5 Warning Signs of Colorectal Cancer

March 21, 2017 7:00 AM

When colon cancer is found early, survival rates are much higher. Know the warning signs — and how family history affects an individual’s risk.

Approximately 135,000 Americans are diagnosed with colorectal cancers each year. It’s the third most commonly diagnosed cancer for both men and women.

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But thanks to routine recommended screenings for people ages 50 and older, colorectal cancers are also among the most preventable.

One of the best lines of defense: knowing your family history and sharing that information with your doctor.

“Family history of colorectal cancer has a major impact on your colorectal cancer risk,” says Elena Stoffel, M.D., assistant professor of internal medicine at the University of Michigan Medical School and director of the Cancer Genetics Clinic at the U-M Rogel Cancer Center.

That risk can vary based on who has had cancer — and when.

“We typically say that the average individual’s lifetime risk for colorectal cancer is about 5 percent,” says Stoffel. “If you have one first-degree relative with colorectal cancer, your risk is roughly double that. But if you have multiple relatives with colorectal cancer, and especially cancers diagnosed at younger ages, then your risk is much higher.”

If cancer develops, catching it early can be the key to better outcomes. The vast majority of colorectal cancers arise from polyps, so screening is important — especially if you are in a high-risk category because of your age or genetic predisposition for cancer. If polyps are found and removed early, they can be prevented from growing into cancers.

SEE ALSO: A Colon Polyp Primer: Know the Types and Your Risk Factors

Doctors, she notes, will recommend cancer screenings at different ages depending on a patient’s personal and family history. Since colorectal cancers can often grow undetected, screening is important, even if you have no symptoms.

Others, however, may experience more direct warning signs.

If you have any of the following symptoms, notify your doctor. They may determine whether you need special testing.

  • Rectal bleeding or blood in the stool

  • Changes in bowel habits, including stools that are narrower than usual

  • Persistent or recurring abdominal pain

  • Anemia

  • Unexplained or unintended weight loss

These symptoms aren’t always indicators of colorectal cancer. Many of these symptoms are common, Stoffel says, and can be caused by other conditions.

Still, they should be enough to warrant a visit to your doctor — and, if you haven’t done so already, a review of your family’s health history.