Cisplatin/fluorouracil plus radiation does not improve disease-free survival for patients with anal cancer compared with mitomycin/fluorouracil plus radiation, according to an article in the April 23 issue of the Journal of the American Medical Association.

Chemoradiation is the preferred primary therapy for patients with anal canal cancer; however, the five-year disease-free survival rate from concurrent fluorouracil/mitomycin and radiation is only approximately 65 percent. It has been suggested that reducing the volume of primary tumor and tumor load in lymph nodes prior to administration of chemoradiation could potentially be effective for treating anal canal cancer.

Jaffer A. Ajani, MD, of the University of Texas M. D. Anderson Cancer Center, Houston, and colleagues conducted a randomized controlled trial comparing treatment with fluorouracil plus mitomycin and radiotherapy versus treatment with fluorouracil plus cisplatin and radiotherapy in 682 patients with anal canal cancer. A total of 644 patients were included in the analysis. The median follow-up for all patients was 2.51 years.

The five-year disease-free survival rate was 60 percent in the mitomycin-based group and 54 percent in the cisplatin-based group. The five-year overall survival rate was 75 percent in the mitomycin-based group and 70 percent in the cisplatin-based group, with more cancer-related deaths in the cisplatin-based group (54 patients) than in the mitomycin-based group (28 patients).

The five-year local-regional recurrence and distant metastasis rates were 25 percent and 15 percent, respectively, for mitomycin-based treatment and 33 percent and 19 percent, respectively, for cisplatin-based treatment. Severe hematologic toxicity was worse with mitomycin-based treatment.

Cisplatin-based treatment resulted in significantly higher cumulative rates of colostomy (19 percent versus 10 percent) and should generally be avoided in this patient population as primary therapy, the authors wrote.

"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. … Options to explore include 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."