Best Practice & Research Clinical Obstetrics & Gynaecology
6Visual inspection methods for cervical cancer prevention
Introduction
Cervical cancer is a major public health problem in many developing countries, and the absolute burden will increase in the future if effective prevention measures are not undertaken. The global estimates for cervical cancer burden in the world around the year 2008 indicated that there were 530,232 new cancer cases, 275,008 deaths, with four-fifths of the estimated global burden occurring in the low- and middle-income countries (LMIC) of South and South East Asia, sub-Saharan Africa, and South and Central America.1 Cytology screening is a time-tested, effective approach to reduce the incidence of cervical cancer through early detection and treatment of high-grade cervical intraepithelial neoplasia (CIN), particularly CIN 3 lesions.
Regularly repeated Pap smear screening linked with treatment has prevented millions of women from developing cervical cancer in high-income countries with well-equipped and resourced healthcare services.2, 3 Most LMIC in Africa and Asia lack screening programmes. Widespread opportunistic screening and the large-scale national or regional cytology screening programmes in Brazil, Cuba, Costa Rica, Chile, Mexico, among others, in Latin America and the Caribbean have been largely ineffective in reducing the cervical cancer burden compared with high-income developed countries.4
The diagnostic and treatment algorithms after a positive Pap smear include three visits for colposcopy, diagnosis and treatment. The sensitivity of a single Pap smear to detect CIN 2–3 lesions ranges between 30 and 60% in most settings.5, 6, 7, 8, 9, 10 Repeated screening at 3–5-year intervals ensure that lesions missed in a given round may be detected in subsequent rounds. Such resource-intensive regimens are not feasible in most LMIC. The low-to-moderate sensitivity and the constraints in implementing and sustaining quality-assured cytology screening in LMIC have led to the evaluation of alternative screening tests such as visual and human papilloma virus (HPV) tests, and new paradigms in low-resource settings.11, 12, 13, *14 Visual inspection with 3–5% acetic acid (VIA) is the most widely evaluated visual test with a large evidence base from a range of field studies in sub-Saharan Africa, China, India, Bangladesh, Thailand, the Philippines and Latin America. Data for visual inspection with Lugol’s iodine (VILI) are rather limited. We discuss whether visual screening can be a pragmatic and effective public health approach for cervical cancer prevention in LMIC by reviewing the feasibility, acceptability, safety, accuracy, efficacy and cost-effectiveness in preventing cervical neoplasia.
Section snippets
New screening paradigms
In recent years, new paradigms have been proposed to maximise participation of women in screening and treatment, cost-effectiveness and efficiency of screening and treatment in low-resource countries.15 These include a low-intensity screening involving a single screen targeted at women aged 30–59 years or 30–49 years*16, *17 or screening at 10-yearly intervals, with emphasis on covering a large proportion of targeted women with a highly sensitive test; providing screening, colposcopy, directed
Visual inspection with 3–5% acetic acid
Visual inspection with acetic acid involves naked eye inspection of the cervix, using a bright torch light or a halogen focus lamp, one minute after the application of 3–5% dilute acetic acid using a cotton swab or a spray.25 Most of the reported experience with VIA involves 4 or 5% acetic acid, which is well tolerated by women. The changes that occur in the cervix in relation to the squamocolumnar junction (SCJ) after acetic acid application visible to the naked eye can be categorised as
Visual inspection with Lugol’s iodine
Visual inspection with Lugol’s iodine involves naked eye examination of the cervix to identify mustard-yellow lesions in the transformation zone of the cervix, after application of Lugol’s iodine. The results are reported immediately after application of iodine. A positive result is based on the appearance of definite mustard-yellow area on the cervix close to the SCJ or the external orifice or on a cervical growth (Fig. 2). Visual inspection with Lugol’s iodine has been investigated in far
Conclusion
Visual inspection with acetic acid, despite all its limitations, is a suitable screening test for premenopausal women in low-resource settings. It can be carried out in all countries and an interested provider can even self learn VIA by referring to manuals and atlases, and can improve performance by continuous practice and self audit. Clinicians and nurses in LMIC should use VIA and VILI in their clinics whenever the opportunity arises to screen women aged 30–59 years. This is the only
Acknowledgements
The authors gratefully acknowledge the assistance provided by Ms Sandrine Montigny and Mrs Krittika Guinot, Screening Group, International Agency for Research on Cancer, Lyon, France, in the preparation of this manuscript.
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