Study shows routine removal of an additional rim of tissue from a lumpectomy cavity cuts repeat surgery and positive margins in half.
NEWS 8 New Haven, Conn. (WTNH)
“Advances like this, that are practice changing and move the field forward, are only possible with the help of our patients who participate in clinical trials. They are both our partners in sowing the seeds of ground-breaking research, as well as the beneficiaries who reap the rewards of the findings.”
~Dr. Anees Chagpar
A Randomized, Controlled Trial of Cavity Shave Margins in Breast Cancer
Authors: Chagpar AB, Killelea BK, Tsangaris TN, Butler M, Stavris K, Li F, Yao X, Bossuyt V, Harigopal M, Lannin DR, Pusztai L, Horowitz NR
Source: N Engl J Med. August 6, 2015;373:503-510.
It is estimated that approximately 20%-40% of women who elect for breast conservation have positive surgical margins after lumpectomy and require additional surgery to achieve clear margins. This study is a prospective, randomized controlled study evaluating whether additional circumferential lumpectomy cavity shave margins performed at the time of surgery reduce the rate of positive margins and need for subsequent re-excision. The authors evaluated the incidence of margin positivity, need for additional surgery, volume of tissue removed, and patient perception of their cosmetic result. Positive margins for invasive cancer were defined as tumor touching the edge of the specimen and for ductal carcinoma in situ as a margin of at least 1 mm.
The study was designed such that surgeons performed their standard lumpectomy and removed any additional margins they thought they might need. Then an envelope was opened in the operating room and the patients were randomized in a 1:1 ratio to having either additional circumferential cavity shave margins performed (shave group) vs no further tissue removed (no-shave group). A total of 235 patients were included in the study. The results showed that the overall volume of tissue excised before randomization did not differ between groups. The total volume resected after randomization was larger in the shave group vs the no-shave group (115.1cm2 vs 74.2 cm2) but there was no difference between the 2 groups in the patients’ perceptions of their cosmetic outcomes or complications. The shave group had a significantly lower rate of positive margins than the no-shave group (19% vs 34%, p = 0.01) and consequently a lower rate of additional surgery for margin re-excision (10% vs 21%, p = 0.02). In conclusion, routine excision of circumferential cavity shave margins reduced the rate of positive margins and subsequent surgery by 50%.