Since March is National Colorectal Cancer Awareness Month, it’s a perfect time to learn important facts about colorectal cancer as well as how to recognize it. Each year, approximately 150,000 new cases of colorectal cancer are diagnosed in the United States. According to data from the National Cancer Institute, this makes it one of the most common types of cancer. Yet as devastating as colorectal cancer is, it remains one of the most preventable types of cancer as long as it is caught during the early stages of the disease.
What is Colorectal Cancer?
Colorectal cancer (CRC) is so named because it refers to the development of cancer cells in either the colon or the rectum. Since both colon cancer and rectal cancer are similar in terms of proximity and progression, they are often lumped together. As with all kinds of cancer, CRC begins with the abnormal growth of cells that can eventually become malignant and spread to other parts of the body. In the case of CRC, this abnormal growth starts in the epithelial cells that make up the inner lining of the colon or rectum.
In almost all cases of colon cancer, the starting point is an abnormal growth called a polyp. These masses of cells are typically benign at first, but if left unchecked, they can continue to grow until they metastasize and spread outside the colon. Polyps are usually categorized by various attributes into several types:
- Adenomatous: Estimated to make up about 70% of all polyps, adenomas are the most common type of polyp. Only a small percentage of adenomas end up being cancerous, but they are the most frequent starting point for colorectal cancer.
- Villous/Tubulovillous: Villous and tubulovillous polyps are subtypes of adenomas, and they represent around 15% of all polyps that are detected in CRC screenings.
- Serrated: Known for its saw-like appearance, the serrated type is considered premalignant because of its relatively higher chance of becoming cancerous.
- Hyperplastic: This type is similar to serrated in appearance, but its low malignancy potential means that it is highly unlikely to become cancerous.
- Inflammatory: Inflammatory polyps are associated with inflammatory bowel disease and other common gastrointestinal maladies, and thus they have essentially no risk of malignancy.
An important aspect of colorectal cancer is that it usually takes a long time to develop. A polyp could be benign and undetected for many years before actually becoming cancerous. This truth about CRC is the primary reason why it’s preventable and why regular cancer screenings are recommended for ages 45-75 (depending on your individual risk factors). If a gastroenterologist detects a polyp during a routine colonoscopy, for instance, it can often be removed right then, long before it could ever develop into cancer.
Warning Signs and Symptoms of Colorectal Cancer
The main reason National Colorectal Cancer Awareness Month exists is to increase awareness of the disease and to highlight the need for screenings. While there is obvious value in understanding and being able to identify symptoms of CRC, it is important to note that the presentation of symptoms means that cancer has already developed. This means that the window for early detection has already passed. Some of the most common signs and symptoms are as follows:
- Blood in stool: Perhaps the most easily detectable symptom is the presence of blood in the stool. In later stages of colorectal cancer, when the growths have become enlarged and contributed to cell death, rectal bleeding or bleeding throughout the large intestine can lead to visible blood when defecating.
- Changes in bowel habits: Sometimes even relatively minor changes in bowel habits can be an indicator of CRC. Diarrhea, constipation, tenesmus (the feeling of an incomplete bowel movement), incontinence, or the narrowing of stools are all possible changes that can occur because of the presence of cancerous polyps or tumors. The changes may be gradual or fairly rapid.
- Weight loss: Sudden or unexplained weight loss (knowing, for instance, that you weren’t trying to lose weight) can be an indicator of CRC for a variety of reasons, including the increased energy requirements of the immune system fighting cancer at the same time as the cancer cells co-opting various resources.
- Anemia: A shortage of red blood cells can mean a number of different things, but in CRC it can happen because of bleeding in the gastrointestinal tract; over time, that blood loss can cause a reduction in red blood cell count. Iron deficiency anemia can also cause weakness, fatigue, or shortness of breath.
- Abdominal pain: Abdominal pains, bloating, and cramping can be either a direct result of a cancerous tumor or an indirect result of some of the other gastrointestinal problems that can emerge because of CRC. These kinds of pains tend to present suddenly and then increase in severity.
- Vomiting: As with many other CRC symptoms, vomiting can be an indirect or direct result of the cancer. In some cases, a tumor causing a blockage in the colon forces waste to backup in the digestive tract.
A crucial point with all of these symptoms (apart from the fact that the preventability of CRC is rendered moot) is that they are all symptoms of a variety of other digestive problems. Indeed, most of the signs and symptoms noted above are more likely to be a sign of one of a number of common gastrointestinal conditions like inflammatory bowel disease (which includes Crohn’s disease and ulcerative colitis), irritable bowel syndrome, or even hemorrhoids. So, while these symptoms may indicate colorectal cancer, the likeliest cause is another, less serious condition.
Colorectal Cancer Risk Factors
Though the nature of colorectal cancer suggests that family history may not be a major risk factor, about 1 out of 3 people who develop CRC have a family member who also had it. Beyond genetics, though, old age and a personal history of inflammatory bowel disease seem to be the major risk factors that can’t be controlled. Surprisingly, all other risk factors fall into the category of risks that can be mitigated through changes to lifestyle and behavior:
- physical inactivity
- American-style diets heavy in red or processed meats
- heavy alcohol consumption
In addition to getting regular colorectal cancer screenings at the appropriate age, the easiest way to prevent CRC is through avoiding unhealthy habits like those listed above (there also countless other physical and mental health benefits of avoiding these as well).
Colorectal Cancer Screening at Cary Gastro
With many types of cancer, regular screening is impractical or expensive. With colorectal cancer, once you turn 45 or 50 (depending on whether you have higher or average risk), you only need to get screened on average once every five years. The screening process can include tests like a colonoscopy, CT scan, or flexible sigmoidoscopy, and these colon cancer screenings allow the gastroenterologist to visually inspect the colon to search for polyps. By simply opting in, you can significantly reduce your chances of developing CRC.
If you’re 45-50 and haven’t been screened yet, National Colorectal Cancer Awareness Month provides the perfect opportunity to take your health into your own hands and get ahead of this disease. At Cary Gastro, we are passionate about helping people take a proactive approach to their digestive health care. If you’d like to learn more or schedule a colon cancer screening test, contact us today to request an appointment.