000471: BCL6 EXPRESION IN PRIMARY BREAST LYMPHOMA (PBL)

Background: PBL represent less than 0.5% of all breast malignancies. Diagnosis, determination of prognostic factors, and optimal management of PBL remain difficult. Methods: Chart revue of clinical and pathological files from 9 patients diagnosed with PBL recorded at the Geneva Cancer Registry between 1973-1998. Immunohistochemistry were performed and specific survival was calculated by Kaplan Meier method. Results: After second lecture, PBL was confirmed in 7 cases. Mean age at diagnosis was 65 years (range: 39-86). Median clinical size of the tumor was 4.5 cm. Five patient had diffuse large B cell lymphoma, 1 follicular lymphoma grade III and 1 MALT-lymphoma. All patients had clinical and radiological findings consistent with breast cancer. Fine needle aspiration missed the diagnosis in1 case and intra-operative frozen sections in 3 cases. All patients had mastectomy or excision, with axillary lymphatic dissection in 5. Four received adjuvant chemotherapy and 1 radiation. Median follow-up was 5.8 years (range: 0.15-16). One patient developed local recurrence and 2 others, systemic disease. Five-year and 10-year overall survivals were 57% and 15% respectively. Of the 3 patients who died from their PBL, 2 had Bcl-2 immunostaining positive but Bcl-6 immunostaining negative tumour. The 3 patients still alive, all had Bcl-2 positive and 2 Bcl-6 positive. Conclusion: PBL generally presents in elderly patients and has an unfavourable prognosis. Lymphoma diagnosis should be established prior to operative interventions. All patients had mastectomy, which is not indicated in PBL. Bcl-6 could be an important prognostic factor if confirmed by a larger study.