title: A comparison of the risks of in-breast recurrence after a diagnosis of dcis or early invasive breast cancer.
abstract: BACKGROUND
  It is controversial whether ductal carcinoma in situ (dcis) is a preinvasive marker of breast cancer or if it is part of a spectrum of small cancers with malignant potential. Comparing clinical outcomes in women with invasive and noninvasive breast lesions might help to resolve the issue.
  
  
  METHODS
  From a database of 2641 patients with breast cancer, we selected women who had been treated with breast-conserving surgery for a cancer that was 2.0 cm or less in size, node-negative, and nonpalpable. No subject received chemotherapy. Cancers were categorized as noninvasive (stage 0, n = 172) or invasive (stage 1, n = 401) based on a review of the pathology records. We compared the actuarial risks of in-breast recurrence after invasive and noninvasive breast lesions before and after adjusting for tamoxifen and radiotherapy.
  
  
  RESULTS
  The 18-year cumulative risk of in-breast recurrence was 35.2% for patients with dcis and 12.8% for patients with small invasive cancers (hazard ratio: 2.4; 95% confidence interval: 1.5 to 3.8; p < 0.0003). After adjustment for radiotherapy and tamoxifen treatment, the difference was small and nonsignificant (hazard ratio: 1.4; 95% confidence interval: 0.9 to 2.4; p = 0.22).
  
  
  CONCLUSIONS
  For women with small, nonpalpable, node-negative breast cancers, the likelihood of experiencing an in-breast recurrence was associated with radiotherapy and with tamoxifen, but not with the presence of cancer cells invading beyond the basement membrane.
authors.affiliation: Women's College Research Institute, Women's College Hospital, and the Dalla Lana School of Public Health University of Toronto, Toronto, ON.
authors.forename: S A
authors.initials: SA
authors.lastname: Narod
authors.affiliation: Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON.
authors.forename: E
authors.initials: E
authors.lastname: Rakovitch
keywords: Breast cancer; dcis prognostic factors; recurrence