Colorectal cancer is the second leading cause of cancer death in the United States, and is a cancer that kills more black than white patients. Although research supports the idea that socioeconomic factors drive the survival disparity, it’s been unclear which factors play the biggest role, making it difficult to design effective intervention strategies. In order to better understand where the bottlenecks occur, Hushan Yang, Ph.D., an Associate Professor of Medical Oncology and researcher at the Sidney Kimmel Cancer Center at Jefferson and colleagues undertook a deep analysis of national patient registries, looking at 68,141 colon cancer patients (6190 black and 61,951 white) and were able to tease apart the contribution of a number of factors.
The study was published in the journal Gastroenterology.
Earlier research had identified leading factors that included lower socioeconomic status, biological differences in the tumor, and less access to treatment. Jefferson researchers first compared black and white patients whose tumors were the same stage, grade, size, and who had similar additional ailments such as obesity – in an attempt to assess the contribution of biological differences in the tumors. When the cancers were matched by these factors, the original disparity in survival was greatly reduced. However, when the researchers also matched black and white patients by the treatment they received for their cancer, they did not see a further reduction in disparity, indicating that the survival disparity is more likely driven by the inherent tumor biology than the treatments they received.
However, differences in treatment did appear to play a role in a subset of colon cancer patients. When the researchers focused on patients with advanced-stage cancers, differences in the therapies and treatments that black and white patients received did impact their survival – a phenomenon that was not apparent in patients with early-stage cancers. In other words, when cancers are more aggressive, black patients may not be getting the same treatment as white patients, which is impacting their long-term survival.
“It is important to think of ways to reduce differences in tumor biology. We can do that by improving early screening in black patients to reduce their tumor aggressiveness at diagnosis and learn more about the biology of their tumors in general,” says Dr. Yang. Additionally, “in advanced-stage colon cancer patients, efforts are needed to provide black patients with better clinical care compared to the care they are receiving today.”