Incidence, prognostic factors and clinical practice of Primary Pulmonary Lymphoma: A large population-based retrospective study

Abstract

Purpose: Primary pulmonary lymphoma(PPL) is a rare disease entity of pulmonary malignancies. The purpose of this study was to learn learn the incidence, treatment and survival of PPL.Methods: The incidence trend of PPL was investigated using Joinpoint regression software provided by National Cancer Institute. Cox regression analysis was performed to identify prognostic factors related to overall survival(OS) and disease-specific survival(DSS). The Kaplan-Meier method and log-rank test were used to evaluate OS and DSS.Results: A total of 1500 PPL patients were included in this study. The incidence of PPL was steadily increasing by annual percentage change(APC) of 2.7%(95%CI 2.0-3.4, P＜0.001). The median age was 66.0(19.0-99.0) years old along with more female(54.4%) patients than male. The most common subtype of PPL was marginal zone lymphoma of mucosa-associated lymphoid tissue(MALT)(41.3%) and diffuse large b-cell lymphoma(DLBCL)(29.7%), and the treatment regimens vary between these two subtype. Age, primary site, surgery, radiation, chemotherapy and laterality were identified as independent prognostic factors. Nomograms constructed for PPL-MALT and PPL-DLBCL to predict 1-, 5-, and 10-year OS and DSS. The area under curve (AUC) and calibration curves exhibit robust and accurate performance.Conclusions: Although rarely diagnosed, the incidence of PPL was steadily increasing in the past four decades. Nomograms for MALT and DLBCL in predicting 1-, 5-, 10-year OS and DSS were reliable. A diagram was drawn to describe PPL-MALT and PPL-DLBCL clinical practice.