Real-World Treatment Sequencing in Vulnerable Patients with Metastatic Colorectal Cancer: A Multicenter Retrospective Study.

Background: Data regarding treatment sequence for vulnerable patients with metastatic colorectal cancer (mCRC) in a real-world setting are lacking.

Objective: We aimed to assess treatment outcomes in second-line or later chemotherapy for vulnerable patients with mCRC in a real-world setting.

Patients And Methods: Vulnerable patients with mCRC who received less intensive treatment ('vulnerable') regimens, i.e. fluoropyrimidines with or without biologics (FP), reduced-dose doublet regimens with or without biologics (Doublet), and anti-epidermal growth factor receptor monotherapy (Anti-EGFR), as first-line therapy between June 2015 and December 2018 were retrospectively reviewed.

Results: A total of 210 patients from 15 hospitals were analyzed. The median age was 78 years (range 28-90), and 44 patients (21%) had an Eastern Cooperative Oncology Group performance status (ECOG PS) score of 2. In the entire population, the median time to treatment failure (TTF) and overall survival (OS) were 7.6 and 21.4 months, respectively. Following the failure of first-line therapy in 195 patients, 74 (38%), 24 (12%), and 13 (7%) patients received vulnerable regimens, full-dose doublet regimens with or without biologics, and other regimens, respectively, whereas 84 (43%) received best supportive care (BSC). In patients receiving vulnerable regimens as second-line therapy, the median TTF and OS were 4.4 and 13.7 months, respectively, while response rate and disease control rate were 18% and 62%, respectively. In 84 patients who received BSC, the median OS was 3.5 months.

Conclusions: Second-line chemotherapy for vulnerable patients with mCRC showed clinically meaningful outcomes; however, few patients received second-line therapy, and survival among patients who received BSC was dismal.