To develop breast cancer outcomes data relating pathologic tumor variables at diagnosis with clinical method of detection.
Anatomic pathologists assessed 30 consecutive breast cancers at each institution, resulting in an aggregate database of 4232 breast cancers.
Hospital-based laboratories from the United States (98%), Canada, Australia, and Belgium.
One hundred ninety-nine laboratories in the 1999 College of American Pathologists Q-Probes voluntary quality improvement program.
Pathologic variables indicative of favorable outcomes included percentage of carcinomas detected at the in situ stage, tumors < or = 1 cm in diameter, and invasive cancers with lymph nodes negative for metastases.
All outcomes measures, including percent in situ carcinomas (26.9% vs 13.8%), tumor size < or = 1 cm (57.8% vs 36.5%), and lymph node-negative status (77.8% vs 64%), were more favorable when tumors were detected by screening mammography (P <.001) compared to all other detection methods.
This study demonstrates an opportunity for pathologists to develop outcomes information of interest to health care organizations, providers, patients, and payers by integrating routine oncologic surgical pathology and clinical breast cancer detection data. Such readily obtained interim outcomes data trended and benchmarked over time can demonstrate the relative clinical efficacy of preventive breast care provided by health care systems long before mortality data are available.