Reintroduction of oxaliplatin for patients with metastatic colorectal cancer refractory to standard chemotherapy regimens.

Abstract

630 Background: Reintroduction of oxaliplatin seems to have clinical benefits for patients with metastatic colorectal cancer refractory to standard chemotherapy regimens. A interim analysis of RE-OPEN study reported 38.9% of disease control rate (DCR) in ASCO GI 2013, but it is still unknown who will receive benefits from reintroduction of oxaliplatin. Methods: Among patients in whom oxaliplatin was reintroduced in the 7 participating hospitals, we retrospectively studied patients who had previously received oxaliplatin and irinotecan and patients who had a response of stable disease or better during initial treatment with oxaliplatin. Results: From June 2009 through January 2013, oxaliplatin was reintroduced in 53 patients (31 men and 22 women). The median age was 64 years, and the performance status was 0 in 24 patients and 1 in 29. The reasons for discontinuing initial treatment with oxaliplatin were progressive disease in 36 patients, adverse events in 14 and others in 3. The response rate (RR), DCR, the median progression-free survival (PFS), and the median overall survival were 3.8%, 47.2%, 105 days, and 313 days, respectively. As for adverse events, allergic reactions to oxaliplatin (grade 1 or higher) occurred in 26% of the patients. RR, DCR, and PFS in 44 patients with the oxaliplatin-free-interval (OFI) over 6 months were 4.6%, 54.6%, and 119 days, respectively, and were statistically better than those in 9 patients with OFI less than 6 months (0%, 11.1%, and 84 days). Reintroduction of oxaliplatin with bevacizumab showed better PFS than that without bevacizumab (114 days and 78 days, respectively). Conclusions: Reintroduction of oxaliplatin was suggested to be one option for the management of colorectal cancer that is resistant to standard therapy, especially in patients with OFI over 6 months. Bevacizumab may enhance the results of reintroduction treatment.