Is Pap smear appropriate for confirmation in VIA-positive woman before having colposcopy?
Abstract
Background and objective: Since 2005, Thailand has launched cervical cancer prevention and control program by using “Dual-track Strategy”. This strategy use two screening methods in targeted-woman, 30-60 years-old, these are Pap smear plus colposcopy and visual inspection with acetic acid (VIA) plus cryotherapy. Both of the tests should be done every 5 years. The goal is to reduce death rate from cervical cancer of at least 50%. Because VIA has high sensitivity, so many VIA-positive women are referred to colposcopists but some hospitals cannot provide colposcopy to all of these women because of too much workload, lack of colposcopist or equipment, or the colposcopists there do not accept VIA as another cervical cancer screening method. By these reasons, Nakornping and other hospitals use Pap smear to confirm the abnormal results in any VIA-positive patients before having colposcopy. This kind of management has never been evaluated in Nakornping Hospital. Therefore, this study was done to evaluate the test qualities of Pap smear in confirmation of abnormal results in our referred VIA-positive women.
Methods: All VIA-positive women referred to Nakornping Hospital during 1st October, 2006-30th May, 2009, were recruited to this study. Pap smears were taken in all women before colposcopy. If there were any abnormal colposcopic findings or unsatisfactory colposcopic findings, tissue biopsies must be done for definite diagnoses. All necessary data had been recorded on a pre-planned data form and then analyzed to evaluate Pap smear’s test qualities by using colposcopic diagnoses as gold standard.
Results: Among 204 referred VIA-positive women, the main reason for referral was large acetowhite lesion, others were lack of cryotherapy equipment, persistent of acetowhite lesion after 1 year post cryotherapy. Abnormal Pap smears were found in only 14 cases. They were 2 ASC-USs, 3 ASC-Hs, 4 LSILs, 4 HSILs, and 1 adenocarcinoma. The final colposcopic diagnosis were 92 negative findings (45.1%), 63 chronic cervicitis (30.9%), 28 LSILs (13.7%), 19 HSILs (9.3%), and 2 invasive carcinomas (1.0%). For confirmation of HSILs or more in this group of women, we found that Pap smear has as low sensitivity as 47.6%, but as high specificity as 97.8%.
Conclusion: Pap smear was not appropriated for confirmation of abnormal results in VIA-positive women before colposcopy because it has low sensitivity (47.6%) in detection of HSILs or more.
Keywords: VIA, Pap smear, Colposcope, Cervical cancer screening
