Obese women are less likely to get screening tests for breast, colon and cervical cancer, researchers said.

Almost 38,000 women completed a survey that asked about height and weight, how often they go to doctors and if they get the tests.

Researcher Raj Padwal said that while body mass index didn't have an effect on breast or colon cancer screening, the rate of women having a Pap smear decreased as BMI went up.

"Obese women are 30 to 40 percent less likely -- depending on the degree of obesity -- to have recommended cervical cancer screening performed," Padwal said.

Overall, 82 percent of women had the test in the last three years.

The obese women said that fear of pain, embarrassment or finding something wrong were the reasons for avoiding the tests.

Padwal said that obesity has been linked to higher rates of some types of cancer.