descriptive statistics and logistic regression were used to analyze the demographic characteristics of women who came to the CHC and women who sought treatment compared with those who didn’t. Results: A total of 3299 women were screened for HPV, an estimated target population reach of 77%. The average HPV positivity rate was 16.7% across both the CHCs and the mop up. Of the 551 women who were HPV positive, 278 of them (50.5%) sought treatment. Characteristics associated with screening at the CHC included being encouraged to come by someone the woman knows, having completed primary school, some secondary school or attending college and above, working in the labor, professional, academic professions, having heard of cervical cancer before, working outside the home, and having missed work to attend screening. Women who came to the CHC had 25% greater odds of seeking treatment compared to women screened in home visits. Characteristics associated with seeking treatment included having tested for cervical cancer before and having missed work to attend screening. Having heard of cervical cancer before was also associated with seeking treatment, but with less precise estimates. Conclusion: Social support for seeking care and knowledge of cervical cancer are associated with women attending community health campaigns that offer self-collected HPV-testing. Other demographics have weak or null associations with care-seeking behavior in this context, suggesting the CHC model with enhanced linkage to care methods could be a way to overcome some of the social and logistical barriers women face for accessing preventative treatment. However, at a treatment linkage rate of only 50%, more work needs to be done to further understand the barriers to care in this context.

Cervical cancer is the second leading cause of death for women worldwide with 85% of deaths occurring in low and middle-income countries, despite being both preventable and treatable if detected early enough. The burden of disease persists primarily due to a lack of access to early diagnostics and significant proportion lost to follow-up. In Peru specifically, the mortality rates of cervical cancer are among the highest in the world with an annual incidence of 48.2 per 100,000.

To provide low-cost and accessible colposcopy while maintaining image quality, the point of care tampon like (Pocket) digital colposcope is being developed in the Tissue Optical Spectroscopy (TOpS) Lab at Duke University. As part of the ongoing Pocket colposcope development and validation, the Generation 3 Pocket colposcope was tested for concordance to the standard-of-care Goldway SLC-2000 digital colposcope in a pilot study conducted in Lima, Peru. The goal of this study is to demonstrate equivalence in clinical diagnostic performance of the Generation 3 Pocket colposcope versus the standard-of-care digital colposcope.

100 patients were enrolled under the IRB approved study protocol Pro00052865. Paired images of cervices were collected with the standard digital colposcope and the Pocket colposcope for each patient using acetic acid and Lugol’s iodine as contrast agents. Biopsies were taken as part of standard-of-care whenever required. The paired images were blinded by device, randomized, and sent with an electronic survey to three Duke affiliated physicians who are highly trained in colposcopy.

The primary outcome measured was level of agreement using an unweighted kappa statistic between 1) overall diagnosis and 2) Reid Colposcopic Index scores for the Generation 3 Pocket colposcope and Goldway colposcope. The secondary outcome measured was sensitivity, specificity, positive predictive value, and negative predictive value.

The percent agreement for all physicians combined between systems for the overall diagnosis was 83.78% with a kappa of 0.5786 and p-value of <0.0000, and the percent agreement for the Reid Colposcopic Index score comparison was 72.3% with a kappa of 0.4366 and p-value of <0.0000 indicating strong concordance. Both systems performed similarly when compared to gold-standard pathology, with level of agreement ~66% and a kappa statistic of ~0.3, and p-values <0.0000.

The Generation 3 Pocket colposcope performed similarly to the standard Goldway colposcope and can be used to increase access to colposcopy, thereby reducing the burden of cervical cancer morbidity and mortality in Peru and around the world.

Background: Despite increasing availability of preventative HPV vaccines and screening strategies, uptake of these effective measures in Kisumu, Kenya is limited by cultural and logistical barriers. Limited understanding and societal perceptions of HPV and cervical cancer are potential sources of stigma that could negatively impact screening behavior. By designing and implementing a stigma-responsive educational intervention, we sought to improve understanding and risk perception and increase the likelihood cervical cancer screening.

Methods: We carried out a study of a stigma responsive strategy to deliver HPV-based cervical cancer prevention services in Kisumu, Kenya. Focus group discussions (FGDs) explored experiences of HPV and cervical cancer screening, health messaging and potential stigma sources. Qualitative analysis of the FGDs informed the development of a stigma-responsive educational video. Four Kisumu County healthcare facilities were randomized to either watch the video or receive standard HPV and cervical cancer education, after which participants at both sites completed a survey to measure HPV- and cervical cancer stigma. Stigma scores were compared between control and intervention groups using linear regression.

Results: Thirty women participated in the focus group discussions. Drivers of stigma included concerns about confidentiality and disclosure of HPV results, fears of cancer or implications of a sexually transmitted infection diagnosis. Anticipated outcomes included illness or death, financial hardship or family abandonment. The FGDs findings informed development of the educational video. A total of 288 women, 109 in the intervention group, completed the stigma survey. Mean HPV and cervical cancer scores were found to be statistically lower in the intervention arm, with Dholuo language associated with higher stigma levels in both arms.

Conclusions: This multi-step study explored knowledge, attitudes and beliefs specific to HPV and cervical cancer health messaging in western Kenya in order to develop and test a stigma-responsive education strategy. The stigma-responsive video demonstrated a quantitative decrease in stigma survey response means for those who watched the video. The pre-pilot design will drive a larger pilot study to examine the effect of the educational video on HPV self-sampling.

Cervical cancer is one of the most common gynecologic malignancies with significant morbidity and mortality globally. However, most pre-cancers are easily treatable such that early detection of cervical abnormalities is critical in improving patient prognosis. Despite the success of current cervical cancer screening methodologies, these techniques are still limited in accuracy, leading to undetected cervical lesions or unnecessary biopsies.

This dissertation will focus on the development of two optical modalities for early detection of cervical dysplasia: angle-resolved low coherence interferometry (a/LCI) and multiplexed low coherence interferometry (mLCI). Originally, a/LCI was developed as a clinical technique for detecting esophageal dysplasia by detecting nuclear enlargement in the basal layer of the epithelium. To improve the clinical utility of a/LCI, a novel processing algorithm was developed using a continuous wavelet transform (CWT) based analysis of the a/LCI data which demonstrated significant improvement in processing speed compared to previous analysis techniques. Future development of this algorithm may open the possibility for real-time clinical analysis of a/LCI data, improving the clinical utility of the instrument.

In addition, the a/LCI instrument was adapted for cervical imaging, and a clinical feasibility study was performed to determine the effectiveness of using a/LCI nuclear morphology measurements for detecting cervical dysplasia. a/LCI optical biopsies were taken from 63 distinct tissue biopsy sites and compared to histopathological analysis of co-registered tissue biopsies. Analysis of the a/LCI nuclear morphology data found a significant increase in the nuclear diameter in the basal layer of dysplastic tissue sites and demonstrated high sensitivity and specificity (both >0.80) for detection of cervical dysplasia and high-grade squamous intraepithelial lesions.

Secondly, mLCI was adapted for collecting A-scans over the cervical epithelium. An mLCI cervical probe was designed and a clinical study was conducted to image 50 patients with the new device. Linear discriminant analysis was performed on the mLCI data to automatically classify the cervical A-scans as either endocervical or ectocervical tissue towards the goal of automatic delineation cervical transformation zone. This device can be combined with a/LCI to direct optical biopsy scans to areas on the cervix which are most likely to harbor tissue dysplasia.

Finally, the two technologies were incorporated into a single multimodal imaging system. First, a benchtop scanning a/LCI system was developed by incorporating an image rotator and 2D scanner into the system to enable radial scanning on the sample. This system was integrated into a handheld probe for cervical imaging. Volumetric imaging using sparse depth scans and the scanning a/LCI technology was validated with a polystyrene microsphere phantom, and a pilot study was conducted to demonstrate the feasibility of using this instrument for comprehensive screening of cervical tissue for precancerous cells.

Introduction: Cervical cancer is one of the leading causes of death for women in Haiti. The purpose of this study was to evaluate the feasibility of HPV self-sampling using CareHPV™ and subsequent treatment with cryotherapy in urban and rural areas of Haiti. CareHPV™ is a vaginal self-sample HPV testing kit used to detect 14 types of high-risk HPV and cryotherapy is a form of treatment that freezes precancerous lesions with CO2 or nitrous oxide. Methods: The study took place in Port-au-Prince and three rural communities within the suburban commune of Leogane. Screening took place at clinics, community centers, and churches. Participants were given consent forms to sign, as well as a demographic questionnaire and an acceptability survey. If their HPV test result was positive, they were called up to three times to go the community clinic for treatment. The number of women that returned for treatment following a positive HPV test result were compared in the urban and rural communities with a chi square test of association and a prevalence rate ratio. Acceptability was measured quantitatively on the Likert Scale. Results: Feasibility was defined as 80% acceptability and 80% treatment uptake. Other factors related to feasibility such as screening numbers and geographical barriers were discussed. Eighty percent acceptability was reached in both rural and urban communities. Eighty percent treatment uptake was only reached in the rural communities, with a treatment uptake of 83.3%. Eighty percent treatment uptake was not reached in the urban communities, with a treatment uptake of 42.1%. The prevalence rate ratio of 1.98 indicates that rural participants were found to be nearly twice as likely to return for treatment than urban participants. The chi square test of association shows that this difference in treatment uptake is significant with an estimated p-value of 0.01 at an alpha of 0.05. Further research is needed to investigate the reasons for higher loss to follow-up for treatment in urban communities to further efforts to establish a national HPV screening program in Haiti.

Cervical cancer disproportionately burdens women in low-resource settings, with over 85% of cervical cancer deaths occurring in developing countries due to lack of access to effective, high-quality screening programs that facilitate early detection and treatment. The aim of this study is to evaluate whether the performance of a transvaginal digital colposcope (TVDC) developed at Duke University is equivalent to the more expensive standard-of-care colposcope at identifying precancerous lesions of the cervix. Thirty-five paired cervix images, with confirmed pathologies and blinded by device, were sent electronically to six physicians, at four separate institutions, Duke University Medical Center (Durham, North Carolina, USA), La Liga Peruana de Lucha Contra el Cancer (Lima, Peru), Cancer Institute WIA (Chennai, India), and Kenyatta University (Nairobi, Kenya). Physicians completed a 1-page survey assessing cervix characteristics and overall severity of precancerous lesions for each image. Analysis included percent agreement between devices as well as identifying patterns across misdiagnosed images. The agreement between physicians using each device is 80.1% with kappa of 0.6049. The TVDC performed equivalent to standard-of-care colposcopy at identifying precancerous lesions of the cervix. Implications of these findings have the potential to create increased access to a culturally appropriate screening technology, thus reducing the burden of cervical cancer throughout the developing world.

Background: Cervical cancer is the fourth most common cancer worldwide, despite its highly preventable nature. Cervical cancer disproportionately affects individuals in low- and middle-income countries (LMICs), especially those in sub-Saharan Africa. Kenya experiences the highest cervical cancer incidence rate within the East African region (33.8 per 100,000 women) and is among the highest in the world. Huchko et al. demonstrated that cervical cancer screening via Human Papillomavirus (HPV)-based self-collection, led by community health volunteers (CHVs), is acceptable and well attended. While well received by communities in Western Kenya, researchers highlighted key barriers to the scale and potential effectiveness of this approach, including a need for electronic data collection and a lack of protocol and decision support tools for healthcare providers, who are often lay providers. Based on high reported mobile phone ownership within Kenya generally and past research documenting success with text message-based delivery of screening results within Western Kenya, the introduction of a mobile application-based intervention to address the identified challenges to cervical cancer screening and prevention appears feasible. This study sought to iteratively develop an mhealth intervention with key stakeholders, evaluate the usability of the intervention, and describe factors that limit and build cervical cancer screening self-efficacy among lay providers.

Methods: Between June 2019 and January 2020, we conducted a two-part study in Kisumu, Kenya to develop and pilot a mobile phone application, “mSaada.” In the first part of the study, between June and August 2019, a purposive sample of 18 participants completed in-depth interviews (IDIs) in two waves to provide a detailed review of the mSaada app and its features. Iterative revisions of the app were informed by participant feedback. During the second part, between October 2019 and January 2020, we conducted a small-scale pilot usability study within three healthcare facilities in Kisumu, Kenya. A convenience sample of 10 community health volunteers incorporated the mSaada mobile application into their daily interactions with clients during cervical cancer screening and education sessions. Participants completed usability and self-efficacy surveys throughout the study period as well as an in-depth interview to provide insight into their experience using mSaada.

Results: Iterative development of the mSaada mobile application resulted in major changes to the app’s user interface, aesthetics and organization, as well as the addition and clarification of educational content included within the platform. Overall, mSaada usability ratings increased significantly during the study period (4.54 to 4.84, p<0.001). During qualitative interviews, participants highlighted the app’s ease of use, impact on their workflow, and the comprehensiveness of the included information as strengths of mSaada. Participants did, however, cite concerns about the feasibility of broader implementation of the platform within Kenya. Overall, CHV self-efficacy increased significantly from the beginning to the end of the study period (4.53 to 4.74, p=0.008). When asked about factors limiting self-efficacy, participants discussed language barriers, time constraints, supply shortage, and privacy issues. Reference materials, personal knowledge, and experience and repetition were seen as factors that build self-efficacy.

Conclusions: While mSaada’s usability increased and the platform was observed to improve lay provider self-efficacy, much research is still needed in this area. Specifically, there is a need to engage women eligible for screening in future studies to help tailor mSaada such that it can best benefit the client population. Also, further development of the technological infrastructure within this setting is needed to promote long-term feasibility and sustainability of an mhealth solution like mSaada.

Our lab focuses on developing and optimizing drug delivery systems for applications in women’s health. In this field, development of drugs and drug delivery systems is hindered by a heavy reliance on empirically derived data, usually obtained from non-standardized, highly variable in vitro and in vivo animal experiments. Further, without a mechanistic understanding of the various phenomena progressing during drug delivery, experiments tend to explore complex parameter spaces blindly and randomly. Deterministic mathematical models can improve the efficiency of this process by informing rational drug and product design. In this work, we were interested in two applications: 1. drug delivery of topically applied anti-HIV microbicides to the female reproductive tract; and 2. Localized intratumoral injections of ethanol-ethyl cellulose mixtures for treatment of cervical lesions. Development of topically applied anti-HIV microbicides to prevent sexual HIV transmission is inefficient, with in vitro and in vivo tests having limited applicability to real product use. This issue is exacerbated by the dependence of drug performance on adherence and drug-administration conditions, which are not tested until clinical trials. Further, the lack of a standardized pharmacodynamic (PD) metric that is dependent on the heterogenous dynamics of viral transport and infection makes it difficult to identify the most promising drug candidates. Here we develop a deterministic mathematical model that incorporates drug pharmacokinetics (PK) and viral transport and dynamics to estimate the probability of infection (POI) as a PD metric that can be computed for a variety of anti-HIV drugs in development. The model reveals key mechanistic insights into the spatiotemporally dependent dynamics of infection in the vaginal mucosa, including susceptibility to infection at different phases in the menstrual cycle. Further, it and can be used as a platform to test novel drugs under several conditions, such as the timing of drug administration relative to the time of HIV exposure. Localized injections of ablative agents, immunotherapeutics and chemotherapeutics have potential for increased therapeutic efficacy against tumors and reduced systemic effects. However, injection outcomes thus far have been largely unsatisfactory, due to unintended leakage of the active pharmaceutical ingredients (APIs) to non-target tissues. Adding a gelling or precipitating agent to the injection can help ameliorate this limitation, by acting to contain the API within the target tissue. One such example is injection of ethanol-ethyl cellulose mixtures. Due to the insolubility of ethyl cellulose in water, this polymer phase-separates in the aqueous tumor environment, forming a fibrous gel that helps contain ethanol, the current ablating agent (and chemotherapeutic drugs in the future), within the boundaries of the tumor. Our collaborators have shown that this strategy can be an effective low-cost treatment strategy for superficial solid tumors, with cervical cancer and cervical dysplasia, and liver cancer, being promising targets. Here we present a mathematical model that enables characterization of the injection process. Our model uses Cahn Hilliard theory to model the phase separation of a precipitating or gelling agent during injection into poroelastic tissue. This theory is linked to the soft mechanics of tissue deformation during the injection, and to mass transport theory for the API. The model predicts key elements of the injection process, including the pressure field, the soft tissue displacement field, the phase constitution of the precipitating or gelling agent in the tissue, and the concentration distribution of the API in the tissue. The model enables us to explore relationships between these elements and fundamental injection and tissue parameters. This can inform design of optimized injection protocols. Select model predictions include that larger injection volumes do not significantly affect cavity volumes but do lead to faster transport of the API to target tumor tissue. However, although higher flow rates lead to larger cavities – in the absence of tissue fracture, and when injected volume is held constant – they also lead to slower delivery of the API into the target tumor tissue. This is due to the shorter injection times. Importantly, concentration distributions of the API are not sensitive to the speeds of precipitation of the precipitating agents or to diffusion coefficients of the API in the dense (gelled) phase of the injectate material. The model presented here enables first-pass exploration of injection parameter space for select tissue types (properties). This can aid in optimization of localized therapeutic injections in a range of applications.

Abstract

Background: While highly preventable cervical cancer remains a leading cause of

cancer in women globally. Sub-Saharan Africa is disproportionately affected, and in

Kenya specifically, over 4,800 new cervical cancer cases are diagnosed and over 2,000

deaths occur each year. While screening for human papillomavirus (HPV) is a more

cost-effective screening strategy with the potential to increase screening uptake, there is

substantial lost to follow-up (LTFU) for treatment following a positive HPV screen. This

study aimed to identify the predictors of successful treatment acquisition and explore

the barriers and facilitators to seeking treatment among HPV positive women.

Methods: This mixed-methods study was integrated into an ongoing clusterrandomized

trial of implementation strategies in rural western Kenya. This study

randomly selected 100 HPV positive women from the original study database and

conducted a treatment acquisition behavior survey. The study sought a 50/50 ratio of

women who were treated and LTFU, but obtained data from 61 treated women and 39

LTFU women. A subset of 10 women in each group were then selected for in-depth

interviews. Analysis included descriptive statistics to compare treated and LTFU

women’s responses to the survey questionnaire. Interview transcripts were coded and

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analyzed through code-by-code comparisons of women who were treated and women

who were LTFU.

Results: Cost of transportation and distance to the health facility were the most

common challenges in seeking treatment among both treated and LTFU women. Among

women who sought treatment, 67% (n=41) reported that their peers knew their HPV test

result, whereas among LTFU women only 38% (n=15) reported that their peers knew

their HPV test result (p=0.007). There was a significant difference in knowing their peers’

HPV result between treated and LTFU women (p=0.03). Partner support was described

by treated and LTFU women similarly, in that most women reported that they relied on

their partners for transportation money, and that men not understanding the disease

may prevent them from supporting their wives in seeking treatment. Additional barriers

included fear of the treatment process, stigma within their community, logistical

barriers, and lack of information on the disease and treatment. Facilitators to treatment

seeking included peer encouragement, support and encouragement of their children,

involving men in educational sessions, bringing facilities closer and providing

transportation to the health facility.

Conclusions: Cost of transportation, distance to the treatment facility, support of

partners and children, feelings of fear and stress, stigma within the community and

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logistical barriers were reported similarly across treated and LTFU groups. The greatest

disparity between the two groups was a lack of social support among LTFU women.

Given the potential impact of involving men and women in the community in

educational sessions, and promoting treatment seeking in groups, interventions that use

these treatment facilitators are needed.

The development of HPV vaccines has generated a great deal of hope that the burden of cervical cancer may be eliminated over the next several decades. However, this enthusiasm may be premature if the genotypes associated with high-grade cervical dysplasia and cancer in other countries does not match the select HPV genotypes that were targeted by current vaccines. The objective of this study was to document the profile of high-risk HPV genotypes that are associated with moderate and high-grade dysplasia in a subset of women living in Port-au-Prince and Leogane, Haiti. Preliminary data collected around the world and by Family Health Ministries in Haiti suggest that the high-grade disease seen in many communities may have a different spectrum than the US and Europe. The cross-sectional study was conducted in two medical clinics situated in the cities of Port-au-Prince and Leogane, Haiti. Genotype-specific distribution from cervical samples collected from 269 women was correlated with corresponding cytopathology results. Genotypes associated with HSIL or invasive cancer were HPV-16 (POR 6.8; 95% CI 2.62-17.86), HPV-18 (POR 4.3; 95% CI 1.46-12.40), HPV-35 (POR 4.3; 95% CI 1.63-11.33), and HPV-58 (POR 7.9; 95% CI 1.95-32.00). HPV-58 appeared to have a higher oncogenic potential than HPV-16 and HPV-18. There was a difference in the HPV genotypic profile found in cervical disease in this Haitian population compared to the United States and Europe. It may be less cost-effective to introduce existing HPV prophylactic vaccines to Haiti; resources may be better spent treating existing disease until more appropriate vaccines are developed.

Problem: Among HIV positive women in Kenya, cervical cancer has the highest incidence of any malignancy. In order to create effective screening strategies for both the primary and secondary prevention of cervical cancer in HIV-infected women, an understanding of the natural history of human papillomavirus (HPV) and HIV co infection is critical.

Objectives: To describe the prevalence of HPV genotypes in HIV infected women with mild dysplasia and those with biopsy-confirmed severe dysplasia and invasive cervical cancer in Eldoret, Kenya. To determine how CD4 count, as a marker of immunocompetence, relates to HPV genotype distribution in patients with compared to those with severe dysplasia and invasive cervical cancer.

Methodology: This was a cross-sectional study recruiting from two groups: women who have invasive cervical cancer and women who have mild dysplasia. Cervical swabs were collected for genotyping, along with a recent CD4 count and relevant sociodemographic and medical data. HPV genotyping for types 6, 11, 16, 18, 26, 31, 33, 35, 39, 43, 44, 45, 51, 52, 53, 54, 56, 58, 66, 68, 69, 70, 71, 73, 74, and 82 was performing using the INNO-LiPA HPV genotyping assay, SPF10 system version 1 (Innogenetics, Ghent, Belgium). Crude and covariate-adjusted prevalence odds ratios were calculated using logistic regression analysis, and were performed separately for each HPV-type. In addition, modification of HPV-type prevalence ratios by CD4 count was analyzed. All data analysis was performed using Stata 12.1 (College Station, TX).

Results: HPV 52 had a significantly higher prevalence in this population than HPV 16 or 18. Neither HPV genotype nor CD4 count had changed the prevalence odds of severe dysplasia and invasive cervical cancer. Participant age, history of syphilis, anemia, vaginal bleeding, and greater than five pregnancies increased the prevalence odds of severe dysplasia and invasive cervical cancer, compared to mild dysplasia.

Conclusions: These findings suggest that duration of HPV infection and host response to infection, rather than HPV genotype or CD4 count, are primarily responsible in the oncogenic transformation of infected cervical tissue. The overwhelming predominance of HPV 52 has implications regarding the efficacy of vaccination against HPV 16 and 18 in the primary prevention of cervical cancer in HIV infected women in Western Kenya.

Addressing disparities in the global cancer burden is a key part of the post-2015 Millennium Development Goals (MDGs). Cervical cancer is emblematic of that disparity, with 85% of cases and cancer-related deaths occurring in low and middle-income countries (LMICs). Many LMICs lack the health care infrastructure and highly trained personnel required for cytology-based screening and subsequent referral colposcopy based diagnosis, which have dramatically reduced the disease burden in wealthier countries. The World Health Organization (WHO) recommends adoption of alternative protocols that employ low-cost and simple-to-use screening technologies and treat all women who are positive based on these tests. Even those who manage to receive a proper diagnostic test are all too frequently lost to follow up care, leading to a disproportionately high burden of cervical cancer mortality in LMICs. One strategy, highly sensitive human papillomavirus (HPV) testing has been shown to reduce the incidence and mortality from cervical cancer when coupled directly with outpatient treatment for women with HPV-positive results. Although, recent guidelines have moved back from this “screen & treat” approach, given concerns about overtreatment. The American Society of Clinical Oncology (ASCO) and World Health Organization (WHO) recently released guidelines recommending that HPV be used as a screening test, followed by triage with visual inspection with acetic acid (VIA) or visual inspection with Lugol’s iodine (VILI) to confirm the presence of lesions. Uptake of HPV testing requires a significant capital investment in the automated device and samples are often banked and run in batches to reduce waste of reagents. While this co-testing methodology may decrease overtreatment, VIA or VILI still remains a poor triage test because of low sensitivity and specificity, and wide variability in interpretation due to poor quality control. Thus, there exists a need for a triage test that is low-cost, easy-to-use, and will provide reliable immediate results at the point-of-care setting.

The goal of the work presented here is to establish the design, development, and validation of a low cost portable digital colposcope that has comparable image quality, functionality, and diagnostic capability when compared to standard-of-care digital colposcopes and gold-standard histopathology.

Three specific aims were proposed to address this goal. First, the conceptualization, design, and validation of this device, the Pocket Colposcope will be presented. The Pocket Colposcope is shaped like a tampon and can be inserted and positioned such that it is 5-50 mm away from the cervix, obviating the need for high-end glass optics, high-resolution cameras, and high power illumination sources used in state of the art colposcopes, which typically operate at a working distance of 300 mm. An off the shelf miniature color complementary metal-oxide-semiconductor (CMOS) camera, with plastic injection molded lens, and small light emitting diodes (LEDs) could be repackaged inside the compact tampon like form factor and powered directly by a smartphone, tablet, or laptop through the universal serial bus (USB).

Each evolution of the Pocket Colposcope was quantitatively assessed with respect to standard-of-care digital colposcope or predicate device using industry standardized protocols and in preparation for the application to the US Food and Drug Administration (FDA) 510(k) preexisting medical device approval pathway. The Edan C3A/C6A digital colposcope (K151878) was used as the predicate reference device within the Pocket Colposcope’s 510(k) application which was successfully approved on September 25th, 2018 (K181034), which was granted on September 25th, 2018. We also characterized and compare the Pocket Colposcope to the standard-of-care digital colposcope at Duke University Medical Center (DUMC) the Leisegang Optik 2 (K140754), which was use as part of multisite international clinical trial evaluating the diagnostic performance of Pocket Colposcope discussed in Aim 2. The essential imaging parameters were characterized with industry standards: ISO 8600-5 used for optical resolution, ISO 8600-3 used for field of view, ISO 9039 and ISO 12233 used for distortion, depth of field, and ISO 18221 used for magnification. The essential illumination characteristics were characterized with: ANSI FL-1 was used for both beam diameter and illumination intensity.

The optical resolution for all the generations of Pocket Colposcope ranged between 10-72 line pairs per mm (lp/mm) and was substantially equivalent to the optical resolution range of 10-29 lp/mm of the pair of predicate devices. The field of view of all generations of the Pocket Colposcope ranged from 8-52 mm and was substantially equivalent to the field of view range of 12-76 mm reported by the predicate device pair. The picture-height distortion for all generations of the Pocket Colposcope ranged between -4.5 to -1.1% and were substantially equivalent to the 3-7% distortion reported by the pair of predicate devices. The depth of field range between 0.5-12 mm for all generations of the Pocket Colposcope were substantially equivalent to 6-20 mm range reported by the predicate device pair.

The illumination intensity range of 2,800 to 20,000 lux for all generations of the Pocket Colposcope was substantially equivalent to the reported range of 3,000 to 24,000 lux of the pair of predicate devices. Similarly, the beam diameter range of 33.8 to 49.0 mm for all generations of the Pocket Colposcope was substantially equivalent to 60-62.1 mm range reported by the pair of predicate devices.

The proof of concept first generation Pocket Colposcope was successful in capturing VIA and VILI images of the cervix, but suffered from issues that were addressed in subsequent generations. These issues included: frequent lens fogging, which required the use of anti-fogging wipes prior to each patient use, the need for ethylene oxide (EtO) gas sterilization between patient uses, a difficulty maintaining image focus due to lack of automated mechanism, and a reduced image quality due to specular reflection from the moist cervical tissue when compared to standard-of-care digital colposcope.

The second aim was to demonstrates concordant diagnostic performance of the Pocket Colposcope when compared to reference standard-of-care digital colposcopes and gold-standard histopathology in a multi-institution clinical trial.

An image concordance study was conducted under IRB approval and written informed consent of participants. Images of the cervix were collected by the Pocket Colposcope and standard-of-care device (if available) along with gold standard histopathology. These image pairs would be split, randomized, and digitally sent to blinded highly trained reviewers for clinical interpretation. These expert colposcopists were blinded to any demographic information of the patient, prior referral test results (Pap smear cytology, HPV status, HIV status, or histopathology), and each other’s interpretation of the image. A secure online questionnaire was sent to reviewers to record their responses. All data was stored securely on a Duke University Medical Center managed REDCap database server.

These interpretations would be compared between the Pocket Colposcope and standard-of-care device to demonstrate concordance performance or level agreement with the devices. The diagnostic performance of the Pocket Colposcope and standard-of-care devices were assessed by comparing the image interpretation to gold-standard histopathology with the generation of 2x2 contingency tables with entries for True Positives (TP), True Negatives (TN), False Positives (FP), and False Negatives (FN). The two binary diagnostic cut-offs were used: normal vs. LSIL/CIN1+ and normal vs. HSIL/CIN2+. From these 2x2 contingency tables sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Lastly, the diagnostic performance would be stratified by level of contrast used using Receiver Operating Characteristic (ROC) curves where the y-axis is the sensitivity and the x-axis is 1-specificity. The resultant area under the curve (AUC) can be compared using logistic regression to determine how changing the type of contrasts used impacts overall diagnostic performance.

A pilot clinical study (n=45 eligible subjects and read by 10 blinded highly trained clinicians) at Duke University Medical Center (Durham, NC) using the Generation 1 and 2 Pocket Colposcope, a standard-of-care digital colposcope (Leisegang Optik 2), using the contrast technique of visual inspection with acetic acid (VIA), and with gold-standard histopathology (from biopsy or post loop electrosurgical excision procedure (LEEP) specimen). The level of agreement between the Pocket Colposcope and standard-of-care when using the LSIL/CIN1+ vs. normal diagnostic cut-off was 77.8% with a moderate strength Cohen’s kappa coefficient () of 0.53, p<0.01. When the diagnostic cut-off was changed to HSIL/CIN2+ vs. normal the level of agreement between Pocket Colposcope and standard-of-care improved to 86.0% with a strong Cohen’s () of 0.64, p<0.01. The Pocket Colposcope and standard-of-care performed similarly when compared to the gold-standard histopathology. The overall accuracy when using the LSIL/CIN1+ vs. normal diagnostic cut-off and comparing to gold-standard histopathology was between 56.1-63.9%, with sensitivity between 39.1-56.0%, with specificity between 73.9-72.7%, for the Pocket Colposcope and standard-of-care, respectively. The diagnostic performance improved for both devices when the diagnostic cut-off was set to HSIL/CIN2+ vs. normal with accuracy climbing to 68.9-74.7%, with sensitivity unchanged 40.9- 56.4%, with specificity improving by ~14% for both systems to 86.1 to 86.4%, with respect to Pocket Colposcope vs. standard-of-care.

The performance of the Pocket Colposcope was now assessed in a resource limited setting with a clinical study (n=129 eligible subjects and read by 4 blinded highly trained clinicians) at La Liga contra Cancer (Lima, Peru) using the Generation 3 and 4 Pocket Colposcope, a standard-of-care digital colposcope (Goldway SLC-2000B), using the contrast techniques of visual inspection with acetic acid (VIA) and visual inspection with Lugol’s iodine (VILI), and with gold-standard histopathology (from biopsy or post loop electrosurgical excision procedure (LEEP) specimen). The level of agreement between the Pocket Colposcope and standard-of-care when using the LSIL/CIN1+ vs. normal diagnostic cut-off was 83.6 % with a strong Cohen’s kappa coefficient () of 0.67, p<0.01. When the diagnostic cut-off was changed to HSIL/CIN2+ vs. normal the level of agreement between Pocket Colposcope and standard-of-care improved to 86.2% with a strong Cohen’s () of 0.66, p<0.01. The Pocket Colposcope and standard-of-care performed similarly when compared to the gold-standard histopathology. The overall accuracy when using the LSIL/CIN1+ vs. normal diagnostic cut-off and comparing to gold-standard histopathology was between 63.9-67.6%, with sensitivity between 71.2-79.8%, with specificity between 57.5-56.6%, for the Pocket Colposcope and standard-of-care, respectively. The diagnostic performance was unchanged for both devices when the diagnostic cut-off was set to HSIL/CIN2+ vs. normal with accuracy of 63.1% for both systems, with sensitivity increasing slightly 80.7-82.2%, with specificity unchanged to 57.5-56.6%, with respect to Pocket Colposcope vs. standard-of-care.

The performance of the Pocket Colposcope was now assessed as part of the multinational clinical study with two additional partner sites joining the two prior sites: Kilimanjaro Christian Medical Center (KCMC) (Moshi, Tanzania) which used a digital camera (Canon SX40HS) as the standard-of-care device for part of the study, however the device broke and wasn’t repaired until this summer so some patients didn’t have matched standard-of-care images) and Centre for Infectious Disease Control Zambia (CDZIR) (Lusaka, Zambia) which used naked eye inspection and did not employ a standard-of-care device for this study. Pocket Colposcope Generation 1 through Beta and standard-of-care device (if available) were used to collect VIA, green light inspection (GLI), and/or VILI depending on the standard of practice at the clinical site. Gold-standard histopathology (from biopsy or post loop electrosurgical excision procedure (LEEP) specimen or post large loop excision of the transformation zone (LEETZ) specimen) were collected for eligible patients. Overall n=388 subjects have been enrolled from four clinical sites, with n=129 subjects undergoing VIA with 10 blinded expert reviewers, with n=92 subjects undergoing VIA+GLI with 7 blinded expert reviewers, with n=127 subjects undergoing VIA+VILI with 6 blinded expert reviewers, and n=40 subjects undergoing VIA+GLI+VILI with 4 blinded expert reviewers. For the purposes of this analysis we will focus on the Pocket Colposcope versus gold-standard histopathology stratified by the types of contrasts used. The overall accuracy when using the LSIL/CIN1+ vs. normal diagnostic cut-off and comparing to gold-standard histopathology increased consistently with type of contrasts used (VIA only, VIA+GLI, VIA+VILI, and culminating with VIA-GLI-VILI) with overall agreement improving from 53.4-70.1% with sensitivity improving from 42.3-68.1%, with specificity improving from 65.3-73.3%. The diagnostic performance when the diagnostic cut-off was set to HSIL/CIN2+ vs. normal generally followed the prior trend with consistent increases with type of contrast used (VIA only to VIA+GLI+VILI) with rising accuracy 55.9-70.8%, with sensitivity increasing 41.9-52.2%, with specificity improving 78.2-88.0%. Increasing the number of contrast agents used significantly improved the diagnostic performance of the Pocket Colposcope when compared to gold-standard histopathology.

The final aim is to add fluorescent imaging capability to the Pocket Colposcope to provide an additional source of contrast targeting metabolic and/or structural biomarkers that will further improve clinical performance of our system to match gold standard histology pathology and expand the application of the device. We there is broad applicability in other organ sites including: oral cavity, gastrointestinal tract, and skin.

The Beta generation of the Pocket Colposcope was modified for fluorescent imaging by adding excitation LEDs, repurposing of the Generation 3 external LED driver circuit to drive the excitation source, a matched band-pass optical filter for emission, reintroduction of cross-polarization to improve the fluorescent signal to noise, and modular tip that houses the LED ring and optical components without destructive modification of the Pocket Colposcope. A proof of concept device was characterized using a similar set of procedures used to assess the Pocket Colposcope for the 510(k) regulatory approval pathway. Ex-vivo and in-vivo pilot animal studies were conducted to demonstrate successful implementation of the fluorescent imaging capability using a FITC (Fluorescein isothiocyanate) tagged binding ligand (HS-27) with a strong affinity for the heat shock protein-90 (Hsp-90) chaperone molecule (a potential biomarker of cancer). The real time visual tracking of diffusion of ethanol from an ethyl-cellulose gel to surrounding tissue by using solvent properties of ethanol for FITC when compared to water (20 mg per mL vs. 0.1 mg per mL). This ethyl-cellulose gel is being investigated as a potential low cost technique for treating cancer with extended release of ethanol over time to localize treatment. Lastly, the fluorescent Pocket Colposcope was used in a pilot ex-vivo clinical studies in subjects undergoing breast biopsy to evaluate the diagnostic potential of HS-27 when compared to gold-standard histopathology.