African-Americans have worse prognosis at colorectal cancer diagnosis

January 16, 2009

African-American patients with colorectal were more likely to present with worse pathological features at diagnosis and to have a worse five-year survival rate compared to Caucasian patients, according to a study conducted by researchers at Thomas Jefferson University.

The results are being presented at the 2009 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium. The study was led by Edith Mitchell, M.D., a clinical professor in the Department of Medical Oncology at Jefferson Medical College of Thomas Jefferson University. Dr. Mitchell is also associate director of Diversity Programs for the Kimmel Cancer Center at Jefferson.

"One possible explanation could be the socioeconomic factors that are often associated with African-American patients," Dr. Mitchell said. "For example, research has shown that African-Americans are less likely than Caucasian patients to have health insurance, and thus they may not receive the screening necessary to detect colorectal cancer at an earlier stage."

Dr. Mitchell and colleagues obtained data from the tumor registry of Thomas Jefferson University Hospital on 2,500 patients treated for colorectal cancer from 1988 to 2007. They compared those data with data obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) database on 244,701 patients with colorectal cancer treated from 1988 to 2005. The researchers collected data on location, stage and histologic grade of the cancer.

In both patient groups, more African-American patients presented with advanced disease (defined as stage III or stage IV) at diagnosis. African-American patients were also more likely to have proximal - on the right side of the colon - disease. Among patients diagnosed with early-stage disease, the risk for nodal involvement was greater in African-American patients.

African-American patients also had a worse five-year survival, both overall and when stratified by cancer stage.

"Right now, we cannot definitely explain why there are such differences between the African-American and the Caucasian patients," Dr. Mitchell said. "We need to do more studies on prognostic factors related to tumor biology, molecular markers and genetics to account for the racial disparities."

Source: Thomas Jefferson University