Value of 4-quadrant biopsies under colposcopy for detecting precancerous lesions in cervical cancer screening

Abstract

To evaluate the value of colposcopical 4-quadrant biopsies for detecting precancerous lesion in cervical cancer screening. We used the data of a cross-sectional screening study in 1999, in which 1,997 women received cervical cancer screening in Xiang Yuan County, Shanxi province. The sensitivity, specificity and accuracy of both 4-quadrant biopsy and colposcopy directed biopsy to detect high-grade or more severe squamous intraepithelial lesions (HSIL+) were calculated. 1,784(89.3%) women who received 4-quadrant biopsies and endocervical curettage were negative. 127(6.4%) women were diagnosed as LSIL, 74(3.7%) women as HSIL and 12(0.6%) cases of squamous cell carcinoma. 1,478(74.0%) women who received biopsies in the sites of abnormal lesions were negative, 463(23.2%) cases of LSIL, 41(2.1%) cases of HSIL, 15(0.8%) cases of squamous cell carcinoma. The positive rate was 26.0%(519/1,997) for colposcopy, and the coincidence rate was 73.7% with pathological diagnosis. Sensitivity and specificity were 81.4% and 76.5% of colposcopy for HSIL+. In total of 519 women were found to be with any abnormal colposcopic appearance. The consistency rate between 4-quadrant biopsies and suspicious lesion-directed biopsies was 96.3%. By suspicious lesion-directed biopsy alone, 14.8% cervical lesions were miss-diagnosed, of which 8.6%(5/58) cases of total HSIL and 24.1%(14/58) cases of all LSIL. 4-quadrant biopsy can detect more HSIL+ lesions and is more accurate than suspicious lesion biopsy alone. As an important triage technique to detect cervical precancerous lesions, it can improve the detection rate of HSIL+ lesions in cervical cancer screening.