A recent report by Blue Cross Blue Shield examined the rate of colorectal cancer diagnoses among people with chronic conditions and those over the age of 50, both of which are at an increased risk of colorectal cancer (CRC). Chronic conditions associated with an increased risk of CRC have risen significantly among millennials, or those aged 22-37 years, between 2014 and 2018:

  • Crohn’s disease and ulcerative colitis increased by 14%
  • Type I and type II diabetes increased by 35%
  • Diagnosed obesity increased by 100%

A study found that those who are obese are 30% more likely to develop CRC than those who are not.

There are several reasons for this: obese individuals tend to have inflammation caused by visceral fat, which can cause damage to the body and increase the risk of cancer. This inflammation can also cause insulin resistance, in which the body doesn’t respond properly to insulin and thus produces more to offset the loss from the resistance. Increased insulin in the body can also boost the availability of estrogen, which can lead to increased cell production and tumor growth.

Increased insulin production also affects individuals with type I & II diabetes. Hyperinsulinemia, a condition where the amount of insulin in the blood is higher than normal, can create an environment in the colon that promotes the development and growth of cancer. There are other theories that hyperglycemia, or having too much sugar in the blood, and chronic inflammation from diabetes raises the risk as well. Further research is needed to examine the link between type II diabetes and colon cancer, but it’s noted that injected insulin used to treat type II diabetes is not linked to colon cancer. The risk is from the type II diabetes itself.

Individuals who have inflammatory bowel disease (IBD), like Crohn’s disease or ulcerative colitis, are at a higher risk of CRC due to inflammation of the colon. Individuals who have had IBD for many years tend to develop dysplasia, especially if their IBD has been left untreated. Dysplasia is a condition where cells in the lining of an organ look abnormal but aren’t yet cancerous, but can develop into cancer over time. It’s important to note that IBD is different from irritable bowel syndrome (IBS), which is not linked to an increased risk of colon cancer.

When compared to those who do not have a diagnosed chronic condition, those who do had a significantly higher risk of CRC:

  • People aged 18-64 with Crohn’s disease and ulcerative colitis had an almost two-times greater risk of CRC.
  • People aged 18-64 with diabetes had a 1.7-times greater risk of CRC and tend to have a less favorable prognosis after diagnosis
  • People aged 18-64 with diagnosed obesity had a 1.3-times greater risk of CRC, with a stronger link among men

Only 31% of people under 50 with Crohn’s or ulcerative colitis have received colon cancer screenings. Data obtained from the Blue Cross Blue Shield Axis survey that examined attitudes toward colorectal screening found that 58% of 18-49 year olds with Crohn’s disease or ulcerative colitis cited knowledge barriers as the reason for not getting screened for CRC. Both age groups—over 50 years and 18-49 years—said they were unaware of the need to be screened because their primary care physician had not recommended it. 61% of study participants over the age of 50 admitted that attitudinal reasons were the main barrier to getting screened for CRC. These reasons range from being uncomfortable with the screening process to being fearful of the results. 48% of 18-49 year olds admitted that they do not believe they’re at risk for CRC, therefore they have not been screened. External barriers, such as testing costs and being too busy, accounted for 26% of reasoning for those over 50 and 25% of those aged 18-49.

Increased awareness of CRC risks and symptoms can lead to a decrease of the amount of late stage diagnoses—if diagnosed early, the 5-year survival rate for CRC is 90%. The American Cancer Society recommends that people with an increased risk of CRC should start screening before the age of 45 and be screened more often. Gastrointestinal specialists advise individuals diagnosed with Crohn’s disease to begin regular colonoscopies 15 years after diagnosis or when they reach the age of 50, whichever comes first, and should continue to get screened every one to three years. Individuals diagnosed with ulcerative colitis are advised to begin regular colonoscopies 8 years after diagnosis or at age 50, whichever comes first, and continue every one to two years.

This article was originally published on August 2, 2020, by Colon Cancer Foundation. It is republished with permission.