Addition of Oxaliplatin to Neo-adjuvant Radiochemotherapy for Irresectable Rectal Cancer, a Phase I Study

Background: The aim was to determine the maximum tolerable dose of oxaliplatin added to (oral) 5FU in irresectable rectal cancer. Patients and Methods: Nineteen patients were treated; 13 patients received 5FU/LV and 6 patients capecitabine. Oxaliplatin was administered on days 1 and 29 at dose levels 85 and 130 mg/m 2 . Four to seven weeks thereafter, surgery was performed. Results: In 6 patients treated with 85 mg/m 2 , one grade 3 elevation of liver transaminases occurred. Of 7 patients who received 130 mg/m 2 , 1 patient experienced a grade III thrombocytopenia and 1 patient died of neutropenic fever, probably due to an urosepsis. Six patients were treated with capecitabine, of whom 3 developed a grade III gastrointestinal toxicity. An R0 resection could be performed in 93%, a pT0-2N0 in 39%, with 2 pCR's. Conclusion: The addition of oxaliplatin at 85 mg/m 2 on days 1 and 29 to radiotherapy and 5FU/LV or capecitabine in irresectable rectal cancer is feasible. The preoperative treatment of irresectable rectal cancer aims at a reduction of the tumor size by using radiotherapy alone or in combination with chemotherapy (neo-adjuvant treatment) (1) If successful, this strategy leads to