Metastatic liver tumors in surgical pathology: impact of contemporary diagnostic and therapeutic paradigms in a tertiary care center

Abstract

We analyzed metastatic liver tumors received in the department of pathology in a tertiary care center over a 3-year period. There were 509 metastatic liver tumors; counterintuitively, there were as many resections (235 cases) as biopsies (274 cases). This unexpected finding reflects contemporaneous organ-specific paradigms for diagnosis and management of metastatic liver disease in oncologic practice, and the association of our practice with a National Cancer Institute-designated comprehensive cancer center with expertise and specialization in liver surgery. We receive a large number of resections for metastatic liver tumors because metastasectomy from a variety of primary tumors is associated with improved overall, and in many instances, disease-free, long-term survival. Metastatic colorectal carcinomas, metastatic neuroendocrine tumors, and metastatic gastrointestinal stromal tumors constituted 78% of resections because the largest body of literature and cumulative experience exists for these lesions. In contrast, breast carcinomas and pancreatic carcinomas, which are the next common metastatic liver tumors were biopsied but rarely resected, because metastasectomy is not the standard of care for these tumors. Immunohistochemistry was performed in less than a quarter of the total number of cases (23%), because the primary tumor site was known in the vast majority of cases. Of the 42 cases with unknown primary tumor, it was elucidated in 50% of the cases by immunohistochemical and clinical work-up. Of the cases with known primary tumor, immunohistochemistry was performed mostly in metastatic breast, colon, and lung carcinomas. In these cases, biomarker analyses provided additional information relevant to clinical management.