[Cytological and histological effects of regional hyperthermia and radiation in cancer of the uterine cervix]

Abstract

Hyperthermia is known to produce tumor-specific effect. Its combination with radiotherapy has been found to enhance antitumor effect and hyperthermia is a new modality of cancer treatment. Here, we report a cytological and histopathological study of the effects of hyperthermia on uterine cervical cancer. Our subject cases were 63 patients with cervical cancer (squamous cell carcinoma). Thirteen cases were treated with hyperthermia. Of these, the clinical stage was I b in 2, stage II in 10, stage III in 1. Before radical operation, external irradiation was given at 40Gy. with Lineac. During this period, the lesion was treated with hyperthermia at 42-45 degrees C for 30-60 min. with a 13.56 MHz RF capacitive heating system "Endoradiotherm 100A" (Kureha Chemical Industry CO. Ltd.) and an intraluminal applicator designed for uterine cervix. The control cases received radiotherapy alone before radical operation. There were 15 cases in Stage I b, 19 in stage II, and 16 in stage III. After the completion of radiotherapy, radical hysterectomy was performed in all cases. The effects of irradiation on the lesion were compared cytologically and histologically for different doses. The evaluation of the irradiation damage in cancer cells in the cytological study was based on findings such as intracytoplasmic vacuolation, the formation of giant nuclei, intranuclear vacuolation and formation of polynuclei. The degree of irradiation damage was classified into 5 grades from Do (little irradiation effect) to Dx (no viable cancer cells remaining), and the irradiation effect in the histopathological study was classified in to 8 grades from Grade 0 to Grade IVC according the Oboshi and Shimosato's classification. Cytological changes at 10Gy. were rated as D3 (relatively extensive irradiation damage in cancer cells) in 38.5% of the hyperthermia group, as compared to about 20% in the control groups. The cases rated Grade II B histologically made up 38.5% of the hyperthermia group: this grade was about 10% in the control groups. This suggests that radiation was more effective in the hyperthermia group than in the control groups, as was also suggested by the cytological results. With irradiation at 30Gy., cytological changes were rated as Dx in 61.5% of the hyperthermia group, as compared to 25.0-26.7% of the control groups. Histological results were Grade III, with only cancer cells regarded as non-viable observed, in 38.5% of the hyperthermia group and Grade IV, with no cancer cells, in another 23.1%. In the control groups, there were no cases with Grade IV, and those with Grade III totalled 12.5-26.7%.(ABSTRACT TRUNCATED AT 400 WORDS)