It may not be the most glamorous subject, but talking about colorectal cancer saves lives. Among cancer affecting both men and women, colorectal cancer is the second leading cause of cancer-related death in the United States. Unlike many cancers, we have effective tools to help decrease the development of colorectal cancer and identify its presence at an earlier stage.
The risk of colorectal cancer increases with age, with more than 90% of the cases we see being diagnosed in people age 50 or older. There are many factors that are associated with an increased risk of colorectal cancer. Some of these risk factors are related to lifestyle choices and are therefore modifiable. Maintaining a healthy weight, being physically active, not smoking or chewing tobacco, avoiding heavy alcohol intake, and eating a balanced diet that limits intake of red or processed meat can all help decrease your risk of colorectal cancer.
Some risk factors cannot be changed. For one, colorectal cancer is more common as we age. It is also more common in people with a personal history of a certain type of colon polyp, called adenomatous, or a previous colon cancer. Being diagnosed with an inflammatory bowel disease, particularly ulcerative colitis, increases your risk. Most colorectal cancers are diagnosed in people who do not have a family history of colon cancer, but nearly 1 in 3 people who are diagnosed with colon cancer do have a family history of the disease. Only about 5% of cases of colorectal cancer are related to an inherited predisposition, but the rate of colorectal cancer is much higher in these individuals than in the general population, and it tends to develop at an earlier age. Two of the more common genetic predispositions are familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (Lynch syndrome). Although we don’t understand why, African Americans have the highest colorectal cancer incidence and mortality rates of all ethnic groups in the US.
Colorectal cancer may cause symptoms as it grows. These symptoms include seeing blood in or on your stool, unintentional weight loss, a change in bowel habits and weakness or fatigue caused by a low blood count.
Screening is the practice of looking for cancer or pre-cancer in individuals without symptoms. Screening is incredibly effective when it comes to colorectal cancer because, from the time the first abnormal cells start to develop, it takes on average 10-15 years for those cells to become a colorectal cancer. Screening is one of our most effective tools for preventing colorectal cancer because it allows us to find and remove precancerous polyps and identify people who would benefit from more frequent screening. Screening can also identify small cancers that aren’t yet big enough to produce symptoms.
There are several screening tools for colorectal cancer, including tests done on your stool, radiographic studies and colonoscopy. The stool studies either look for evidence of trace blood that isn’t enough to be seen by the naked eye or look for altered DNA that can be associated with abnormal cells in the colon. Stool studies that look for blood need to be repeated every year if negative. A negative stool DNA test needs to be repeated every three years. A CT or virtual colonoscopy is a radiographic study that involves cleaning out the colon at home and then coming into the hospital for a CT scan. If any abnormalities are seen, the study needs to be followed up with a colonoscopy at a later date. If the study is negative, it should be repeated every five years. Stool studies and virtual colonoscopy are only appropriate for patients with an average risk of colorectal cancer. A colonoscopy is a procedure that is done using a small fiber-optic tube and air to examine the lining of the colon after a prep has been completed the day before. Colonoscopy allows for the identification of polyps and removal, or biopsy if too large, at the same time as the procedure. Depending on the findings during the procedure and individual risk factors, colonoscopy may be repeated every year for high-risk individuals to a more typical range of 3-5 or 8-10 years.
Talking to your doctor about your risk factors can help identify the most effective and appropriate screening test for you. In general, screening is recommended between the ages of 50 and 75, though there are reasons to start earlier or stop later for some people. It is estimated that only about two-thirds of adults in the US are up to date with their colorectal cancer screening. Every year, about 140,000 people in the US will be diagnosed with colorectal cancer, and 50,000 people will die from it. Our best tool to decrease both of these numbers is screening. Talk to your doctor today.
Talk to your primary care provider about your risk factors. If you don’t have one, check out Sheridan Memorial Hospital’s Internal Medicine practice or call: 307.675.2650