There is limited evidence for activity of irinotecana dn Erbitux for emtastatic squamous cell cancer of the anus. One is a case report of a a female patient with refractory anal cancer who achieved an excellent response to the combination of cetuximab and irinotecan after having failed single-agent irinotecan. The other is a report on 7 patients with metastatic anal cancer treated with cetuximab - a chimeric antibody against EGFR - on a compassionate use basis along with the results of KRAS mutational analysis. Marked tumor shrinkage was noted in several patients using cetuximab monotherapy or cetuximab/irinotecan combination as first or subsequent treatment line (usually after failure of cisplatin-based regimens). Two out of seven patients harbored KRAS mutations. Both patients had progressive disease receiving cetuximab, while the remaining 5 patients had either a partial remission (n = 3), a minor remission (n = 1) or no change lasting 6 months after previous rapid tumor progression.
Both are preliminary communications and no prospective studies have yet been done. This is an intriguing but still experimental therapy for anal carcinomas.
EPhan, Lan K. M.P.A.S., P.A.-C.; Hoff, Paulo M. M.D., F.A.C.P. Evidence of Clinical Activity for Cetuximab Combined with Irinotecan in a Patient with Refractory Anal Canal Squamous-Cell Carcinoma: Report of a Case Diseases of the Colon & Rectum: doi: 10.1007/s10350-006-0786-9
Nadine Lukan et al, Cetuximab-Based Treatment of Metastatic Anal Cancer: Correlation of Response with KRAS Mutational Status Oncology Vol. 77, No. 5, 2009