Breast Cancer Mortality Higher in Hispanic Women
Hispanic women are more likely to die from breast cancer than non-Hispanic white women, according to research presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, held Dec. 6-10, 2011.
“This difference may be associated with a tumor phenotype that is less responsive to chemotherapy,” said Kathy B. Baumgartner, Ph.D., professor of epidemiology and associate dean for faculty affairs in the School of Public Health and Information Sciences at the University of Louisville in Kentucky. “Increased awareness of this ethnic disparity is needed to improve survival in Hispanic women with breast cancer.”
Breast cancer is the most common cancer and is the second cause of cancer death in women in the United States. Incidence and survival rates vary by ethnicity, and previous research has demonstrated a trend toward poorer survival in Hispanic women.
From 1992 to 1996, Baumgartner and colleagues conducted the New Mexico Women’s Health Study (NMWHS), a statewide, population-based, case-control breast cancer study that examined the difference between Hispanic and non-Hispanic white women for breast cancer risk. In all, 692 women with a first primary breast cancer participated.
In a recent study, researchers followed the 577 women with invasive breast cancer through 2008 to assess differences in long-term survival between Hispanic and non-Hispanic white women in the NMWHS.
Hispanic women were about 20 percent more likely to die from breast cancer than non-Hispanic white women, which is consistent with other reports, Baumgartner said. After adjusting for age, stage, lymph node involvement and estrogen receptor (ER) status, the researchers saw the risk drop considerably to almost equal that of non-Hispanic white women - suggesting that “the ethnic difference in breast cancer mortality may be mostly biologically based,” Baumgartner said.
Incidence & Mortality
From 2004-2008, the median age at diagnosis for cancer of the breast was 61 years of age. Approximately 0.0% were diagnosed under age 20; 1.9% between 20 and 34; 10.2% between 35 and 44; 22.6% between 45 and 54; 24.4% between 55 and 64; 19.7% between 65 and 74; 15.5% between 75 and 84; and 5.6% 85+ years of age.
The age-adjusted incidence rate was 124.0 per 100,000 women per year. These rates are based on cases diagnosed in 2004-2008 from 17 SEER geographic areas.
Incidence Rates by Race Race
All Races 124.0 per 100,000 women
White 127.3 per 100,000 women
Black 119.9 per 100,000 women
Asian/Pacific Islander 93.7 per 100,000 women
American Indian/Alaska Native 77.9 per 100,000 women
Hispanic 92.1 per 100,000 women
US Mortality
From 2004-2008, the median age at death for cancer of the breast was 68 years of age. Approximately 0.0% died under age 20; 0.9% between 20 and 34; 5.7% between 35 and 44; 14.9% between 45 and 54; 21.1% between 55 and 64; 19.8% between 65 and 74; 22.3% between 75 and 84; and 15.3% 85+ years of age.
The age-adjusted death rate was 23.5 per 100,000 women per year. These rates are based on patients who died in 2004-2008 in the US.
In addition, Hispanic women who received chemotherapy were about 1.5 times more likely to die from breast cancer compared with non-Hispanic white women who received chemotherapy, after adjusting for age and the characteristics noted above.
“It is not clear how much of this ethnic difference in survival is due to socioeconomic factors influencing access to screening and treatment or to biological ones,” Baumgartner said. “Some studies suggest that Hispanic women are more likely to develop ER-negative tumors that are resistant to chemotherapy.”
She added, “Altered response to chemotherapy may partly explain the Hispanic vs. non-Hispanic white disparity in breast cancer survival.”
Does Race or Ethnicity Affect Breast Cancer Risk?
All women should be aware of their risk for breast cancer; it can affect women of every age, race, and ethnic group. However, the rates of developing and dying from breast cancer vary among various racial and ethnic groups.
According to the National Cancer Institute, white, non-Hispanic women have the highest overall incidence rate for breast cancer among U.S. racial/ethnic groups, while Korean American women have the lowest rate. Among women ages 40-50, African American women have a higher incidence of breast cancer than white women. African American women also have the highest death rate from breast cancer; Chinese American women have the lowest death rate.
Several factors have been found to impact the breast cancer incidence and death rates among racial and ethnic groups. Differences in certain lifestyle behaviors - such as diet, exercise, and acceptability of smoking and alcohol use - can impact the risk of many diseases, including heart disease and breast cancer.
The higher death rate from breast cancer among African American women has been linked to the stage, or extent, of the cancer at the time it’s diagnosed. Studies show that African American women tend to seek treatment when their cancer is in a more advanced, less treatable stage.
There was no difference between Hispanic and non-Hispanic white women for all-cause or non-breast cancer mortality.
Baumgartner and her colleagues will continue to monitor this cohort for the long term. This research was supported by a grant from the National Cancer Institute and the James Graham Brown Cancer Center.
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The mission of the CTRC-AACR San Antonio Breast Cancer Symposium is to produce a unique and comprehensive scientific meeting that encompasses the full spectrum of breast cancer research, facilitating the rapid translation of new knowledge into better care for patients with breast cancer. The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio, the American Association for Cancer Research (AACR) and Baylor College of Medicine are joint sponsors of the San Antonio Breast Cancer Symposium. This collaboration utilizes the clinical strengths of the CTRC and Baylor and the AACR’s scientific prestige in basic, translational and clinical cancer research to expedite the delivery of the latest scientific advances to the clinic. The 34th annual symposium is expected to draw nearly 8,000 participants from more than 90 countries.
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Source: American Association for Cancer Research (AACR)