Breast cancer multifocality-multicentricity and survival outcomes.

Abstract

1104 Background: Studies have consistently shown a correlation between multifocal (MF) and multicentric (MC) breast cancers and the rate and extent of lymph node metastases, but the literature is divided on whether there is a corresponding impact on survival outcomes. In the absence of compelling evidence to dictate otherwise, the convention according to current TNM staging guidelines has been to stage and treat MF and MC cancers according to the diameter of the largest lesions, without taking other foci of disease into consideration. We evaluated a large single institution cohort of MF and MC breast cancers to determine their frequency, clinico-pathological characteristics and effect on survival outcomes. Methods: MF and MC were defined pathologically as more than one lesion in the same quadrant and more than one lesion in separate quadrants, respectively. Patients were categorized by presence or absence of MF or MC disease. Kaplan-Meier product limit method was used to calculate relapse-free survival (RFS), breast cancer-specific survival (BCSS) and overall survival (OS). Cox proportional hazards models were fit to determine independent associations of MF/MC disease with survival outcomes. Results: Out of 3924 patients, 942 (24%) had MF (n=695) or MC (n=247) disease. MF and MC disease was associated with higher T-stages (T2 26% vs. 21.6%; T3 7.4% vs. 2.3%, P<0.001), higher nuclear grade (grade 3 44% vs. 38.2%, P<0.001), lymphovascular invasion (26.2% vs. 19.3%, P<0.001) and lymph node metastases (43.1% vs. 27.3%, P<0.001). After a median follow up of 51 months, MC but not MF breast cancers were associated with significantly worse 5-year RFS (90% vs. 95%, P=0.02) and BCSS (95% vs. 97%, P=0.01), and a trend towards worse 5-year OS (92% vs. 93%, P=0.08). After controlling for other risk factors, multifocality and multicentricity did not have an independent impact on RFS, BCSS or OS. This was true for the subset of T1N0 breast cancers as well. Conclusions: MF and MC breast cancers occurred in 24% of the cases and were associated with poor prognostic factors, but they 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.

Management of Early Node-Positive Breast Cancer in Australia: A Multicentre Study

“…Due to these confounding factors, it was decided to include TM and age in the multivariant analysis and to exclude multifocality. These results are similar to those reported in a study examining mulitfocality and multicentricity in breast cancer .…”

Multifocal and Multicentric Breast Cancer is Associated with Increased Local Recurrence Regardless of Surgery Type

“…A more recent study by Lynch et al. included 292 patients who underwent BCT and did not find an association with local recurrence in patients undergoing lumpectomy despite larger and more aggressive tumors in the MF/MC cohort . In our cohort of patients, MF/MC disease was associated with worse LC and DFS regardless of surgery type.…”

Breast Cancer Tissue Markers, Genomic Profiling, and Other Prognostic Factors: A Primer for Radiologists

“…Studies (35)(36)(37) show that patients with multifocal or multicentric disease have worse disease-free survival rates and higher rates of locally recurrent and metastatic disease. Lynch et al (36) suggested that this may be secondary to larger tumor size, higher histopathologic grade, lymphovascular invasion, and lymph node involvement in patients with multifocal and/or multicentric disease compared with patients with unifocal disease. However, whether a multifocal and/or multicentric tumor is an independent prognostic factor is controversial and currently not considered a part of the TNM staging system (Fig 2).…”