A prospective multicenter study of primary breast lymphoma in the rituximab era: Prognostic implication of beta 2 microglobulin and interlukin-6 & interlukin-10 L. Ezz Elarab1, E. Hamada2, A. Mostafa1, A. Saber2, M. Abdel-Gawad3, R.M. Haggag4, H.D. Darwish5, S.A. Elhassanin6, M. Swellam7 1Clinical Oncology, Ain Shams University Faculty of Medicine, Cairo, Egypt, 2Clinical Oncology, Minya University Medical School, Minya, Egypt, 3Clinical Oncology, Faculty of Medicine, Assuit University, Cairo, Egypt, 4Medical Oncology, Zagazig University Faculty of Medicine, Zagazig, Egypt, 5Medical Oncology, Damietta Cancer Institute (DCI), Damietta, Egypt, 6Clinical Oncology, Faculty of Medicine, Menoufiia University, Cairo, Egypt, 7Biochemestry, Genetic Engineering and Biotechnology, National Research Center, Cairo, Egypt Background: Primary breast diffuse large B-cell lymphoma (DLBCL) is a rare entity representing � 2% of extra-nodal non-Hodgkin lymphoma. We aimed to define clinical profile, prognostic factors and the incidence of the central nervous system (CNS) relapse in the era of rituximab and clarify the prognostic value of beta2 microglobulin(B2M), interlukins-6 (IL-6) and interlukin -10(IL-10). Methods: Between Jan 2012 to Dec 2016, a prospective analysis of 28 patients presenting to 7 academic Egyptian centers. All patients were females. Only patients with newly diagnosed stage I and II disease DLBCL were included. Patients with evidence of baseline CNS disease and patients with hepatitis B and HIV were excluded. All patients were scheduled to receive R-CHOP protocol plus involved- field radiotherapy. The prognostic significance of B2M, and IL-6 and 10 were assessed. Results: About 75% presented with breast mass, 4 cases with inflammatory symptoms, 3 cases were discovered by mammography. Right breast was more involved (64%), 86% had � 1 ECOG performance status, and LDH elevated was in 39% and 18% had B symptoms. HCV was positive in 32% (9 patients). Stage I was detected in 57%. The stage–modified International prognostic index was�1 in 54%. Ten cases underwent breast surgery (2 modified radical mastectomy, 8 conservative breast surgery). Complete response was achieved in 23/28 (82%) with median follow-up of 28 months, 39% of patients had relapsed, contralateral breast was the site of initial relapse in two cases, 11% developed CNS relapse and 21% in other nodal and extranodal sites. Three years disease free survival and overall survival were 68% and 79%. Favorable prognostic factors according to univariate analysis were stage I, IPI�1, tumor size < 5cm, B2M. IL6 and IL-10, while for multivariate analysis they were IPI�1 andB2Mand IL-6. Conclusions: Primary breast DLBCL has high rate of CNS relapse in spite of era of rituximab so CT or MRI of CNS is necessary during follow-up. Prophylaxis to CNS should be considered in the initial treatment to improve outcome. In addition, assessment of pretreatment serum levels of B2M, and IL-6 in newly diagnosed DLBCL may indicate a possible prognostic role. Legal entity responsible for the study: Lobna Ezz el-arab. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.