• Mayo Clinic Minute: Colorectal cancer by the numbers

Colorectal cancer is one of the most common and deadly forms of cancer, but it's also one of the most preventable. Dr. John Kisiel, a Mayo Clinic gastroenterologist, says the biggest reason is that not enough people are getting screened regularly.

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Colorectal cancer numbers may surprise you ...

"... about 150,000 new diagnoses and 50,000 deaths each year, unfortunately," Dr. Kisiel says.

Colorectal cancer is the fourth most common form of cancer behind breast, lung and prostate cancers.

"Colorectal cancer is the most preventable ─ but often least-prevented type ─ of cancer in the United States because only about a half to maybe two-thirds of patients are participating in screening," Dr. Kisiel says. "That means that a third to a half of patients are not participating in screening."

Dr. Kisiel says everyone over 50 should be screened regularly. If caught early, colorectal cancer is usually very treatable. But the lack of screening makes it one of the most deadly forms of cancer.

It's more common in men, but women should be screened, as well.

It's also more prevalent in the African-American population, which is why Dr. Kisiel recommends that African-Americans and patients with family history of polyps or cancer discuss screening in more detail with their health care provider.

He says if patients wait until they show symptoms of colorectal cancer to get treatment, their odds of surviving drop significantly. That's why regular screening to catch it early is the key.