Clinical Effectiveness of Oncological Treatment in Metastatic Colorectal Cancer Is Independent of Comorbidities and Age.

We aimed to investigate the effectiveness of oncological treatments in metastatic CRC related to comorbidities and age. This retrospective study included 1105 patients from three oncological centers. aaCCI and CCI was available from 577 patients. An aaCCI > 3 was of the highest predictive value compared to other aaCCI-levels, CCI or age (p < 0.001 for all). Treatment (best supportive care (BSC), systemic treatment only (STO) and resection of metastases (ROM)) significantly prolonged survival in patients with aaCCI > 3 (STO: HR 0.39, CI 0.29-0.51; ROM: HR 0.16, CI 0.10-0.24) and patients older than 70 years (STO: HR 0.56, CI 0.47-0.66; ROM: HR 0.23, 0.18-0.30). Median overall survival was shorter in patients with aaCCI or age > 70 years and interaction for treatment type not significant for aaCCI, but significant for age older or younger than 70 years (STO: p = 0.01; ROM p = 0.02). BSC is more often considered as optimal care for patients with an aaCCI > 3 (37.6% vs. 12.4%; p < 0.001) or age > 70 years (35.7% vs. 11.2%; p < 0.001). Older patients or patients with comorbidities benefit from cancer-specific therapy independently of their age and comorbidities.