Incidence, Prognostic Factors and Survival Outcome in Patients With Primary Hepatic Lymphoma.

Aim: The objective of our study was to investigate the epidemiologic characteristics, prognostic factors and survival in patients with. primary hepatic lymphoma (PHL). Methods: PHL patients diagnosed between 1983 and 2015 were identified from the SEER database. Overall survival(OS) and disease-specific survival (DSS) was evaluated using the Kaplan-Meier method and log-rank test. Multivariate Cox regression analysis was performed to identify the independent prognostic factors and these factors were integrated to develop nomograms to predict 1-, 5-, and 10-year OS and DSS. Decision curve analysis (DCA) was conducted to compare the clinical utility between nomograms and Ann Arbor stage system. Results: A total of 1182 patients were identified with PHL. The mean age was 61.7 ±17.1 years with a male to female of 1.6:1. Diffuse large B-cell lymphoma (59.8%) was the most common histological subtype. The incidence of PHL steadily increasing by an annual percentage change (APC) of 2.6% (95% CI 2.0–3.2, p < 0.05). The 1-, 5-, and 10-year OS rates were 50.85%, 39.6% and 30.4%, respectively, and the corresponding DSS rates were 55.3%, 47.9%, and 43.3%, respectively. Multivariate Cox regression analysis revealed that age, sex, race, marital status, Ann Arbor stage, histological subtype, surgery and chemotherapy were independent prognostic factors for survival. The concordance indexes (C-indexes) and calibration plots showed our nomograms had robust and accurate performance. Additionally, DCA revealed that the nomograms were superior over the Ann Arbor stage system with more clinical net benefits. Conclusion: PHL were rare but the incidence has been steadily increasing over the past four decades. Survival has improved in recent years. Surgery or chemotherapy could provide better OS and DSS. The established nomograms were more accurate and applicable than the Ann Arbor stage system in predicting 1-, 5- and 10-year OS and DSS.