Combination chemotherapy with Regorafenib in metastatic colorectal cancer treatment: A single center, retrospective study

Background: Regorafenib has been demonstrated as effective in refractory metastatic colorectal cancer. Combination use with chemotherapy has not been reported. We examined the efficacy and safety of adding chemotherapy to Regorafenib for the treatment of metastatic colorectal cancer(mCRC) patients. Methods: We recruited mCRC patients at our institute who received either regorafenib monotherapy or regorafenib in combination with other chemotherapies. All patients had received chemo and target therapies and presented with disease progression before regorafenib treatment. The primary end point was overall survival. Findings: Between September1, 2015 and May 31, 2017, 100 mCRC patients at our institute received regorafenib treatment. 39 patients were excluded due to poor performance, lack of timely treatment, or inadequate clinical data. A total of 34 patients received regorafenib combined with other chemotherapies, and 27 patients received regorafenib alone. Median follow up time was 10.4 and 6.1 months, respectively. The primary end point of median OS was higher in the combination group than in the single use group (20.9m vs 10.3m, p = 0.015). The most frequent adverse events were hand-foot skin reactions(16[47.1%]vs 12[44.4%]), fatigue(6[17.6%] vs 7[25.9%]), gastrointestinal discomfort (7[20.6%] vs 6[22.2%]), neutropenia (4[11.8%] vs 1[3.7%]), diarrhea(4[11.8%] vs 1[3.7%]), and mucositis(5[14.7%] vs 1[3.7%]). Conclusion: The present study showed the efficacy and side effects of regorafenib combination treatment. Superiority in median OS and median PFS was noted in the combination group. The sampling difference between the study and observation groups effects justifies the comparison. Further clinical evidence of combination therapy efficacy is pending future studies.