ArticlesEffect of visual screening on cervical cancer incidence and mortality in Tamil Nadu, India: a cluster-randomised trial
Introduction
Cervical cancer is the most common cancer among women in many developing countries, where 85% of the estimated 493 000 new cases and 273 000 deaths in 2002 occurred worldwide.1 Although population-based cervical cytology screening has resulted in a substantial reduction in cervical cancer burden in developed countries, lack of screening or inefficient cytology screening programmes contribute to the high risk seen in sub-Saharan Africa, south and southeast Asia, Oceania, Central and South America, and the Caribbean.2, 3, 4
The difficulties in organising cytology screening in developing countries have prompted the assessment of alternative methods like visual inspection with 3–5% acetic acid (VIA) for prevention of cervical cancer. In several studies, VIA had an acceptable sensitivity in detecting cervical intraepithelial neoplasia (CIN).4, 5, 6, 7, 8, 9, 10, 11 Although model-based studies suggest that low-intensity, single-round of VIA screening once a lifetime is a cost effective method to reduce disease burden,12, 13, 14, 15 whether it can achieve a significant reduction in cervical cancer incidence and mortality in real programme settings is unclear. The Christian Fellowship Community Health Centre, India, and the International Agency for Research on Cancer (IARC) of WHO, France, jointly did a cluster randomised trial to assess the efficacy of VIA screening to reduce cervical cancer incidence and mortality in a high-risk population in India.16 The results, after 7 years from the beginning of the screening, in terms of reduction in cervical cancer incidence and mortality are described in this paper.
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Design
The study design and methods of this trial were described in detail in a baseline paper.16 Clusters (panchayaths or municipal units) were first assigned numbers, and a statistician in IARC, not involved in the project, randomly assigned these numbers into two groups using computer-generated random numbers. Of the 114 clusters in seven subdistricts of the Dindigul district randomly chosen for the study, 57 were randomised to each group. The two groups were then randomly assigned either to an
Results
Figure 1 shows the flow of study clusters and eligible women throughout the trial. All 49 311 eligible women in the intervention and the 30 958 in the control groups were interviewed. The study groups were well balanced for distribution of religion, occupation, income, and menopause, but some differences were observed for age, education, marital status, and parity (table 1). Only two of the eligible women had ever had previous cervical screening.
Enumeration of households and eligible women
Discussion
Successful screening leads to reduction in cervical cancer incidence by detection and treatment of CIN. Strategies involving cytology screening and multiple visits for diagnosis and treatment are impractical in low-resourced and most medium-resourced developing countries. We show that cervical cancer burden can be reduced by a single round of VIA screening. Our findings indicate that VIA is a simple, feasible, and effective method to prevent cervical cancer and death among deprived populations
References (35)
- et al.
Cervical cancer screening by simple visual inspection after acetic acid
Obstet Gynecol
(2001) - et al.
A critical assessment of screening methods for cervical neoplasia
Int J Gynaecol Obstet
(2005) - et al.
Trends in mortality from cervical cancer in the Nordic countries: association with organised screening programmes
Lancet
(1987) - et al.
GLOBOCAN 2002: cancer incidence, mortality and prevalence worldwide. Version 1.0. IARC Cancer Base No 5
(2004) - et al.
Cancer incidence in five continents, vol VIII. IARC Scientific Publications No 155
(2002) - et al.
Effective screening programs for cervical cancer in low- and middle-income developing countries
Bull World Health Organ
(2001) IARC Handbooks on Cancer Prevention. Vol 10. Cervix cancer screening
(2004)University of Zimbabwe/JHPIEGO Cervical Cancer Project: visual inspection with acetic acid for cervical cancer screening: test qualities in a primary-care setting
Lancet
(1999)- et al.
Evaluation of alternative methods of cervical cancer screening in resource poor settings
Cancer
(2000) - et al.
Direct visual inspection for cervical cancer screening: an analysis of factors influencing test performance
Cancer
(2002)