Treatment and prognosis of primary pulmonary lymphoma: A long-term follow-up study

Primary pulmonary lymphoma (PPL) is a rare disease with not well-defined optimal treatment. Outcomes and follow-up are variable in published data. Objectives: To define the outcome and optimal treatment strategies in PPL. Methods: We reviewed the medical records of 49 patients with PPL treated in three Italian Hematological Institutions between 2002 and 2018. Results: Thirty-eight (77.5%) cases were indolent PPL, and 11 (22.5%) cases were aggressive PPL. The majority of patients were asymptomatic at diagnosis, early stages (stages IE-IIE), normal serum LDH, no bone marrow involvement, and low or low-intermediate risks of IPI. Local therapy ± immunotherapy or immuno-chemotherapy was possible in 18/49 (37%) patients. Twenty-eight (57%) patients were treated with immuno-chemotherapy after biopsy. Waiting and watching were reported in 3 (6%) patients. Overall, the CR and ORR were 83.7% and 95.9%. With a median follow-up of 62.5 months (range 0.8-199 months), the estimated 5- and 10-year OS rates were 85% and 72.3% for all patients, 89.2% and 80.3% for indolent PPL, and 70.7% and 47.1% for aggressive PPL. Aggressive PPL tended to have a high risk of progression in the first months (P =.056). No advantages were found for indolent PPL who received immuno-chemotherapy or more conservative approaches. Conclusion: Our studies confirm the epidemiological and favorable survival of patients with PPL, suggesting a very conservative approach, particularly in indolent subtypes.