Age-related systemic treatment and survival of patients with metachronous metastases from colorectal cancer

Background: Although the spectrum of systemic treatment for metastatic colorectal cancer (mCRC) has widened, there is a paucity of evidence for the feasibility and optimal use of these systemic agents in elderly patients. The present study provides real world data on the age-related systemic treatment and survival of CRC patients with non-resectable metachronous metastases. Methods: All consecutive patients with non-resectable metastases from primary resected CRC were extracted from the Eindhoven area of the Netherlands Cancer Registry (NCR). Patients receiving palliative systemic therapy were enrolled (n = 385). Systemic treatment and survival were analyzed according to age at diagnosis of metastases. Results: Patients aged >= 75 years more often received first-line single-agent chemotherapy than their younger counterparts (63% vs. 32%, p < .0001). First-line single-agent chemotherapy was often prescribed without additional targeted therapy (78%). Advanced age (>= 75 years) was associated with a lower probability of receiving all active cytotoxic agents compared to patients aged < 60 years at time of diagnosis of metastases (odds ratio (OR) 0.2, 95% CI 0.10-0.77). In a multivariable Cox regression analysis with adjustment for age and other relevant prognostic factors, the total number of received systemic agents was the only predictor of death (hazard ratio (HR) 0.7, 95% CI 0.61-0.81). Conclusion: The beneficial effect of treatment with all active systemic agents on survival (simultaneously or sequentially prescribed) should be taken into account when considering systemic therapy in patients with mCRC. In light of our results, future studies are warranted to clarify the role of potential targeted therapy in elderly mCRC patients, who are often not candidates for combination chemotherapy and treatment with all active cytotoxic agents.