1.   Incidence of second primary tumours among childhood cancer survivors.

2.   With the exception of computed tomography most radiological investigations can not identify the primary tumour in metastatic disease of unknown origin.

3.   It is not the primary tumour that kills, but secondary growths elsewhere in the body.

4.   DNA ploidy significantly correlated with the invasion of the primary tumour.

5.   Patients and their relatives in category D are clearly at greatly increased risk of a first or subsequent primary tumour and need life-time surveillance.