Association of clinical and pathologic variables with lumpectomy surgical margin status after preoperative diagnosis or excisional biopsy of invasive breast cancer.

PURPOSE: To evaluate the impact of preoperative diagnosis in obtaining negative lumpectomy margins.
MATERIALS AND METHODS: Five hundred and thirty five patients who underwent breast conserving therapy for stage I/II cancer from 1971 to 1996 were included in this IRB-approved retrospective analysis. Three hundred and ninety five patients had a defined inked margin status after initial excision. The following factors were evaluated for correlation with margins at initial excision: age (< or >45), grade (3/1 or 2), family history (present/absent), histology (lobular/other), estrogen receptor (ER) status, presence of extensive intraductal carcinoma (EIC), presence of lymphovascular invasion (LVI), and biopsy type (excisional/preoperative).
RESULTS: Biopsy type (P < 0.0001), EIC (P = 0.002), ER status (P = 0.02), lobular histology (P = 0.02) and age (P = 0.02) were significantly correlated with initial margin status among the entire group. For patients who underwent preoperative diagnostic biopsy, 52% (35/67) had negative initial margins as compared to 29% (94/328) for excisional biopsy. Among patients who underwent preoperative biopsy, only lobular histology (P = 0.04) and LVI (P = 0.04) were related to initial margin status. The rate of re-excision was 34% for patients diagnosed preoperatively versus 61% with excisional biopsy (P < 0.0001). The percentage of patients with negative final margin status was similar with either core/needle or excisional biopsy (79 and 78%, respectively).
CONCLUSIONS: Preoperative diagnosis is the most significant predictor of initial margin status in patients undergoing breast conservation. Patients with lobular histology may require improved preoperative and/or intraoperative assessment to increase the rate of negative margins at initial excision.