ZEBULON, N.C. — Colon cancer is the most curable form of cancer if caught early. Yet, more than half of those who should be screened for it are not. Now, there is an effort to turn that around.

A series of public service announcements may get more people thinking about colon cancer screening.

Sue Kiryluk's diagnosis five years ago came in the midst of her work on the North Carolina Colorectal Study. The registered nurse said she has too much to live for to not practice what she preaches -- colon cancer screening begins at age 50.

"I went for a routine screening as part of my physical and discovered that I had colon cancer," Kiryluk said. "I didn't have any symptoms, so if I hadn't had the screening, it would have gone further."

The most common symptom of colon cancer is not having any symptoms at all. When symptoms do appear, it means the cancer is advanced and your chances of surviving are greatly reduced.

"We could prevent 90 percent of colon cancer if people got their cancer discovered early, but most people don't do that," said Dr. Robert Sandler, a gastroenterologist at the University of North Carolina.

A colonoscopy can find polyps that can be removed before they become cancerous. Even if tumors are found, treatment options have greatly improved over the past five years.

"With a combination of five drugs instead of just one drug, our armamentarium has increased dramatically and there's a lot more we can do for patients," said Dr. Richard Goldberg, an oncologist at the University of North Carolina.

Doctors recommend colon cancer screening for most people beginning at age 50, but new guidelines issued this month from the American College of Gastroenterology advise African-Americans to begin screening five years earlier at 45 years of age.