Natural history of false-negative papanicolaou smears: a prospective study using screening colposcopy in addition to cytology.

The regular Papanicolaou (Pap) smear is cornerstone of women's preventive healthcare. The introduction of the regular Pap smear as a screening tool for cervical cancer has markedly decreased the number of deaths from cervical cancer. During the past decade, however, the rate of death from cervical cancer has remained relatively static. This screening method is known to have a high rate of false-negative results; therefore, serial examinations are necessary for optimal sensitivity. The sensitivity of the routine pelvic examination is further increased with the addition of colposcopy to cytologic screening. Patients identified as having disease by colposcopy and biopsy but not by Pap smear (false-negative), are followed up, and the progression of their disease is documented until the Pap smear reflects the known change. A total of 276 patients whose Pap tests showed "no abnormal cells" and mild dysplasia (CIN-1 [cervical intraepithelial neoplasia]) by colposcopy and biopsy, who opted not to be treated, were followed up as a function of time. The results of the Pap test on the 276 patients progressed to a low-grade squamous intraepithelial lesion (LGSIL) or higher within 42 months. In this study, false-negative Pap tests that were identified by simultaneously performed colposcopy became positive within 42 months; therefore, careful repetitive screening is necessary. The author argues that a definitive, prospective study on the addition of colposcopy or similar adjunct procedure to the routine pelvic examination, in selected cases, is needed.