Health experts predict that there will be more than 100,000 new cases of colon cancer and more than 45,000 cases of rectal cancer in the United States this year. Cancers that start in the colon or rectum are known as colorectal cancer, the third most common cancer among women and men in the U.S., according to the American Cancer Society (ACS).

The "Silent Killer"

You may have heard colorectal cancer referred to as a “silent killer,” but what exactly does that mean? Because colorectal cancer may not produce any symptoms right away or may produce vague symptoms that can easily be ignored, it’s often not diagnosed until it has progressed into advanced stages of the disease. The lack of symptoms until later stages are why colorectal cancer is known as a “silent killer” and why colorectal surgeons stress the importance of early detection.

What are the Colorectal Cancer Warning Signs?

Since colorectal cancer may not cause symptoms right away, you should keep an eye out for warning signs that may indicate something is wrong with your colon or rectum. Matthew Skancke, MD, is a colorectal surgeon with Holy Cross Health Partners. He suggests watching for changes in your bathroom habits. “If you’re having a change in bowel function, constipation, vague abdominal pain, bleeding in your stools—those are things that can all be indicators that something is afoot or that something is going on in your digestive tract that may be significant, or it may not.” Here are some specific warning signs to look for:

  • A change in bowel habits, such as constipation or diarrhea, that continues for more than several days
  • Blood in the stool, which can cause the stool’s color to appear dark brown or black
  • Rectal bleeding with bright red blood
  • Persistent abdominal cramping, aches, or pain
  • A feeling of the need to have a bowel moment that’s not relieved by having one
  • Unintended weight loss
  • Fatigue and weakness
  • Nausea or vomiting

It’s important to note that many of these symptoms can be caused by conditions other than colorectal cancer. If you experience any of these issues, you should see your doctor as soon as possible so that their cause can be determined and treated appropriately. “The main point is do not ignore symptoms,” Dr. Skancke says. “Ignoring symptoms never does anyone any good. It just leads to a surprise later on. And that's what we're trying to avoid. We want everyone to be well informed as to what's going on with their body and specifically in their colon and their rectum.”

Why You Should Get a Colonoscopy

Because symptoms of colorectal cancer often don’t appear until the disease is in an advanced stage, early detection is crucial. Regular screening tests are the most important way to find colorectal cancer in its early stages when treatment is most successful. When colorectal cancer is found at an early stage, the five-year survival rate is approximately 90 percent, according to ACS. Both ACS and the U.S. Preventive Services Task Force recommend that individuals with an average risk of developing colorectal cancer start regular screenings at the age of 45, with continued regular screenings through the age of 75. You’re considered to be of average risk if you don’t have any of the following:

  • A personal history of colorectal cancer or polyps, inflammatory bowel disease (Crohn’s disease or ulcerative colitis), and radiation treatment to the abdomen or pelvic area for a prior cancer treatment
  • A family history of colorectal cancer
  • A hereditary colorectal cancer syndrome, such as Lynch syndrome (hereditary nonpolyposis colon cancer, or HNPCC) or familial adenomatous polyposis (FAP)

Once you decide to get screened for colorectal cancer, your doctor will likely recommend a colonoscopy. A colonoscopy is a painless procedure where a gastroenterologist or surgeon looks inside your colon and rectum using a fiber-optic camera. During the procedure, suspicious lesions are photographed and biopsied when appropriate. If precancerous lesions are detected, they can also be removed at the time of colonoscopy. Recovering following a colonoscopy is easy and patients routinely go back to their daily activities the following morning.

While there are other non-invasive methods to screen for colon and rectal cancer, positive results on non-invasive testing mandate a colonoscopy, and negative results can give a false sense of security.

Colon Cancer Screening Saves Lives

Holy Cross Health colorectal surgery experts Bradley Bennett, MD, and Matthew Skancke, MD, discuss early screening, diagnosis and treatment options for colorectal cancer.