Changing incidence and geographical distribution of malignant paediatric germ cell tumours in the West Midlands Health Authority region, 1957-92.

The West Midlands Regional Children's Tumour Research Group holds high-quality data from 1957 on all childhood cancers in the West Midlands Health Authority region. Since it has been reported that malignant germ cell tumours are increasing in incidence in the north-west of England, we undertook to examine rates in this region and to map the distribution of cases in order to assess any geographical changes in incidence rates. We identified a total of 102 malignant germ cell tumours (MGCTs) between 1957 and 1992. The average age-standardised rate was 1.6 per million per year in the period 1957-74 and 3.6 per million per year during 1975-92, a significant increase (P = 0.0004). Particular increases were noted in older children (10-14 years); P = 0.0002) and in yolk sac (endodermal sinus) tumours (P = 0.004). A small excess was also observed in Asian children when compared with other diagnoses. Geographical analysis showed particularly higher rates at health district level in the West Midlands conurbation as compared with the other areas in the period 1975-92. These factors suggest the possibility that industrial/urban or population effects may be implicated in the observed increase in childhood MGCT and we recommend these areas for further studies.