Efficacy and safety of TAS-102 in clinical practice of salvage chemotherapy for metastatic colorectal cancer

Background: TAS-102 is an anti-metabolite which demonstrated activity against multidrug-resistant advanced colorectal cancer. Its major toxicities are hematological disorders. Patients and Methods: Background, TAS-102 efficacy, toxicities and outcomes for patients with multidrug-resistant advanced colorectal cancer from six Institutions of the Kyushu Medical Oncology Group were retrospectively surveyed. Results: Forty-three patients, including fragile patients due to declining performance status and other comorbidities (37%) were analyzed. Efficacy was reflected in an objective overall response of 3%, median progression-free survival of 74 days (2.5 months) and median overall survival of 229 days (7.6 months). The most frequent Common Terminology Criteria for Adverse Events grade 3/4 adverse events were neutropenia (44%), leukopenia (26%) and anemia (23%). Febrile neutropenia was found in 7%. Sub-group analysis demonstrated an improved outcome on treatment with the sequence regorafenib-TAS-102. Conclusion: TAS-102 was safely administered to modestly fragile patients with equivalent efficacy to that for the non-fragile population. Further investigation of sequential treatment using regorafenib and TAS-102 is needed.