Canadian breast cancer guidelines: have they made a difference?

Area of Science:

• Oncology
• Surgical Oncology
• Health Services Research

Background:

• The Canadian Clinical Practice Guidelines for Breast Cancer aimed to standardize breast cancer treatment.
• Significant variations in surgical care were observed prior to guideline implementation.

Purpose of the Study:

• To evaluate the impact of Canadian breast cancer guidelines on reducing variations in surgical care.
• To assess changes in province-wide surgical care rates and surgeon variations before and after guideline introduction.

Main Methods:

• A population-based cohort of 7022 women diagnosed with breast cancer in Manitoba (1995-2003) was analyzed.
• Four measures of surgical care were examined: breast-conserving surgery, axillary assessment, axillary node dissection in noninvasive disease, and adequacy of axillary node dissection.
• Generalized linear models were used to assess variations among surgeons and changes over time.

Main Results:

• Clinically significant variations were found in all four measures of surgical care.
• These variations were statistically significant for three out of the four measures.
• No significant differences in province-wide rates or surgeon variations were observed before and after guideline implementation.

Conclusions:

• The Canadian breast cancer guidelines did not achieve their objective of reducing treatment variation.
• New strategies for guideline dissemination and implementation are necessary to improve adherence and outcomes.