Data in literature are discordant about multifocality (MF) and multicentricity (MC) as prognostic factors in breast cancers (BC). The goals of this large retrospective study were first to determinate if MF/MC is an independent prognostic factor in a real-world population, and second to evaluate the impact of local surgery of MF/MC BC on survival.
This study included 32257 women first treated by surgery at the Institut Curie between 1981 and 2008 for a first invasive BC without metastasis. MF/MC BC was diagnosed in 2823 patients. The Kaplan-Meier product limit method was used to calculate 10-year overall survivals (OS), loco-regional disease free survivals (LRDFS) and distant disease free survivals (DDFS). Cox proportional hazards models were used to determine independent associations of MF/MC with survivals.
MF/MC was associated to younger patients (54 vs 58 y, p < 0.05), more histological grade 3 BC (32.2% vs 26.7%, p < 0.05), more lymph node involvements (43% vs 33%, p < 0.05). Patients with MF/MC BC had more radical surgery (65% vs 32%, p < 0.05), less sentinel lymph node procedures (11% vs 15%, p < 0.05), and more chemotherapy (42% vs 30%, p < 0.05). With median follow-up of 90 months, 10-years OS were 79.2% for unifocal BC and 80.9% for MF/MC BC (p = 0.0941). LRDFS was better in case of MF/MC BC (96.4% vs 92.6%, p = 0.001). But MF/MC did not have an independent impact on LRDFS on multivariate analysis. Concerning DDFS, MF/MC seems to be an independent prognostic factor (HR: 0.72; 95% CI[0.5278 -0.9996]; p = 0.049). In MF/MC BC, radical surgery was associated to higher histological grade (p < 0.05), higher Ki67 index (15 vs 6, p < 0.05), more lymph node involvements (50% vs 29%, p < 0.05). Patients treated by mastectomy received more chemotherapy (47% vs 32%, p < 0.05) and hormone therapy (64% vs 54%, p < 0.05). After adjusting for all these factors, we did not observe survival differences in multivariate analysis between conservative and radical surgery.
MF/MC is more a biological management challenge rather than a surgical challenge. Conservative surgical treatment can be proposed to MF/MC BC depending on the biology of the cancer and the potential aesthetic results.
Clinical trial identification
All authors have declared no conflicts of interest.