When Should Colon Cancer Screening Begin?

The Importance of Early Cancer Detection

Colon cancer is a progressive illness, meaning it gets worse as time goes on. The longer cancer goes untreated, the more symptoms a person will experience. Cancer is malignant, with cells that spread throughout the body, infecting other tissues with new cancerous growths. This process is known as metastasis and makes the late stages of colon cancer extremely difficult to eradicate. If only a few cells escape treatment, the cancer will return stronger than before.

The Surveillance, Epidemiology, and End Results (SEER) database tracks survival statistics for different types and stages of cancer. These are the five-year relative survival rates for different colon cancer stages, as presented by the American Cancer Society:

• Localized: This cancer has not spread outside the colon or rectum. The five-year relative survival rate is 90%.
• Regional: This cancer has spread to tissues and lymph nodes near the colon. The five-year relative survival rate is 74%.
• Distant: This cancer has spread to distant parts of the body, such as the liver or lungs. The five-year relative survival rate is 10%.

As you can see, survival rates drop significantly as cancer spreads. For this reason, early detection is essential. The sooner colon cancer is diagnosed, the more treatment types will be available and the more effective they will be. The patient will often avoid side effects of aggressive treatments and get better with little risk of recurrence.

What Is Colon Cancer Screening?

Colon cancer screening is a medical test used to detect the presence of colon cancer before symptoms appear. Early detection of colon cancer can be difficult. Most cases of colon cancer do not show signs or symptoms in the early stages. By the time noticeable symptoms appear, the cancer may have already metastasized. As a result, symptom-based detection is often unreliable.

This is where cancer screening comes in. Screening tests help physicians identify colon cancer at an early stage, before symptoms appear. This allows treatment to begin much sooner, giving the patient the best possible chance of a successful recovery.

How Is Colon Cancer Screening Done?

Medical oncologists employ several different methods for colon cancer screening. The method depends on the facility and the patient’s risk level. Multiple tests may be used if cancer is suspected. These are some common methods used for colon cancer detection:

Stool Test

Stool tests check small samples of stool, or solid waste, for signs of colon cancer. There are two types. A fecal occult blood test (FOBT) looks for invisible traces of blood in stool, which may indicate polyps or another condition. A DNA stool test checks for genetic changes in colon cells found in stool, as a genetic change could be a sign of cancer.

Colonoscopy

Colonoscopy is the most common type of colon cancer screening. It uses a camera mounted on a flexible stem, called a colonoscope, to inspect the inside of the colon. The patient must first prepare by clearing out their entire colon with a liquid rinse as directed by the physician. The anus is then expanded using carbon dioxide, and the colonoscope is inserted. The physician uses the colonoscope to examine the entire rectum and colon for abnormal growths and other signs of cancer.

Flexible Sigmoidoscopy

This type of screening test uses a tool similar to a colonoscope, called a sigmoidoscope. The tool is used to examine the entire rectum and the bottom 20 inches of the colon. Because a sigmoidoscopy is slightly less invasive than a colonoscopy, it requires less intensive preparation. It is a less thorough examination, and patients are rarely sedated for this test.

CT Colonography

Computed tomography (CT) colonography is a type of medical imaging test. It uses advanced X-rays to take detailed images of the inside of the colon. These images are reassembled into a complete 3D scan that physicians can examine for polyps, tumors, or other signs of cancer. If any abnormalities are found, a colonoscopy or sigmoidoscopy may be recommended for a closer analysis.

What Are the Risk Factors for Colon Cancer?

The recommended screening schedule depends on a patient’s level of risk. Medical oncologists do not yet know what causes cancer. However, a handful of colon cancer risk factors have been tied to higher occurrences of this condition. These include:

• Age 50 or older
• Ashkenazi Jewish or African American ethnic background
• A family history of colon cancer
• Familial adenomatous polyposis, a rare condition that causes extra tissue (polyps) to form in the large intestine and rectum
• Lynch syndrome, a non-symptomatic condition affecting how DNA self-repairs
• Previous diagnosis of polyps or other cancers
• A history of inflammatory bowel disease
• Eating large amounts of red or processed meats
• Consuming large amounts of alcohol

These factors do not guarantee that a person will develop colon cancer. They may, however, increase a person’s risk of cancer. If any of these are true for you, speak with your primary care physician about your cancer risk. You may wish to pursue early or more frequent screening to ensure that colon cancer is detected if it develops.

When Should Colon Cancer Screening Begin?

According to colon cancer screening recommendations from the American Cancer Society, people at average risk of colon cancer should start regular screening at age 45. The recommended screening schedule is the same for men and women, but varies depending on the screening method chosen:

• Fecal immunochemical test (FIT): This test should be performed every year.
• Fecal occult blood test (FOBT): This test should be performed every year.
• Multi-targeted stool DNA test: This test should be performed every three years.
• Sigmoidoscopy: This test should be performed every three years.
• CT colonography: This test should be performed every three years.
• Colonoscopy: This test should be performed every ten years.

Colon cancer screening should continue through age 75, provided the person maintains good health and has a life expectancy of more than 10 years. Screening between the ages of 75 and 85 depends on the patient’s preferences and screening history, though screening should not continue past 85.

People at higher-than-average risk of colon cancer should consider beginning screening before age 45. This includes those with a personal history of polyps or inflammatory bowel disease, a hereditary cancer syndrome, or a family history of cancer. These individuals may also get screened more often. There are no screening guidelines specifically for at-risk patients. Instead, these individuals should speak with their primary care provider about their risk factors to determine what screening schedule is best.

Receive Colon Cancer Treatment at RCCA

If you are at increased or high risk of developing colon cancer, or if you are 45 or older, you should receive regular colon cancer screenings.

Colon cancer and other cancer types are treated at Regional Cancer Care Associates (RCCA), a group of more than 100 medical oncologists and hematologists who provide care to more than 30,000 new patients and 265,000 established patients each year. RCCA offers some of the best therapies for cancer patients, including targeted treatments such as immunotherapy or hormone therapy, following the same evidence-based methods as major academic medical centers.