Colon cancer is a cancer that occurs in the large intestine, also known as the large bowel, which forms part of the digestive tract. It comprises the colon, rectum, and anus. Sometimes, colon cancer is called colorectal cancer, which encompasses both colon cancer and rectal cancer.
Colorectal cancer is the third most common cancer (excluding skin cancers) diagnosed in men and women in the United States. There’s an overall lifetime risk of 1 in 23 for men and 1 in 25 for women, and it typically affects older adults.
Learn more about the early warning signs of colon cancer, who is at increased risk, and screening tests that help with early detection and cancer prevention.
The incidence of colon cancer is on the rise in adults younger than 50 years old, collectively known as early-onset colorectal cancer, for reasons not yet known. Since the mid-1990s, the rate has increased by about 1% per year according to the American Cancer Society.
Colorectal cancer is treatable, usually with a combination of surgery and anticancer drugs such as chemotherapy, immunotherapy, and targeted therapies. Five-year survival rates are significantly higher when the cancer is caught in the early stages as demonstrated by statistics published by the National Cancer Institute.
Men and women with localized cancer (meaning it hasn’t spread) have a 90.1% survival rate at five years compared to 14.6% for those with metastatic disease (spread beyond the bowel to distant sites). It’s therefore vital to be aware of the early warning signs of colon cancer and to see a doctor if you’re concerned.
Colon cancer signs and symptoms depend on the specific location of the mass and the extent of the disease. Unfortunately, in many cases, symptoms don’t occur until the disease is advanced, or the cancer has spread. This highlights the importance of education and screening tests to improve early detection.
Signs and symptoms of colon cancer can be non-specific and some overlap with common benign conditions such as hemorrhoids and irritable bowel syndrome. Many of us may occasionally experience symptoms such as abdominal pain, bloating, constipation, or diarrhea so it’s difficult to know when to be concerned.
It’s important to note that when associated with colorectal cancer, symptoms are often persistent and severe— and they change or progress over time. That said, if you experience any of the symptoms described above, be sure to see a doctor so the cause can be identified and treated.
The National Cancer Institute carried out a study of over 5,000 patients with early-onset colorectal cancer (onset before the age of 50 years) to identify “red flag” signs and symptoms. Abdominal pain, rectal bleeding, diarrhea, and iron deficiency anemia were associated with an increased risk of early-onset colorectal cancer. The study subsequently concluded that early recognition of “red flag” signs and symptoms may improve early detection and timely diagnosis of colorectal cancer.
If you have any of the symptoms listed, it does not mean you have cancer. However, it’s crucial to consult your primary doctor or healthcare provider for a full assessment and clinical examination.
They will likely do blood tests to look for iron deficiency anemia and a stool sample to look for blood. You might be referred to a gastroenterologist for further tests such as a colonoscopy. This is a test that involves a camera going into the rectum to get a closer look at the bowel. If there are any concerning findings, a biopsy would be taken and sent to pathology who will determine if the cells look cancerous, benign (non-cancerous), or precancerous.
Although no single cause of colon cancer has been identified, there are both modifiable and non-modifiable risk factors associated with the disease.
Colon cancer almost always develops from a polyp, which is a non-cancerous growth that forms in the inner lining of the colon or rectum. Colon polyps are common and often harmless. Most do not turn into cancer and the risk of malignancy depends on the type of polyp and also the size and quantity.
Polyps don’t usually cause symptoms, so they are usually picked up incidentally or on screening tests. If you possess risk factors, getting colorectal cancer screenings is one of the most important actions to help cancer prevention.
Additionally, there are rare diseases such as Lynch syndrome and Familial adenomatous polyposis, which run in families. These conditions cause genetic defects resulting in an increased risk of colon cancer and other types of cancer. It’s an important consideration in young adults with a family history of cancer, specifically colorectal cancer. If you have relatives who have had colorectal cancer you may want to talk to your doctor about screening tests.
In addition to regular screenings, learn about how to reduce your risk factors by increasing your physical activity and adopting healthier eating habits.
Screening tests are performed to look for disease when a patient does not possess symptoms. It’s the best method for colon cancer prevention and early detection.
Colon cancer screening is particularly important as colorectal cancer may only present with symptoms in the later stages. The death rate from colorectal cancer has been declining in older adults and it’s believed that colon cancer screening is partly attributable.
The U.S. Preventive Services Task Force recommends adults aged 45 to 75 should get colorectal cancer screenings. Those at an increased risk should consult their doctor about when to commence colon cancer screening. There are different tests that can be done, each with its individual advantages and disadvantages.
Your doctor may ask for a stool sample or suggest a colonoscopy, which is the gold standard for colon cancer screening. A colonoscopy can identify and remove precancerous polyps before they develop into cancer, thereby reducing your cancer risk. It has been shown that polypectomy reduces colorectal cancer incidence and mortality. These tests will need to be done at regular intervals, so your doctor will discuss which tests and regimens are best for you based on your risk factors.
You may need to start screening earlier than 45 years of age if:
Early warning signs of colon cancer can be vague and non-specific. Look out for “red flag” symptoms such as abdominal pain, rectal bleeding, and a change in bowel habits. It’s important to get to know your body and understand what is normal for you in order to detect any changes early and seek medical attention.
There are many risk factors for colorectal cancer and other types of cancer that can be modified with positive lifestyle changes. Take charge and feel empowered to make those positive changes to reduce your risk.
Screening with a colonoscopy is also vital for early detection and cancer prevention. Take the Ezra five-minute quiz to learn more about your cancer risk and discover which tests might be beneficial for you. While a colonoscopy is the screening test for colon cancer, you can screen up to 13 other organs with potential cancers with the Ezra Full Body Scan. It could be the key to early detection.
