Colorectal Cancer: A Primer

In a previous blog we discussed colorectal cancer and how briefly talked about how it now manifests earlier in millennials in comparison with the previous generations. Today, we’re going to go in-depth about the disease and provide you with all the information you need about colorectal cancer.


The U.S. National Cancer Institute describes colorectal cancer as a “cancer that starts in the colon or rectum.” The same source goes on to say that “during digestion, food moves through the stomach and small intestine into the colon. The colon absorbs water and nutrients from the food and stores waste matter (stool). Stool moves from the colon into the rectum before it leaves the body.”

For this reason, most cases of colorectal cancers are adenocarcinomas, or “cancers that begin in cells that make and release mucus and other fluids.” The tumors first develop from polyps or abnormal growths along the inner wall of the colon or rectum. If left unremoved, these polyps can grow and develop into cancerous cells.

It is among the top four most common cancers in the United States, and the second leading cause of cancer death in the country.

Causes and Risk Factors

As with majority of cancers, experts are unsure what exactly causes colorectal cancer. However, it can be preventable. Here’s what you need to know about minimizing your risk.

First of, there are two factors to consider here: risk factors, and protective factors. Risk factors are things that increases the likelihood that a person would contract the disease. On the other hand, protective factors lessen these risks. The idea is to tip the scale towards having more protective factors than risk factors.

Unfortunately, it’s not always as clean cut as that. For starters, there are several risk factors that you can do nothing about. Some of these are having a genetic predisposition to the cancer, such as having a parent or a close relative diagnosed with the disease. Having conditions such as ulcerative colitis, Crohn’s disease, or irritable bowel disease also increases your chances of having colorectal cancer.

However, there are numerous things you can do to minimize your risk, particularly in terms of improving your protective factors. For instance, improve your diet as indulging in a diet rich in animal protein, saturated fats, high calories, and excessive alcohol consumption, are all seen as risk factors. Likewise, avoid a diet that is very low in dietary fiber. You should also stop smoking, as there have been numerous studies that said smoking increases a person’s likelihood of contacting colorectal cancer and death. Furthermore, you should exercise regularly, as being physically inactive is considered as a risk factor.  


Screening plays a critical role in the early detection of colorectal cancer. As this cancer is one that can be prevented by removing the polyps before they become cancerous, more and more doctors are now encouraging their patients to get screened earlier. Colorectal cancer is oftentimes diagnosed by the following diagnostic procedures and tools:

  • Colonoscopy – A colonoscopy is a medical procedure where the doctor would insert a colonoscope or a long, slender, and flexible tube into the patient’s rectum. A camera is attached to this tube, which enables the doctor to see the colon and the rectum on a monitor. This way, the doctor would be able to see if there are any polyps. If there are, then they can remove the polyps there and then. Sometimes tissue samples are also taken to be biopsied later.

This procedure usually requires preparation which would be given to you by your doctor. Oftentimes patients are given laxatives and dietary restrictions before the procedure. Also, many doctors would give out anesthesia or a mild sedative for colonoscopies.

  • Fecal occult blood test – Also known as blood stool test, this diagnostic procedure would require the patient to submit a stool sample. This would enable the doctors to see if there is blood on the stool. However, this test is not failsafe as there are several kinds of cancer that do not bleed. Likewise, bloody stools can also be caused by a number of reasons, including poor diet and taking food with excessive food coloring.
  • Stool DNA test – Similar to a fecal occult blood test, this one requires patients to submit a stool sample. It analyzes DNA markers on the stool that may indicate precancerous polyps cells or colon cancers. This test is accurate in detecting colon cancer, although it cannot detect all DNA mutations. In case the test comes back positive, then the doctor would likely request for another test, such as a colonoscopy.
  • CT colonography – An alternative to colonoscopy, this one requires the use of a machine that takes images of the colon to screen patients for abnormal growths in their colon or rectum. This non-invasive procedure gives those who are at an increased risk of contacting the cancer to get a pre-screening that is accurate while at the same time better-tolerated. If there are suspicious growths however, then the patient would still require a traditional colonoscopy.

These are just some of the diagnostic tools utilized by physicians to screen a patient for colorectal cancer. The diagnostic procedure or tool would depend upon the patient’s tolerance and the increased risk to getting the disease.


Treatment for colorectal cancer is typically straightforward. Depending on the severity of the cancer, then the patient can either have surgery, chemotherapy, radiotherapy, or a combination of treatment methods.

  • Surgery – The most common form of treatment for colorectal cancer, surgery would entail the removal of malignant tumors and nearby lymph nodes. The bowels would be sewn back together, and depending on the severity of the cancer, the rectum may be taken out. In its place would be a colostomy bag which would collect stools. This can become a permanent solution if it is not possible to put the bowels together.
  • Chemotherapy – Chemotherapy involves the use of medicines to get rid of the cancerous cells. The medicine may be used before surgery to shrink the tumors.
  • Radiotherapy – Meanwhile, radiotherapy entails the use of high energy radiation to destroy the cancerous cells. It can also be used before the surgery to shrink he tumors.

As in most cases, early detection can be a potent tool against colorectal cancer. Therefore, it is imperative that you get screened sooner particularly if you have a history of colorectal cancer in the family.

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