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 each 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 American Pathologists Q-Probes voluntary quality improvement program.

MAIN OUTCOME MEASURES: 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.

RESULTS

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.

CONCLUSIONS

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.