Study, year	Patients (N)	Outcomes
Couch, 1996 [4]	50	-Study design: germline DNA from 50 MBC cases (unselected for family history) analyzed for mutations in BRCA2 -9 disease-associated mutations detected, with 7 of 9 seen in the 50 MBC cases -BRCA2 mutations estimated to account for 14% of MBC, all but one of which had a family history of male and/or female breast cancer
Thorlacius, 1996 [2]	9	-Study design: 9 families with a history of MBC studied to determine linkage between BRCA2 and hereditary MBC -Among mutation carriers, there are 12 MBC cases, accounting for 40% of all males diagnosed with breast cancer in Iceland over the past 40 years -3 (25%) of the 12 cases had no family history of breast cancer (no statistical significance reported)
Friedman, 1997 [3]	54	-Study design: population-based series of 54 MBC cases analyzed for germline mutations in BRCA1/2 -No germline BRCA1 mutations found -2 (4%) MBC cases carried truncating BRCA2 mutations, and only 1 of those carrying a mutation had a family history of cancer (ovarian cancer in a first-degree relative)
Mavraki, 1997 [11]	26	-Study design: screening of DNA from 26 MBC cases to determine the frequency of BRCA2 germline mutations -BRCA2 mutation detected in 3 (12%) out of 26 cases -3 mutations resulting in frameshifts and premature termination of translation identified
Haraldsson, 1998 [1]	34	-Study design: the coding region of the BRCA2 and AR genes in breast tumors from 34 MBC patients were analyzed -No cases of germline AR mutations were observed, but the number of AR polyglutamine repeats were lower among BRCA mutation carriers -5 different BRCA2 germline mutations were seen in 7 (20.6%) of the 34 cases, all of which resulted in the formation of truncated protein products
Csokay, 1999 [9]	18	-Study design: a series of 18 MBC patients analyzed for germ-line mutations in BRCA1/2 -No germline BRCA1mutation was observed -6 (33%) of the 18 MBC cases carried truncating mutations in the BRCA2gene and none of them reported a family history for breast/ ovarian cancer -4 (22%) patients had a family history of breast/ovarian cancer in ≥1 firstor second-degree relative; no BRCA2mutation was detected among them
Young, 2000 [5]	145	-Study design: case-control study of 64 cases and 81 controls to investigate whether increased length of CAG repeat sequence in AR is associated with development of MBC -There was no statistical significance in the distribution of CAG repeats in AR among MBC cases and controls (p = 0.916) -No difference between median CAG repeat length of cases and controls (p = 0.765) -Sequences of ≥30 repeats were found only among cases
Basham, 2002 [22]	94	-Study design: population-based study of 94 MBC aimed to establish to prevalence of BRCA1 and BRCA2 mutations -No disease-associated mutations were identified in BRCA1 -5 disease-associated variants were seen in BRCA2 -The carrier frequency of BRCA2 mutations was 6% (95% CI: 2 - 13)
Frank, 2002 [33]	76	-Study design: prevalence of germline mutations in BRCA1/2 analyzed in 76 MBC cases -Deleterious mutations were seen in 21 (28%) of 76 cases, with 8 mutations occurring in BRCA1 and 14 in BRCA2(one Ashkenazi individual had one mutation in each gene) -No statistical significance in mutation prevalence in men with a family history of breast or ovarian cancer versus those without -No statistical significance in mutation prevalence in MBC patients of Ashkenazi ancestry compared with those of non-Ashkenazi ancestry
Meijers-Heijboer, 2002 [29]	2691	-Study design: genome-wide linkage search of 718 families in which breast cancer susceptibility is not due to BRCA mutation -CHEK21100delC variant in 13.5% of patients from families with MBC (p = 0.00015) -CHEK21100delC variant results in an ~10-fold increase of MBC risk in non-carriers of BRCA1 and BRCA2 mutations (statistical significance not reported) -9% of MBC cases attributable to CHEK2*1100delC (statistical significance not reported)