[Non-surgical possibilities for the treatment of colorectal cancers].

The 5-year survival rate after radical excision of colorectal carcinoma has not increased for thirty years. The development of adjuvant therapy should bring marked progress, but none of the clinical trials so far conducted has shown an improvement which could mean a statistically significant difference in survival. Preoperative radiotherapy decreases the tumor volume and the incidence of invaded lymph nodes. The results of postoperative radiotherapy and chemotherapy are favourable, and the final answer with regard to their effectiveness can be expected in the near future.