Objective: To determine the performance of liquid-based cytology using ThinPrep in the postirradiation surveillance of women with gynecologic malignancies.
Methods: Patients with endometrial and cervical cancer treated with primary or adjuvant radiotherapy between 2000 and 2002 were identified. Details regarding tumor characteristics, treatment, and cytologic and histologic results were abstracted. Binomial variables were compared with the chi-square test. The performance characteristics of liquid-based cytology were evaluated.
Results: A total of 302 liquid-based cytologic samples from 121 women were evaluated. Overall, 294 (97.4%) of the specimens were adequate for interpretation and 132 (44.9%) were within normal limits. Benign cellular changes, including benign radiation changes, were identified in 141 (47.6%). Atypical squamous cells (ASCUS) were found in 15 (5.1%), recurrent dysplasia in 4 (1.3%), and recurrent carcinoma in 2 (0.7%). Follow-up of the 15 ASCUS smears revealed 13 (86.7%) normal smears and 2 cases of squamous intraepithelial lesions. Benign findings were noted in three of the four smears with SIL. The sensitivity for the detection of SIL was 33%, the specificity 99%, and the positive predictive value (PPV) 25%. Of the 4 patients with local recurrences, 2 were detected by cytology. The sensitivity for the detection of recurrent carcinoma was 50%, with a specificity and PPV of 100%.
Conclusions: ThinPrep for the surveillance of women with gynecologic malignancies treated with radiotherapy is associated with a high rate of satisfactory samples and a low rate of equivocal and ASCUS cytology.