Center impact on survival in metastatic colorectal cancer trials.

Abstract

e14062 Background: Surgeon-volume and hospital-volume influence morbidity and mortality in patients undergoing surgery for cancer, but data are missing concerning influence of chemotherapy (CT) center on outcome in patients treated with CT. The aim of the present study was to evaluate the center effect on survival in patients treated with CT for metastatic colorectal cancer. Methods: Individual patient data from 3 randomized trials evaluating first-line CT in patients with metastatic colorectal cancer were pooled. Patients were separated in different groups according to each center’s volume of inclusion. Baseline characteristics, overall survival (OS), progression-free survival (PFS), response rates, second-line chemotherapy and rate of surgery of metastasis were analyzed. Results: Between 1998 and 2006, 1042 patients were enrolled in 70 centers from 6 countries. Four groups were created (Table). Median OS in groups A and D were 19.3/24.5 months, respectively (HR=1.39 [95% CI: 1.13-1.70], P=.003). There was no difference between the four groups concerning PFS (P=.70), response rates (P=.20) and administration of second-line CT (P=.10). However, oxaliplatin reintroduction and surgery of metastasis were more often performed in group D than in the other groups (P<.001). Conclusions: These data suggest that overall survival could be influenced by center. This could be partly explained by specific therapeutics strategies such as treatment reintroduction and surgery of metastasis. Patient distribution. Group A Group B Group C Group D Center inclusion rate (%) <3 [3-7] [7-12.5] ≥12.5 No. of patients 260 246 257 279 No. of centers 52 11 5 2 Overall response rate (%) 59 54 58 63 Oxaliplatin reintroduction (%) 16 24 32 39 Surgery of metastasis (%) 9 14 18 25 Second-line chemotherapy (%) 70 72 63 65 Median PFS (months) 8.4 8.1 8.2 8.7 Median OS (months) 19.3 20.8 19.2 24.5