Epidemiology of liver metastases

•5.14 % of primary cancer patients from 2010 to 2015 presented with synchronous liver metastases.•The most common primary sites with synchronous liver metastase were breast and colorectal cancers.•The primary site was more varied in older patients, with synchronous liver metastases from gastrointestinal, melanoma, bladder, and lung cancers.•Survival for patients with liver metastasis was significantly decreased as compared to patients without liver metastasis. The objectives of this study were to (1) characterize the epidemiology of liver metastases at the time of primary cancer diagnosis (synchronous liver metastases), (2) characterize the incidence trends of synchronous liver metastases from 2010−2015 and (3) assess survival of patients with synchronous liver metastases. The Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015 was queried to obtain cases of patients with liver metastases at the time of primary cancer diagnosis. The primary cancers with an incidence rate of liver metastasis >0.1 are presented in this analysis. Among 2.4 million cancer patients, 5.14 % of cancer patients presented with synchronous liver metastases. The most common primary site was breast cancers for younger women (ages 20–50), and colorectal cancers for younger men. As patients get older, a more heterogenous population of the top cancers with liver metastases emerges including esophageal, stomach, small intestine, melanoma, and bladder cancer in addition to the large proportion of lung, pancreatic, and colorectal cancers. The 1-year survival of all patients with liver metastases was 15.1 %, compared to 24.0 % in those with non-hepatic metastases. Regression analysis showed that the presence of liver metastasis was associated with reduced survival, particularly in patients with cancers of the testis, prostate, breast, and anus, and in those with melanoma. The most common primary sites for patients with liver metastases varied based on age at diagnosis. Survival for patients with liver metastasis was significantly decreased as compared to patients without liver metastasis.