Cross sectional study of conventional cervical smear, monolayer cytology, and human papillomavirus DNA testing for cervical cancer screening

Abstract

Objectives: To compare the sensitivity, specificity, and interobserver reliability of conventional cervical smear tests, monolayer cytology, and human papillomavirus testing for screening for cervical cancer. Design: Cross sectional study in which the three techniques were performed simultaneously with a reference standard (colposcopy and histology). Setting: Public university and private practices in France, with complete independence from the suppliers. Participants: 828 women referred for colposcopy because of previously detected cytological abnormalities and 1757 women attending for routine smears. Main outcome measures: Clinical readings and optimised interpretation (two blind readings followed, if necessary, by consensus). Sensitivity, specificity, and weighted κ computed for various thresholds of abnormalities. Results: Conventional cervical smear tests were more often satisfactory (91% v 87%) according to the Bethesda system, more reliable (weighted κ 0.70 v 0.57), and had consistently better sensitivity and specificity than monolayer cytology. These findings applied to clinical readings and optimised interpretations, low and high grade lesions, and populations with low and high incidence of abnormalities. Human papillomavirus testing associated with monolayer cytology, whether systematic or for atypical cells of undetermined significance, performed no better than conventional smear tests. Conclusions: Monolayer cytology is less reliable and more likely to give false positive and false negative results than conventional cervical smear tests for screening for cervical cancer. What is already known on this topic What is already known on this topic New technologies have been developed to improve the detection of cervical cancer and its precursors and reduce the rate of false negative results from conventional cervical smear tests In several countries liquid based monolayer cytology is replacing conventional smear tests, despite controversy about whether these more expensive tests perform better What this study adds What this study adds Conventional cervical smear testing is superior in terms of low and high grade lesions and in populations with a low or a high incidence of abnormalities Monolayer testing is less reliable and should not replace conventional cervical smear testing