Study finds why black women less likely to survive breast cancer
Black women continue to have lower breast cancer survival rates than white women.
Data on 5-year survival rates revealed that black women have fewer screenings, poorer health at the time of diagnosis and more advanced disease when the cancer is found, a new study released in the July 24/31 issue of JAMA revealed.
The authors explained that for the last two decades, the U.S. has been aware of the disparities in treatment between ethnicities and races.
The American Cancer Society says that women have a 93 percent 5-year survival rate if their breast cancer is caught at stage 0. That percentage drops to 88 percent if the cancer is at stage I. If the cancer is at stage IV, the 5-year survival rate is 15 percent.
The researchers looked at 7,375 black women aged 65 years and older diagnosed with breast cancer between 1991 and 2005 and compared them to 7,375 white patients. The patients came from 16 U.S. Surveillance, Epidemiology and End Results (SEER) sites in the SEER-Medicare database.
All the patients received follow-up care through December 2009. Each black patient was matched to a white patient in three different categories: demographics (age, year of diagnosis and SEER site), presentation (demographics plus co-existing conditions and tumor characteristics) and treatment (presentation plus aspects of surgery, radiation therapy and chemotherapy).
The researchers found for 5-year survival rates, 69 percent of white women were still alive compared to only 56 percent of black women. Overall, black women had a 12.9 percent less chance of surviving to that 5-year mark. When all categories were factored in, the average survival rate was still 4.4 percent lower for black women.
Around 12.6 percent of black patients did not receive any treatment for their breast cancer, compared to 5.9 percent of whites. The average diagnosis to treatment time for black women was 29.2 days, but for white women it was just 22.5 days. Black women were also less likely to start treatment within three months of diagnosis. They were also more likely to just receive breast-conserving surgery without any additional treatment (like chemotherapy, surgery or radiation) than their white counterparts.
"By the time blacks (visit a doctor), they're so sick that treatment isn't changing the outcomes," lead author Dr. Jeffrey H. Silber, director for the Center for Outcomes Research at Children's Hospital in Philadelphia, said to the Los Angeles Times. "The outcome is already fated to be poor when patients come in with such advanced disease."
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Silber added that the issue may boil down to the fact that black women don't get enough medical care so the disease can be caught earlier. When compared to their counterparts, black women were 8 percent less likely to have at least one primary care visit and were about 12 percent less likely to be screened for breast cancer. They also had significantly lower rates of colon cancer and cholesterol screening.
"It's a primary care problem," he said.
In an accompanying editorial published in the same issue, Dr. Jeanne Mandelblatt, associate director for population sciences at Georgetown University in Washington D.C., said there were some slight problems with the study's methodology. For example, the authors didn't factor in how hormone therapy given after initial treatments could lower the risk of death for patients, and some of the data regarding chemotherapy was incomplete.
Dr. Laura Kruper, director of the Cooper-Finkel Women's Health Center and co-director of the breast oncology program at the City of Hope Cancer Center in Duarte, Calif., told HealthDay that she agreed that the missing information on treatments did take away from some of the accuracy of the study. She pointed out, however, that it was almost impossible to know all those factors and take them into consideration.
"In a statistically elegant way, they (the researchers) tried to parse out where the disparities in survival were," Kruper, who was not involved in the study, said. "Now we need out figure out why they are presenting later. It's not just screening. It's about access, and it's due to education and socioeconomic factors."
Mandelblatt agreed though that the researchers' conclusion was correct overall.
"Ultimately, for any cancer control strategy to succeed, improved care quality appears to be a necessary, but not sufficient condition to eliminate race-based mortality differences in the U.S.," she wrote.
