It’s been known for 20 years that black women have worse survival rates than white women after a breast cancer diagnosis. Researchers have been trying to figure out why this is.
A new study suggests that two factors contribute to the difference in survival rates:
- Breast cancer in black women is at a more advanced stage when diagnosed compared to breast cancer in white women.
- Black women are less likely to have regular doctor visits, so are more likely to have other health problems in addition to breast cancer when diagnosed.
The research was published in the July 24, 2013 issue of the Journal of the American Medical Association. Read the abstract of “Characteristics Associated With Differences in Survival Among Black and White Women With Breast Cancer.”
The study compared 7,375 black women 65 years and older who had been diagnosed with breast cancer between 1991 and 2005 to three sets of 7,375 white women who had also been diagnosed with breast cancer. The three sets of white women were matched to the black women in terms of:
- demographic information (set one): age, year of diagnosis, and clinic location
- presentation information (set two): demographic information plus other health conditions the women had, as well as cancer characteristics including stage, size, grade, and estrogen-receptor status
- treatment information (set three): presentation information plus information on surgery, radiation, chemotherapy, and other treatments
The information came from the SEER (Surveillance, Epidemiology, and End Results) database maintained by the Centers for Disease Control.
For women matched by demographic information there was a 12.9% difference in survival rates between black women (55.9%) and white women (68.8%). This difference didn’t change between 1991 and 2005.
But when the researchers looked at women matched by presentation information, the difference dropped to 4.4%. And when the black and white women were matched by treatment information, the difference dropped to 3.6%. This suggests that differences in treatments account for only about 0.8 points of the 12.9% difference in survival rates between black and white women.
Still, treatments were different between black and white women. Black women were less likely to have lumpectomy followed by radiation or chemotherapy that included a taxane. Black women also were more likely to have a treatment delay of longer than 3 months after diagnosis (5.8% vs. 2.5%) or to receive no breast cancer treatment at all (12.6% vs. 8.2%) compared to white women.
But overall, the differences in presentation information seemed to affect survival rates the most. In the 6 months to 1.5 years before breast cancer was diagnosed, black women were much less likely to get adequate health care:
- 80.5% of black women had visited a doctor for primary care compared to 87% of presentation information-matched white women
- 23.5% of black women had breast cancer screening compared to 31% of presentation information-matched white women
- 33.7% of black women had cholesterol screening compared to 38% of presentation information-matched white women
- 16.5% of black women had colon cancer screening compared to 21.3% of presentation information-matched white women
Black women also were more likely to have other health conditions that could affect their survival rates after breast cancer, including diabetes and congestive heart failure.
Black women also were less likely to have hormone-receptor-positive breast cancer than white women. Hormone-receptor-positive breast cancers have receptors for the hormones estrogen and/or progesterone, which tell the cancer cells to grow. Hormone-receptor-positive breast cancers usually can be treated successfully with some type of hormonal therapy medicine, including tamoxifen and aromatase inhibitors. In general, hormone-receptor-positive breast cancers have a better prognosis than cancers that are hormone-receptor-negative.
ALL women – no matter their age, ethnicity, economic status, or other health conditions – deserve the best care and the best prognosis possible if breast cancer develops. Differences that affect prognosis, including screening, access to care, and timely care – should be eliminated.
Regular doctor visits and breast cancer screening is a good place to start. Breast cancer that is diagnosed early is typically easier to treat and offers the best survival chances. Regular screening for breast cancer, including annual mammograms and breast exams by a medical professional, is important for everyone. Paying for healthcare can be difficult, especially if you have limited income and no or inadequate health insurance or are covered only by Medicare. But if you're older than 40, skipping regular mammograms is NOT an option. Stick with the screening plan you and your doctor decide is best for you. If scheduling problems or cost concerns are stopping you from getting a mammogram, talk to your doctor, a hospital social worker, or a staff member at a mammogram center. Ask about free mammogram programs and healthcare services in your area. It's YOUR health and YOUR future and you deserve the best care possible.