Association between c-Met expression and tumor recurrence in colorectal cancer patients after liver resection.

Abstract

3559 Background: c-Met is a receptor for hepatocyte growth factor that has been implicated in the pathogenesis and growth of a wide variety of human malignancies, including colorectal cancer (CRC). The aim of the present study was to clarify the correlation between c-Met protein expression in the primary lesion and relapse-free survival (RFS) in patients who had undergone curative hepatectomy for colorectal metastases. Methods: Between January 2004 and December 2009, formalin-fixed paraffin-embedded sections of surgical specimens from 108 CRC patients who had undergone hepatectomy were obtained at a single center. We performed immunohistochemical staining to detect c-Met expression. c-Met expression levels were scored dependent on staining intensity; 0, negative; 1, weak; 2, moderate; 3, strong. We defined scores 0 and 1 as c-Met-low, and scores 2 and 3 as c-Met-high. The Kaplan-Meier method and Cox proportional hazards model were used to investigate relationships between c-Met expression, patient characteristics, and RFS. Results: We identified 65 males and 43 females with a median age of 62 years. A total of 53% of patients underwent simultaneous resection of primary and metastatic liver lesions, and the others underwent metachronous resection. High levels of c-Met expression (c-Met-high) in the primary tumor were observed in 52% of patients. There were no differences in terms of size or number of metastatic liver lesions between the c-Met-low patients and the c-Met-high patients. RFS was significantly shorter in the c-Met-high patients (9.7 months) than that in the c-Met-low patients (21.1 months) in primary tumors (p=0.013). Multivariate analyses demonstrated that c-Met-high (hazards ratio [HR], 1.73; 95% confidence interval [95% CI], 1.08-2.79 for c-Met-high vs. c-Met-low) and hepatic resection for synchronous disease (HR, 2.17; 95% CI, 1.36-3.46 for synchronous vs. metachronous resection) were associated with worse RFS. Conclusions: High levels of c-Met expression in the primary tumor were associated with shorter RFS after hepatic metastasectomy.