Because several cofactors may influence the development of cervical intraepithelial neoplasia (CIN) in young women, we compared differences in behaviors (sexual activity, contraception, and cigarette use), sexually transmitted disease (STD) infection rates (Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and herpes simplex virus), and cervical maturation (age of menarche and percentage of cervical ectopy) in groups of sexually active female adolescents with and without CIN. Those with CIN were compared with three non-CIN groups: (1) teenagers who were referred to a teen colposcopy clinic but had no evidence of CIN (high-risk group), (2) teenagers seen at a gynecology clinic without STD symptoms (asymptomatic group), and (3) teenagers seen at the gynecology clinic with STD symptoms (symptomatic group). The percentage of cervical ectopy was measured by colpophotography. Subjects with CIN had more lifetime sexual partners than the asymptomatic group (p less than 0.001) and were more likely to smoke cigarettes than either gynecology clinic group (p less than 0.01). No differences in behaviors existed between the CIN and high-risk groups. The mean age of menarche in those with CIN was 1 year older than all three non-CIN groups (p less than 0.05), and those with CIN had a greater area of ectopy than those without CIN (p less than 0.02). Those with CIN were more likely to have a past or present history of C. trachomatis infection than the two gynecology clinic groups; no difference was found between the CIN and high-risk groups. We conclude that cofactors such as smoking, sexual promiscuity, and C. trachomatis infection may influence cervical vulnerability. However, cervical biologic immaturity is an important risk factor for development of CIN in adolescent girls.
PIP: From April-September 1986, researchers asked all 14-19 year old females attending the University of California at San Francisco's Teen Colposcopy Clinic to take part in an epidemiologic study of risk factors for cervical intraepithelial neoplasia (CIN). The 4 comparison groups consisted of a CIN group, a high risk group (external warts or abnormal Pap smear, no CIN, similar behavioral risk factors as CIN group), as asymptomatic group, and a symptomatic group (negative Pap smears and lower genital tract infection complaints). The CIN group was more likely to smoke or have smoked than the asymptomatic and symptomatic groups (p.01) and to use oral contraceptives than the asymptomatic group (p.02). In addition, patients with CIN had more lifetime sexual partners than did the asymptomatic group (p.001). The teens in the CIN group reached menarche on average 1 year later than did those in any of the comparison groups (p.05). This also had a greater area of ectopy than the other 3 groups (p.02). External genital warts occurred more often in the CIN group than in either the asymptomatic or symptomatic groups (p.001). Further, the CIN and high risk groups were more likely to have had any sexually transmitted disease than the asymptomatic (p.001) or symptomatic (p.01) groups. In addition, chlamydiosis occurred more often in the CIN group than in the asymptomatic (p.001) or symptomatic groups (p.03). The results indicate that cervical biologic immaturity may play an important role in development of CIN in adolescents. They also showed that CIN patients had more ectopy than the others thereby demonstrating that cervical biologic immaturity may rend the epithelium vulnerable to human papilloma virus invasion and neoplastic change.