Associated cancers in parents and offspring of polycythaemia vera and myelofibrosis patients.

Polycythaemia vera (PV) and primary myelofibrosis (MF) show concordant familial clustering but limited population level data are available on the aggregation of other discordant neoplasms in these families. We used the Swedish Family-Cancer Database to assess risks for VP and MF in families of cancer patients. A total of 3530 first PV and 1606 MF patients were identified, with high concordant familial risks. Several discordant familial associations were found for PV (acute myeloid leukaemia, Hodgkin disease, prostate and bladder cancers) or for MF (chronic lymphatic leukaemia, colorectal, kidney and cervical cancers) or for both (nervous system, eye and endocrine tumours).