Rising incidence of colorectal cancer in younger generations – Study

University of Missouri-Kansas City researchers discovered that the prevalence of colorectal cancer increased by 500 percent in children ages 10 to 14 and by 333 percent in teenagers ages 15 to 19.

When the researchers examined colorectal cancer rates in adults and children between the ages of 10 and 44, they discovered that incidences had increased across the board.

“Colorectal cancer is no longer considered just a disease of the elderly population. It means that there is a trend. We don’t know what to make of it yet, it could be lifestyle factors or genetics, but there is a trend,” said lead researcher Dr Islam Mohamed, an internal medicine resident physician at the University.

Even while occurrences have increased, there are still very few cases overall in individuals under 40, and cases in those under 30 are still uncommon.

Only 17,930 Americans under 50 were expected to have colorectal cancer in 2020 by the American Cancer Society.

As for the rate of cases, in 2020, only 0.6 children ages 10 to 14 per 100,000 population were diagnosed with colorectal cancer compared to 0.1 per 100,000 in 1999.

Diagnoses in teens age 15 to 19 went from 0.3 to 1.3 per 100,000, and in young adults ages 20 to 24, cases rose from 0.7 to two per 100,000.

Escalations were also found in older adults, with rates rising by 71 percent to 6.5 per 100,000 people in aged 30 to 34 and by 58 percent to 11.7 per 100,000 in ages 35 to 39 in 2020.

While the 40-to-44 age group had a lower percentage increase of 37 percent, the group had the highest incidence rate, reaching 20 per 100,000 people in 2020.

Incidence rate is the number of new cases of a disease divided by the number of persons at risk for the disease. When rates are low to start with, any increase can be significant.

In the view of Dr Folasade May, an associate professor of medicine in the University of California, Los Angeles Vatche and Tamar Manoukian Division of Digestive Diseases, “When you are starting off with a very rare disease in 15-year-olds and you add a couple cases, you are going to have a huge percentage increase.

May added that while the overall increases are worrying, it is reassuring to see that the oldest age group had the smallest percentage increase, because 40-44 year olds had the biggest number of cases to begin with.

Experts are not sure what’s behind the unprecedented rise, and are exploring whether modern diets, antibiotics or even fungal infections could be at play.

Colorectal cancer normally begins as a small growth, called a polyp, on the inner lining of the colon or rectum — part of the large intestine. Over time, the cells in these polyps can start to divide uncontrollably, triggering the cancer.

It often doesn’t cause any or very few symptoms in the early stages, which is why doctors say everyone aged 45 and over should get screened for the cancer once a decade. It is also possible to get screened at an early age after talking to doctors.

Early warning signs of the disease can include a change in bowel habits, blood in feces, unexplained weight loss and sudden fatigue or weakness — brought on by blood loss.

If caught in the early stages, before it spreads to other areas, the charity Fight Colorectal Cancer says nine in 10 patients will live beyond five years after their diagnosis.

But should the cancer not be detected until stage three, the five-year survival rate drops to 71 percent. At stage four, just 14 percent of patients live for another five years.