The colon and rectum are part of the body’s gastrointestinal tract. The colon makes up the first 6 feet of the large intestine, and the rectum makes up the last 6 inches. Cancers of the colon and rectum are typically grouped together as colorectal cancer because they have some characteristics in common, most notably the presence of abnormal growths called polyps.
According to the American Cancer Society, an estimated 104,610 new cases of colon cancer and 43,340 cases of rectal cancer will be diagnosed in the US in 2020, and an estimated 53,200 people will die of colorectal cancer this year. Not counting some skin cancers, colorectal cancer is the third leading cause of cancer-related deaths in the US. Approximately 4.4 percent of men and 4.1 percent of women will be diagnosed with colorectal cancer in their lifetime.
Colorectal cancers generally begin as polyps that form in the lining of the colon or rectum. Most of the time, these polyps are harmless, but over time – sometimes many years – one or more of the polyps can turn cancerous. Often, the polyps cause no symptoms, especially early on, but eventually symptoms may develop.
When they are present, symptoms of colorectal cancer may include rectal bleeding; blood in your stool or in the toilet following a bowel movement; diarrhea or constipation that won’t go away; changes in your normal bowel habits, such as size, shape or frequency; abdominal pain or cramping; bloating or feeling full; appetite changes; weight loss; and fatigue.
Cancer is the result of mutations to the genes responsible for cell growth and reproduction, and these changes cause the cells to grow out of control. Some gene mutations are inherited and passed on in families, and some are acquired during your lifetime.
There are several inherited syndromes, including familial adenomatous polyposis (FAP) and Lynch syndrome, that can lead to colorectal cancer, but most gene mutations that lead to cancer are acquired mutations. That is the case with colorectal cancer, and certain risk factors may play a role in causing the mutations that lead to colorectal cancer.
Some of those risk factors you can change and some you can’t. Risk factors you cannot change include age – colorectal cancer is much more common after age 50; having a personal history of colorectal polyps or colorectal cancer, a personal history of inflammatory bowel disease, or a family history of colorectal cancer;, race – African Americans have the highest incidence and mortality rate of all racial groups in the US; or having type two diabetes.
There are also colorectal cancer risk factors that you can change. These include being overweight or obese, being physically inactive; eating a diet that is high in red meat and processed food, not getting enough Vitamin D, smoking, and drinking a lot of alcohol.
If you have symptoms that are suspicious of colorectal cancer or if something shows up on a screening test, your doctor will likely order certain diagnostic tests for colorectal cancer. These include blood tests and a diagnostic colonoscopy, which looks at the full length of your colon.
During both screening and diagnostic colonoscopies, your doctor will remove any abnormal looking polyps and surrounding tissue to examine under a microscope to look for cancer cells. This procedure is called a biopsy. If cancer is detected, you and your doctor together will plan a course of treatment.
Treatment for colorectal cancer may include surgery, which is the main treatment for this cancer, radiation therapy, systemic therapy, or a combination of these treatments. Systemic therapy is the use of medication to kill cancer cells. The types of systemic therapies used for colorectal cancer include chemotherapy, targeted therapy, and immunotherapy.
The key to winning the battle against colorectal cancer is to find it in its early stages, when treatment is most effective. The best way to catch it early is through routine screening. The US Preventive Services Task Force recommends several screening strategies, including stool tests, flexible sigmoidoscopy, colonoscopy, and CT colonoscopy (virtual colonoscopy).
You should begin screening for colorectal cancer when you turn 50 and continue to be screened at regular intervals determined by your doctor. The timing of your screening is based on your personal risk factors for colorectal cancer. If you have multiple risk factors, you may need to begin screening at an earlier age or get screened more often.
Don’t be a statistic. Get screened for colorectal cancer and save your life!