HLA phenotype and clinicopathological behaviour of germ cell tumours: possible evidence for clonal evolution from seminomas to nonseminomas.

Analysis of 101 patients with germ cell tumours of the testis who have been typed for HLA DR antigens has provided confirmatory evidence for an association of DR5 with the development of seminoma and demonstrated an association of DR7 with metastases. These observations taken with the suggestion of HLA linkage in the small numbers of familial cases reviewed, does suggest that there is an HLA linked gene involved in the clinicopathological behaviour of germ cell tumours. Though of only theoretical interest at present these observations may be of considerable importance in the future given the observation in mice that transfection of missing MHC genes into a malignant tumour can produce a vaccine that enables previously unexposed animals to resist the original malignant tumour (Hui et al., 1984).