(RxWiki News) For years, colon cancer has appeared to be more dangerous for blacks than for other groups. Researchers say more screening and earlier detection could close this racial gap in colon cancer survival.
The reasons why colon cancer survival rates are lower in blacks than other groups are not yet understood, according to the American Cancer Society (ACS). But a new study found that most of the disparity in survival may be explained by poorer health of black patients at the time of diagnosis. Higher cancer rates among blacks did not appear to be due to differences in treatment, the authors of this study said.
The ACS highlights many factors that may reduce colon cancer risk. These include eating less red meat and more fresh fruits, vegetables and whole grains. Patients may also lower their risk of colon cancer by exercising regularly, maintaining a healthy weight, not smoking and limiting alcohol intake. And, the authors of this study said, screening and earlier colon cancer detection could be key to keeping black patients healthy.
This study was conducted by Jeffrey H. Silber, MD, with the Center for Outcomes Research at The Children’s Hospital of Philadelphia, and colleagues.
"The difference in health between whites and blacks at diagnosis is large," Dr. Silber told dailyRx News. "Blacks present with more advanced colon cancer.”
To illustrate this point, Dr. Silber pointed out that 21.8 percent of blacks in the study were diagnosed with stage 4 cancer, while only 16.6 percent of matched whites presented with stage 4 cancer. Stage 4 cancer has advanced to the point that it is far more difficult to treat than lesser stages of cancer.
Blacks also were diagnosed less frequently with stage 1 and stage 2 colon cancer than the white patients (about 42 percent versus 50 percent).
“This disparity in cancer stage makes treatment less effective,” Dr. Silber said.
Blacks in this study were more likely to have more comorbid conditions. A comorbid condition is a disease or disorder that occurs at the same time as the primary disease — which, in this case, is colon cancer. In this study, patients had comorbid conditions like congestive heart failure, diabetes, history of heart attack, stroke and hypertension.
For instance, black patients had higher rates of diabetes (25 percent versus 17 percent in whites) and heart failure (12.7 percent versus 10.6 percent).
“All this contributes to worse outcomes,” Dr. Silber said.
Dr. Silber and colleagues analyzed data on 7,677 black Medicare patients who were 65 or older and diagnosed between 1991 and 2005. They compared treatment and outcomes to 7,677 white patients. They followed the patients until the end of 2009.
Overall, the difference in survival rates between white and black patients was 10 percent, with white patients living an average of 19 months longer.
“Although we, like others, saw a significant racial disparity in receipt of treatment, we found that its overall contribution to the survival disparity was small,” Dr. Silber and team wrote.
These researchers estimated that all recorded treatment differences explained only 0.6 percent of the 10 percent difference in the five-year survival of patients.
“Efforts to decrease racial disparities in colon cancer survival may be best focused on prevention and early detection of disease,” Dr. Silber and colleagues wrote.
The Centers for Disease Control and Prevention recommends regular screening for colon cancer starting at age 50. People at higher risk of developing colon cancer are urged to begin screening at a younger age.
“Colon cancer is best detected by routine colonoscopy,” Dr. Silber said. “Our work, and others, would suggest that a good relationship with a primary care provider is very important in helping to work out a screening and prevention plan.”
This study was published Dec. 15 in the Annals of Internal Medicine.
The Agency for Healthcare Research and Quality and the National Science Foundation funded this research. Conflict of interest disclosures were not available at the time of publication.