Black patients diagnosed with colorectal cancer commonly known as colon cancer face a greater risk of mortality than white patients affected by the same disease, according to a study published in August by a team of researchers led by Samir Soneji, an assistant professor at the Dartmouth Institute for Health Policy and Clinical Practice. The team also found that this disparity has widened over time.
"One of the important demographic patterns have been growing disparities in mortality of African-Americans and Caucasians," Soneji said. "We see that same pattern in colorectal cancer."
Using data from death certificates across the United States from 1960 to 2005 and information from the Surveillance, Epidemiology and End Results database which includes information about the stage, type and site of the cancer, as well as patients' sex, age and race at the time of diagnosis researchers compared the observed survival rates between black and white patients. Researchers also compared survival rates among patients diagnosed with different stages of colorectal cancer, correcting for differences caused by the time of patients' diagnoses.
"Overall, colorectal cancer mortality rates have a strong racial disparity," Soneji said. "There is progress against Caucasian mortality rates and stagnation for African-Americans. Things have gotten better for whites over time and comparatively worse for African-Americans."
For overall colorectal cancer mortality rates, researchers found that, while mortality rates for white females declined 54 percent over the time period of 1960 to 2005, rates for black females decreased by only 14 percent. For white men, mortality rates dropped 39 percent, while mortality rates for black men instead rose 28 percent.
The study also analyzed mortality rates within the specific stage of colorectal cancer at the time of diagnosis and found that mortality rates were higher for blacks in each group than for whites during each of the last four decades.
The researchers were the first group to illustrate that the risk of death for black colorectal cancer patients is growing over time, across genders and all stages of the disease, according to the study.
In the 1970s, the likelihood of death for a black patient was 1.11 times greater than that for a white patient, the researchers found. In the last decade, a black patient was 1.33 times more likely to die from colorectal cancer than a white patient.
The results of the study suggest that the medical and public health communities should advocate for the most targeted screening for the most at-risk groups, Soneji said.
"We want to screen the [largest] number of people who would benefit the most, because colorectal cancer is one of the few cancers where screening is going to be helpful," he said.
Soneji said that this study is an "excellent example" of the differences in mortality rates when there are great disparities in quality of and access to health care among different races.
Researchers began the study in 2008 at the University of Pennsylvania, where Soneji continued researching demographics after receiving a doctorate in demography from Princeton University.
