Childhood and adolescent ovarian malignant tumors in Israel - A nationwidestudy

Objectives. To determine the incidence of ovarian malignant tumors in child hood and adolescence, to ascertain the frequency distribution of the variou s tumor types and to assess time trends in Israel on a nationwide basis. Methods. The study group included all Israeli Jewish patients less than or equal to 19 years old with histologically confirmed ovarian malignancies, d iagnosed in Israel from 1970 to 1994. Data were obtained from the Israel Ca ncer Registry. The effects of age at diagnosis and period of diagnosis were analyzed using the Poisson regression. Results. Among the 82 patients identified, the most frequent tumors (72.0%) were of germ cell origin and among those about one third were dysgerminoma s. Epithelial tumors were diagnosed in 26.6% of the patients and most of th ese were borderline malignancies. The incidence rate (IR) for the total gro up of ovarian malignancies in the 0-19 age group was 0.52 and for ages 5-19 it was 0.71 per 100,000. After adjustment for age, a significant linear tr end for a decrease of germ cell tumors over time was found, stemming from a decrease of dysgerminomas. A significant trend for increase in the IRs wit h age was also found. In addition, a steep rise in the age specific IRs of epithelial borderline tumors was noted in the last 5 year period. Conclusions. The IRs of ovarian malignancies in childhood and adolescence i n Israel, as in other countries, is very low as compared to adults and the most common tumors are of germ cell origin while malignant epithelial tumor s are very rare. A time period effect in the germ cell tumors that resulted from an inexplicable significant decrease in the age specific IRs of dysge rminomas, was observed. A significant increase in borderline tumors was als o noted and may be attributed to greater awareness of pathologists to this entity.