[Cervical cancer of the uterus. Analytic epidemiology]

Malignant tumour in cervix is an important cause of death in young women. Through community programmes of detection and early diagnosis, a significant reduction in the incidence of invading forms and mortality due to this cause has been achieved. Knowing the Prevalence of premalignant lesions and cancer in the sexually active women population, establishing the frequency of risk to different factors and associated risk to these ones in this population, constitutes a part of this study objectives.

A transversal study is carried out, with a sample of population older than 20 years or younger, but sexually active, constituted by 4262 women, selected at random from a population of 7222 persons cared in family planning centers and distributed in 15 localities. In every case, the colposcopy has been made in a systematic way, associated to the cytology with a biopsy of every atypical image. Among the risk factors studied, the expositions to Rx, sexual promiscuity, genital infections, mycosis and infertility are included. The existence, as a clinical discovery, of a suspected lesion or an atypical colposcopy are includes as risk markers. The test of, the calculation of Odds Ratio, and 95% confidence interval, the etiological fractions, the multivariant analysis and the calculation of OR, adjusted to qualitative variables and the comparison of means for quantitative variables, are used in the analysis. The programme SAS is used as a software.

The prevalence of cancer found was 0.938 per one thousand women and the frequency of precursory lesions was 38.2 per one thousand. The comparative study with regard to different variables between women with benign deteriorations or normality and women presenting a diagnosis of premalignant lesions or carcinoma, proves that, without existing differences in relation to age, beginning of sexual relations ans number of pregnancies, the risk of suffering from cervix cancer increases with sexual promiscuity, exposition to Rx, genital infections, mycosis and infertility.

On the basis of the prevalence detected, it is considered necessary keep and to increase the coverage of actions of cervix cancer prevention in women, increasing the participation of the whole of sexually active women in the programmes. The presence of risk factor would modify the number and periodicity of gynecological controls.