Factors associated with clear biopsy margins and clear reexcision margins in breast cancer specimens from candidates for breast conservation.

BACKGROUND: The aim of this study was to identify variables associated with clear biopsy margins and clear reexcision margins of breast cancer specimens from patients who are candidates for breast conservation. STUDY
DESIGN: The records of breast cancer patients were reviewed to identify candidates considered for breast conservation after biopsy. Factors associated with obtaining histopathologically clear excisional biopsy margins and clear reexcision margins were studied in 674 excisional biopsy specimens and in 197 reexcision specimens.
RESULTS: Clear biopsy margins were associated with older patient age (p = 0.0446), family history of breast cancer (p = 0.0008), diagnosis by fine needle aspiration (p = 0.0000), small tumor size (p = 0.0010), absence of ductal carcinoma in situ (p = 0.0004), and absence of extensive intraductal carcinoma (p = 0.0117). In multivariate analysis, only diagnosis by fine needle aspiration and small tumor size were associated with clear biopsy margins. Clear margins in reexcision specimens were associated with small tumor size (p = 0.0086), close or unknown biopsy margins (p = 0.0003), and absence of nodal involvement (p = 0.0014). In multivariate analysis only biopsy margin status and node status were associated with clear reexcision margins.
CONCLUSIONS: These data indicate that obtaining clear biopsy margins is facilitated by small tumor size and by having a preoperative diagnosis by fine needle aspiration. The majority of patients undergoing reexcision will have clear margins although this is significantly less likely when the biopsy margins are involved or when nodal involvement is present.