Cisplatin No Better than Standard Therapy for Anal Canal Cancer
Adapted from the NCI Cancer Bulletin.Replacing mitomycin with cisplatin in chemoradiotherapy for cancer of the anal canal failed to improve either disease-free survival or overall survival and resulted in more patients needing colostomies, according to a study in the April 23, 2008, issue of the Journal of the American Medical Association (see the journal abstract).
Current standard therapy for anal canal cancer consists of fluorouracil plus mitomycin and radiotherapy. Previous studies have established that chemoradiation is more effective for smaller tumors. Researchers wondered whether initial chemotherapy with fluorouracil and cisplatin could improve outcomes by shrinking tumors before they were treated with the same agents and radiotherapy.
In this randomized phase III clinical trial (see the protocol summary), 644 patients with anal canal cancer received standard treatment with fluorouracil plus mitomycin and concurrent radiotherapy or induction chemotherapy with fluorouracil plus cisplatin, followed by concurrent treatment with fluorouracil, cisplatin, and radiation.
After a median follow-up of 2.5 years, the estimated five-year disease-free survival rate was 60 percent for patients in the mitomycin group, compared with 54 percent in the cisplatin group. Estimated rates of overall survival, local recurrence, and distant metastasis were all worse for patients in the cisplatin group. In addition, at five years an estimated 19 percent of patients who received cisplatin needed colostomies, compared with 10 percent of patients who received mitomycin.
"These findings do not support the use of cisplatin in place of mitomycin in combination with fluorouracil and radiotherapy in the treatment of anal canal carcinoma," conclude principal investigator Dr. Jaffer A. Ajani of the University of Texas M.D. Anderson Cancer Center and his colleagues.