Survival, Recurrence, and Clinicopathological Characteristics in Multifocal and/or Multicentric versus Unifocal Locoregional Breast Cancers: Results of a Large Breast Cancer Registry

Much is still unknown regarding the clinicopathology and prognosis of patients with multifocal/multicentric breast cancer (MMBC). We herein compared the clinicopathology and prognosis of patients with unifocal and MMBCs. This cross-sectional research is a part of Shiraz Breast Cancer Registry (SBCR). We studied all the patients in the SBCR (n=6145). Ultrasound reports were used to differentiate between MMBCs and unifocal breast cancers (BCs). All the patients were examined with mammography and the diagnosis was confirmed postoperatively via pathology reports. After exclusion, 4045 patients entered the study (n=1072 and n=2973 for multifocal/multicentric and unifocal BCs, respectively). The mean follow-up period was 57.9 (0.27-275) months. Patients with MMBCs had higher rates of mastectomy (48% vs. 40.1%; P < 0.001) and higher rates of HER-2 overexpression (32.1% vs. 26%; P = 0.001) compared with those with unifocal BCs. Tumor size, lymph node involvement, type of axillary management, chemotherapy, radiotherapy, hormonal therapy, recurrence rates, histological grade, lymphovascular invasion, axillary node involvement, estrogen and progesterone receptor expression status, tumor, node, and metastasis staging were not significantly different between the groups. Five-year overall survival was 88.3% and 89% (P = 0.8) for unifocal and MMBCs, respectively; moreover, five-year disease-free survival was 80.2% and 81.2% (P = 0.41), respectively. Despite the controversy regarding prognosis and surgical management in MMBCs, we found that MMBCs had similar clinicopathological features and prognosis compared to unifocal BCs. Survival, recurrence, and metastasis were similar among the two groups.