Surgical pathology-based outcomes assessment of breast cancer early diagnosis - A College of American Pathologists Q-Probes study in 199 institutions

Objective.-To develop breast cancer outcomes data relating pathologic tumor variables at diagnosis with clinical method of detection. Design.-Anatomic pathologists assessed 30 consecutive breast cancers at eac h institution, resulting in an aggregate database of 4232 breast cancers. Setting.-Hospital-based laboratories from the United States (98%), Canada, Australia, and Belgium. Participants.-One hundred ninety-nine laboratories in the 1999 College of A merican Pathologists Q-Probes voluntary quality improvement program. Main Outcome Measures.-Pathologic variables indicative of favorable outcome s included percentage of carcinomas detected at the in situ stage, tumors l ess than or equal to1 cm in diameter, and invasive cancers with lymph nodes negative for metastases. Results.-All outcomes measures, including percent in situ carcinomas (26.9% vs 13.8%), tumor size less than or equal to7 cm (57.8% vs 36.5%), and lymp h node-negative status (77.8% vs 64%), were more favorable when tumors were detected by screening mammography (P < .001) compared to all other detecti on methods. Conclusions.-This study demonstrates an opportunity for pathologists to dev elop outcomes information of interest to health care organizations, provide rs, patients, and payers by integrating routine oncologic surgical patholog y and clinical breast cancer detection data. Such readily obtained interim outcomes data trended and benchmarked over time can demonstrate the relativ e clinical efficacy of preventive breast care provided by health care syste ms long before mortality data are available.