Comparative efficacy of TAS-102 and chemotherapy rechallenge in the third-line setting and beyond in patients with advanced colorectal cancer: A retrospective study.

78 Background: The optimal approach to third line therapy for patients with metastatic colorectal cancer remains a subject of debate. Options include Trifluridine/Tipiracil (TAS-102), TAS-102 with bevacizumab, regorafenib, chemotherapy rechallenge with or without an anti-EGFR agent, or fruquintinib. This study aims to evaluate the efficacy of standard of care TAS-102, TAS-102 with bevacizumab, or regorafenib versus chemotherapy rechallenge in patients with metastatic colorectal cancer in the third line setting and beyond. Methods: We conducted a retrospective analysis of patients with metastatic colorectal cancer who received either TAS-102 with or without bevacizumab, regorafenib or chemotherapy rechallenge with or without an anti-EGFR agent between 2018 and 2023, at the Ministry of National Guard for Health Affairs in Riyadh, Saudi Arabia. Patients received such agents in the third line setting and beyond. Results: A total of 75 patients were included in this study, with 39 patients receiving TAS-102 with or without bevacizumab, or regorafenib, and 36 receiving chemotherapy rechallenge. The median patient age was 58 years (range 28-81), with the majority being males at 55%. Among the chemotherapy rechallenge group, 31% were treated with cetuximab and 6% had panitumumab rechallenge, some of which were guided by cell free DNA liquid biopsy testing. In the other group, 66% received regorafenib, 26% TAS-102 alone, and 8% TAS-102 with bevacizumab. At the time of analysis, 56% of patients had passed away. Median overall survival for patients who received TAS-102 with our without bevacizumab, and regorafenib in the third line setting was found to be 13.1 months. Whereas for patients who received chemotherapy rechallenge, their median overall survival was 19.5 months. Conclusions: Patients with metastatic colorectal cancer who received chemotherapy rechallenge in the third line setting survived longer compared with patients who received TAS-102 with or without bevacizumab, or regorafenib.