Colorectal cancer (CNC) is the second-leading cause of cancer-related deaths among U.S. men and women, but as many as 23 million older adults are not getting tested for it, CBS News reported.

The new data comes from the Centers for Disease Control and Prevention's (CDC) Vital Signs report, published on its website Nov. 5. The report found that one in three (23 million) adults between the ages 50 and 75 are not submitting to recommended CNC screenings.

In 2002, 54 percent of that age group were caught up with recommended screenings and that figure only improved by 2010 to 65 percent. However, the new report, detailing 2012 statistics, found those numbers to be leveling off at 65.1 percent.

CNC is the leading cause of cancer-related deaths for non-smokers and can either originate in the rectum or colon. Screenings are recommended because they can start out as polyps or adenomas and can easily turn into cancer. According to the American Cancer Society, the potential threat of a polyp is fairly avoidable when spotted and removed early on.

According to the CDC report, addressing CNC early on adds about five years onto one's lifespan 90 percent of the time.

The report said colonoscopy screenings are the best way to identify potential for CNC, but there are also two at-home tests also proven effective: the guaiac fecal occult blood test (FOBT) or the fecal immunochemical test (FIT). Those do-it-yourself tests can alert someone if there is an issue that needs to be addressed by a doctor or just to reassure a healthy patient.

CDC director Dr. Tom Frieden emphasized a proactive attitude about undergoing any type of test.

"The bottom line is the best test is the test that gets done," said Frieden.

"Colonoscopy is clearly preferred for high-risk people," he said. "But for others, there's not a huge difference."