Patient, hospital, and neighborhood factors associated with treatment of early-stage breast cancer among Asian American women in California.

BACKGROUND Clinical guidelines recommend breast-conserving surgery (BCS) with radiation as a viable alternative to mastectomy for treatment of early-stage breast cancer. Yet, Asian Americans are more likely than other groups to have mastectomy or omit radiation after BCS. METHODS We applied polytomous logistic regression and recursive partitioning to analyze factors associated with mastectomy, or BCS without radiation, among 20,987 California Asian Americans diagnosed with stage 0 to II breast cancer from 1990 to 2007. RESULTS The percentage receiving mastectomy ranged from 40% among U.S.-born Chinese to 58% among foreign-born Vietnamese. Factors associated with mastectomy included tumor characteristics such as larger tumor size, patient characteristics such as older age and foreign birthplace among some Asian Americans ethnicities, and additional factors including hospital [smaller hospital size, not National Cancer Institute cancer center, low socioeconomic status (SES) patient composition, and high hospital Asian Americans patient composition] and neighborhood characteristics (ethnic enclaves of low SES). These hospital and neighborhood characteristics were also associated with BCS without radiation. Through recursive partitioning, the highest mastectomy subgroups were defined by tumor characteristics such as size and anatomic location, in combination with diagnosis year and nativity. CONCLUSIONS Tumor characteristics and, secondarily, patient, hospital, and neighborhood factors are predictors of mastectomy and omission of radiation following BCS among Asian Americans. IMPACT By focusing on interactions among patient, hospital, and neighborhood factors in the differential receipt of breast cancer treatment, our study identifies subgroups of interest for further study and translation into public health and patient-focused initiatives to ensure that all women are fully informed about treatment options.