Waxman also said that "the tradition of doing a Pap test every year has not been supported by recent scientific evidence."
Cervical cancer rates have dropped more than 50 percent in the last 30 years in the United States, according to the guidelines -- a decline that's been largely attributed to widespread use of the Pap test.
But a review of studies showed that screening less frequently produces similar results, Waxman said.
Most women in the United States who die from cervical cancer were not screened at all or were screened infrequently, the review showed. According to American Cancer Society estimates, 11,270 new cases of cervical cancer will be diagnosed in the United States this year, and the disease will cause 4,070 deaths.
Screening can be done with either the conventional Pap test or a newer liquid-based cytology, according to the new guidelines. Both tests look for changes in the cervical cells that can lead to cancer.
The starting age was moved to 21, Waxman said, to avoid unnecessary treatment of teens. The rate of infection with human papillomavirus, or HPV, which can cause cervical cancer, is high in teens who are sexually active, he said, but the immune system typically clears HPV within one or two years among younger women.
And, he added, recent research has shown an increase in premature births among women who were treated for precancerous HPV-related lesions with excisional procedures. So, Waxman said, the new thinking is to leave the younger cervix be, to avoid unnecessary procedures.
The new guidelines apply to healthy women, Waxman said, excluding for instance, those who have compromised immune systems, have HIV or who were exposed to diethylstilbestrol, or DES, in the womb. Those who've gotten the new HPV vaccine are urged to follow the guidelines.
Previous research had found that some doctors were over-prescribing the Pap test
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