Adjuvant irradiation of gastrointestinal malignancies: impact on local control and tumor cure.

Radiation therapy has recently been used more frequently in the adjuvant treatment of gastrointestinal malignancies. A number of studies have shown a high local failure in patients with Stages B2 and C rectal carcinomas and in Stages B3, C2 and C3 colon carcinomas. In rectal cancer, both randomized and non-randomized studies have demonstrated improved local control and survival with the use of adjuvant radiation. Randomized studies have not been performed in colon cancer, but preliminary data from MGH indicate improved local control and survival in some patient subsets with the use of local irradiation after resection. Both gastric and pancreatic cancer have a greater propensity to distant metastases. A review of failure patterns after resection has, nonetheless, shown a high incidence of local recurrence and small prospective randomized studies have recently demonstrated a survival advantage with the use of adjuvant irradiation.