The value of screening as an approach to cervical cancer control in Iceland, 1964-1986.

The effect of screening for cervical cancer on time trends in incidence and mortality from that disease, and the occurrence of pre-invasive cervical lesions during the period 1964-1986, were analyzed. After commencement of screening in 1964 all the above parameters increased for a short initial period but then fell markedly. From 1980, coinciding with a sharp rise in regular attendance rate, there was an increase in incidence up to 1984, followed by a decrease. The rate of pre-invasive stages also increased from 1980, but appears to be levelling off. The cervical cancer mortality rate decreased significantly during the study period. In more recent years, a shift in the occurrence of cervical cancer and pre-invasive lesions from older to younger women has been observed. Screening still appears to be effective in the control of squamous-cell carcinomas of stages I B and over, but not of adeno- and adenosquamous carcinomas.