title: Inadequate margins of excision when undergoing mastectomy for breast cancer: which patients are at risk?
abstract: BACKGROUND
  We analyzed the margin status and risk factors for inadequate margins among patients who underwent skin-sparing mastectomies (SSM) and traditional total mastectomies (TM).
  
  
  METHODS
  Patients undergoing mastectomies from 2003 to 2009 were included. Margins of excision were considered positive if carcinoma was at an inked margin and were considered close if such disease was within 2 mm of an inked margin.
  
  
  RESULTS
  A total of 426 patients were identified. The mean age was 60 years and 90% were white. Mean tumor size was 2.6 cm and 44% had multiple ipsilateral carcinomas. Of 426 patients, 177 (42%) underwent SSM with reconstruction and 249 (58%) TM. The rate of positive or close margins on the initial specimen was 29% for SSM vs. 12% for TM (P < 0.01), and the rate of reoperation for margins was 7% for SSM vs. 2% for TM (P < 0.01). Logistic regression analysis revealed that independent risk factors for initial close or positive margins included SSM (odds ratio 2.36, 95% confidence interval [95% CI] 1.05-5.30), multiple ipsilateral tumors (OR 2.12, 95% CI 1.05-4.24), and upper-inner quadrant location (OR 2.58, 95% CI 1.07-6.19). Mean follow-up time was 28 months, and the local recurrence rate was 0.9%. Local recurrence rates were not different for those undergoing SSM (1.1%) vs. TM (0.8%, P = NS).
  
  
  CONCLUSIONS
  Mastectomy patients undergoing SSM, with multiple ipsilateral tumors, and/or upper-inner quadrant disease are at significantly higher risk for inadequate margins of excision. These patients warrant more vigilant intraoperative attention to margin status to ensure adequate margins at the end of the first operation.
authors.affiliation: Section of Surgical Oncology, Department of General Surgery, Mayo Clinic in Arizona, Phoenix, AZ, USA.
authors.forename: Fariha
authors.initials: F
authors.lastname: Sheikh
authors.forename: Alanna
authors.initials: A
authors.lastname: Rebecca
authors.forename: Barbara
authors.initials: B
authors.lastname: Pockaj
authors.forename: Nabil
authors.initials: N
authors.lastname: Wasif
authors.forename: Ann E
authors.initials: AE
authors.lastname: McCullough
authors.forename: William
authors.initials: W
authors.lastname: Casey
authors.forename: Peter
authors.initials: P
authors.lastname: Kreymerman
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Gray
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D016462:Mammaplasty; D008408:Mastectomy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery*; D009367:Neoplasm Staging; D011183:Postoperative Complications; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult