Prognostic factors and nomogram for survival prediction in patients with primary pulmonary lymphoma: a SEER population-based study.

Primary pulmonary lymphomas (PPLs) are rare lymphoproliferative malignancies arising from the lungs. The prognostic factors and optimal management of PPL have not been clearly defined due to its rarity. This study sought to characterize the significant prognostic factors and develop a validated nomogram for individualized prediction of survival outcomes in patients with PPL. A total of 2325 patients diagnosed with PPL between 1983 and 2010 were identified using the Surveillance, Epidemiology, and End Results (SEER) database. Older age at diagnosis, males, Hispanic race, non-marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue histology, Ann Arbor stage IV were significantly associated with worse OS on multivariable analysis. All treatment modalities, including chemotherapy, surgery, and radiotherapy were independent predictors of survival on univariable analysis. The nomogram built demonstrated good discriminative ability and calibration, with the C-index of 0.690 and 0.730 in the training and validation cohorts, respectively.