title: Test characteristics of visual inspection with 4% acetic acid (VIA) and Lugol's iodine (VILI) in cervical cancer screening in Kerala, India.
abstract: Simple and inexpensive methods based on visual examination of the cervix are currently being investigated as alternative methods of cervical screening. The test characteristics of visual inspection with 4% acetic acid (VIA), and Lugol's iodine (VILI) and conventional cytology were investigated in a cross-sectional study involving 4,444 women aged 25 to 65 years in Kerala, India. While detection of any acetowhite area constituted a low-threshold positive VIA, detection of well-defined, opaque acetowhite lesions close to or touching the squamocolumnar junction constituted a high-threshold positive VIA test. Detection of definite yellow iodine nonuptake areas in the transformation zone close to or touching the squamocolumnar junction constituted a positive VILI test. Cytology was considered positive if reported as atypia or worse lesions. All screened women were evaluated by colposcopy and biopsies were directed in 1,644 women (37.0%), which allowed the direct estimation of sensitivity, specificity and predictive values. The reference diagnosis was based on a combination of histology and/or colposcopy. True disease status was defined as CIN 2 and worse lesions. A total of 149 (3.4%) women had CIN 2 or worse lesions. The sensitivities of low-threshold VIA, high-threshold VIA, VILI and cytology to detect CIN 2 or worse disease were 88.6%, 82.6%, 87.2% and 81.9%, respectively; the corresponding specificities were 78.0%, 86.5%, 84.7% and 87.8%. Our results indicate that VIA and VILI are suitable alternate screening tests to cytology for detecting cervical neoplasia in low-resource settings.
authors.affiliation: International Agency for Research on Cancer, 150 cours Albert Thomas, Lyon 69008, France. sankar@iarc.fr
authors.forename: Rengaswamy
authors.initials: R
authors.lastname: Sankaranarayanan
authors.forename: Ramani
authors.initials: R
authors.lastname: Wesley
authors.forename: Somanathan
authors.initials: S
authors.lastname: Thara
authors.forename: Namrata
authors.initials: N
authors.lastname: Dhakad
authors.forename: Bharathykutty
authors.initials: B
authors.lastname: Chandralekha
authors.forename: Paul
authors.initials: P
authors.lastname: Sebastian
authors.forename: K
authors.initials: K
authors.lastname: Chithrathara
authors.forename: Donald Maxwell
authors.initials: DM
authors.lastname: Parkin
authors.forename: Madhavan Krishnan
authors.initials: MK
authors.lastname: Nair
mesh_terms: D019342:Acetic Acid; D000328:Adult; D000368:Aged; D002584:Cervix Uteri / Q000166:cytology / Q000473:pathology; D004396:Coloring Agents; D003430:Cross-Sectional Studies; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007194:India; D007202:Indicators and Reagents; D007454:Iodides; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D010808:Physical Examination; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000473:pathology; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000473:pathology
chemical_list: D004396:Coloring Agents; D007202:Indicators and Reagents; D007454:Iodides; D019342:Acetic Acid; C010389:Lugol's solution