Irinotecan in esophageal cancer.
The limited effectiveness of chemotherapy in esophageal cancer used to palliate metastatic disease or to combine with radiotherapy in locally advanced disease has prompted the evaluation of new systemic agents. Irinotecan (CPT-11, Camptosar) has shown promising activity in a number of gastrointestinal cancers, including esophageal cancer. The phase II evaluation of the combination of weekly irinotecan and cisplatin has shown encouraging response rates exceeding 30% to 50% in esophageal and gastric cancer. Novel regimens include the combination of irinotecan with mitomycin (Mutamycin), the taxanes docetaxel (Taxotere) and paclitaxel, and continuous infusion fluorouracil (5-FU). Irinotecan is an active radiosensitizer, and trials have evaluated the combination of irinotecan with concurrent radiotherapy. We completed a phase I trial combining weekly irinotecan, cisplatin, and concurrent radiotherapy in locally advanced esophageal cancer. Minimal toxicity has been observed, with no grade 3/4 esophagitis or diarrhea, and hematologic toxicity was also surprisingly minimal. Full doses of weekly irinotecan (65 mg/m2) and cisplatin (30 mg/m2) could be combined safely with concurrent radiotherapy, with a significant rate of pathologic complete response. Phase II evaluation of this chemoradiotherapy regimen as preoperative therapy is planned at single institutions and at the cooperative group level in the United States. Further phase I and II investigation of combined irinotecan, cisplatin, and concurrent radiation is ongoing with the addition of targeted agents, including celecoxib (Celebrex), cetuximab (Erbitux), and bevacizumab (Avastin). Alternative combinations of irinotecan with radiotherapy, including the addition of docetaxel and continuous infusion 5-FU, are also undergoing phase I and II evaluation.