[The age for beginning and the frequency for performing the Pap test]

The increase in sexual activity among teenagers has been well documented. One apparent result is the increasing prevalence of cervical cytological abnormalities in this age group over the last 20 years. The adolescent cervix appears to be especially vulnerable to the initiation of carcinogenesis. Consequently, the significance of early age at first coitus is thought to be related to the biologic changes that occur in the cervix during puberty. Large epidemiologic studies have implicated sexuality as the initiator of a sequence of multistage events that destabilize the healthy cervix and culminate in cervical cancer. The median interval between age at first coitus and the development of CIN1 is 9 years, with a progressive 2.5 year increase for each degree of progression from CIN 1 through 3. Unfortunately, the precise mechanism by which that biologic variable, early age at first coitus, predisposes to CIN remains enigmatic. Nevertheless, there is no doubt that the earlier the age at first coitus, the higher the risk factor. Among virgins the incidence of cervical cancer is essentially zero. Among sexually active adolescent girl no cases of invasive carcinoma have been found, but carcinoma in situ had a prevalence rate of 2.6 per 1,000 15-19 years old, whereas cervical dysplasia ranges from 0.8 to 3.5% of screened sexually active teenagers populations. Adolescents who have never been sexually active clearly do not need to be screened for cervical cancer. On the contrary teenagers with the risk factors of sexually transmitted disease or multiple sex partners should be annually screened soon after onset of sexual activity.(ABSTRACT TRUNCATED AT 250 WORDS)