In order to estimate the effects of radiation on cancer tissue, cytopathological findings, BrdU labelling index (L.I.), tumor markers and C-myc oncogene products were examined in 30 patients of uterine cervical cancer, before radiation, at around 10Gy, 30Gy, 50Gy and at the end of the therapy. In order to assess the radiotherapeutic effects, the cytological, histological, immunohistological findings were evaluated by Papanicolaou's classification, Oboshi and Shimosato's grading system and BrdU L.I.
In the cytology, the radiation effect, such as the enlargement and vacuolation of the nuclei and cytoplasm, was observed at around 10Gy of radiation, and significantly increased at around 30Gy showing lysis of the cells and pyknosis of the nuclei. The histological observation recorded remarkable change in the cancer tissue at around 30Gy of radiation. The BrdU L.I. showed a meaningful decrease around 30Gy in the radiosensitive cases compared with the radioresistant cases.
Moreover, immunohistochemical investigation indicated the location of SCC and SLX in the cytoplasm of the cancer cells and of C-myc product in the nuclei. A distinct radiation effect was found in the C-myc oncogene product at around 10Gy. Ras oncogene was not found in the adenocarcinoma cases investigated.
From these findings it is concluded that BrdU L.I., revealed by immunohistological study, is the most suitable indicator to estimate the response of radiation in cancer cells of the uterine cervix and that C-myc oncogene product has the potentiality to be used as a prognostic factor in uterine cervical cancer treated by radiation therapy.