Changes in apoptotic and mitotic activity in rectal carcinoma after short-term cytostatic therapy as possible predictive factors.

Fifteen patients with rectal adenocarcinoma were endoscopically biopsied and given short-term [5 fluorouracil (5FU) (600 mg/m2) and Ca-Folinate (60 mg/m2) for two days] cytostatic therapy. Seven days later the tumor was resected or a second biopsy was performed. Apoptotic and mitotic indices were determined in the tumor tissue before and after the short-term chemotherapy. The patients were treated thereafter with long-term, intermittent 5 FU administration and followed up clinically for 4-13 months. Three patients showed progression of the disease, twelve improved or showed no tumor progression. An increase of the apoptotic index and decrease of the mitotic index after the short-term cytostatic treatment were seen in the tumor tissue of responder cases. Non-responders showed increase or no change in mitotic activity, and decrease or no change in apoptotic activity. These findings suggest that apoptotic and mitotic response to short-term cytostatic therapy may be additional predictive factor in rectal adenocarcinoma.