Lessons from the hepatoblastoma-familial polyposis connection.

BACKGROUND Approximately one-third of hepatoblastoma (HB) patients have associated congenital abnormalities, but familial recurrence is rare, except in association with familial adenomatous polyposis (FAP). This correlation may be missed if not actively sought, with implications for long-term outcome and management. METHODS We retrospectively investigated 3 families with an HB-familial polyposis connection, from a cohort of 113 FAP families (1989 - 2010). Data were analysed to assess clinical problem, treatment, complications and management. Long-term morbidity and functional outcome were analysed to identify management difficulties. RESULTS Three FAP families (2.65%) had an HB association. In one case, undiagnosed FAP at the time of HB diagnosis was only detected 5 years later, when the mother presented with advanced colorectal carcinoma. A chromosome 5 APC gene mutation (exon 15 codon 793 C→T) was then identified. In a second case, a non-related male child presented with a stage 4 multifocal HB with lung metastases. Genetic studies identified an APC gene mutation (exon 6 codon 232 C→T). Further family investigation showed >20 related FAP patients. A third HB-FAP association was identified in a known FAP family early in the study, prior to the availability of genetic testing. CONCLUSION Although a rare association, a family history of FAP in HB patients is an important 'hidden connection'. Germline variation may be outside the usual FAP gene site. Identifying families with unknown HB/FAP is important due to long-term management implications and follow-up.