Treatment and outcomes of primary breast lymphoma.

Purpose: To evaluate treatment and outcomes in a population-based cohort of patients diagnosed with primary breast lymphoma.

Methods And Materials: Prognostic factors, management, and outcomes (local control, lymphoma-specific survival, and overall survival) were analyzed for all patients diagnosed with limited-stage, primary breast non-Hodgkin lymphoma (n = 50) diagnosed in British Columbia between 1981 and 2009.

Results: The median follow-up was 3.5 years; 64% presented with a breast mass. Histologic subtypes were indolent (n = 16 [32%]) or aggressive (n = 34 [68%]). Of those with indolent lymphoma, 81% had stage I, and 19% had stage II disease; 13% received no initial treatment; 75% received radiotherapy (RT) alone. One (6%) patient received surgical resection alone, and 1 (6%) patient received surgical resection in addition to RT. Of those with aggressive lymphoma, 62% had stage I and 38% had stage II disease; 3% received no initial treatment; 6%, RT alone; 38%, chemotherapy only; 41%, chemotherapy and RT; 9%, surgical resection alone; and 3%, surgical resection in addition to chemotherapy and RT. In patients with indolent and aggressive disease, 5-year local control estimates were 92% and 96%, lymphoma-specific survivals were 91% and 71%, and overall survivals were 75% and 54%, respectively. On univariate analysis, stage (I vs. II) (P = .006) and RT use (P = .032) were statistically significant predictors of improved overall survival in patients with indolent breast lymphoma. Combined chemoradiation was associated with a trend for improved overall survival (P = .061) in patients with aggressive disease. There were 4 cases of central nervous system relapse, all occurred in subjects with aggressive primary breast lymphoma.

Conclusions: Patients with indolent breast lymphoma were most frequently treated with RT alone and achieved high rates of local control and survival. Patients with aggressive histology most often treated with chemotherapy, alone or combined with RT, had excellent local control but lower survival compared with indolent disease. Improved systemic therapies are needed to improve outcomes for patients with aggressive breast lymphoma.