Prognosis of primary hepatic lymphoma: A US population-based analysis

OBJECTIVE: Primary hepatic lymphoma (PHL) is a rare malignancy with lesions confined to the liver. It is characterized by a large number of monomorphic, medium-sized lymphocytic infiltrates in the hepatic sinusoid. Due to the rarity of this malignancy, our current understanding of PHL is limited. METHODS: We collected incidence, mortality, and clinical data of PHL patients diagnosed between 1975 and 2016 using the Surveillance, Epidemiology, and End Results (SEER) database. The annual percentage changes (APCs) and prognoses were analyzed using the Joinpoint and R package. RESULTS: Among the 1,372 patients, white males were prevalent, and the most common histological subtype was diffuse large B-cell lymphoma (DLBCL). The incidence and mortality rate of PHL was 0.075/100,000 person-years and 0.055/100,000 person-years, respectively. The annual incidence rate of PHL increased significantly, with an APC of 2.74% (P < 0.001). The 3- and 5-year overall survival (OS) rates of patients with PHL were 43.553% and 39.242%, respectively. The 3- and 5-year relative survival (RS) rates were 46.925% and 45.300%, respectively. Multivariate Cox regression analysis revealed that older age, black, DLBCL, and advanced-stage disease were independent predictors of unfavorable OS and RS. The C-index and receiver operating characteristic (ROC) analysis confirmed the prognostic value of the nomograms established in this study. CONCLUSION: The nomogram established in this study is a robust tool to predict the prognosis of PHL patients.