CATCH - Community Access to Cervical Health
Invasive cervical carcinoma is a major cancer of women in the developing world. Nearly one-fourth of the new cervical cancer cases worldwide is estimated to occur in India, where a large majority is identified in an advanced and inoperable stage of disease. This is a public health tragedy, since among all major human cancers; cervical cancer is potentially the most preventable. It can be easily diagnosed in its pre-invasive stage, because the cervix is readily accessible for inspection and sampling and pre-invasive cervical abnormalities persist for many years and can be effectively treated.
Proof of prevention by early detection is evident in that the cervical cancer burden in the USA in the 1940's was similar to that of India at present, but had decreased by over 70% by the 1980's as a result of effective Pap smear screening programs and treatment of identified pre-invasive lesions. Despite the success seen in the US and elsewhere, it has been difficult, for various reasons, to establish and maintain effective Pap smear programs in India and other areas of the developing world. However, in the past few years, there has been a marked progress in our understanding of the etiology and molecular pathogenesis of cervical cancer. It is now recognized that cervical cancer in all parts of the world is the end result of a process that is initiated by infection of the genital tract with high-risk human papillomaviruses (HPVs) and that only a small proportion of infected women develop invasive cancer many years after the initial infection.
Many new strategies of cervical cancer screening monopolize on the understanding of HPV infection as a necessary cause of cervical cancer. These strategies may allow the application and development of more objective screening tools that can be successfully implemented in resource-poor settings. Further more, many viral and cellular factors mediate the development of cervical cancer and it may be possible to incorporate some of these biomarkers in the new and promising strategies of primary cervical cancer screening.
The CATCH Study is designed as a population-based study to evaluate the performance of three cervical cancer screening assays in rural India: Pap smear, HPV DNA testing and visual inspection of the cervix after acetic acid application (VIA).
To compare the test characteristics (sensitivity, specificity, positive and negative predictive values and referral to colposcopy rates) of each of the following three screening methods for the detection of prevalent high-grade squamous intra-epithelial lesions (HSIL) and/or invasive cervical carcinoma:
- Pap smear
- Visual inspection of cervix (VIA)
- HPV DNA in clinician collected specimens (HPV-C)
- Sowjanya P*, Jain M, Rani U, Padma S, Das M, Shah KV, Rao BN, Ramadevi R, Gravitt P, Ramakrishna G. Prevalence and distribution of high-risk HPV types in invasive squamous cell carcinoma of the cervix and in normal women in Andhra Pradesh, India. BMC Infect Dis. 2005;5(1):116.
- Sowjanya AP*, Paul P, Vedantham H, Ramakrishna G, Vidyadhari D, Vijayaraghavan K, Laksmi S, Sudula M, Das M, Shah KV, Gravitt PE, for the CATCH Study Group. Suitability of self-collected vaginal samples for cervical cancer screening in peri-urban villages in Andhra Pradesh, India. Cancer Epidemiol Biomarkers Prev. 2009;18(5):1373-8.
- Vedantham H, Silver MI, Kalpana B, Rekha C, Karuna BP, Vidyadhari K, Mrudula S, Ronnett BM, Vijayaraghavan K, Ramakrishna G, Sowjanya P, Laxmi S, Shah KV, Gravitt PE, for the CATCH Study Team. Determinants of VIA (visual inspection of the cervix after acetic acid application) positivity in cervical cancer screening of women in a peri-urban area in Andhra Pradesh, India. Cancer Epidemiol Biomarkers Prev. 2010;19(5):1373-80.
- Gravitt PE, Paul P, Katki HA, Vedantham H, Ramakrishna G, Sudula M, Kalpana B, Ronnett BM, Vijayaraghavan K, Shah KV. Effectiveness of VIA, Pap, and HPV DNA testing in a cervical cancer screening program in a peri-urban community in Andhra Pradesh, India. PLoS ONE. 5(10):e13711. doi:10.1371/journal.pone.0013711.
- Piyathilake CJ, Badiga S, Paul P, Vijayaraghavan K, Vedantham H, Sudula M, Sowjanya P, Ramakrishna G, Shah KV, Partridge EE, Gravitt PE. Indian women with higher serum concentrations of folate and vitamin B12 are significantly less likely to be infected with carcinogenic or high-risk (HR) types of human papillomaviruses (HPVs). Int J Women Health. 2010;2:7-12.
- Silver MI*, Paul P, Sowjanya P, Ramakrishna G, Vedantham H, Kalpana B, Shah KV, Gravitt PE. Shedding of Epstein-Barr virus and cytomegalovirus from the genital tract of women in a peri-urban community in Andhra Pradesh, India.
J Clin Microbiol. 2011;49(7):2435-9.