Screening for cervical intraepithelial neoplasia and cancer in the Sheffield STD clinic.

I undertook a prospective study of the incidence of histologically confirmed cervical intraepithelial neoplasia (CIN) and cancer in women attending a sexually transmitted disease (STD) clinic, and correlated the findings to cervical cytology reports, age, and history of STD of the affected women. Of 2017 women screened, 75 (3.7%) had dyskaryotic cervical smears. Colposcopically directed biopsy tests gave an overall detection rate of 0.55% for CIN3, which was similar to the national average. The false negative rate was 2.9% and cytology tests alone underestimated the degree of pathological change in 12 (30%) of 40 women with mild dyskaryosis. Women under 20 years old made up 43% of those with CIN1 and 38% of those with CIN2. The detection rate of CIN3 was 0.65% for women aged 15-34, which was higher than the national average and suggested earlier onset of CIN3 in our clinic population. There was a high association between genital warts and cervical precancer. This preliminary study confirms the need for routine non-selective screening of women attending STD clinics by cervical cytology tests, colposcopic examination, and biopsy tests where indicated.