Experimental use of cisplatin no better than standard treatment, researchers say
TUESDAY, April 22 (HealthDay News) -- Compared to the standard treatment regimen for anal canal cancer, the use of the chemotherapy drug cisplatin before other treatments didn't improve disease-free survival and resulted in a higher rate of colostomy procedures, says a U.S. study.
Currently, the preferred primary therapy for patients with anal canal cancer is chemoradiation (concurrent use of radiation and the anti-cancer drugs fluorouracil/mitomycin), which achieves a five-year survival rate of about 65 percent, according to background information in the study.
It's been suggested that reducing cancer in the primary tumor and in the lymph node or nodes prior to chemoradiation might improve disease-free survival. Pilot studies using cisplatin prior to chemoradiation showed promise.
In this new, randomized controlled trial, Dr. Jaffer A. Ajani, of the University of Texas M.D. Anderson Cancer Center in Houston, and colleagues compared treatment with fluorouracil plus mitomycin and radiation therapy to treatment with fluorouracil plus cisplatin and radiation therapy.
The findings from 644 patients showed a five-year, disease-free survival rate of 60 percent in the mitomycin group and 54 percent in the cisplatin group. The five-year overall survival rate was 75 percent in the mitomycin group and 70 percent in the cisplatin group. There were more cancer-related deaths in the cisplatin group (54) than in the mitomycin group (28).
The five-year, local-regional cancer recurrence and distant metastasis rates were 25 percent and 15 percent, respectively, for the mitomycin group and 33 percent and 19 percent, respectively, for the cisplatin group. Severe blood toxicity was worse in the mitomycin group. The cisplatin group had a higher rate of colostomy (19 percent vs. 10 percent).
"The question remains how to further improve disease-free and colostomy-free survival relative to the continued standard of concurrent chemoradiation with fluorouracil and mitomycin," the study authors wrote. "Options to explore included targeted agents (e.g., results with concurrent cetuximab plus radiation for head/neck cancer), dose escalation with intensity-modulated radiation plus concurrent chemotherapy, and surgical excision of residual cancer after concurrent chemoradiation at an earlier interval, when sphincter preservation may still be feasible in select patients."
The study was published in this week's issue of the Journal of the American Medical Association.
The American Cancer Society has more about anal cancer.
-- Robert Preidt
SOURCE: Journal of the American Medical Association, news release, April 22, 2008
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