1. ¹Department of Surgical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, The Netherlands
2. ²Department of Epidemiology and Bioinformatics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
3. ³Department of Surgery, Martini Hospital, van Swietenlaan 4, PO Box 30033, 9700 RM Groningen, The Netherlands
4. ⁴Comprehensive Cancer Center North Netherlands, Waterloolaan 1/13, PO Box 330, 9700 AH Groningen, The Netherlands

Correspondence: Dr MAJ de Roos, E-mail: mderoos@tiscali.nl

Received 13 June 2005; Revised 5 September 2005; Accepted 5 September 2005; Published online 18 October 2005.

Abstract

The aim was to study the effect of compliance with guidelines on local recurrence (LR)-free survival in patients treated for ductal carcinoma in situ (DCIS). From January 1992 to December 2003, 251 consecutive patients had been treated for DCIS in two hospitals in the North Netherlands. Every case in this two-hospital sample was reviewed in retrospect for its clinical and pathological parameters. It was determined whether treatment had been carried out according to clinical guidelines, and outcomes in follow-up were assessed. In addition, all patients treated for DCIS in this region (n=1389) were studied regarding clinical parameters, in order to determine whether the two-hospital sample was representative of the entire region. In the two-hospital sample, 31.4% (n=79) of the patients had not been treated according to the guidelines. Positive margins were associated with LR (hazard ratio (HR)=4.790, 95% confidence interval (CI) 1.696–13.531). Breast-conserving surgery and deviation from the guidelines were independent predictors of LR (HR=7.842, 95% CI 2.126–28.926; HR=2.778, 95% CI 0.982–6.781, respectively). Although the guidelines changed over time, time was not a significant factor in predicting LRs (HR=1.254, 95% CI 0.272–5.776 for time period 1992–1995 and HR=1.976, 95% CI 0.526–7.421 for time period 1996–1999). Clinical guidelines for the treatment of patients with DCIS have been developed and updated from existing literature and best evidence. Compliance with the guidelines was an independent predictor of disease-free survival. These findings support the application of guidelines in the treatment of DCIS.