Malignant epithelial tumours in children: incidence and aetiology.

The purpose of this study was to establish the incidence of carcinomas in children, changes in incidence over a 30-year period, and to identify features of possible aetiological significance. A total of 173 cases were identified, but after review of the histopathology, 30 patients were excluded because they were considered to have benign epithelial tumours or malignant tumours of nonepithelial origin. Seven other cases were excluded because pathology material was not available. Overall, in 28% of cases, the diagnoses were changed by pathology review. Thus, 136 children in the West Midlands Region diagnosed 1957-1986 were included, with carcinoid tumours (44) and tumours of skin (22), nasopharynx (14), salivary gland (13), adrenal cortex (13), thyroid (9), large bowel (5), other (16). Excluding carcinoids, the age-standardised incidence rate was 2.4 x 10(6) per year. Male:female ratio was 0.7:1 and 66% were aged > 10 years. Incidence increased from 1.5 to 3.3 x 10(6) per year. Genetic factors predisposing to carcinoma included tyrosinosis, MEN II and III, congenital adrenal hyperplasia and basal cell naevus syndrome. There was a case of Li-Fraumeni syndrome and several other patients had relevant family histories. Probable "environmental" causes included antenatal exposure to stilboestrol or hydroxyprogesterone hexanoate, stilboestrol given for premature menarche, neonatal hepatitis and prior radiotherapy. The aetiology of carcinomas in children is multifactorial, both genetic and environmental factors being important. The incidence is increasing.