Colorectal cancer is typically viewed as a concern for older individuals. However, the disease has seen a significant increase among younger adults, and recent studies have shown that colorectal cancer, cancer in the colon or rectum, is on the decline among older Americans.
The American Cancer Society (ACS) found that colon cancer rates have dropped steadily for individuals born before 1950. While this is fantastic news in itself, researchers have discovered that colorectal cancer rates are rising sharply for individuals born after 1950.
Researchers have concluded that young adults born in 1990 have double the risk of developing colon cancer and quadruple the risk of developing rectal cancer, compared to individuals born in the 1950s.
Why is Colorectal Cancer on the Rise in Younger People?
While close to 90 percent of colorectal cancer cases still occur in people 50 and older, there has been a considerable increase in cases among people aged 20 – 49.
The rise of colorectal cancer among younger adults began in the mid-1980s when adults aged 20-39 were increasingly diagnosed with colorectal cancer. Then, during the mid-1990s, adults between the ages of 40-54 experienced an increased diagnosis of colorectal cancer.
For the most part, older individuals have shown a decline in developing colorectal cancer as a result of routine colon cancer screenings encouraged by the medical community. However, many in the medical community are left puzzled by the increased rates of colorectal cancer developments in younger Americans.
Rocky Mountain Cancer Centers oncologist Sujatha Nallapareddy, MD, says, “The incidence of colorectal cancer is rising in younger people, and it’s not clear why.” However, Nallapareddy and other colorectal cancer specialists believe that there are probably multiple reasons that are attributing to increased rates of colorectal cancer among young adults.
Possible Explanations of Increased Colorectal Cancer Among Young Americans
Researchers are not exactly sure why the increase in colon cancer is occurring in young adults, but studies suggest certain lifestyle changes are to blame, including:
- An Increase in Type 2 Diabetes Type 2 diabetes is prevalent among younger adults, especially those born after 1950. Specialists are looking to determine if there is a possible correlation between the increased rates of type 2 diabetes and the increased rates of colorectal cancer among younger adults.
- Increased Use of Antibiotics Researchers have also theorized that there could be a possible link between the increased use of antibiotics during childhood that is now leading to increased development of colorectal cancer. The increased use of antibiotics upsets the natural balance of microbes in the gut.
- Unhealthy and Negative Changes in Diet A third possible explanation researchers believe could be attributed to the increased colorectal rates among younger adults is unhealthy diets. Since the 1950s, our society’s diets have changed drastically. There is much more consumption of fast food, sugar, and processed meats.
- The Rise of Obesity Rates The number of obesity instances in the 18-27 age range has increased drastically over time. Obesity is a risk factor in the development of many cancers in both men and women, including colon and rectal cancers.
More studies will be needed before a clear answer can be reached about the real causes behind these increased developments of colorectal cancer.
Updated Colon Cancer Screening Guidelines
It is predicted that about 12% of colorectal cancer cases will be diagnosed in people under 50. Therefore, The ACS now recommends that testing for colorectal cancer should begin at age 45 (instead of 50 as previously recommended), or even younger for those with a family history of colon or rectal cancer.
After 45, people in good health should continue regular colorectal cancer screenings through the age of 75. After the age of 75, colon cancer screenings should be done on a case-by-case basis.
Basic Colorectal Screening Guidelines
- The ACS recommends that people with an average risk of colon or rectal cancer start regular screenings at age 45.
- People who are in good health should continue regular colorectal screenings until the age of 75.
- People aged 76 through 85 should be screened on a case-by-case basis, looking at the individual’s life expectancy, overall health, and prior screening history as a guideline.
- People over the age of 85 should no longer go through the colorectal cancer screening process.
Criteria of Being an Average-Risk Individual for Colorectal Cancer
The amount of risk someone faces for developing colorectal cancer is an important factor in determining when they should begin screening. You are considered “average risk” for developing colon cancer or rectal cancer if you do not have a:
- personal history of colorectal cancer.
- personal history of certain types of polyps.
- family history of colorectal cancer.
- personal history of inflammatory bowel disease.
- personal history of receiving radiation to the abdomen or pelvic area to treat prior cancer.
- hereditary colorectal cancer syndrome.
If you do have a personal or family history of any one of these symptoms or diagnoses, it is recommended that you start colorectal cancer screenings before the age of 45. You should talk with your primary care doctor about their recommendations for your personal medical history.
Definitive Factors that Increase Colorectal Cancer Development
While specialists are unsure as to why colorectal cancer is on the rise among younger adults, there are risk factors that are proven to increase colorectal cancer development in adults of all ages.
Colorectal cancer risk factors include:
- Being overweight or obese
- Physical inactivity
- A diet high in red meat
- Smoking
- Excessive alcohol consumption
- Family history
- A history of type 2 diabetes
To protect your health and general well-being, it is in your best interest to eat a balanced diet and partake in physical activity three times per week. Avoiding smoking and excessive alcohol consumption will also help you to remain physically fit while also lowering your risk of colorectal cancer development.
Signs and Symptoms of Colon and Rectal Cancer
Even while working to live a healthy lifestyle, you always have the potential to develop cancer. Dr. Nallapareddy believes that patients need to be more aware of factors that increase the risk of colorectal cancer and early warning signs that they may have developed colorectal cancer. Early detection and diagnosis will lead to the best possible outcome for colorectal patients. This is why it is important to know and be able to recognize the signs and symptoms of colorectal cancer.
Unfortunately, individuals who develop colorectal cancer in their 20s or 30s are often in the advanced stages by the time they are diagnosed. That is why understanding the symptoms of colorectal cancer and taking immediate action is so vital.
For early detection of colon or rectal cancer, be on the lookout for these common symptoms:
- Diarrhea, constipation, or other changes in bowel habits that last more than a few days
- A feeling that you are unable to empty your bowels
- Rectal bleeding
- Dark stools, or blood in the stool
- Cramping or abdominal pain
- Constant fatigue
- Unexplained weakness
- Unintended weight loss
Regardless of age, if you experience any of these symptoms, consult with a doctor immediately. As colorectal cancer is on the rise in young adults, both patients and physicians need to be more aware and proactive towards its diagnosis and treatment.
Dr. Nallapareddy also suggests that all primary care physicians consider the possibility of colorectal cancer more readily. She says, “I know if a 30-year-old comes in with bleeding, many primary care physicians will say it’s hemorrhoids. I would suggest those physicians be more vigilant — if patients are symptomatic, do a colonoscopy regardless of age.”
Related blog: 5 Common Signs of Colon Cancer That Are Easy to Overlook
To learn more about colorectal cancer, including detection, diagnosis, staging, and treatment options including immunotherapy head on over to our colorectal cancer section on the website.
Originally published June 2016. Updated January 2024.
