Retrospective analysis of efficacy and safety of third-line chemotherapy for metastatic colorectal cancer among elderly patients receiving targeted therapy in early lines

Background/Purpose About one-half of metastatic colorectal cancer (MCRC) patients are ≥70 years of age. There is uncertainty regarding the benefit patients derive from advanced chemotherapy lines. In this study, we aim to evaluate the efficacy and safety of third-line chemotherapy treatments among MCRC patients. Methods Consecutive patients 70 years or older at the time of diagnosis of metastatic disease who received third-line chemotherapy at the Tel-Aviv Sourasky Medical Center between the years 2000-2009 were collected. Data on demographics, stage of disease, treatment lines and oncological outcomes were extracted from their medical files. Results Only 34 out of 63 patients (54%) available patients received third-line treatments. The (median) age of all patients, third-line patients and the remaining patients, were similar (74.5, 74 and 75.3 years, respectively, P = NS). Following third-line treatments, only 9% had a partial response, and the disease was stable in 29% of patients seen. Thirteen weeks is the median duration of third-line treatments. Only three patients had symptomatic relief. Importantly, 15 patients (44%) required dose reduction or treatment delay due to toxicity (neutropenia or thrombocytopenia). The median survival (mOS) is 9 months for patients with first-line treatment, 19 months for second-line treatment and 37 months for third-line treatment (Log Rank < 0.0001). There was a significant association between the number of lines of treatment and the mOS (P = 0.0001). Conclusion Third-line chemotherapy treatment of elderly MCRC patients was associated with a minor clinical response, a considerable number of side effects, but a longer survival rate. Third-line chemotherapy in fit elderly patients should be pursued, however, protocols must be adjusted before third-line treatment is implemented.