Salud Pública de México (Jan 2003)
Early detection of cervical cancer with visual inspection methods: a summary of completed and on-going studies in India
Abstract
India is a high-risk country for cervical cancer which accounts a quarter (126 000 new cases, 71 000 deaths around 2 000) of the world burden. The age-standardized incidence rates range from 16-55 per 100 000 women in different regions with particularly high rates in rural areas. Control of cervical cancer by early detection and treatment is a priority of the National Cancer Control Programme of India. There are no organized cytology screening programmes in the country. The technical and financial constraints to organize cytology screening have encouraged the evaluation of visual inspection approaches as potential alternatives to cervical cytology in India. Four types of visual detection approaches for cervical neoplasia are investigated in India: a) naked eye inspection without acetic acid application, widely known as 'downstaging'; b) naked eye inspection after application of 3-5% acetic acid (VIA); c) VIA using magnification devices (VIAM); d) visual inspection after the application of Lugol's iodine (VILI). Downstaging has been shown to be poorly sensitive and specific to detect cervical neoplasia and is no longer considered as a suitable screening test for cervical cancer. VIA, VIAM and VILI are currently being investigated in multicentre cross-sectional studies (without verification bias), in which cytology and HPV testing are also simultaneously evaluated, and the results of these investigations will be available in 2003. These studies will provide valuable information on the average, comparative test performances in detecting high-grade cervical cancer precursors and cancer. Results from pooled analysis of data from two completed studies indicated an approximate sensitivity of 93.4% and specificity of 85.1% for VIA to detect CIN 2 or worse lesions; the corresponding figures for cytology were 72.1% and 91.6%. The efficacy of VIA in reducing incidence of and mortality from cervical cancer and its cost-effectiveness is currently being investigated in two cluster randomized controlled intervention trials in India. One of these studies is a 4-arm trial addressing the comparative efficacy of VIA, cytology and primary screening with HPV DNA testing. This trial will provide valuable information on comparative detection rates of CIN 2-3 lesions by the middle of 2003. The expected outcomes from the Indian studies will contribute valuable information for guiding the development of public health policies on cervical cancer prevention in countries with different levels of socio-economic and health services development and open up new avenues of research.
