July 14 (HealthDay News) -- Only half of U.S. men and women older than 50 are getting screened for colorectal cancer, despite the success these tests have in reducing deaths linked to the disease, a new report says.

Still, the current rate of screening is an improvement from the 43 percent who received the tests back in 2000, the researchers noted. The statistics come from a national survey conducted by the U.S. Centers for Disease Control and Prevention (CDC) in 2005. Experts discuss the findings in the July issue of Cancer Epidemiology, Biomarkers & Prevention.

"Colorectal cancer is one of the leading cancer killers in the United States, behind only lung cancer. Screening has been shown to significantly reduce mortality from colorectal cancer, but a lot of people are still not getting screened," Jean A. Shapiro, a CDC epidemiologist, said in a news release issued by the journal's publisher, the American Association for Cancer Research.

Insurance coverage may be part of the problem, Shapiro said. Only 24 percent of people lacking health insurance had colorectal cancer screening compared with more than 50 percent of insured Americans. "If we can increase the number of people who have health care coverage, we should be able to increase colorectal cancer screening rates," Shapiro said.

Beyond health insurance, the researchers reported that people were far more likely to have had colorectal cancer screening tests if they were college educated, had a household income of $75,000 or more, and had seen their doctor at least twice in the previous year. Of those who saw their doctors in the past year, about half who did not receive testing said they had "never thought about it." Another 20 percent said their doctor did not order the test.

"Many doctors are aware, but some may still need to be educated about the importance of colorectal cancer screening," Shapiro said.

SOURCE: American Association for Cancer Research, news release, July 14, 2008