Impact of routine pathology review on treatment for node-negative breast cancer.

PURPOSE: Routine secondary pathology review influences diagnosis and treatment among patients diagnosed with breast cancer. The impact of review on patients with node-negative breast cancer and the nature of the pathology elements leading to management changes are not well described.
METHODS: Patients with node-negative, invasive, or in situ breast cancer and evaluable nodes referred to the British Columbia Cancer Agency during two time periods between 2004 and 2007 were included. Pathologists with expertise in breast cancer reviewed the original reports and slides. Biomarker testing was not routinely repeated. Medical record review was conducted to determine whether original pathology was changed and whether recommended therapy was affected.
RESULTS: Among 906 eligible patients, 405 (45%) received a pathology review. Univariate comparisons revealed that reviewed patients were younger (P < .001) and more likely to have close margins (P < .001), whereas other characteristics were similar. A total of 102 pathology changes were documented among 81 patients (20%). The most frequently changed elements were grade (40%) and lymphovascular (26%), nodal (15%), and margin (12%) status. These changes resulted in 27 treatment modifications among 25 patients (6%). Treatment changes were primarily related to nodal and margin status, and only two of 27 were related to measurement of tumor biology in women with estrogen receptor-positive, node-negative breast cancer.
CONCLUSION: Reported rates of change are significant and warrant routine secondary pathology review among patients with node-negative breast cancer or ductal carcinoma in situ before final treatment is recommended. Review remains relevant in the era of gene expression signatures to determine margin and nodal status.