Basal fell carcinoma (BCC) is the most common malignant skin tumour. T
here is evidence that the number of patients who develop more than one
basal cell carcinoma (mBCC) is increasing. The aim of this study was
to elucidate possible risk factors for developing mBCC. Among twelve r
isk factors considered, skin tumour among relatives was the strongest,
with an odds ratio of 10.9 (p < 0.001). The second strongest risk fac
tor was sunburn after the age of 60, odds ratio 4.4 (p < 0.001). The r
esults suggest that the presence of skin tumour in the family and sunb
urn after age 60 are independent factors associated with mBCC. To our
knowledge this has not previously been reported.