Analysis of response to radiation therapy of patients with cervical adenocarcinoma compared with squamous cell carcinoma. MIB-1 and PC10 labeling indices

Abstract

Background: The MIB-1 monoclonal antibody is a marker of cycling cells and the PC10 monoclonal antibody is a marker of proliferating cell nuclear antigen in paraffin sections. This study was conducted to elucidate the difference in response to radiotherapy (RT) between cervical adenocarcinomas and squamous cell carcinomas, focusing on cell proliferation.

Methods: A total of 196 biopsy specimens taken from the cervical carcinomas of 14 consecutive patients with adenocarcinoma and 62 patients with squamous cell carcinoma before and after RT at doses of 9 and 27 Grays (Gy) were investigated for MIB-1 and PC10 immunoreactivities.

Results: In adenocarcinomas, the mean MIB-1 labeling indices before and after RT at 9 and 27 Gy were 28%, 21%, and 26%, respectively, whereas the mean PC10 labeling indices were 15%, 13%, and 14%, respectively. In squamous cell carcinomas, the mean MIB-1 labeling indices before and after RT at 9 and 27 Gy were 38%, 53%, and 26%, respectively, and the mean PC10 labeling indices were 23%, 23%, and 11%, respectively.

Conclusions: Cervical adenocarcinomas have a lower cycling cell population and their indices show no change during RT. Squamous cell carcinomas have a higher cycling cell population and show a transient increase of the MIB-1 cycling cell population at 9 Gy of RT. These findings suggest a difference in response to RT between adenocarcinomas and squamous cell carcinomas.