A high-tech screening tool for cervical cancer is facing pushback from more than a dozen patient groups, who warn that the genetic test could displace a simpler, cheaper and more established mainstay of women’s health: the Pap smear.

The new test from Roche uses DNA to detect the human papillomavirus, or HPV, which causes nearly all cases of cervical cancer. While such technology has been available for years, Roche now wants the FDA to approve its test as a first-choice option for cervical cancer screening, bypassing the decades-old Pap test.

But a number of women’s groups — including the American Medical Women’s Association and Our Bodies Ourselves — warn that moving to a DNA-based testing model would be a “radical shift” in medical practice that could lead to confusion, higher costs and overtreatment.

“It replaces a safe and effective well-established screening tool and regimen that has prevented cervical cancer successfully in the U.S. with a new tool and regimen not proven to work in a large U.S. population,” state the groups in a letter to FDA Commissioner Dr. Margaret Hamburg. The letter is signed by 17 patient advocacy groups, including Consumers Union, the Cancer Prevention and Treatment Fund and the National Alliance for Hispanic Health.

Chief among the advocates’ concerns is that HPV-only testing could lead to overtreatment of younger women who carry the virus but have little risk of developing actual cancer. Most sexually active young people will contract HPV, though their bodies usually eliminate the virus within a few months. Only years-long infections develop into cancer.

“Unfortunately the HPV test by itself isn’t very useful because so many young women have HPV that will disappear without any treatment,” said Diana Zuckerman of the Cancer Prevention and Treatment Fund. “Having an HPV test without also getting a Pap smear to check for problems is going to scare a lot of women who are not developing cervical cancer.”

An FDA spokeswoman said the agency could not comment on the letter since it deals with a product under review.

For decades the Pap test was the only screening option for cervical cancer — and it’s had a remarkably successful track record. The number of cervical cancer cases reported in the U.S. has decreased more than 50 percent in the past 30 years, primarily due to increased Pap screening.

Still, an estimated 12,000 cases of cervical cancer are expected to be diagnosed this year, a fact that has spurred development of genetic tests such as the one from Roche and other test makers.

Medical guidelines have been evolving rapidly to try and incorporate both techniques. Under the latest guidelines from the American Cancer Society, a Pap test is recommended every three years for women 21 to 29 years old. Women 30 and older should have both a Pap test and an HPV test every five years, or a Pap test alone every three years. Women who have had an HPV vaccine should still follow screening guidelines.

HPV screening is not recommended for women in their 20s because it increases the odds of more invasive testing that can leave the cervix less able to handle pregnancy later in life.