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).