Recognizing Risk Factors & Screening Options for Colorectal Cancer
What is Colorectal Cancer?
Colorectal cancer is a type of cancer that starts in the colon or rectum. These are parts of the large intestine – a tube-shaped organ in the belly that helps with digestion.
Colorectal cancer typically begins with polyps—non-cancerous growths on the lining of the large intestine. While polyps can form randomly, some hereditary conditions lead to an increased number of them. Most polyps are harmless, but certain types, such as adenomas and sessile serrated polyps, have a higher risk of becoming cancerous. When cells within a polyp start dividing abnormally and rapidly, they can form a cancerous tumor.
Risk Factors for Colorectal Cancer
Although it is difficult to determine the exact cause of colorectal cancer, studies have identified certain factors that may increase your risk.
Modifiable Risk Factors (lifestyle-related risks):
- Not eating enough fiber and eating too many unhealthy fats
- Regular consumption of processed meats
- Moderate to heavy alcohol use
- Smoking
- Obesity and lack of physical activity
Non-Modifiable Risk Factors (genetic or medical conditions):
- Personal or family history of colorectal cancer
- Previous adenomas or sessile serrated polyps
- Inflammatory bowel diseases (Ulcerative colitis, Crohn’s colitis, etc.)
- Genetic conditions like Lynch syndrome or Familial Adenomatous Polyposis (FAP)
- Personal history of cystic fibrosis
- History of cancer in childhood, adolescence or young adulthood
Signs and Symptoms of Colorectal Cancer
Colorectal cancer symptoms can vary based on the tumor's size and location. Common signs to watch for include:
- Bright red blood in the stool
- Black colored and/or tarry (sticky) stools
- Abdominal pain, cramping or gas
- Changes in bowel habits (constipation, diarrhea or narrow stools)
- Unintentional weight loss
- Anemia (low hemoglobin levels)
If you experience any of these symptoms, talk to your doctor. They can perform a screening or refer you to a specialist if needed.
Colorectal Cancer Screening Guidelines
As recommended by the National Comprehensive Cancer Network, individuals should follow the screening recommendations below:
- Ages 45-75: Routine screening is recommended for those with a life expectancy of at least 10 years.
- Ages 76-85: Screening decisions should be based on overall health, medical conditions and discussion with a doctor.
- Age 86 and older: Screening is not recommended.
For those with a family history of colorectal cancer:
- If an immediate family member has had colorectal cancer, start screening at age 40 or 10 years before their diagnosis—whichever comes first.
People at higher risk should talk with their doctor to determine the best time to begin screening.
Colorectal Cancer Screening Options
There are several ways to screen for colorectal cancer. Talk to your doctor to find the best option for you. If you are at higher risk, a colonoscopy is the preferred method.
Non-Invasive Screening Tests (Stool or Imaging-Based):
- Fecal Occult Blood Test (FOBT) / Fecal Immunochemical Test (FIT): Detects hidden blood in stool
- Multi-Target Stool DNA Test (Cologuard): Checks for hidden blood and DNA changes linked to colorectal cancer
- CT Colonography (Virtual Colonoscopy): Uses a CT scan to look for polyps or abnormal growths
- Capsule Colonoscopy: A small camera captures images of the digestive tract for evaluation
Invasive Screening Tests (Endoscopic Procedures):
- Colonoscopy: A flexible tube with a camera examines the entire colon and rectum for polyps or abnormal growths. Polyps can be removed and tested.
- Flexible Sigmoidoscopy: Similar to a colonoscopy but only inspects the lower part of the colon (sigmoid colon and rectum).
The frequency of screening depends on the test used and the results. If a non-invasive test is positive, a colonoscopy is required for further evaluation and potential polyp removal. Endoscopic procedures are the only methods that allow for polyp removal and biopsy, helping to prevent or detect colorectal cancer early.
Knowing your family history and recognizing risk factors, signs and symptoms, and available screening options are all essential for early detection and prevention of colorectal cancer. It is never too early to talk with your doctor about colorectal cancer screening.
