[The effects of preoperative irradiation therapy in advanced stomach cancer].

Over the past 20 years the survival rate for advanced stomach cancer among Japanese remains the same. In order to increase the survival rate, 17 years ago we initiated a type of preoperative irradiation therapy as an adjunct to surgery. We have tried to develop an adequate plan for indication of preoperative irradiation. The results obtained were as follows. 1. In this study we used a computer simulated method which aided in determining a suitable plan for adjunct irradiation therapy. 2. The adequate total dosage ranged 3,000 +/- 1,000 rads, with a 2 weeks waiting period between irradiation treatment and surgery, especially for advanced gastric cancer invading to ss and up to 6 cm in diameter. 3. Histopathological findings from resected specimen, using pH 4.1 TBM staining method, indicated decrease in the depth of the carcinoma and extent and size of the tumor as well as degeneration and/or disappearance of the cancer cells due to the preoperative therapy. 4. We identified the decrease of metastatic rates of the regional lymphnodes in the irradiation group. 5. Clinical results indicated an improved resectability rate of 6.1% and an approximate 12.1% increase in the 5 years survival rate.