Epidemiology and pathogenesis of cervical cancer

Abstract

The majority of the estimated incidence of 471,000 new cases for invasive cervical cancer (CX) and 215,000 cancer deaths occurs in the developing countries. For Germany the CX accounts at 8th position of all cancers in women in 1997 with 5,800 newly diagnosed cases. But, every fourth woman between 25th- and 35th-year of life has been affected by CX. This counts at the upper third of the incidence in the European Union (EU). The estimated loss of live-years for women affected by CX is about nine years. The lethality for all stages of invasive cervical cancer is about 30%. For the last two decades stagnation of the reduction of mortality by CX has been reported for EU and the USA, especially affecting woman up to 35th-year of life. The percentage of this age group of all primary operative treated CX at the Leipzig University Hospital between 1979 and 1999 was 26.2%, with a mean age of 43.4 +/- 11.1 years. Improved screening for CX in the western countries and a change in environmental factors have been caused an increase of cervical precancerous (CIN-) lesions. The frequency of CIN-lesions has been estimated to be 100-times higher than the incidence of invasive cancer (21.1) in Germany. The pathogenesis of CX is multistage and CIN I and II represent highly regressive lesions, whereas CIN III requires therapeutic intervention, caused by high progression rate. The Bethesda-classification of low und high grade squamous intraepithelial lesions (SIL) cannot be recommended for biopsies or conisation specimens. Dsyplastic lesions of endocervical columnar epithelium should not be graded, the only general accepted lesion represents the adenocarcinoma in situ (ACIS). Both, CIN and ACIS represents proliferative active lesions, caused by infection with HPV. But the detection of morphologic alterations, associated with HPV, like koilocytes, are inverse correlated with the grade of the CIN-lesion.