Background. Although breast-conserving surgery was used with increasing frequency during the 1980s for management of breast cancer, most women still undergo mastectomy, and a substantial variation has been documented in the proportion of women receiving breast-conserving surgery across regions of the country. Using data from the Surveillance, Epidemiology, and End Results (SEER) Program for 1983–1986, we assessed characteristics of the county of residence as predictors of receipt of breast-conserving surgery and determined whether regional variation persisted after considering these characteristics.
Methods. The data used involved all 19,661 non-Hispanic white women with localized breast cancer diagnosed in 1983 through 1986 in the nine SEER regions. Information on county characteristics was obtained from standard sources and merged with the SEER data. Univariate and multivariate statistical methods were used to assess the effects of county characteristics on type of surgery for breast cancer.
Results. As anticipated, age was a strong predictor of type of surgery. In analyses that controlled for age, county characteristics that significantly predicted receipt of breast-conserving 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 multiple logistic regression, substantial regional variation persisted.
Conclusions. Regional variation in treatment of localized breast cancer 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.