Nov. 20 (Bloomberg) -- Women should begin cervical cancer screenings at age 21 rather than an earlier age, and most women younger than 30 can get the exam every two years instead of annually, a physicians’ group said.

The revised guidelines released today by the American College of Obstetricians and Gynecologists also recommend that women 30 and older get screened with a so-called Pap test once every three years, instead of every two to three years. The American Cancer Society’s gynecologic cancer director said the society agreed with the advice of the doctors’ organization that additional screenings may lead to unnecessary treatment.

The ob-gyn organization is the second medical group this week to recommend less-frequent cancer screenings, citing scientific data. A U.S.-backed panel said Nov. 16 that most women in their 40s shouldn’t get annual mammograms to prevent breast cancer, setting off protests from women, physicians and health advocacy groups such as the cancer society.

“The data is very good that a Pap test every two years is as good as a Pap test every year,” said Alan Waxman, the lead author of the new guidelines and a professor of obstetrics and gynecology at the University of New Mexico in Albuquerque, in a telephone interview. The additional tests are inconvenient and costly, and research shows “it doesn’t make a difference in terms of lives saved,” he said.

Mammogram Dispute

The guidelines pushing back regular breast cancer tests using mammograms for most women until age 50 were presented Nov. 17 by the U.S. Preventive Services Task Force, a government- supported panel of doctors formed in 1984 to give advice on screening, counseling and preventive medicines based on an impartial assessment of scientific evidence.

Those suggestions were immediately discounted by the American Cancer Society. Republicans in the U.S. Congress opposed to the Democratic health-care overhaul, led by Senator Sam Brownback of Kansas, pointed to the task force guidelines as proof the Obama administration plans to ration care. Kathleen Sebelius, the U.S. health and human services secretary, said Nov. 18 the recommendations of the task force won’t determine what services are covered by the federal government.

It’s an “unfortunate coincidence” that the Pap test guidelines are coming out the same week as the controversial mammogram recommendations, said Waxman, the author of the cervical cancer report, said. “I wrote the guidelines for Pap smears back in April.”

Not Challenged

The cervical cancer guidelines were not immediately challenged by women’s group and other doctors, as the mammogram suggestions were.

“This is actually good news for women,” said Cindy Pearson, executive director of the National Women’s Health Network, a Washington-based advocacy group, in a telephone interview. “If the college’s announcement encourages their doctors to follow these guidelines, women’s health will be better as a result.”

The ob-gyn college is revising guidelines, adopted in 2003, that young women start Pap tests three years after beginning sexual intercourse, or by age 21, whichever occurred first. Women 30 and older who have had three consecutive normal tests should be screened once every three years, according to the recommendations published today in the journal Obstetrics & Gynecology.

In a Pap test, cells are scraped from the surface of the cervix and examined under a microscope. The tests have been credited with helping to lower cervical cancer rates in the U.S. by more than 50 percent in the past 30 years, according to the ob-gyn college.

Virus Cause

Most cases of cervical cancer are caused by the human papillomavirus, or HPV, a sexually transmitted infection, according to the Mayo Clinic Web site.

The cancer can be prevented with the Gardasil vaccine, made by Whitehouse Station, New Jersey-based Merck & Co., and Cervarix from GlaxoSmithKline Plc, of the U.K. Both target HPV and are approved for adolescent and young adult females.

This year, 11,270 new cases of cervical cancer will be diagnosed in the U.S. and 4,070 women will die of the disease, according to the National Cancer Institute. Six in 10 cervical cancers occur in women who have never had a Pap test or been tested in the past five years, according to the Atlanta-based U.S. Centers for Disease Control and Prevention.

Many doctors recommend once-a-year screenings after age 21, though women may avoid the tests because they are uncomfortable, Saslow said.

‘See Value’

“I think many practitioners will see the value in not screening these young women, knowing that they will be screening them soon,” said George Sawaya, an associate professor at the University of California, San Francisco, and director of the cervical cancer screening clinic at San Francisco General Hospital. “There’s very little to be gained by screening too soon but there are certainly harms that could be incurred.”

The cancer society agrees with the new guidelines though it still formally supports the screening recommendations that have been in place since 2002, said Debbie Saslow, director of breast and gynecologic cancer for the Atlanta-based group. The group plans a formal review next year of its cervical cancer screening recommendations, she said.

“The risk of getting cervical cancer as a teenager is, literally, one in a million,” Saslow said in a telephone interview yesterday. “We are doing all that screening to prevent one-in-a-million cancers.”

10 to 20 Years

Unlike breast cancer, which can grow quickly, cervical cancer “can take 10 to 20 years to go from an infection with the virus to actual cancer,” Saslow said.

Even if the HPV rate is high among sexually active young women, the infection often clears their bodies without treatment, said Waxman, the study author. There are also some drawbacks to treating infections.

“The treatments we use for the pre-cancers have been associated with increased risk of premature births in women who get pregnant subsequently,” Waxman said.

There are about 5 million abnormal Pap test results in the U.S. each year and only a few thousand of those tests actually detect a cancer, Saslow said. The abnormal tests can also lead to unnecessary tests, biopsies, she said.

Women who have a higher-than-average risk for cervical cancer -- including those infected with the AIDS virus, kidney transplant recipients or people who have been previously diagnosed with cervical cancer -- may need more frequent screenings, the doctors’ group said.

To contact the reporters on this story: David Olmos in San Francisco at dolmos@bloomberg.net; Rob Waters in San Francisco at rwaters5@bloomberg.net.

Last Updated: November 20, 2009 05:47 EST