Tumors in Iceland. 12. Malignant tumours of the corpus of the uterus. A histological classification, epidemiological considerations and survival.

All malignant tumours of the corpus of the uterus diagnosed in Iceland during 1955-1984 and available for review were typed histologically, using both the WHO Classification and the more recent classifications proposed by the International Society of Gynecological Pathologists. Of a total of 391 tumours 53 were excluded for various reasons. Of the 338 remaining tumours 309 were carcinomas, 17 sarcomas, 10 mixed Müllerian tumors and 2 choriocarcinomas. The adenocarcinomas were by far the most common of the carcinomas, comprising 93%. The incidence of carcinomas is similar to that found in the other Nordic Countries. A considerable increase in the incidence of adenocarcinomas was observed during the survey period and this was largely due to a steady steep rise in incidence of the best differentiated or Grade I tumours. This might be looked at as supportive evidence for the etiological role of estrogen replacement therapy which has been in constantly increasing use during the latter two decades of the study period. The mean age at diagnosis increased during the survey period. Generally, survival of patients did not clearly improve during the period but, however, increased considerably for the better differentiated tumours. Finally, we give our evaluation of the two systems of classification used in the study.