MITOMYCIN IN ANAL-CANAL CARCINOMA

One hundred and ten patients with primary epidermoid cancers of the an al canal were treated in a series of prospectively designed, nonrandom ized protocols of split-course radiation therapy with concurrent admin istration of 5-fluorouracil (5-FU) with or without mitomycin. The addi tion of mitomycin was associated with improved primary tumor control r ates (87 vs. 58% at 4 years, p = 0.005) and improved 4-year actuarial cause-specific survival (80 vs. 64%, p = 0.02). Hematologic toxicity w as the most frequent acute side effect of mitomycin use. No long-term toxicity was attributed to mitomycin only. Mitomycin appeared to benef it patients principally through improved control of cancer in the irra diated volume; there was no evidence of reduced risk of extrapelvic me tastases. Several investigators have reported high rates of control of epidermoid anal cancers with preservation of anorectal function follo wing concurrent treatment with mitomycin, 5-FU, and radiation. Mitomyc in's role in anal cancer is being evaluated in a randomized clinical t rial by the Radiation Therapy Oncology Group. The mechanisms of any in teractions between mitomycin and radiation or other cytotoxic drugs in clinical practice remain to be determined.