While new and better treatments have improved the odds of survival for patients diagnosed late stage colorectal cancer, that progress has been largely confined to non-Hispanic whites and Asians and those under age 65, according to a new study. American Cancer Society researchers led by Helmneh Sineshaw, M.D., MPH, find there have been no significant increases in survival rates for Hispanics and non-Hispanic blacks with metastatic colon cancer. The study, appearing in the January issue of Cancer Causes and Control, concludes that the findings underscore the need for concerted efforts to increase access to new treatments for minority groups and older patients, as well as a better understanding of the factors contributing to the disparities in survival.
For their study, researchers analyzed data from the 13 population-based cancer registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, which covers about 14 percent of the United States population. They looked at survival improvement for metastatic colorectal cancer across major ethnic groups and two broad age ranges (20-64 and over 65 years). Just fewer than 50,000 patients (49,893) were included in the analysis.
The analysis found overall five-year survival rates increased significantly between 1992/1997 and 2004/2009 for non-Hispanic whites (9.8% to 15.7%) and for Asians (11.4% 17.7%). The increases were not statistically significant for non-Hispanic blacks (8.6% to 9.8%) or Hispanics (14.0% to 16.4%). And while survival rates increased significantly for those 65 and over for non-Hispanic whites, those increases were much smaller than the increase among those ages 20 to 64.
The authors conclude that increases in survival from metastatic colorectal cancer, presumably from improvements in treatment, has been largely confined to younger non-Hispanic whites and Asians, and that there has been no statistically significant increase in survival for non-Hispanic blacks and Hispanics.
"We know from previous studies that when people of any race get equal care they have similar outcomes," said Dr. Sineshaw. "But studies show there are significant inequalities in the dissemination of new treatments, likely leading to the gaps in survival our analysis found. The reasons why ethnic minorities are not getting equal treatment are complicated, but likely include poorer health coming into the system and lower socioeconomic status, which clearly leads to barriers to good health care. Those same factors likely lead to less aggressive treatment for older patients, as well."
"Studies like this tell us what happens when not everyone is given the best care available," said Richard C. Wender, M.D., chief cancer control officer of the American Cancer Society. "We need a concerted effort to make sure all Americans, regardless of skin color, age, or socioeconomic status, reap the lifesaving benefits of better care."
Sineshaw et al., (2014). Disparities in survival improvement for metastatic colorectal cancer by race/ethnicity and age in the United States, EPub Ahead of Print, Cancer Causes and Control, doi: 10.1007/s10552-014-0344-z [Abstract]