Medline ® Abstract for Reference 55

OBJECTIVES: To evaluate the benefit of screening for hepatocellular carcinoma (HCC) in gene carriers of acute intermittent porphyria (AIP) and estimate the annual incidence of HCC in this group.

SUBJECTS: All AIP gene carriers aged≥55 years from the northernmost county in Sweden, Norrbotten, were invited for screening in this prospective study every 1-1.5 years during the period 1994-2009. We registered all HCC cases amongst AIP gene carriers in the northern region of Sweden (four counties). We compared gene carriers with repeated screening intervals of<2 years (Group A) with controls (Group B; i.e. gene carriers who had never been screened, those screened for the first time or screened at intervals of>2 years, or dropouts). The screening included radiological examination of the liver and relevant laboratory tests.

RESULTS: A total of 62 AIP subjects participated in the study, comprising 33% of the total AIP population aged>55 years in the northern region of Sweden. HCC was diagnosed in 22 AIP subjects (12 men and 10 women), mean age 69 (59-82) years. Amongst these subjects, 73% had experienced prior AIP attacks. The incidence rate ratio for HCC was 64 (52 in men and 93 in women). There were no cases of hepatitis B/C or alcohol abuse. Liver cirrhosis was rare. Liver resection could be performed in most subjects in Group A. Fourteen patients died of HCC, one in Group A and 13 in Group B. Compared with those who were not screened regularly, screening was associated with improved 3-year and 5-year survival (P = 0.005 and 0.038).

CONCLUSIONS: Screening for HCC in carriers of AIP enables early diagnosis and a choice of potentially curative treatments with improved prognosis. We recommend annual screening using liver imaging for AIP gene carriers>50 years of age.