Primary breast diffuse large B-cell lymphoma (DLBCL) is a rare presentation of non-Hodgkin's lymphoma. A significant risk of contralateral breast involvement and a tendency for central nervous system (CNS) progression have been identified in previous studies. Optimal treatment strategies for primary breast DLBCL have remained undefined, although the combination of anthracycline-based chemotherapy and radiotherapy may be considered to be the best treatment option in these studies. However, despite the administration of aggressive treatment, prognosis is still poor, even in localized disease, with 5-year progression-free survival rates of approximately 50% to 65% in most series. Therefore, other therapeutic options must be explored.~During the last decade, several studies have shown that rituximab plus CHOP or CHOP-like chemotherapy significantly improves clinical outcomes of patients with DLBCL. However, the relevance of rituximab in the management of this rare extranodal lymphoma has never been studied. Moreover, several studies have also suggested the possibility that prophylactic intrathecal chemotherapy might be effective in reducing CNS recurrence.~Thus, this trial is designed to prospectively evaluate the treatment strategy, which addressed the safety and efficacy of a combined therapy that included R-CHOP21 and prophylactic intrathecal chemotherapy using methotrexate.
The purpose of this study is to clarify the impact of rituximab on clinical outcomes in patients with primary breast diffuse large B-cell lymphoma and also to investigate the role of prophylactic intrathecal chemotherapy using methotrexate for reducing central nervous system (CNS) recurrence.