According to the American Cancer Society, excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. Estimates for the number of colorectal cancer cases in the United States for 2017 are 95,520 new cases of colon cancer and 39,910 new cases of rectal cancer. It is the third leading cause of cancer-related deaths in women in the United States and the second leading cause in men. It is expected to cause about 50,260 deaths during 2017.
Perhaps even more alarming, a recent study in the Journal of the National Cancer Institute revealed that incidents of colon cancer have increased by 1 to 2.4 percent each year since 1985 in adults ages 20 to 39. The study shows that people born in 1990 have double the risk of colon cancer than those born in 1950, and four times the risk of rectal cancer. The study focuses its attention on Generation X adults—those born between the early-to-mid 1960s and the late 1970s to early 1980s—and millennials, who were born between the early 1980s and the 2000s.
“Although the total number of cancer cases is declining, the incidence of colorectal cancer in men and women under the age of 50 has been steadily increasing. These increases are driven predominantly by left-sided cancers in general (tumors that are located on the left side of the colon) and rectal cancer in particular,” noted Elie Chahla, MD, a gastroenterologist with HSHS Medical Group. “A younger patient in his mid 30s without any risks who I evaluated recently for anemia was diagnosed with rectal cancer. And yet another patient in his mid-40s with mild rectal bleeding, who thought he might have internal hemorrhoids. I told him that we cannot take any risks and we planned his colonoscopy which revealed a large cancerous lesion.”
Colorectal cancers can also be named colon cancer or rectal cancer, depending on where they start. Colon cancer and rectal cancer are often grouped together because they have many features in common. “In its earliest stage, it typically starts as a small polyp or a small growth,” explained Dr. Chahla. “As time progresses, the polyp will grow in size, acquire more aggressive features, and will eventually turn into a cancer that initially is localized and then it can spread beyond to different organs throughout the body. This is why we try to break this cycle early on by removing the polyps during a colonoscopy.”
There are multiple risk factors for colorectal cancer. Some are unavoidable, such as family history, so if you have a close relative with colon cancer (such as a parent or sibling), this would definitely increase your risk for colon cancer. If you have more relatives with colon cancer, this risk will become higher.
In addition to family history, there are some genetic factors that can be identified. Two significant ones are Lynch Syndrome, an inherited condition that significantly increases the risk of cancers in the digestive tract, and the other one is familial adenomatous polyposis (FAP), another inherited condition where numerous polyps can develop in the large intestine. Either will put you at a much higher risk for colon cancer. These patients require specific surveillance or follow-up testing that is different from the general population. With FAP, for example, it is 100% certain that the patient will develop colon cancer. This group of patients also requires specific screening and surveillance for other cancers too.
Another risk factor is ethnicity. African Americans have a higher risk and higher incidences of colorectal cancer. This is why for African Americans; screenings are recommended beginning at the age of 45 rather than 50. The extent of disease, duration and amount of inflammation in a subset of patients with inflammatory bowel disease (Crohn’s or Ulcerative colitis) is also a risk factor for colorectal cancer.
“Lifestyle risk factors that can be avoided include smoking, obesity and diabetes,” warned Dr. Chahla. “Regular physical activity can help protect against disease, as can eating healthy and nutritious foods, avoiding high fat in the diet, as well as avoiding excess alcohol and red meat. Living a good, healthy lifestyle will help protect against colon cancer.”
The Centers for Disease Control and Prevention (CDC) warns that colorectal polyps and colorectal cancer don't always cause symptoms, especially at first. Someone could have polyps or colorectal cancer and not know it. That is why getting screened regularly for colorectal cancer is so important. If you have any of these symptoms, talk to your doctor. They may be caused by something other than cancer.
“The symptoms that we ask patients to look for include any signs of gastrointestinal bleeding, abdominal pain, unexplained weight loss, or anemia—often indicated by fatigue, lack of energy or trouble breathing at which time we will check the blood count to determine if they might be anemic and losing blood. Sometimes the bleeding can be microscopic and not visible to the eye,” said Dr. Chahla. “Less common symptoms include abdominal distension, nausea, and vomiting. The patient should be on the lookout for these symptoms, especially if they have not had a colorectal cancer screening by the age of 45 or 50.”
When symptoms present themselves, there are multiple diagnostic techniques and technologies that are used to accurately diagnose and treat.
The stool screening test, checks for tiny amounts of blood in feces (stool) that cannot be seen visually, as both polyps and colorectal cancers can bleed. Newer stool screening tests check for DNA mutations associated with colon cancer. And the colonoscopy can both diagnose and treat polyps, typically during the same procedure.
“During the colonoscopy procedure, we have the ability to identify the polyp, and remove it in a single procedure and under the same sedation,” said Dr. Chahla. “This is a huge source of relief for patients, knowing that you can diagnose and treat at the same time a pre-cancerous lesion.”
Colonoscopies are usually scheduled beginning at the age of 50 if you don’t have any risk factors. However, if you have a family history of colon cancer, you should start this process sooner, at the age of 40, or even earlier—typically 10 years before the youngest member in your family was diagnosed. For example, if your father was diagnosed at age 45, you should start getting screenings at age 35 and sometimes genetic testing might be needed to diagnose the affected individual. The number and size of the polyps determine how often you will be scheduled for future testing. If you have no polyps or benign polyps and have no risk factors, it is typically every 10 years.
While Gen Xers and millennials are typically too young for screenings, you should seek medical attention with your primary care physician if you are experiencing any of the classic symptoms at any age.
Dr. Chahla concluded, “In the last two decades, we have definitely seen more colorectal cancer in younger generations below the age of 50. The direct reason is not clear and is yet to be defined. Besides genetic predisposition, the environmental and lifestyle factors definitely play an important role. The good news is diagnostic and treatment options have never been better. The most important consideration is to suspect, diagnose, and treat … early.”
“No matter what your age, your best plan of action begins with a discussion with your primary care provider or specialist. While you can’t change your family history, there are steps you can take, including monitoring for signs and symptoms and making healthy lifestyle changes.”