Black Americans With Diabetes At A Higher Risk For Colorectal Cancer

Everyday Health

Individuals of African American descent who have been diagnosed with diabetes should engage in discussions with their healthcare providers to assess their susceptibility to colorectal cancer. Recent extensive research indicates a substantial reduction in the likelihood of developing colorectal cancer among those who undergo colonoscopies.

Black Americans, in particular, confront a heightened risk concerning the co-occurrence of diabetes and colorectal cancer compared to other demographic groups. The U.S. Office of Minority Health reports that African American adults exhibit a 60 percent higher likelihood of diabetes diagnosis in comparison to their white counterparts. Additionally, the American Cancer Society notes that Black Americans are 20 percent more prone to colorectal cancer compared to most other ethnic groups.

New revelations further underscore the severity of this risk for those suffering from concurrent diabetes. A study encompassing a majority of 54,000 participants from low-income African American communities revealed that individuals diagnosed with diabetes faced a 47 percent higher risk of developing colorectal cancer compared to those without a diabetes diagnosis. These findings emphasize the critical importance of proactive discussions with healthcare providers to assess and mitigate the risks associated with diabetes and colorectal cancer in the Black American population.

“Type 2 diabetes and colorectal cancer disproportionately burden individuals of low socioeconomic status and African American race,” Shaneda Warren Andersen, PhD, an assistant professor of population health sciences in the School of Medicine and Public Health at the University of Wisconsin in Madison, and her study coauthors had written. “These findings suggest that given the emerging association between diabetes and elevated risk for colorectal cancer, screening via colonoscopy for individuals with diabetes may help to mitigate risk.”

The study, released on November 14 in JAMA Network Open, included 54,597 participants from the southeastern United States, aged between 46 and 58. Approximately two-thirds of the participants were Black, and 64 percent were women. A majority of the participants had an annual income of less than $15,000.

In the study, around 300 individuals out of 26,000 with diabetes were found to have developed colorectal cancer, in contrast to about 200 cases among the 28,600 participants without diabetes.

Screening Lowers Cancer Risk Significantly

Dr. Warren Anderson and her research team emphasized the significant impact of colonoscopy screening in reducing the risk of cancer development. Their findings revealed that individuals with diabetes who underwent colonoscopies had an 18 percent higher risk of developing cancer compared to those without diabetes. Notably, this risk surged to a staggering 100 percent higher for individuals with diabetes who had never undergone a colonoscopy. These results underscore the vital role of regular colonoscopies, particularly among individuals with diabetes, in mitigating the risk of cancer.

“Colonoscopy is the gold standard for colorectal cancer screening tests because it normally detects colorectal cancer cancer early,” said Christine L. Sardo Molmenti, PhD. She us an associate professor and cancer epidemiologist in the department of occupational medicine, epidemiology, and prevention with Zucker School of Medicine at Hofstra-Northwell in Hempstead, New York. “We can prevent cancer by removing precancerous polyps, which is really the key.”

The American Cancer Society underscores the significance of detecting colorectal cancer in its early stages, where the five-year relative survival rate reaches approximately 90%. However, this rate can plummet to as low as 13% in advanced stages when the cancer has metastasized.

Other Colorectal Risk Factors

The researchers noted a higher risk of cancer in individuals with a shorter duration of diabetes compared to those with a longer history of the condition. Participants with diabetes for two to five years were over twice as likely to receive a cancer diagnosis compared to those with diabetes for 5 to 10 years.

Dr. Molmenti, an external expert not affiliated with the study, suggests that individuals with a longer history of diabetes may benefit from increased healthcare attention and regular medical check-ups, potentially contributing to a lower cancer risk in this group.

“They may be getting more regular screenings, which prevents cancer in the later stages, while those more newly diagnosed with diabetes might not be fully into the healthcare system,” she said.

The connection between diabetes and cancer risk also increased for those who were former or current smokers. “Cigarette smoking is inflammatory and may exacerbate the inflammatory mechanisms of diabetes hypothesized to contribute to colorectal cancer,” Warren Anderson and her coauthors had also written.

Previous studies indicate that elevated blood sugar levels resulting from diabetes could potentially contribute to the multiplication of tumor cells. Additionally, separate research suggests that increased insulin levels associated with diabetes may stimulate the growth of cancer cells.

Interestingly, the analysis did not uncover a correlation between body mass index (BMI) and an elevated risk of cancer. This finding was deemed unexpected by Molmenti, especially considering prior research indicating that obesity might play a role as a contributing factor in cancer development.

Steps to Take to Lower Disparities in Colorectal Cancer

Drawing upon the identified outcomes, the authors of the study reached the overarching inference that actively engaging in diabetes prevention and control measures could potentially contribute to the mitigation of existing disparities in colorectal cancer rates.

The diminished involvement in colorectal cancer screenings observed among individuals with this condition led researchers to suggest that enhancing educational efforts and facilitating increased access to colonoscopies within the Black community might serve as instrumental strategies in addressing and minimizing the prevailing disparities in colorectal cancer outcomes.

“Colorectal cancer is probably the most preventable cancer of all the cancers that are out there, but awareness about the importance of screening is really where we have a big deficit,” Molmenti said.

Adults seeking to assess their screening options according to their risk factors are advised by Molmenti, a member of the Colorectal Cancer Alliance‘s Medical Scientific Advisory Committee, to utilize an online screening quiz developed by the Alliance.