According to Atlanta-based Centers for Disease Control and Prevention, black women under 60 years old are more likely to die from breast cancer than white women in the same age group. In fact, data from 2015 showed black women had a 39 percent higher breast cancer death rate.

New research from Emory University, the American Cancer Society (ACS) and the Dana-Farber Cancer Institute points to differences in health insurance as the culprit.

The findings, published in the Journal of Clinical Oncology, included data from the National Cancer Data Base on 563,497 black and white women between the ages of 18 and 64 who had been diagnosed with stage I to stage III breast cancer between 2004 and 2013.

The researchers examined five factors for the study:

  • Demographics (age, stage, state, year of diagnosis, etc.)
  • Comorbidities (other health conditions)
  • Insurance (lack of insurance, private insurance, Medicare/Medicaid, etc.)
  • Tumor characteristics (size, type, stage, etc.)
  • Treatment (chemotherapy, hormonal therapy, surgery, etc.)

The findings

They found that insurance explained one-third of the additional risk of death among the black women compared to white women diagnosed by early-stage breast cancer.

Additionally, almost three times as many black women (22.7 percent) were either uninsured or had Medicaid insurance compared to white women (8.4 percent).

“Lack of insurance is a barrier to receipt of timely and high-quality treatment and screening services,” study authors wrote.

Other major factors that explained the differences: tumor characteristics (23.2 percent), comorbidities (11.3 percent) and treatment (4.8 percent).

Nearly 80 percent of the women in the study had the most common type of breast cancer (hormone receptor-positive breast cancer) and according to the researchers, when matched for factors such as insurance, comorbidity and others, those factors accounted for a combined 76.3 percent of the total excess risk of death in black patients.

The authors noted that when it came to treatment differences, black and white women contrasted most for hormone therapy, which, according to ACS, is typically used after surgery to help reduce the chance of recurrence.

“Several studies reported that black women are less likely to complete chemotherapy and hormone therapy,” study author Ahmedin Jemal told the ACS. “This could be for many reasons, including problems with transportation or the inability to pay for medicine.”

Additionally, previous research has shown that black women get lower quality mammograms and are less likely to have a follow-up appointment after receiving abnormal mammograms.

And insurance is vital for both high-quality cancer care and for early detection.

“We know so much about cancer prevention and control,” Jemal, who is also vice president of the ACS surveillance and health services research program, said. “But we’re not applying it to the whole population equally. We have to make the standard of care available to everyone, including people with low income. And blacks are disproportionately represented in that group.”