Factors associated with Trifluridine/Tipiracil (TAS-102) effectiveness in patients with refractory metastatic colorectal cancer: real-life data from the Czech Republic.

Abstract Background: Trifluridine/tipiracil (TAS-102) is effective in refractory metastatic colorectal cancer (mCRC). Currently, no predictive biomarkers are established and used in clinical practice. Methods: We analyzed data of 160 patients treated with TAS-102 in real clinical practice in the Czech Republic. Different factors associated with progression-free survival (PFS) and overall survival (OS) were evaluated. Results: Median PFS was 3.3 months, and median OS 10.2 months. Factors significantly associated with PFS and/or OS were: ECOG performance status (PS), time from diagnosis of mCRC > 24 months, initiation of treatment > 3 months from last fluoropyrimidine, number of metastatic sites, baseline CRP level, WBC count, neutrophils count, monocytes count, neutrophil to lymphocyte ratio, development of neutropenia, thrombocytopenia, diarrhea, required dose reduction and cycle delay. We developed a scoring system TAScore from factors available at the beginning of treatment. One point each was assigned to the following factors (PS, diagnosis of mCRC > 24 months, initiation of TAS-102 > 3 months from fluoropyrimidine, baseline CRP, WBC, monocytes count < 0.5 × 10 9 /L) and patients were divided into 3 groups: high risk group (0 to 1 point), intermediate (2 to 3), favorable with 4 or more points. OS according to risk group was: 5.7 months for high risk, 8.7 for intermediate, 12.8 for favorable (P < 0.001). TAScore was also associated with PFS (P < 0.001). Conclusions : TAS-102 is effective in patients with refractory mCRC. We propose simple scoring system TAScore to help with precise patient selection at the beginning of TAS-102 treatment.