What is a clear margin in breast conserving cancer surgery?

OPINION STATEMENT: Team work is the key to successful breast conservation therapy. Patient education and the informed consent process should include a discussion about the importance of margin status. Specimen management is critically important to obtain the highest quality information about margins. Operating technique should avoid trauma to or disruption of the specimen surface. The specimen should be oriented for the pathologist using standard techniques including sutures, clips, or colored inks. Specimen radiography is mandatory to confirm complete resection of the target tissues and can be used to direct additional margin resections during the initial procedure. With a well-designed and oriented specimen, the pathologist can give an accurate description of the margin distance for both the invasive and in situ components of the cancer. In most cases, decision-making about margins will be straightforward. Positive margins should be re-excised or the treatment is converted to mastectomy. Clear margins (>5 mm) require no further surgical therapy. "Close" margins (1-4 mm) will remain a point of controversy because of conflicting reports from clinical series. At UAB, decision for re-excision is made on a case-by-case basis. Routinely 2 mm is considered adequate, however, volume of disease and intraductal component are important considerations when making recommendations.