ASSESSMENT OF VISUAL INSPECTION WITH ACETIC ACID (VIA) AS A SCREENING TEST FOR CERVICAL NEOPLASIA IN COMPARISON WITH CYTOLOGIC SCREENING

Abstract

This study has been designed to compare visual inspection of cervix with acetic acid (VIA test) with cytology as an accepted method for screening of cervical carcinoma and its precursors. 1200 eligible women were examined by both Pap-smear and VIA tests in Imam Khomeini Hospital, a referral general hospital in Tehran, Iran. Those who had abnormal results in one or both of the screening tests (n = 308) and those who had clinically suspicious lesions even if the tests were negative in addition to 10% of otherwise normal patients with negative tests (totally 290 patients) were referred for colposcopy and biopsy if mandated. From 598 patients who were introduced to colposcopy services, 355 patients required biopsies or endocervical curettage (ECC). Those with CIN I or worse lesions diagnosed by histology were considered true-positive. VIA results were positive in 191 women (16.1%) and cytology was abnormal (for ASCUS or worse lesions) in 226 women (19%). VIA and cytology detected 130 (74%, 95% CI: 68%-81%) and 126 (72%, 95% CI: 65%-79%) cases respectively, yielding a sensitivity ratio of 1.03. VIA detected 31 lesions which were cytologically negative and cytology detected 27 lesions which were negative by VIA; 18 cancerous and precancerous lesions were missed in both modalities. The approximate specificities of VIA and cytology were 94% (95% CI: 93%-95%) and 90.2% (95% CI: 88%-92%) respectively. Also, the positive predictive values were 68.1% (95% CI: 61%-75%) and 55.7% (95% CI: 49%-62%) respectively. These results indicate that VIA and cytology had very similar performance in detecting CIN I or worse lesions in this study.