[The proliferative activity of stomach cancer and evaluation of its individual radiosensitivity]

An indirect immunofluorescent method with polyclonal antibodies to thymidine was used to assess the proliferative activity (PA--percent of cells in the S-phase of the cell cycle) of 79 stomach tumors from primary cancer patients. Stomach cancer PA was shown to vary from 0.1 to 69.7%. PA did not depend either on a tumor size or a degree of the involvement of regional lymph nodes. The mean PA of well-differentiated adenocarcinoma was slightly lower (14.9 +/- 4.7%) than that of low differentiated ones. Of 79 patients a tumor process was interpreted as a resectable one in 62. They were given preoperative irradiation at a total focal dose of 36 Gy followed by operation. In addition to initial investigation PA in tumor biopsy specimens was assessed after delivering a dose of 12 Gy. PA changes at the beginning of a course of irradiation were compared with a degree of a radiation injury of tumor tissue after a course of irradiation was discontinued in 32 (explorative laparotomy was performed in 30). It was shown that tumor radioresistance could be predicted in unchanged PA indices of their increase at the beginning of a course of irradiation with the probability of 95%.