Association of porphyria cutanea tarda and primary liver cancer: report of ten cases.

Studies of the association between porphyria cutanea tarda (PCT) and primary liver cancer have produced conflicting reports. The incidence of this liver tumor was studied in 138 PCT patients (7.2%) and in 358 non-porphyric cirrhotic patients (5.6%), and no statistically significant differences were found between them (p>0.5). Nevertheless the incidence of such association was significantly higher (chi square=10.91, p<0.001) in the PCT group (24.3%) than in the non-porphyric cirrhotic group (6.7%) when only males with underlying liver cirrhosis were considered. These results suggest that the high incidence of liver tumor in PCT is not merely related to hepatic cirrhosis. The cause of such as association remains unclear. Primary liver cancer may reveal a prior deficiency in uroporphyrinogen-decarboxylase, but the possibility that the enzyme abnormalities were caused by the liver carcinoma also exists.