Clinical characteristics and prognosis of primary breast lymphoma: Cleveland Clinic experience.

Abstract

e19035 Background: Primary Breast lymphoma (PBL) is a rare form of extranodal non-Hodgkin lymphoma (NHL). The majority of PBL are diffuse large B-cell lymphoma (DLBL). Current treatments can achieve an overall survival of 5 years in 80% of the patients. We evaluated prognostic factors and survival rates in PBL patients at Cleveland clinic foundation (CCF). Methods: We retrospectively identified patients diagnosed with PBL at CCF between January 2004 and January 2018. Baseline characteristics were compared between the indolent and aggressive lymphoma groups using two sample T-test for continuous variables, chi-square test and fisher’s exact test for categorical variables. Overall survival (OS) was estimated by the Kaplan-Meier method and compared by the log-rank test. Results: A total of 36 patients with PBL were identified, of whom 35 patients (97.2%) were females with a median age of 66 years (34-95). Of all patients, 23 (63.9%) were indolent lymphoma and 13 (36.1%) were aggressive lymphoma. The most common subtypes were marginal zone lymphoma (33.3%), DLBL (25%) and follicular lymphoma (19.4%). Only 2 patients (5.6%) had implant-associated anaplastic large T-cell lymphoma. There was significant difference in presentation between indolent and aggressive lymphoma patients; 78.3% of indolent lymphoma patients presented with incidental mammogram lesions compared to 30.8% of aggressive lymphoma patients (P-value = .019).Seventy five percent of the patients presented with stage IE, 16.7 % presented with stage IIE and 8.3% presented with stage IV. Treatment received included chemotherapy (55.6%), radiotherapy (47.2%), surgeries (16.7%), and rituximab (80% of patients received chemotherapy). Six patients (16.7%) didn’t receive treatment. Only one patient received central nervous system prophylaxis. Median follow-up of patients was 37.1 months. Three-year OS for patients with indolent and aggressive PBL was 94.4% (95% CI 84.4% - 100%) and 90.9% (95% CI 75.4% - 100%), respectively (p = 0.69). Conclusions: Marginal zone lymphoma was the most common subtype in our cohort. Indolent lymphoma commonly present as incidental mammogram finding. Prognosis of PBL is not affected by histologic subtype, tumor stage and bilateral breast involvement. Current treatments achieve good control of the disease.