A retrospective cohort study evaluating the safety and efficacy of TAS-102 in patients with metastatic colorectal cancer (HGCSG1503): Analysis of tumor location.

Abstract

802 Background: Recent analysis from some clinical trials showed that primary tumor location in patients with metastatic colorectal cancer (mCRC) correlates with different outcome. The J003 trial and RECOURSE trial revealed the safety and efficacy of TAS-102 for patients with metastatic colorectal cancer (mCRC). In March 2014, TAS-102 was approved in Japan. However, the impact of primary tumor location in mCRC treated TAS-102 is unclear. Methods: We retrospectively analyzed the clinical data of 411 patients who received TAS-102 in the multi-institutional retrospective study (HGCSG1503). This study was analyzed by CTCAE v4.0 for adverse events (AEs), RECIST v1.1 for response rate (RR)/disease control rate (DCR). To compare with right-sided tumor (RT : Cecum to Transverse colon) and left-sided tumor (LT : Descending colon to Rectum), Fisher’s exact test was used in terms of patient characteristics, AE, RR/DCR, and Log-rank test was used in terms of TTF, PFS and OS. Results: Patients with RT and LT were 137 and 274, respectively. The patient’ characteristics between RT and LT were generally balanced except for Gender (Male ; 45.3% in RT, 56.9% in LT ; p = 0.028), Age (Median ; 68.0y in RT, 66.0y in LT ; p = 0.007), Liver metastasis (70.8% in RT, 57.7% in LT ; p = 0.010), Peritoneal metastasis (47.4% in RT, 24.5% in LT ; p < 0.001), and KRAS exon2 status (wild ; 40.5% in RT, 59.0% in LT ; p = 0.001). The AEs between RT and LT were also generally balanced except for Platelet count decreased (≥Grade 3 ; 8.8% in RT, 2.9% in LT ; p = 0.014). RR/DCR were 0/30.9% in the RT and 0.8/40.3% in the LT (p = 1.000/0.088). Median TTF was 2.2 months in the RT and 2.1 months in the LT (HR 0.962, p = 0.712). Median PFS was 2.2 months in the RT and 2.2 months in the LT (HR 1.024, p = 0.826). Median OS was 7.3 months in the RT and 7.3 months in the LT (HR 1.114, p = 0.327). Conclusions: As a result of this analysis, efficacy was no significant difference between RT and LT for patients who were administered TAS-102 in the real-world clinical practice. This analysis suggested TAS-102 benefits mCRC patients regardless of primary tumor location. Clinical trial information: 000020551.