Objective: We aimed to present new histopathological features of metastatic liver nodules as more reliable prognostic factors after surgical resection for colorectal metastatic cancer.
Methods: Clinicopathological features, including newly proposed histopathological ones, of 63 consecutive patients were reviewed retrospectively to determine which most strongly correlated with long-term prognosis after hepatectomy for metastatic tumors from colorectal cancers, using univariate and multivariate analysis.
Results: The 1-, 3-, and 5-year cancer-related survival rates after hepatectomy were 87.8%, 55.2%, and 47.3%, respectively. New histopathological features we proposed, which are expansive growth, marginal fibrosis, and peritumorous lymphocytic infiltration of hepatic tumor, were significant prognostic factors for cancer-related survival after hepatectomy in an univariate analysis. Also in a multivariate analysis, i.e., a stepwise Cox regression analysis, infiltrative, i.e., not expansive, growth of hepatic tumor was one of significant and independent poor prognostic factors for survival after hepatectomy, with moderate to severe lymphatic vessel involvement of the primary colorectal lesion, microscopic cancer invasion at the surgical margin of hepatectomy, and extrahepatic distant metastases.
Conclusions: Our results suggest that our proposed new histopathological features of hepatic metastases were good predictors of prognosis after surgical resection for hepatic metastases from colorectal cancer. Especially, infiltrative growth of hepatic tumor is strongly correlated with a poor prognosis after hepatectomy.