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/m2. Four to seven weeks thereafter, surgery was performed.

Results: In 6 patients treated with 85 mg/m2, one grade 3 elevation of liver transaminases occurred. Of 7 patients who received 130 mg/m2, 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/m2 on days 1 and 29 to radiotherapy and 5FU/LV or capecitabine in irresectable rectal cancer is feasible.