Influence of patient characteristics, socioeconomic factors, geography, and systemic risk on the use of breast-sparing treatment in women enrolled in adjuvant breast cancer studies: an analysis of two intergroup trials.

PURPOSETo investigate the frequency of breast-sparing treatment among breast cancer patients subsequently enrolled in national cooperative group studies of adjuvant chemotherapy.PATIENTS AND METHODSA data base was formed of 5,172 patients randomized onto two intergroup trials. Lumpectomy rates were analyzed within study-defined risk strata and across geographic regions. Significant predictors of lower lumpectomy usage were determined in multivariate analyses with variables that described patient and disease characteristics, systemic risk strata, geographic region, and socioeconomic indicators based on zip code of residence.RESULTSBreast-conservation rates were 30% in the node-negative and 15% in the node-positive trials, with a wide geographic variation within each study (range, 14% to 49% and 9% to 31%, respectively). Lumpectomy use declined with increasing tumor size and did not exceed 40% even for tumors < or = 1 cm with negative nodes. With increasing risk of systemic relapse, frequency of lumpectomy ...