PROGNOSTIC-SIGNIFICANCE OF DNA CYTOMETRY OF POSTIRRADIATION CERVICOVAGINAL SMEARS

BACKGROUND. Cytologic sampling is performed routinely after radiothera py for cervical carcinoma. The prognostic significance of postirradiat ion dysplastic and atypical cells is uncertain because of difficulties in distinguishing preneoplastic and cancerous changes from benign rad iation changes. DNA cytometry studies may provide a more objective met hod of identifying significant lesions. METHODS, Postirradiation cervi cal carcinoma patients with cervical/vaginal smears containing atypica l or dysplastic cells were identified prospectively. Papanicolaou smea rs were destained, restained with a Feulgen stain, and evaluated for D NA content using image cytometry. Pathologic and clinical records were monitored on each patient for evidence of recurrence or biopsy-proven dysplasia. RESULTS, Of 46 patients, 14 had been diagnosed on cytology as having atypical squamous cells, 4 as having atypical/suspicious ce lls, 12 with low grade squamous intraepithelial lesions (SIL), 3 with high grade SIL, and 13 with ungraded SIL. DNA histograms were classifi ed as follows: 14 diploid, 19 polyploid, and 13 aneuploid. Cytologic d iagnosis and histogram type were correlated significantly and both cor related with clinical outcome. The probability of either postirradiati on dysplasia or recurrence was as follows: SIL, 82%; suspicious, 100%; polyploid, 79%; and aneuploid, 92%. Patients with atypical squamous c ells of undetermined significance or diploidy most frequently had nega tive follow-up (57% each). AU patients with both SIL and aneuploidy de veloped either dysplasia or recurrence. The stage of disease did not c orrelate with outcome or histogram pattern. CONCLUSIONS, DNA analysis of postirradiation cytologic smears demonstrating atypia or dysplasia may provide useful ancillary information. The presence of aneuploidy u sually signifies either recurrence or dysplasia. Polyploidy most frequ ently occurs in dysplastic processes, whereas diploid histograms usual ly denote a benign disease course. (C) 1998 American Cancer-Society.