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 (stage IE-IIE), normal serum LDH, no bone-marrow involvement and low, or low-intermediate risks 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. Wait and watching was reported in 3 (6%) patients. Overall the CR and ORR were 83.7% and 95.9%.With a median follow-upof 62.5 months (range 0.8-199 months), the estimated 5 and 10 years 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.