Clinicopathological characteristics and prognostic factors of primary pulmonary lymphoma

BACKGROUND: Primary pulmonary lymphoma (PPL) is a rare extranodal lymphoma originating from the lung, accounting for 0.5–1.0% of primary lung malignant tumors. Previous case reports or cohort studies included a limited sample size; therefore, the understanding of the disease remains inadequate, and clinical data regarding PPL are limited. METHODS: Patients with PPL diagnosed histologically and radiologically between January 2000 and December 2019 at our center were retrospectively analyzed. RESULTS: In total, 90 consecutive cases were included in this research. Forty-seven (52.2%) patients were female, and the median age was 54 years old. Non-Hodgkin’s lymphoma (PPNHL) was the most common type of PPL (71/90, 78.9%), and mucosa-associated lymphoid tissue (MALT) lymphoma was the most common pathological subtype of PPNHL (56.3%) followed by diffuse large B-cell lymphoma (DLBCL) (32.4%). Thirty-nine (43.3%) patients underwent surgical treatment, and the others received chemotherapy alone or combined with radiotherapy. The estimated 5-year overall survival (OS) rates of MALT lymphoma and non-MALT lymphoma were 68.9% and 65.9%, respectively. Univariate analysis of PPL showed that clinicopathological features that significantly correlated with worse OS were age over 60 years (P=0.006<0.05), elevated LDH (P=0.029<0.05) and β2-MG (P=0.048<0.05) levels, clinical stage II2E and greater (P=0.015<0.05), and nonsurgical treatment (P=0.046<0.05). Age (P=0.013<0.05) was an independent prognostic factor for the 5-year OS of patients through multivariate analysis. CONCLUSIONS: Age over 60 years old, elevated LDH and β2-MG levels, clinical stage II2E disease or higher, and nonsurgical treatment were associated with poor prognosis in patients with PPL. Age can be used as a potential independent prognostic factor for PPL.