DETERMINANTS OF RECEIVING BREAST-CONSERVING SURGERY - THE SURVEILLANCE, EPIDEMIOLOGY, AND END RESULTS PROGRAM, 1983-1986

Background. Although breast-conserving surgery was used with increasin g frequency during the 1980s for management of breast cancer, most wom en still undergo mastectomy, and a substantial variation has been docu mented in the proportion of women receiving breast-conserving surgery across regions of the country. Using data from the Surveillance, Epide miology, and End Results (SEER) Program for 1983-1986, we assessed cha racteristics of the county of residence as predictors of receipt of br east-conserving surgery and determined whether regional variation pers isted after considering these characteristics. Methods. The data used involved all 19,661 non-Hispanic white women with localized breast can cer diagnosed in 1983 through 1986 in the nine SEER regions. Informati on on county characteristics was obtained from standard sources and me rged with the SEER data. Univariate and multivariate statistical metho ds were used to assess the effects of county characteristics on type o f surgery for breast cancer. Results. As anticipated, age was a strong predictor of type of surgery. In analyses that controlled for age, co unty characteristics that significantly predicted receipt of breast-co nserving surgery included physician-to-population ratio, education and income levels, the presence of a cancer center, and the presence of a city of at least 100,000. After controlling for these factors using m ultiple logistic regression, substantial regional variation persisted. Conclusions. Regional variation in treatment of localized breast canc er across the SEER regions is not explained by patient's age or county characteristics. Research is needed to address the decision making of individual patients and their physicians regarding type of surgery.