HLA-DQB1-ASTERISK-0303 AND ASTERISK-0301 ALLELES INFLUENCE SUSCEPTIBILITY TO AND PROGNOSIS IN CUTANEOUS MALIGNANT-MELANOMA IN THE BRITISH CAUCASIAN POPULATION

The presence of lymphocytic infiltrates within primary cutaneous malig nant melanoma (CMM), documented spontaneous tumour regression and gene tic linkage with chromosome six in familial cases all suggest that imm unogenetic factors may modulate disease progression An association has been suggested between HLA DQB10301 and CMM in US patients but no su ch investigation has been performed in the UK population. Polymerase c hain reaction-based HLA class II DRB1, DQA1 and DQB1 typing of 99 UK-b ased CMM patients was performed using DNA extracted from archival form alin-fixed and paraffin max-embedded surgical biopsies, enabling retro spective access to clinical follow-up data. An increase in frequency o f the HLA DQB10303 genotype among CMM patients was identified compare d to control subjects (19.2% vs 5.8%; P-c = 0.003; RR = 3.9) while HLA DQB10301 was associated with more advanced and therefore poorer prog nosis primary tumours (e.g. HLA DQB10301 allele frequency: 20.1% vert ical growth phase vs 4.0% horizontal growth phase; P-c = 0.03; RR = 6. 1). These findings suggest that the HLA DQB1 locus, and in particular the HLA DQB10303 and *0301 alleles, may play an important role in det ermining the risk of development and the prognosis of CMM within the U K population.