LOCAL FAILURE AND MARGIN STATUS IN EARLY-STAGE BREAST-CARCINOMA TREATED WITH CONSERVATION SURGERY AND RADIATION-THERAPY

Objective The authors determined whether microscopically positive surg ical margins are detrimental to the outcome of early stage breast canc er patients treated with conservation surgery and radiation therapy. S ummary Background Data The optimal extent of breast surgery required f or patients treated with conservation surgery and radiation therapy ha s not been established. To achieve breast preservation with good cosme sis, it is desirable to resect as little normal tissue as possible. Ho wever, it is critical that the resection does not leave behind a tumor burden that cannot be adequately managed by moderate doses of radiati on. It is not known whether microscopically positive surgical margins are detrimental to patient outcome. Methods The records of 259 consecu tive women (262 breasts) treated with local excision (complete removal of gross tumor with a margin) and axillary dissection followed by rad iation therapy for clinical stage I and II infiltrating ductal breast cancer at Duke University Medical Center and the University of North C arolina between 1983 and 1988 were reviewed. Surgical margins were con sidered positive if tumor extended to the inked margins; otherwise the margins were considered negative. Margins that could not be determine d, either because the original pathology report did not comment on mar gins, or because the original specimen had not been inked were called indeterminate. Results Of the 262 tumors, 32 (12%) had positive margin s, 132 (50%) had negative margins, and the remaining 98 (38%) had inde terminate margins. There were 11 (4%) local failures; 3/32 (9%) from t he positive margin group, 2/132 (1.5%) from the negative margin group, and 6/98 (6%) from the indeterminate group. The actuarial local failu re rates at 5 years were 10%, 2%, and 10%, respectively, p = 0.014 pos itive vs. negative, p = 0.08 positive vs. indeterminate (log rank test ). Margin status had no impact on survival or freedom from distant met astasis; 63 patients who originally had positive or indeterminate marg ins were re-excised. Two of 7 with positive margins after re-excision versus 1/56 rendered margin negative had a local recurrence. Conclusio ns The authors recommend re-excision for patients with positive margin s because of improved local control of those rendered margin negative and identification of those patients at high risk for local failure (t hose who remain positive after re-excision). Because margin status imp acts on local control, tumor margins after conservation surgery should be accurately determined in all patients.