Mass screening in Sweden for cancer of the uterine cervix. Results and epidemiologic effect.

The mass screening program in Sweden for cancer of the uterine cervix, which was started in 1964, is now almost nation-wide. Approximately a quarter of a million women are screened every year. The attendance varies between 55 and 90%. Approximately two per cent of the screened female population is invited to further examination or treatment. The yield through the mass screening program varies between 3.5 and 10 positive cases per 1000 examined women. The incidence of cancer of cervix is decreasing. This is most evident in those counties, which have been carrying out the screening program for about ten years. The stage distribution in cancer of the cervix has not been changed by the screening program. Mortality in cancer of the cervix is unchanged. There has been an enormous increase in the number of diagnosis of cancer in situ of the cervix, which is a difficult practical problem.