The purpose of this study was to compare the multifocal (MF)/multicentric (MC) breast cancers with unifocal (UF) breast cancers in terms of tumour characteristics, treatment methods, loco-regional recurrence and survival rates.Patients who were treated with a diagnosis of early-stage breast cancer (stage I,II) and had regular follow-up were included in the study. MF tumours were defined as having more than one tumour focus in the same quadrant, whereas MC tumours refered to the presence of more than one tumour focus in different quadrants.In total, 1865 patients with invasive breast cancer were evaluated, 1493 (80.1%) of whom had UF cancer, 330 (17.7%) had MF cancer, and 42 (2.3%) had MC cancer. After comparing the groups with each other, it was seen that MF and MC breast cancers occurred more often at early ages and that lymph node invasion (LNI) was greater. No differences were seen between the 3 groups in terms of local recurrence-free survival (RFS) and overall survival (OS) rates . In multivariate analysis, it was found that MF and MC tumours had no impact on local recurrence and OS. In multivariate analysis, it was understood that HER2 positivity and triple-negative breast cancer (TNBC) had an impact on local recurrence, and age, lymphovascular invasion (LVI), T3 tumour, lymph node positivity and TNBC subtype had an impact on OS.Although MC and MF tumours show aggressive features such as high lymph node positivity and LVI, they have similar loco-regional recurrence and survival rates to UF tumours.
