More people are getting life-saving screening for colon cancer, but many still need to be examined, according to the Centers for Disease Control and Prevention.

The number of patients being screened for colon cancer increased to 63 percent in 2008, up from 52 percent in 2002, says the CDC. However, 22 million people should be examined for the disease, but haven't been yet.

Cancer is an expensive disease and those who lack adequate health insurance coverage may experience difficulty paying for care.

The CDC found that 66 percent of adults with health coverage were screened for the disease, compared to only 36 percent who are uninsured.

While the increase in cancer screening rates shows progress, some doctors say more work needs to be done.

"It's encouraging to see more adults getting recommended cancer screenings," said CDC director Dr. Thomas Frieden. "But we have more to do, especially when it comes to getting more people screened for colorectal cancer, which kills more American non-smokers than any other cancer."

Almost 50,000 people died from colon colorectal cancer last year, according to the American Cancer Society. Some deaths may have been prevented with earlier treatment.