Survival of children with thyroid cancer in Europe 1978--1989.

Thyroid cancers are rare in childhood with between 0.4 and 1.5 cases per million, 2--3 times as frequent in girls as in boys. However, following the Chernobyl accident, a remarkable incidence increase was observed in children exposed to radioactive iodine fall-out. Survival after thyroid cancer in childhood is thus of interest. In the EUROCARE II study, excluding most of Eastern Europe, a total of 165 childhood thyroid cancers were reported during the period 1978--1989, of which 134 were aged 10--14 years. The childhood cancer registry in England and Wales contributed 39% of the cases, and another 24% came from the Nordic countries, the rest from other parts of west, south, east and central Europe. The 5-year survival was for both genders combined 97% (95% confidence interval (CI): 93--99), 98% (95% CI: 91--100) for boys and 97% (95% CI: 91--99) for girls, with no significant difference between the genders. Survival was high during the entire study period, and variations influenced by the small numbers. As for adults, long-term follow-up beyond 10--20 years is needed to clearly demonstrate excess mortality as a consequence of the cancer.