BACKGROUND: Despite advances in perioperative management, the 5-year survival rate of patients with esophageal adenocarcinoma (Barrett's cancer) is poor. Adjuvant immunotherapies are currently the subject of clinical trials. The prognostic role of tumor-infiltrating T-lymphocytes (TILs) expressing CD45 has only been investigated in primary tumors. The significance of TILs in the target organs of distant metastases, in particular the liver, is unclear. This study examined the influence of CD45-positive cells in liver parenchyma and primary tumors on cumulative survival.
MATERIALS AND METHODS: The density of CD45-positive cells was analyzed immunohistochemically using tissue microarrays. Sixty-five patients for whom a liver biopsy was available in addition to the primary tumor were included in the study. Liver metastases were found in 21 patients. The results of the immunohistochemical analysis were correlated with patient's outcomes. The Cox proportional hazard model was used to compute mortality hazard ratio in consideration of clinical variables.
RESULTS: Elevated density of CD45-positive cells in the liver biopsy corresponded with a better cumulative survival rate (p<0.001), while no significant differences were found for primary tumors. Multivariate Cox regression analysis showed that a high density of CD45-positive cells in the liver parenchyma was an independent prognostic parameter of longer overall survival (hazard ratio(HR)=0.432, p=0.048).
CONCLUSION: The density of CD45-positive cells in the liver parenchyma is an easily measured prognostic biomarker that can identify patient subgroups with a better prognosis. In addition, the density of CD45-positive cells in the liver may assist as a criterion for selecting patients with a high potential for response to adjuvant immunotherapy.