Does Nipple-Ward Positive Margin Contribute to a Higher Rate of Re-Excision Procedures After a Lumpectomy with Pathology-Confirmed Positive Margins? A Retrospective Study.

Background: Positive margins on lumpectomy specimens are associated with a twofold increased risk of local breast tumor recurrence. Prior literature has demonstrated various techniques and modalities for assessing margin status to reduce re-excision rates. However, there is paucity of literature analyzing which margin contributes to the highest re-excision rates. Therefore, the primary aim of the study was to investigate whether the nipple-ward margins resulted in a higher rate of re-excision in our patient population.

Methods:  A retrospective chart review was performed on patients who had re-excision surgery. Nipple-ward margin was identified by correlating radiological and pathological reports. A cut-off of more than 25% was used to demonstrate correlation between nipple-ward margin and re-excision rate.

Results: A total of 98 patients' data were analyzed, with 41 (41.8%), 14 (14.3%), 5 (5.1%), and 38 (38.8%) diagnosed with DCIS, IDC, ILC, and mixed pathology on their margins, respectively. Overall, 48% (n=47) of the positive margins were nipple-ward, with 44.7% (n=21) reporting DCIS. Upon stratification, 45 (45.9%) cases were single-margin positive, with 26 (57.8%) being nipple-ward. Furthermore, the remaining 53 (54.1%) patients had multiple positive margins, with 21 (39.6.7%) nipple-ward cases.

Conclusion: Positive nipple-ward margins significantly contribute to a higher re-excision rate p < 0.001; 48% of re-excision surgeries had positive nipple-ward margins, and 57.8% of positive single-margin cases were nipple-ward. Taking an additional shave during initial lumpectomy decreases re-excision rates. However, planning a lumpectomy procedure with a more elliptical rather than a spherical resection with additional cavity shave (ie, larger volume) in the nipple-ward direction and minimizing the remaining cavity shaves so the total volume resected remains unchanged. Nevertheless, future studies with larger sample sizes are required to bolster our findings.