A new study has found that in Black, low-income adults, type 2 diabetes may increase the risk of developing colorectal cancer.
Studies have shown that Black adults tend to have higher rates of diabetes than their white counterparts, and it has been found that Black adults also have higher rates of colorectal cancer. Additionally, it has been found that diabetes may increase the risk of colorectal cancer. However, the possible relation between these conditions has not been extensively studied in low-income Black adults, according to the study authors.
Publishing their results on Tuesday in JAMA Network Open, researchers from the University of Wisconsin analyzed data from about 54,597 participants. Most of the participants in the study—66%—were African American, and 53% had an income of less than $15, 000 per year, making this one of the first studies to characterize the increased risk of colorectal cancer in the presence of diabetes in this group.
Of this group, 25,992 had diabetes, while 28,605 did not. In the diabetes group, 289 of the participants, or about one percent, developed colorectal cancer. In the non-diabetes group, 197 of the participants, or about .7%, developed colorectal cancer. In other words, the people with diabetes were about 47% more likely to develop colorectal cancer.
However, people with diabetes who got screened were 18% more likely to develop colorectal cancer, while people who did not get screened were more than twice as likely to develop colorectal cancer compared to people without diabetes. According to the authors, this suggests that preventative screening may help people with diabetes avoid developing colorectal cancer.
Interestingly, when compared to patients who have been diabetic for five to 10 years, patients who have been diabetic for two to five years were more at risk for developing colorectal cancer. However, the authors say that this may be explained by “increased interactions with the health care system after diabetes diagnosis, allowing for cancer screening opportunities.”
In other words, it may look like this group has a higher risk because colorectal cancer is being detected more often, but this might be because this group is engaging with the healthcare system more, and may have increased access to preventative screenings. This actually may reduce the risk of colorectal cancer overall.
While the exact reason that diabetes may contribute to colorectal cancer isn’t concretely known, the authors speculate that having a higher blood sugar level may be favorable to cancer cells.
The authors conclude that “Increased interactions with the health care system following a diabetes diagnosis, including increased referrals to [colorectal cancer] screening, may be important for mitigating the harm of diabetes-related metabolic dysfunction, particularly in early diabetes, on [colorectal cancer] risk.”
Research has shown that awareness of colon cancer, especially among Black individuals, increased after the death of Chadwick Boseman from the disease.