Colorectal Cancer FAQs with Bruce Porterfield, MD, PhD and Sherri Porterfield, RN, MSN

February 14, 2018

Schedule Coloscopy

As a kid, the only time I wondered about a colon was whether I used it correctly when writing a paper. As I neared the age of 50, I worried if the 5 feet of my colon was healthy. More people need to worry about their colon too. Colorectal cancer is the 3rd most common cancer diagnosed in both men and women in the United States and is the 3rd leading cause of deaths caused by cancer.1 Colorectal cancer is most often diagnosed in adults over the age of 50 though over the last few decades there has been an increase in the diagnosis of colorectal cancers in adults younger than 50.  

What is the large Intestine (aka the colon)?

The large intestine is made up of the ascending colon, the transverse colon, the descending colon, the sigmoid colon and the rectum. The function of the large intestine and rectum is to remove fluid and salt from waste, store waste and to eliminate waste.

How does colorectal cancer develop?

Most colorectal cancers begin as a polyp which is an overgrowth of the inner lining of the colon or rectal wall. There are two common types of polyps: hyperplastic and adenomas (considered pre-cancerous). One half to one-third of individuals will have 1 or more adenomas which over time (approximately 5-10 years) could become cancerous if not removed.

What are the signs and symptoms of colorectal cancer?

Most often there are NOT symptoms with early disease which is why having colorectal screening is so important. Only 39% of colorectal cancers are detected when the cancer is limited to the colon or rectum1. This is early-stage disease and there is a higher likelihood of a cure. Symptoms of colon cancer include bleeding from the rectum, blood in the stool/toilet, constipation/diarrhea lasting several days, unintentional weight loss, change in stool shape or habit, abdominal cramping, an urge to have a bowel movement that doesn’t go away after a bowel movement, decreased appetite, anemia and fatigue.

Is colorectal cancer hereditary?

5% of colorectal cancers are hereditary

About 5% of colorectal cancers are hereditary. If first-degree relatives (parents, siblings, children) have colorectal cancer, one’s risk is 2-3 times higher.1 The risk increases if colorectal cancer is diagnosed at younger ages. Several inherited conditions such as Lynch syndrome and Familial adenomatous polyposis increase the risk for colorectal cancer. It is essential you are familiar with your family history as it can influence the timing of your screenings.

What is a screening colonoscopy?

A screening colonoscopy is a procedure performed on asymptomatic individuals while they are sedated. A flexible scope with a lighted camera is used to visualize the entire colon and rectum. The colonoscopy is the gold standard to detect and prevent cancer; cancer is prevented when, during the procedure, polyps are removed. The colonoscopy may not detect all polyps including those that are flat and very small. It’s best to complete the colonoscopy prep as directed to ensure the colon is completely cleaned out so it can be better visualized. The colonoscopy is not without risk of complications and you should have a thorough understanding of the benefits and risks.

When should I have a colonoscopy?

According to the American Cancer Society, if you have an average risk of colorectal cancer, your first colonoscopy should begin at age 45 and should be repeated every ten years if there are not any concerning findings. If you are African American, you are at a higher risk of colorectal cancer and your screenings should begin before age 45. If there is a family history of colorectal cancer, screening is recommended five years earlier than the age at which colorectal cancer was diagnosed. Individuals, who are higher risk such as those with hereditary syndromes or Inflammatory Bowel Disease i.e. Chron’s and Ulcerative Colitis, will begin screening well before the age of 45 and will have less time between screening intervals.

What if I don’t want to have a colonoscopy? Are there other ways to detect colorectal cancer?

There are various other screening options including the flex sigmoidoscopy, virtual colonoscopy, and several stool tests. Each of these tests has benefits, various availability and limitations. Most notably, if one of these tests is positive, a colonoscopy will still be recommended. Furthermore, these tests detect cancer but do not prevent cancer.

What is the prognosis when diagnosed with colorectal cancer?

The 5-year overall survival rate (the number of people with colon cancer still alive five years after diagnosis) for all stages of colorectal cancer is 65%. For those diagnosed with early disease, the 5-year survival is 90%.2 Currently, 63% of adults over the age of 50 have had a type of colorectal screening.3 The National Colorectal Cancer Roundtable estimates that if 80% of these adults are screened, 277,000 new cases could be prevented and over 200,000 deaths could be avoided within 20 years.4

Can I prevent colorectal cancer?

Here are several recommendations that may decrease your risk of colorectal cancer.

  • Physical activity of 150 minutes of moderate to intense activity per week even if started late in life
  • Diets with adequate calcium intake, higher intake of fiber, fruits and vegetables and lower intake of red meats and processed meats
  • Limiting alcohol consumption to 1 drink/day for women and 2 drinks/day for men
  • Not smoking
  • Maintaining a healthy body mass index and weight

Promising Research

The scientific medical community recognizes that current colorectal cancer screenings are invasive, inconvenient, uncomfortable and sometimes unaffordable. A recent study shows promise of a blood test that may be able to detect colorectal cancer.

Colorectal screening can save lives but only if people get screened. The best test is the one you will do.

Authors: Bruce W. Porterfield, MD, PhD is a medical oncologist / hematologist at our Green Valley office. Sherri Porterfield, RN, MSN is a Patient Navigator and Community Education Liaison at our Green Valley office


  1. 1 American Cancer Society. 2018. Cancer Facts & Figures 2018.
  2. 2
  3. 3 American Cancer Society. 2017. Colorectal Cancer Facts and Figures 2017-2019.
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Categories: Cancer Prevention, Cancer Risks, Signs & Symptoms, Cancer Screening, Colorectal Cancer