Diffuse large B-cell lymphoma of the breast: prognostic factors and treatment outcomes

Background: The breast is a rare site of extranodal involvement of diffuse large B-cell lymphoma (DLBCL). We aimed to assess the clinical characteristics, prognostic factors, and treatment outcomes of breast DLBCL. Patients and methods: We retrospectively analyzed 113 patients (from our institution and the literature) between 1973 and 2014. The primary end point was overall survival (OS). Kaplan-Meier OS curves were compared with the log-rank test. Cox regression analysis was applied to determine the prognostic factors for OS, progression-free survival (PFS), local control (LC), and cause-specific survival (CSS). Results: A total of 113 patients were included in the study: 42 cases from our hospital and 71 cases from 12 publications. The median age at diagnosis was 58 years. With a median follow-up time of 39.2 months, the estimated 5-year OS, PFS, LC, and CSS were 71.4%, 58.8%, 75.6%, and 74.9%, respectively. In multivariate analysis, more than four cycles of chemotherapy, having localized cancer, lumpectomy with or without axillary lymph node (ALN) dissection, and low to low-to-intermediate International Prognostic Index were favorable factors for OS. For PFS, significant prognostic factors were rituximab use, B symptoms, and tumor size. As for the local group, lumpectomy with or without ALN dissection and more than four cycles of chemotherapy were favorable factors for OS. Tumor size >4 cm and nonuse of rituximab were adverse factors for PFS. Twenty-one patients (18.6%) developed local relapse and 33 (29.2%) developed systemic relapse. Eight patients had central nervous system relapse (7.3%). Conclusion: Our results reveal that local and extended staging criteria can reflect the different prognosis and treatment outcomes of breast DLBCL. Rituximab use, lumpectomy, and more than four cycles of chemotherapy are recommended as a treatment regimen. However, further study is warranted to validate our data.