With the exception of skin cancer, colon cancer ranks 3rd amongst the most common cancers in the US. In 2022 alone, the American Cancer Society estimates about 106,000 new cases of colon cancer and 45,000 new cases of rectal cancer.
Colorectal cancer is a disease where cells in the colon or rectum grow uncontrollably. The colon is the large intestine, and the rectum connects the colon to the anus for getting rid of waste. Abnormal growths called polyps sometimes develop in these parts of your gastrointestinal system and can turn into cancer.
Screening tests can find abnormal growths so they can be removed before becoming cancerous. The tests also help to detect cancer early so that treatment can begin. The lifetime risk of getting colorectal cancer is about 4.3% in men and 4.0% in women.
Colon Cancer Statistics by Age
Your risk of developing colorectal cancer rises as you get older. Additional risk factors include:
- Inflammatory bowel diseases, like ulcerative colitis or Crohn’s disease
- Family history of colorectal polyps or colorectal cancer
- Genetic syndromes, like hereditary non-polyposis colorectal cancer or familial adenomatous polyposis
- A sedentary lifestyle
- Diets low in fiber and high in fat
- Being overweight
- Tobacco and alcohol use
- Low vitamin D levels in the blood
The majority of colorectal cancer cases are in adults 50 years of age and older. But 12% of cases are diagnosed in those younger than 50, amounting to about 49 new daily cases.
Like most types of cancers, for every 5-year age group, the incidence doubles. At the age of 50, the incidence increases by about 30%. The median age of colorectal cancer diagnosis is 66 years for men and 69 years for women.
The colon cancer age range is going down considerably — it has shifted from an average of approximately 72 years in the early 2000s to 66 years today. This is because the incidence is increasing in younger adults and declining in older age groups, partially due to screening.
There may often be no symptoms of early colon cancer. As a tumor grows, you may notice bleeding, and it could block the intestine. Symptoms often include:
- Rectal bleeding
- Blood in the stool or toilet
- Darker stools
- Bowel habit changes
- Lower abdominal pain or cramping
- Having the urge to have a bowel movement although the stomach is empty
- Long-lasting constipation or diarrhea
- Unintentional weight loss
- Lack of appetite
Maintaining a diet high in fruits, vegetables, and whole grains generally lowers your colorectal cancer risk. Increased risk has been associated with diets high in processed meats and red meat.
Regular screening for colon cancer usually starts at 45. The US Preventive Services Task Force recommends colorectal cancer screenings for people aged 45 to 75. These tests may include testing stool samples, colonoscopy, flexible sigmoidoscopy, or a virtual colonoscopy.
Though most people begin screening at 45, you may need to get tested at an earlier age. This is especially true if you have any of the risk factors listed above. Always speak to a doctor about changes in your bowel habits. Early detection is key to successful treatment.