Prognostic factors of Chinese patients with primary pulmonary non-Hodgkin's lymphoma: The single-institute experience in Taiwan

Primary pulmonary lymphoma (PPL) accounts for less than 1% of patients with non-Hodgkin's lymphoma, with no report in Chinese patients. This study aims to analyze the clinical features and prognosis of this population. Patients with biopsy-proven pulmonary lymphoma were reviewed and re-classified by a hema-pathologist. Between 1992 and 2005, a total of 22 patients were identified (16 men and six women), with a mean age of 70 years. The histological subtypes included marginal zone B-cell lymphoma of mucosa-associated lymphoid tissues (MALT) in 12 patients (54%), diffuse large B-cell lymphoma in nine (41%), and one case of lymphomatoid granulomatosis. Diseases mainly manifested as pulmonary nodules or masses in 73% of patients, with a higher rate of hilar/ mediastinal lymphadenopathy in non-MALT patients (8% vs. 80%, P = 0.002). In eight patients (36% of 22), diagnoses were only conclusive until the biopsy via thoracotomy. Eighteen patients (82%) received chemotherapy. The 5-year rates of overall survival (OS) were 91% and 21% for MALT and non-MALT types of PPL, respectively. Patients who had received surgical resection tended to have a better 5-year OS rate (P = 0.077). The Cox-regression analysis showed that two factors - elevated serum lactate dehydrogenase level and hilar/mediastinal lymphadenopathy at diagnosis - were independently associated with a poor OS, with a hazard ratio of 10.370 and 5.171 (P = 0.01 and 0.033), respectively. In conclusion, the histological subtypes of Chinese PPL patients were similar to those in previous reports, with no increasing incidence of T-cell immunophenotype. The two prognostic factors provided additional information in managing these patients.