Changes in apoptotic and mitotic index, bcl2, and p53 expression in rectum carcinomas after short-term cytostatic...

Twenty patients with rectal adenocarcinoma were endoscopically biopsied and given short-term cytostatic therapy [5-fluorouracil (5-FU) (600 mg/m(2)) and Ca-folinate (60 mg/m(2)) for 2 days]. Seven days later, the tumor was resected or a second biopsy was performed. Apoptotic and mitotic indices as well as (mutant) p53 and bcl(2) expression 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 7-26 months. Six patients showed progression of the disease and died, whereas 14 improved or showed no tumor progression. Significant increase of the apoptotic index and nonsignificant decrease of the mitotic index after the short-term cytostatic treatment were seen in the tumor tissue of responder cases. Nonresponders showed no change in both mitotic activity and apoptotic activity. Both survivors and deceased showed high mutant p53 expression, and the changes after short-term 5-FU treatment were not significant. Expression of bcl(2) was present in only 5 cases, with the postchemotherapy changes being not significant. These findings suggest that apoptotic response to short-term cytostatic therapy may be an additional predictive factor in rectal adenocarcinoma.