Irinotecan, cisplatin, and radiation in esophageal cancer

The limited effectiveness of currently available chemotherapy in the treatment of advanced esophageal cancer, and the poor survival achieved in locally advanced disease with combined chemoradiotherapy with or without surgery, have prompted the evaluation of new agents. Irinotecan (CPT-11, Camptosar) has promising single-agent activity in gastrointestinal cancers. In phase II evaluation of weekly irinotecan plus cisplatin, response rates have exceeded 30% in esophageal and gastric cancers. Irinotecan is an active radiosensitizer in preclinical studies and clinical trials in lung cancer. We performed a phase I trial of weekly irinotecan, cisplatin, and concurrent radiotherapy in locally advanced esophageal cancer. Induction chemotherapy with irinotecan and cisplatin was given prior to radiotherapy, over 6 weeks, cycled on a 2-week-on, 1-week-off schedule to relieve dysphagia. Radiotherapy was given subsequently in 180-cGy daily fractions to a total dose of 5,040 cGy. Doses of chemotherapy, when given with concurrent radiotherapy, were cisplatin at 30 mg/m2 followed by irinotecan at escalated doses (40, 50, 65, and 80 mg/m2), on days 1, 8, 22, and 29. Among 18 patients entered in the trial, minimal toxicity has been observed, with no grade 3/4 esophagitis or diarrhea. Hematologic toxicity has been minimal. Dose-limiting toxicity (ie, requiring more than a 2-week delay in radiotherapy) has been seen in one of three patients at the 80-mg/M2 irinotecan dose level, and accrual continues at this dose level. Among 13 evaluable patients, five complete responses have been seen (38%), including three pathologic complete responses in 10 patients undergoing surgery (30%). Asymptomatic pulmonary emboli were noted on the posttreatment computed tomography scan in 3 of 15 patients, prompting the addition of warfarin sodium (Coumadin) prophylaxis on protocol. Full doses of weekly irinotecan (65 mg/ m2) and cisplatin (30 mg/m2) can be combined safely with concurrent radiotherapy in patients with locally advanced esophageal cancer.