The Facts About Colorectal Cancer

Colorectal cancer is the name given to any cancer that develops in the colon, also known as the large intestine, or in the rectum. According to National Cancer Institute SEER data, an estimated 151,000 new cases of colorectal cancer will be diagnosed in 2022, representing 7.9 percent of all new cancer cases.

Colorectal cancer is the fourth most common type of cancer. An estimated 52,000 Americans will die from the disease in 2022 alone, making it the second-deadliest type of cancer.

The five-year relative survival rate for colorectal cancer is 65.1 percent, meaning two-thirds of people diagnosed with it live at least another five years. However, as with any cancer, early detection can dramatically improve those odds. Regular colonoscopy screenings at the appropriate age with consideration for your risk factors are important.

The colon is the part of the digestive system that's also known as the large intestine.

As part of the digestive tract, the colon absorbs water, minerals and some nutrients from food that's mostly digested and processes it into feces. It uses muscular contractions to push the stool along its 6-foot length and out of the anus. There is a lot of room for abnormal growths called polyps to develop in such a large organ. Certain types of polyps can develop into cancer if they're not removed.

The rectum is the final six inches of the large intestine that ends with the anus. It has a diameter similar to the sigmoid colon, which is the name for the last section of the large intestine just before the rectum. However, the rectum widens somewhat near the anus because this is the place that acts as a temporary holding area for feces.

As the rectum becomes full, stretch receptors inside its walls stimulate the urge to defecate. Cancer similar to colon cancer can develop in the rectum, too. During a colonoscopy—the primary tool used for early detection of colorectal cancer—the healthcare provider checks for polyps in the rectum, too. Complications associated with defecation can result in some rectal cancer patients given the potential involvement of muscles and sphincters that enable defecation. That is one differentiating factor compared to colon cancer alone.

Colorectal cancer includes cancer of both the colon and the rectum, but of those, there are several subtypes.

According to the Memorial Sloan Kettering Cancer Center, the most common colon cancer diagnosis is a type called adenocarcinoma, cancer of the cells that line the inside of the colon.

Other types include carcinoid tumors—cancer of the hormone-producing cells of the colon—and gastrointestinal stromal tumors, which are rare in the colon but can be found anywhere in the digestive tract. Lymphoma typically starts in the lymph nodes but can occasionally start in the colon as well.

A handful of specific inherited gene mutations can put you at risk of colorectal cancer, but they affect a very small percentage of people.

Since it is difficult to pinpoint an exact cause of colorectal cancer in every individual patient—it can result from a complex of causes—healthcare providers focus the discussion on common risk factors, which include:

• Being overweight or obese
• Being sedentary
• Having a history of polyps or colorectal cancer
• Consuming certain types of meat products, including cooking meats at high temperatures
• Being vitamin D deficient
• Having inflammatory bowel disease (IBD)
• Moderate to heavy alcohol use
• Being older
• Eating a diet high in red meat
• Smoking
• Having a family history of colorectal cancer

One of the reasons so many ads and PSAs encourage people to get screened for colorectal cancer when they are eligible is that it often presents no symptoms in the early stages. Diagnosing colorectal cancer and precancerous polyps early in their development most often happens as a result of a colonoscopy.

In its later stages, colorectal cancer may present with some of the following symptoms:

• Pain in the abdomen
• Bleeding from the rectum
• Weight loss
• Progressive constipation or diarrhea
• Fatigue
• Weakness
• Vomiting
• A mucus-like substance in the stool
• Altered food cravings/behaviors

The primary tool for colorectal cancer screening is a colonoscopy. It's a simple, painless test in which the doctor inserts a narrow scope through your anus to look for any suspicious polyps in your colon as well as other abnormalities of the mucosa or lining of your colon. If any polyps are detected, the doctor can usually safely excise or biopsy them immediately, depending on the size. Or they can refer you for a more advanced surgical excision.

The U.S. Preventive Services Task Force recently lowered the recommended age to start getting regular colonoscopies from 50 to 45 based on data that showed more younger people being diagnosed. People with any of the following risk factors may consider getting screened even sooner:

• A family history of colorectal cancer
• Obesity
• Crohn's disease or ulcerative colitis
• Adenomatous polyps

The colonoscope consists of a thin, flexible tube with a light and camera that allow for the noninvasive visualization of the lining of your rectum and colon. It also provides the ability to pass smaller tubes and instruments used for the biopsy and removal of polyps. The operator inserts the scope into the anus of a patient who has been sedated and carefully follows their colon to the point where it meets their small intestine. As they draw the scope back out, they scan the surface of the inside of the colon and rectum, looking for polyps and other growths.

Perhaps the biggest upside to the technology is that at the same time it is detecting troublesome polyps, doctors can also remove or biopsy abnormal tissues and polyps for further workup to evaluate for cancer or other infectious/inflammatory diseases.

A virtual colonoscopy is a less-invasive version of the colonoscopy that doesn't require sedation. It's typically performed for individuals who have certain bleeding disorders, cannot tolerate anesthesia, or have other health conditions precluding use of colonoscopy as a screening tool.

Virtual colonoscopies use computed tomography (CT) technology, which is a special type of X-ray that shoots pictures of the inside of your body from a number of angles. Specialized software then processes the images and stitches them together to form a 3D image that allows a radiologist—a physician trained in interpreting medical imaging—to evaluate the inner lining of the colon and rectum for any abnormal growths or polyps.

The point to remember about virtual colonoscopies is that if a polyp is found, further workup with a colonoscopy or surgery may be required for removal of the polyp. Overall, the goal is to minimize potential complications for high-risk patients.

Diagnosing colorectal cancer usually starts with a colonoscopy. The doctor removes any suspicious polyps, growths or abnormal tissue, which is then sent to a pathologist for microscopic analysis.

For some patients who cannot get a colonoscopy, for reasons discussed above, other screening tools exist. These include fecal tests that check for occult blood in your stool or blood tests to assess for signs of anemia, organ dysfunction or tumor markers.

A sigmoidoscopy could be performed to check your sigmoid colon, the section just above the rectum.

If the colonoscopy biopsy results or the stool/blood tests are concerning for cancer, further workup is often performed. This can include medical imaging such as CT scans or PET scans to assess for progression/spread to regional tissues or distant tissues, which is called staging.

While there is no certain way to prevent colon cancer, you can lower your risk by making or changing certain lifestyle choices:

• Get screened when appropriate
• Maintain a health body mass and weight
• Stay physically active
• Eat a healthy diet full of anti-inflammatory whole foods, such as fruits, vegetables, grains and nuts
• Avoid processed meats, such as hot dogs, sausage and certain lunch meats, and non-meat processed foods
• Limit your intake of red meat, especially meats cooked at high temperatures
• Drink alcohol only in moderation
• Quit smoking

Some studies say a daily multivitamin that contains folate, as well as making sure you get enough vitamin D, can help prevent colorectal cancer. Discuss any such supplementation with your physician, who can order appropriate lab tests to assess for deficiencies.

Colorectal cancer comes in many different varieties and is found in different locations. A whole host of factors inform the treatment decisions any patient will reach, along with their medical team. Your cancer's stage—which indicates how much the cancer has spread to the colon, regional/surrounding tissues and/or distant organs—as determined by your oncologist, is an important factor in choosing the best treatment path.

In general, colorectal cancer treatment options may include one or more of the following:

• Polyp removal during a colonoscopy
• Surgery to remove a polyp
• Partial colectomy to remove the affected section of the bowel
• Partial colectomy, along with removing nearby lymph nodes
• Adjuvant chemotherapy (chemotherapy following surgery)
• Radiation therapy

According to colorectal cancer support groups, 41 percent of survivors of all types of cancer experience a decrease in sexual functioning, and 52 percent have body image issues. What's more, the body may undergo physiological changes after treatment that involves surgery, chemotherapy or radiation. All of those treatments may sometimes cause erectile dysfunction (ED) or impair vaginal lubrication, which may hamper sexual health.

Further complicating sexual activity is the possible creation of a stoma, which is basically an opening in the abdominal wall where the normal bowel is attached for disposing of stool/feces. A stoma procedure is often performed when a portion of the colon or bowel affected by cancer is removed.

Remember, though, that help is available. Being open and honest with your partner and asking your medical team for referrals to appropriate counselors can go a long way toward restoring a fulfilling sex life after colorectal cancer.

Every individual who undergoes treatment for colorectal cancer is different, and each case is unique. Regardless, undergoing treatment—even for cancer that is in remission—is undoubtedly stressful and difficult. It is even more trying for people living with ongoing cancer.

Your healthcare team is there to help you overcome these kinds of challenges. Ask your doctor about putting together a survivorship care plan for you. This plan should lay out a few details:

• A suggested schedule of follow-up visits and tests
• A list of possible short- and long-term side effects and what to watch out for
• Suggestions for how you can improve your overall health

You may also want to ask for a referral to a therapist or counselor who has experience working with cancer survivors.

Colorectal cancer is one of the deadliest and most common types of cancer. The silver lining is that timely screening has a track record of detecting it early and saving lives. Talk with your doctor about when you should start being screened, and be sure to research your family history of colorectal cancer. Also, consider making lifestyle changes that can help reduce your risk.

But if colorectal cancer does strike, know that medical technology and the precision with which healthcare providers can tailor a treatment plan to each individual means you have a fighting chance to survive.

What are the first signs of colorectal cancer?

Colorectal cancer is notoriously symptom-free until it has advanced beyond the earliest stages. However, once it has progressed, here are some of the first signs you may notice:

• Changes in your bowel movements that last more than a few days, including diarrhea, constipation or narrowing of the stool 
• A feeling that you need to go to the bathroom that remains even after you go
• Bleeding from the rectum with bright red blood
• Blood in the stool, which may make the feces appear dark or black
• Abdominal pain or cramping
• Fatigue and weakness
• Unintended weight loss

How do you get colorectal cancer?

Like all cancers, colorectal cancer happens due to a wide array of factors, including your genes, environment, lifestyle and other factors. It's usually impossible to pin down one cause. However, we can point to some known risk factors:

• Age
• Family history
• Personal history of inflammatory bowel disease
• Personal history of polyps or colorectal cancer
• Gene mutations
• Being overweight or obese
• Being physically inactive
• A diet high in red meat and/or processed meats
• Frequently cooking meats at high temperatures, like frying or grilling
• Smoking
• Moderate to heavy alcohol use

How fatal is colorectal cancer?

Colorectal cancer has a five-year relative survival rate of 65.1 percent, meaning about two-thirds of people diagnosed with it live at least five more years.

However, colorectal cancer is projected to kill more than 52,000 people in 2022 alone, making it the second-deadliest type of cancer.