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Prostate cancer (PrCa) is a significant public health problem. In the European Union, approximately 200 000 men are diagnosed annually with the disease. There are 35 515 cases (Cancer Research UK, 2009a) per year in the United Kingdom and 10 239 deaths (Cancer Research UK, 2009b). It is now the commonest male non-cutaneous cancer diagnosed in the United Kingdom; the lifetime risk of being diagnosed with PrCa is 1 in 10 (Cancer Research UK, 2009a). Although the increase in population screening is leading to an increase in diagnosis, many men will not develop aggressive disease. However, it is recognised that some PrCa cases have a particularly poor prognosis. Although there are some histological and stage predictors of prognosis (Kattan and Scardino, 2002), until recently, none of them have been related to inherited factors. Multiple aetiologies have been proposed to contribute to the development of PrCa. There is strong evidence that inherited genetic factors are important and exhibit significant familial aggregation in some men, particularly when affected at a young age (Woolf, 1960; Edwards and Eeles, 2004). There is a recognised association of breast cancer with PrCa in families (Thiessen, 1974; Anderson and Badzioch, 1992; Tulinius et al, 1992). Male relatives in breast cancer families in Iceland have a 2–3-fold risk of PrCa (Sigurdsson et al, 1997). The breast cancer predisposition genes BRCA1 and BRCA2 have been reported to increase the risk of PrCa by three-fold and seven-fold, respectively, in male mutation carriers ascertained through a family history of breast cancer (Ford et al, 1994; Struewing et al, 1997; Breast Cancer Linkage Consortium, 1999). Analyses of PrCa relative risks (RR) in male mutation carriers in breast cancer families from the Breast Cancer Linkage Consortium showed an RR of 4.65 (95% CI: 3.48–6.22) of PrCa in male BRCA2 mutation carriers (the RR is 7.33 below the age of 65 years) and of 1.07 (0.75–1.54) in BRCA1 carriers (with an RR of 1.82 (1.01–3.29) for men under 65 years of age) (Thompson and Easton, 2001, 2002). The estimated cumulative incidence of PrCa by the age of 70 years is 7.5–33%. Recent studies have suggested that the risk of PrCa in BRCA2 mutation carriers may be as high as an RR of 23-fold at age 60 years (Edwards et al, 2003). Studies from Iceland have reported that germline mutations in BRCA2 may be involved not only in susceptibility to PrCa but also in the aggressiveness of the disease (Sigurdsson et al, 1997; Tryggvadottir et al, 2007). However, these individuals all carried a common founder mutation (999del5 in BRCA2). Narod et al (2008) have reported that PrCa survival in BRCA2 mutation carriers is much shorter (median survival from diagnosis was 4 years) when compared with BRCA1 carriers' survival (median survival from diagnosis was 8 years). In PrCa, in which the BRCA2 germline mutation status was unknown, allele loss at the BRCA2 locus has been shown to be a prognostic factor for survival on univariate analysis (Edwards et al, 1998), and loss of the wild-type allele would imply a tumour suppressor mechanism in predisposition to this disease in BRCA2 mutation carriers, but it is not known whether this is a surrogate for high grade or is due to mutation per se (Knudson, 1971; Willems et al, 2008). A BRCA2 genomic screening study has previously been undertaken by ourselves, and six potentially pathogenic germline BRCA2 mutations were found in a set of 263 PrCa patients diagnosed at ⩽55 years (2.3%) (Edwards et al, 2003). In this study we report clinical follow-up data and the results of loss of heterozygosity (LOH) analyses on PrCa tumours from the mutation carriers in this report. We then studied a second validation data set of men with germline mutations in the BRCA2 gene from a cancer genetics clinic and assessed their survival to confirm our results in a different UK data set of male BRCA2 mutation carriers with PrCa.