[Cancers of the colon and the rectum: news in 1992]

Five studies presented at the 1992 ASCO meeting are analysed. Kligerman's study was designed to determine if pre-treatment with WR-2721 could protect normal tissues from the toxicities induced by radiation therapy (in 100 patients with advanced rectal cancer). This pre-treatment resulted in a 13% reduction of moderate and severe acute toxicity. No WR-2721 patient experienced moderate or severe late toxicities compared to five in the group without pre-treatment. The complete response rate was higher in the WR-2721 group and there was no major WR-2721 related toxicity. Minski studied the acute toxicity (during treatment and two weeks after) of combined pelvic radiation therapy, 5-FU and leucovorin when delivered pre-operatively (16 patients) versus post-operatively (25 patients) in patients with rectal cancer. The toxicity criteria were fatigue, diarrhea, tenesmus, bowel movements, dysuria and erythema. Grade 3+ toxicity was more important in the post-operative therapy group (48% versus 13%). Given this high incidence of grade 3+ toxicity future randomized trials should explore the pre-operative approach. The final report of the inter group study of 5-FU plus levamisole as adjuvant therapy for stage C colon cancer was made by Moertel. With a median follow-up time of 5.5 years, the 5-FU plus levamisole treatment has reduced the recurrence rate by 39%, the cancer related death rate by 32% and the overall death rate by 31%. Most of the recurrences occurred during the first two years. There was a decrease in the liver, great omentum, peritoneum and lung metastases, but there was no modification in loco-regional recurrence rate.(ABSTRACT TRUNCATED AT 250 WORDS)