Disparities in breast cancer outcomes continue to exist for African-American women

May 4 2009

New research published in the May issue of the Journal of the American College of Surgeons shows that dramatic disparities in breast cancer outcomes continue to exist for African-American women, regardless of the age at which they are diagnosed, extent of the cancer, type of treatment or socioeconomic status.

The study represents the largest population-based analysis of breast cancer outcomes data to date, including more than 60,000 patients in the state of Florida.

Although government programs to improve access to breast cancer screening and treatment have been in place for nearly two decades, African-American women continue to suffer a high breast cancer mortality rate, even though the incidence of breast cancer in this population is lower than in Caucasian women.

The research indicates that breast cancer outcomes for African-American women might be improved by lowering the recommended age of initial screening from 40 years to 33 years, the age at which the percentage of African-American women who develop breast cancer is similar to the percentage of Caucasian women in whom the disease develops under 40 years of age.

"Current screening guidelines are not sufficient in detecting breast cancer in African-American patients because the disease has already developed in over 10 percent of these women by age 40," said Leonidas G. Koniaris, MD, FACS, Surgical Oncology DeWitt Daughtry Family Department of Surgery, University of Miami, Miller School of Medicine. "However, even with earlier diagnosis, our analysis uncovered serious socioeconomic barriers that prevent many African-American women with breast cancer from receiving the latest, most specific treatments."

The analysis identified 63,472 patients with invasive breast cancer using the Florida Cancer Data System and data from the state's Agency for Health Care Administration. Overall, 90.5 percent of patients were Caucasian and 7.6 percent were African American. More than half of the study population (59.4 percent) lived at or below 10 percent of the federal poverty level, according to the 2007 United States Census Bureau report. Five-year survival was calculated from the time of initial diagnosis to the date of last contact or death.

African-American patients presented with breast cancer at a younger age and a more advanced stage, with approximately 72.1 percent of African-American women diagnosed before the age of 65, in comparison with 50.3 percent among Caucasian women (p<0.001). Whereas the majority (68 percent) of Caucasian women were diagnosed with disease that had not spread beyond the breast, only 52.4 percent of African-American women presented with localized disease. Metastatic disease was seen nearly twice as often in African-American women when compared with Caucasian women (5.9 percent versus 3.1 percent; p<0.001). Overall, African-American women had a significantly lower overall five-year survival rate compared with Caucasian women (68.6 versus 79.4 percent, p<0.001).

Upon diagnosis, African-American patients were less likely than Caucasian patients to undergo surgical therapy. Furthermore, among those patients who did undergo surgical therapy, survival rates for African-American women were still considerably lower than for Caucasian women. Similarly, African-American patients who received nonsurgical therapy (e.g., chemotherapy) had a lower rate of survival compared with Caucasian patients who received similar treatments.

A stepwise multivariate analysis revealed a significant decrease in the risk of death observed for African-American patients upon adjustment for stage of presentation, suggesting that disparities in breast cancer outcomes are, in part, a result of advanced stage at diagnosis.

Researchers also identified socioeconomic status as an independent predictor of poor breast cancer outcomes. Patients in the lowest socioeconomic status category (>15 percent living under the federal poverty level) were diagnosed with higher rates of metastatic disease (4.1 percent vs. 2.8 percent; p<0.001) than patients in the higher-income categories. Patients of low socioeconomic status were treated less frequently with surgical therapy. Five-year survival was statistically decreased as poverty level increased for all types of treatment, whether surgical or nonsurgical.