MONDAY, Oct. 26 (HealthCare Tips) -- New research finds that blacks are at much higher risk of developing colorectal cancer than other groups of people, and they are more likely to be diagnosed at a later stage of the disease.

Researchers from the California Pacific Medical Center examined medical records regarding more than a half million cases of colorectal cancer that were diagnosed from 1973 to 2004.

They were scheduled to present their findings Monday at the American College of Gastroenterology annual meeting in San Diego.

Black males were more than twice as likely as Asian-American men to be diagnosed with a kind of colorectal cancer known as proximal cancer. Their annual rate of cases was 25.2 per 100,000, vs. a much lower 11.7 per 100,000 among the Asian-American men.

There was a similar disparity between black women (21.9 annual cases per 100,000) and Asian-American women (11.4 cases per 100,000).

Researchers said both male and female blacks also had much higher rates than whites and Hispanics.

"I was surprised at how big the differences were between the various groups," said study author Dr. Robert Wong said in news release from the center. "I had done similar research on liver cancer in the past and found that racial and ethnic differences were present, but not nearly as stark as this."

Blacks also had more severe cases of the disease, with rates of advanced cancer in both genders nearly double that of in Hispanics.

"I think access to care plays a huge role in determining who is at risk and how great that risk is," Wong said. "But access alone does not explain all the differences. It's likely that for some socioeconomic groups education is also critical. Members of certain groups may not have enough information on education and the importance of screening."

Colorectal cancer is the third most common cancer in the United States. Among types of cancer, only lung cancer kills more people.