[Results of a case-control study of the current effect of various factors of cervical cancer risk. 2. Contraceptive behavior and the smoking factor].

We considered in this study 309 patients with cervical intraepithelial neoplasia (CIN) or invasive cervical carcinoma and 490 women without pathological changes in the cervical epithelium. The interviews was performed using a standardised questionnaire. The percentage of women who attended screening programmes for cervical carcinoma amounted to 83.5% for the study group and 81% for the control group. The relative risk (RR) for developing CIN or invasive cervical carcinoma increased with the use of hormonal contraceptives; the increase being statistically significant (RR = 3.5; p = 0.006). Moreover easy use of oral contraceptives (< 18 years, 18-20 years, 21-25 years vs > 25 years) and prolonged use of oral contraceptives were associated with a significant increased of the relative risk. In contrast, women who used IUD had a very low relative risk (RR = 0.6; p = 0.005). 54.5% of the patients in the study group and 41.6% of those in the control group were smokers. We observed that smoking increases the relative risk for cervical carcinoma or CIN (RR = 1.7; p = 0.01). The duration of smoking and the number of cigarettes smoked were observed to increase the risk for cervical carcinoma, the increase being statistically significant.