T cell infiltrate predicts long-term survival following resection of colorectal cancer liver metastases.

Overview

BACKGROUND: While tumor infiltrating lymphocytes (TIL) have been shown to independently predict survival in primary colorectal cancer, the prognostic implications of TIL in resectable colorectal cancer liver metastases (CRCLM) have not been previously defined. This study examines the correlation between TIL numbers and survival following hepatic resection. METHODS: We studied patients who survived or=10 years following CRCLM resection. Immunohistochemistry was performed on tissue microarrays (TMAs) to determine the number of T cells within CRCLM. Correlation between TIL frequency and or=10 year survival was determined while controlling for established prognostic factors. RESULTS: Of 162 patients, 104 survived or=10 years. Independent correlates of 10-year survival following CRCLM resection included a high number of CD8 T cells, a low number of CD4 T cells, and a clinical risk score of