Secondary Breast Cancer Rates Higher in African-American Women

The following articles are based on presentations at the Fourth American Association for Cancer Research Conference on The Science of
Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved held September 18-21, 2011, in Washington, DC

WASHINGTON, DC—The overall incidence of breast cancer is generally higher among white women than black women. The incidence of a second breast cancer in the opposite breast, however, is higher among black women, according to new data.

Researchers have found that, when cancer is diagnosed in women aged younger than 45 years, the incidence of primary breast cancer is higher among blacks than among whites. And “when the disease does occur in blacks early on, it tends to be more aggressive, more likely to be estrogen-receptor negative, and it is more likely to cause death,” said lead researcher Nsouli-Maktabi Hala, who is a PhD graduate of George Washington University, Washington, DC.

She and her colleagues found that when cancer is diagnosed at an older age, the incidence is higher among white women. Because most breast cancers are diagnosed in older women, the overall incidence is higher in whites.

“While the incidence of breast cancer is generally higher among whites for first-time diagnosis, we found the incidence of the second contralateral diagnosis was higher among blacks,” said Hala. “This was unexpected. Blacks usually have a higher mortality rate than whites from the first cancer, so you would expect blacks to have lower rates of second cancers.” She said usually about 4% of all breast cancer patients will present with a second primary cancer contralaterally.

The researchers used Surveillance, Epidemiology, and End Results Registry 9 data to evaluate breast cancer incidence among 415,664 white women and 39,887 black women diagnosed with primary breast cancer aged 19 years or older and possible development of a second cancer in the opposite breast. Results showed that 22,290 (40.7%) developed a second primary breast cancer, of which 18,142 (4%) occurred in the opposite breast. Incidence of second primary cancers of the opposite breast was higher among black women, and 15,101 (83.2%) of second contralateral cancers developed in those who were diagnosed with first breast cancer at age 45 or older.

The researchers also found that the average age of the second primary contralateral cancer diagnosis tended to be lower in blacks (59 years of age) than in whites (67 years of age). Contralateral breast cancer tended to occur within the first 2 years of the primary breast cancer diagnosis. “This should alert the physician to watch patients very carefully,” Hala said.

Study coinvestigator Donald Henson, MD, who is with George Washington Cancer Institute, said these findings should be of particular interest to oncology nurses. “African-American women need to be more closely followed and longer than what we usually do. So they need to be followed past 6 years,” said Henson. “I think these data are something that you need to know as an oncology nurse and counsel your patients about. It is important to know some statistics about this so the nurses can better counsel their patients.”