Multifocality and multicentricity in breast cancer and survival outcomes

Results: Of 3924 patients, 942 (24%) had MF (n = 695) or MC (n= 247) disease. MF/MC disease was associated with higher T stages (T2: 26% versus 21.6%; T3: 7.4% versus 2.3%, P< 0.001), grade 3 disease (44% versus 38.2%, P< 0.001), lymphovascular invasion (26.2% versus 19.3%, P < 0.001), and lymph node metastases (43.1% versus 27.3%, P< 0.001). MC, but not MF, breast cancers were associated with a worse 5-year RFS (90% versus 95%, P= 0.02) and BCSS (95% versus 97%, P = 0.01). Multivariate analysis shows that MF or MC did not have an independent impact on RFS, BCSS, or OS. Conclusions: MF/MC breast cancers were associated with poor prognostic factors, but were not independent predictors of worse survival outcomes. Our findings support the current TNM staging system of using the diameter of the largest lesion to assign T stage.