Colon Cancer

Colon cancer can develop in any part of the large intestine but may not cause any bothersome symptoms at its early stages. Its symptoms may also be similar to other conditions affecting the digestive system, so getting checked for an accurate diagnosis is important. Talk to your doctor about how often you should get screened for this condition, depending on your risk factors. At Nacogdoches Medical Partners, we are equipped with the tools and knowledge to diagnose and treat colon cancer.

What Is Colon Cancer?

Colon cancer occurs when malignant cells develop in the colon tissues. The colon, about five feet long, is the main part of the large intestine and functions to absorb water from stool and delivers stool to the rectum. Colon cancer is cancer that begins in any part of the colon, namely:

• Ascending colon – starts with a pouch called cecum, which receives undigested food from the small intestine.
• Transverse colon – the part of the large intestine that goes across the right side of the body to the left.
• Descending colon – the part of the colon that travels down on the left side.
• Sigmoid colon – the S-shaped part of the colon which is connected to the rectum.

Colon cancer is different from rectal cancer, which affects the rectum, the organ that holds stool before it is ready to be released. Colon and rectal cancers are also different from colorectal cancer, which is when a tumor is found at the junction of the rectum and sigmoid colon.

What Causes Colon Cancer?

Colon cancer has no specific cause, but certain risk factors may increase your risk of developing this condition. Risk factors include:

• Aging
• Personal or family history of colon cancer
• History of adenomas or abnormal colon polyps
• Obesity
• Cigarette smoking
• Having Crohn’s disease or ulcerative colitis for at least eight years

Most colon cancers start as a growth called polyp on the colon’s inner lining. Not all polyps can become cancerous, but there are specific types of polyps that have a higher chance of turning into cancer. Polyp types include:

• Adenomatous polyps (adenomas) - these polyps may change into cancer. Its types include tubular, villous and tubulovillous.
• Hyperplastic polyps and inflammatory polyps – these types of polyps are more common but are generally not pre-cancerous. Some people with hyperplastic polyps that are more than 1 cm (about 0.39 in) might need to undergo colonoscopy more often.
• Sessile serrated polyps (SSP) and traditional serrated adenomas (TSA) - have a higher risk of becoming colon cancer.

What Are Signs of Colon Cancer?

Colon cancer may not always cause symptoms until it has grown or spread. Many symptoms of colon cancer may also be caused by irritable bowel syndrome, hemorrhoids, inflammatory bowel or other conditions. Get checked if you experience the following colon cancer symptoms for proper diagnosis:

• Constipation, diarrhea or other changes in bowel habits that last for more than a few days
• Bright red or very dark blood in the stool
• Bleeding in the rectum
• Abdominal pain or cramping
• Fatigue and weakness
• Unexplained weight loss
• Feeling of incomplete bowel release
• Frequent gas pains or bloating
• Vomiting

Colon cancer found in its early stages before you experience any symptoms may be easier to treat. That’s why it’s important to talk to your doctor about routine colon cancer checkups based on your risk factors.

How Is Colon Cancer Diagnosed?

Your doctor will do a physical exam and inquire about your health history during your consultation. A digital rectal exam may also be conducted if needed to feel the rectum for any unusual lumps or other abnormalities. The following are other tests that may be performed if necessary:

• Fecal occult blood test (FOBT) - aims to check stool for blood that is only visible through a microscope. It has two types, namely, guaiac FOBT and immunochemical FOBT.
• Sigmoidoscopy – checks inside the rectum and sigmoid for polyps or other abnormalities by using a sigmoidoscope, a tube-like instrument with a camera lens and lighting attached.
• Colonoscopy – uses a colonoscope, a tube-like device similar to a sigmoidoscope but can examine the whole large intestine. Both sigmoidoscopy and colonoscopy are capable of harvesting tissue samples for biopsy or laboratory checking for signs of cancer.
• DNA stool test – aims to find abnormal genetic changes in the stool that may be signs of cancer.

After colon cancer is diagnosed, staging will be done to determine if the cancer has spread within the colon or other parts of the body. Learning what stage a cancer is can help your healthcare team create a colon cancer treatment plan. According to the National Cancer Institute, colon cancer localized in the bowel is often curable and highly treatable. Approximately 50% of patients are cured with surgery as the primary treatment form.

How Is Colon Cancer Treated?

Colon cancer treatment options will depend on a range of factors, such as your diagnosis, severity of cancer, overall health, medical test results and more. Keep in mind that some cancer diagnostic tests or staging procedures may be repeated to help your healthcare team plan your treatment. Decisions about whether to change, continue or stop treatment may depend on the results of these tests. Some tests may still be needed even after your treatment to check your progress and monitor whether the cancer has come back.

These are seven types of standard treatment for colon cancer:

• Surgery – colon cancer surgery aims to remove the part of the colon affected by cancerous polyps or tumors along with surrounding tissue with its lymph nodes and blood vessels. The patient’s cancer stage will determine which type of colon surgery they may need. Less-invasive procedures may address early-stage cancers (stages 0 and I), while more invasive surgery may have to be done for later-stage cancers (II, III and IV).
• Radiofrequency ablation – uses a special probe with tiny electrodes that eliminate colon cancer cells.
• Cryosurgery or cryotherapy – uses a special instrument to freeze and destroy abnormal tissue.
• Chemotherapy – a cancer treatment option that is considered a “systemic” treatment because the chemotherapy drugs travel throughout the body to kill cancer cells that have spread to parts of the body away from the original cancer tumor.
• Radiation therapy – uses radiation to eliminate cancer cells or prevent them from growing. Its two types include external and internal radiation therapy.
• Targeted therapy – destroy cells by using drugs or other substances. Targeted therapies usually cause less harm to normal cells than radiation or chemotherapy do.
• Immunotherapy – substances made in the laboratory or by the body are used to boost the patient’s body’s natural defense mechanism against cancer.