A survey from California confirms that people are more likely to get screening or diagnostic tests for colorectal cancer if they have health insurance and a regular source of health care. While that finding is in line with previous studies, the new survey also offers some insights into other factors responsible for low prevalence of screening—particularly among ethnic minorities and women.

Researchers from the University of California, Los Angeles, analyzed portions of the 2001 California Health Interview Survey (CHIS). Their findings were published in the journal Cancer (2004;101:2523–2532). The CHIS is a comprehensive statewide telephone survey conducted in English, Spanish, and several Asian languages. Using multiple languages assured that minority groups often excluded from such surveys because of language difficulties were included in the current study, said lead researcher Ninez Ponce, PhD, MPP, Assistant Professor of Health Services at the UCLA School of Public Health.

“Including these racial, ethnic, and linguistic groups is particularly important in accurately evaluating the nation's progress in cancer screening,” she said.

Ponce and her colleagues examined responses from 22,343 adults aged 50 and older; race and ethnicity were divided into White, African American, Asian, Latino, American Indian/Alaskan Native, and other/multiracial categories. Respondents were asked about fecal occult blood testing in the 12 months before the interview and about flexible sigmoidoscopy or colonoscopy in the previous 5 years.

Overall, 54% of California adults over 50 reported being tested for colorectal cancer (the survey did not distinguish between screening and diagnostic procedures), a result that exceeds the national average for screening prevalence, which was 41% for men and 38% for women according to the 2000 National Health Interview Survey (NHIS) (Cancer 2003;97:1528–1540).

Whites and African Americans reported similar rates of colon testing: 51% and 50%, respectively, in the 50 to 64 age group and 63% and 62% in the 65 and older group. Asians and Latinos lagged, however. Just 33% of Latinos in the younger age group and 52% in the older group reported colon testing. Among Asians, the figures were 41.7% among those 50 to 64 and 55% among those 65 and older.

The reasons for not receiving colon cancer testing differed by race/ethnicity and by gender. Whites were more likely to say they didn't get tested because their doctor had not told them they needed testing. Asians and Latinos, however, were more likely to cite an absence of any problems as a reason for not getting tested.

That finding points to a need to better tailor messages to these groups about the need for colorectal cancer screening, the researchers said. Other experts agree.

“Undoubtedly this is an area where research is critically needed that is culture-specific, that addresses words we use, how we present the information, etc.,” said Richard Wender, MD, Alumni Professor and Chair of the Department of Family Medicine at Thomas Jefferson University. Wender, who is also a member of the CA editorial board and the ACS Colorectal Cancer Advisory Group, was not involved in the research.

Women, too, were more likely than men to say they didn't get tested because their doctor didn't tell them it was necessary. That finding was surprising, Ponce and colleagues said, because breast and cervical cancer screening tests are widely recommended and used. One possible explanation suggested by the authors is that, “… some women use obstetrician/gynecologists as their primary care doctors, and it has been shown that physicians in this specialty are much more likely than other primary care physicians to conduct fecal occult blood test by digital rectal examination … a nonstandard approach that is discouraged in major guidelines.”

Wender noted that other studies have also found a suggestion of gender bias in colon cancer screening. The reasons for the discrepancies, however, are not entirely clear. Physicians may be too busy with other topics, he said, or women may not feel threatened by colon cancer in the same way they do by, say, breast cancer.

“Having a cancer that is not specific to gender [may be an issue],” Wender said. “Men ‘own’ prostate cancer, women ‘own’ breast cancer, no one ‘owns’ colon cancer. It's harder to get excited about it.”

The most reliable predictor of colon cancer testing in the study was having both health insurance and a regular source of medical care. Among people 65 and older, 66% of those who had Medicare and supplemental insurance, and a regular source of care, reported being tested.

That figure suggests that the United States is making progress in improving colon can-cer screening rates, Wender said. But a 66% screening rate still falls far short of the 80% or so screening rates seen for breast and cervical cancer, he added.

“There's a unique set of barriers that confront screening for colon cancer that are not confronted with other cancers,” he said. “We won't get past 80% unless we work on insurance obstacles.”

Doctors and patients can both do more to improve rates of colon cancer screening, said Ponce.

“Consumers need to know that the colorectal cancer tests are prevention measures and save lives,” she said. “Once they turn 50, they should ask their doctors about getting tested. Doctors need to be knowledgeable about clinical guidelines and be mindful of cancer screening schedules for their patients. Reminders for both the patient and doctor have been shown to be helpful.”

Prevention and early detection of colorectal cancer is a top priority for the ACS, which has launched a nationwide plan to increase public awareness of the need for colon cancer screening, advocate for insurance coverage of such screening, and encourage physicians to recommend these tests to patients who need them. The strategy includes distinct advertising campaigns aimed at physicians and consumers and is based on research findings regarding barriers and motivators for colon cancer screening.

“For the general public, there are a lot of misperceptions of colorectal cancer,” said Durado Brooks, Director of Prostate and Colorectal Cancer for the ACS. “People do still believe that if they don't have family history then they're not at risk, and they also don't appreciate the tremendous preventive benefits available from screening. They're unaware that we can find polyps and remove them before cancer occurs.

“There's also the belief that if it is relevant to them, then their doctor would talk to them about it, so if their doctor doesn't bring it up, they're not likely to bring it up to their doctor.”

That means physicians must do more to assure patients are getting screened appropriately, Brooks said.

“Most doctors screen some of their patients, but not all doctors have systems in place to make sure all of their eligible patients are screened,” he said. 

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Figure  . Having insurance and a regular source of care are the primary predictors of colon cancer screening, a California survey finds. (Photo courtesy of Olympus.)

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