ANN ARBOR, Mich. -- Hospitals that treat more black cancer patients have worse survival rates on average for patients with breast and colon cancer, regardless of race, according to a new study from the University of Michigan Comprehensive Cancer Center.
The research helps explain why African-Americans with breast or colon cancer are less likely than white patients to survive the disease.
"This work highlights the importance of how where a patient receives treatment for cancer affects survival after cancer surgery. An important next step will be to determine which system factors are amenable to interventions aimed at improving the quality of cancer care," says study author Tara M. Breslin, M.D., assistant professor of surgery at the U-M Medical School.
The study used five year survival data from the Surveillance Epidemiology and End Results-Medicare-linked database, a federal collection of cancer incidence, survival, and prevalence. The researchers analyzed data from 25,571 breast cancer patients, 9.7 percent of whom were black, and 22,168 colon cancer patients, 11.8 percent of whom were black. The patients were treated in 436 hospitals.
The study appears in the Aug. 20 issue of the Journal of Clinical Oncology.
Survival rates were lower for black patients than for white patients with both breast and colon cancer. But hospitals where more than half the patients were black had an increased risk of dying after five years for both black and white patients, compared to hospitals where fewer than 10 percent of patients were black.
All breast cancer patients treated at predominantly black hospitals had a 32 percent increased risk of death after five years, compared with those treated at hospitals that see few black patients. Similarly, colon cancer patients had a 27 percent higher risk of dying at five years.
The researchers also examined patient factors, such as age, cancer stage, other medical conditions and socioeconomic status. They found that after accounting for these factors, black patients still had higher mortality rates.
"Efforts aimed at increasing early detection through screening and decreasing incidence with preventative services are essential for decreasing racial disparities in mortality, but where a patient receives care after a cancer diagnosis may be equally important," says senior study author Arden M. Morris, M.D., M.P.H., assistant professor of surgery at the U-M Medical School and chief of general surgery at the VA Ann Arbor Healthcare System.
The study did not identify what specific hospital factors were at play, but the researchers plan further analyses to determine which hospital systems and aspects of standard therapy are poorly delivered or absent in hospitals serving a high percentage of minority patients.
Cancer statistics: 194,280 Americans will be diagnosed with breast cancer this year, and 106,100 will be diagnosed with colon cancer, according to the American Cancer Society.
Additional authors: Niya Gu, Sandra L. Wong, Emily V. Finlayson, Mousumi Banerjee and John D. Birkmeyer, all from U-M
Funding: National Cancer Institute
Reference: Journal of Clinical Oncology, Vol. 27, No. 24, pp. 3945-3950
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