High prevalence of cervical dysplasia in STD clinic patients warrants routine cytologic screening.

The results of routine cervical cytology screening at a Planned Parenthood Center (PPC) clinic were compared to those at a nearby sexually transmitted diseases (STD) clinic in Seattle. Cervical cytologic findings were consistent with cervical intraepithelial neoplasia (CIN), grades 1 (mild dysplasia), 2 (moderate dysplasia), or 3 (severe dysplasia to carcinoma in situ) in 502 (5.9 per cent) of 8,504 PPC patients and 87 (11.4 per cent) of 764 STD patients (p = .001). This rate for STD patients is five times that reported for the general population. Sixty-three PPC patients and 31 STD patients with screening smears consistent with CIN 1 or 2 underwent further prospective study by us, including repeated cytologic and colposcopic examinations. Thirty-seven (59 per cent) of 63 PPC patients and 26 (84 per cent) of 31 STD patients (p = .02) had at least on additional smear or colposcopy consistent with CIN and were advised to undergo cervical biopsy. Among those who underwent recommended biopsy, CIN was confirmed histologically in 15 (50 per cent) of 30 PPC patients and 11 (61 per cent) of 18 STD patients. Thus, the proportion of patients who had screening cytologic findings consistent with CIN, the proportion with persistent cytologic or colposcopic findings consistent with CIN on retesting, and the proportion of those biopsied who had histologically confirmed CIN, all were higher for STD than for PPC patients. There is a serious need for cytologic screening in STD clinics throughout the nation.