WEDNESDAY, April 4 (HealthDay News) -- Obese white women are less likely than normal-weight white women or blacks of any weight or gender to seek potentially life-saving colon cancer screenings, according to a new study.

This reluctance is especially serious because obesity is associated with a higher risk for colon cancer and an increased risk of death from the disease, noted study leader Dr. Nisa Maruthur, an assistant professor in the general internal medicine division at Johns Hopkins University School of Medicine in Baltimore.

"Being concerned about your weight usually is good, but here it appears to be keeping people from a test we know saves lives," Maruthur said in a Hopkins news release. "Obese white women may avoid screening because they feel stigmatized and embarrassed to disrobe for the tests."

Colonoscopy and fecal occult blood tests are two methods of colon cancer screening. The U.S. Preventive Services Task Force recommends that adults aged 50 to 75 undergo colonoscopy on a periodic basis, but only 20 percent of women and 24 percent of men over age 50 do so, the study authors pointed out in background information in the news release.

For the new study, the researchers reviewed the findings of 23 published studies that included information on body mass index (BMI) and colon cancer screening. BMI is a measurement that takes into account height and weight. A BMI between 18.5 and 24.9 is considered normal weight, between 25 and 29.9 is considered overweight and 30 or more is considered obese.

Overall, the Hopkins team found no link between higher BMI and lower rates of colon cancer screening. They did find such a link in obese white women, however.

Compared to normal-weight white women, those with a BMI between 30 and 34.9 were 13 percent less likely to be screened, and those with a BMI of 40 or higher were 27 percent less likely to be screened.

There was some indication that obese white men also are reluctant to undergo colon cancer screening, but further research is needed to confirm that data.

The study is published in the April 4 online issue of the journal Cancer Epidemiology, Biomarkers and Prevention.

Previous research by the same Johns Hopkins team found that obese white women are also less likely to seek mammography breast cancer screening and Pap smear screening for cervical cancer.

In addition to feeling reluctant to disrobe, another reason obese women may avoid the screening is because they may be dealing with other higher-priority health concerns, the researchers suggested.

More information

The U.S. National Cancer Institute has more about colorectal cancer screening.