Background: To study the performance of routine follow-up Pap smears after curative radiotherapy (RT) for Chinese cervical cancer (CC) patients.
Methods: In 1996, 50 patients with non-metastatic CC received curative RT. Forty-six patients had routine follow-up Pap smears and constituted the study group. Details regarding clinical characteristics were retrospectively abstracted. Pap smear results were obtained via national Pap smear database linkage and chart review. The Pap smear results during recurrence-free survival (RFS) were analyzed and compared with clinical outcomes to study the performance characteristics.
Results: After 34 (2 approximately 105) months' median follow-up, the clinical outcomes were isolated central recurrence (ICR), other recurrence (OR), and no evidence of disease (NED) for six, 20, and 20 patients, respectively. During 22 months' median RFS (range 2-105), 422 Pap smears (including missing data, n = 33) were performed. Most of the Pap smear results were within normal limits (65.8%) or benign (reactive changes or atrophy with inflammation) (25.2%). Atypical cells, low-grade squamous intraepithelial lesion (LSIL), high-grade intraepithelial lesion (HSIL), and carcinoma were found in ten (2.6%), 11 (2.8%), 11 (2.8%), and three (0.8%) specimens, respectively. Follow-up of the 21 atypical cells/LSIL smears among seven patients revealed five NED with normal/benign smears, one NED with HSIL and one OR with HSIL. Follow-up of the 11 HSIL smears among four patients revealed two ICR, one OR and one NED with HSIL. Follow-up of the three carcinoma smears revealed three ICR (one followed by HSIL in a repeat Pap smear before ICR). The sensitivity for the detection of ICR by carcinoma smears was 50%, with a specificity and positive predictive value (PPV) of 100%.
Conclusion: Few (approximately 3%) of the routine follow-up Pap smears after CC patients receiving curative RT were HSIL/carcinoma, but most (4/6) of these patients turned out to be ICR.