Malignant ovarian tumours in childhood in Britain, 1962-78.

The files of the Childhood Cancer Research Group and of the Oxford Survey of Childhood Cancers were scrutinized for all the ovarian neoplasms registered in England, Scotland and Wales in children under age 15 years throughout the period 1962-78. Among 172 cases confirmed as malignant ovarian tumours, 145 (84%) were tumours of germ cell origin (54 dysgerminomas, 36 malignant teratomas, 26 endodermal sinus tumours, 4 embryonal carcinomas, 2 pure choriocarcinomas, 20 mixed germ cell neoplasms, 3 gonadoblastomas), 13 (8%) were epithelial carcinomas (3 serous or undifferentiated, 10 mucinous), 9 (5%) were sex-cord stromal tumours (3 granulosa cell, 3 Sertoli-Leydig, 3 unclassified) and 5 (3%) were other miscellaneous tumour types. Less than 10% of the neoplasms occurred at age less than 5 years, approximately 20% from 5-9, and greater than 70% from 10-14 years. Germ cell neoplasms of greater malignancy (immature teratomas, endodermal sinus tumours) occurred in a significantly higher proportion at younger age (less than 10 years) than dysgerminomas (P = 0.01). The overall incidence (approximately 1.7 cases per 10(6) per annum) did not show any noticeable trend over the 17-year period considered. The clustering of two confined cases and, possibly, a third case, of germ cell neoplasms in three generations of the same family pointed to a genetic component in the aetiology of some of these neoplasms. A large number of sex related and mental or neurological abnormalities was also reported in case children. The 10-year survival rates, determined by the life-table method were: epithelial carcinomas 73%, sex-cord stromal tumours 44%, dysgerminomas 73%, malignant teratomas 33%, endodermal sinus tumours 39%, embryonal carcinomas 25%, other germ cell neoplasms 30% and gonadoblastomas 100%. Apart from cell-type, factors associated with prognosis were clinical stage (in all types), size and degree of histological differentiation (in malignant teratomas, but only when stage was not allowed for). The adoption of efficacious polychemotherapy regimens completely changed the prognosis of germ cell tumours other than dysgerminomas (from 29% to greater than 85% disease-free survivors in the present series).