EXPRESSION OF MUTANT P53 GENE IN SQUAMOUS CARCINOMA ARISING IN PATIENTS WITH RECESSIVE DYSTROPHIC EPIDERMOLYSIS-BULLOSA

Epidermolysis bullosa, a rare genodermatosis, is characterized by incr eased skin fragility manifest as blistering and sometimes accompanied by scarring. The latter is particularly severe in the recessive dystro phic variant and may be complicated by the development of squamous car cinoma in up to 30% of patients. We have studied 23 such tumours in si x patients with this variant, with an anti-serum to p53 protein. Twent y-six per cent of the squamous carcinomas labelled positively for muta nt-type p53 protein. This low figure, however, reflects the large numb er of well-differentiated tumours in this series, where 14 out of 15 w ere negative. In the moderate to poorly differentiated examples the po sitivity rate was 63%. Of the three patients in the latter category, o ne has died from disseminated tumour and another has wide-spread metas tases. The findings support the hypothesis that mutant p53 protein exp ression correlates with poorer tumour differentiation. They also sugge st a possible correlation between p53 protein expression and tumour be haviour.