Background:To establish the contribution of eight founder alleles in three DNA damage repair genes (BRCA1, CHEK2 and NBS1) to prostate cancer in Poland, and to measure the impact of these variants on survival among patients.Methods:Three thousand seven hundred fifty men with prostate cancer and 3956 cancer-free controls were genotyped for three founder alleles in BRCA1 (5382insC, 4153delA, C61G), four alleles in CHEK2 (1100delC, IVS2+1G>A, del5395, I157T), and one allele in NBS1 (657del5).Results:The NBS1 mutation was detected in 53 of 3750 unselected cases compared with 23 of 3956 (0.6%) controls (odds ratio (OR)=2.5; P=0.0003). A CHEK2 mutation was seen in 383 (10.2%) unselected cases and in 228 (5.8%) controls (OR=1.9; P<0.0001). Mutation of BRCA1 (three mutations combined) was not associated with the risk of prostate cancer (OR=0.9; P=0.8). In a subgroup analysis, the 4153delA mutation was associated with early-onset (age ⩽60 years) prostate cancer (OR=20.3, P=0.004). The mean follow-up was 54 months. Mortality was significantly worse for carriers of a NBS1 mutation than for non-carriers (HR=1.85; P=0.008). The 5-year survival for men with an NBS1 mutation was 49%, compared with 72% for mutation-negative cases.Conclusion:A mutation in NBS1 predisposes to aggressive prostate cancer. These data are relevant to the prospect of adapting personalised medicine to prostate cancer prevention and treatment.

Despite ongoing trials of PARP inhibitors in the treatment of breast cancer (BC), the extent of poly(ADP-ribose)polymerase-1 (PARP-1) protein expression in BCs, which may influence treatment results, is not known. The purpose of this report is to assess expression of PARP-1 in BC including BRCA1-associated, triple negative (TN), and basal-like tumors. Immunohistochemistry with a PARP-1 antibody on tissue microarrays from 130 BRCA1-associated and 594 BRCA1-non-related BCs was used. The vast majority of breast carcinomas expressed high level of nuclear PARP-1 protein and a small percentage of tumors exhibited both nuclear and cytoplasmic PARP-1 expression. There was a significant difference between the mean nuclear PARP-1 quickscore in BRCA1-associated versus BRCA1-non-associated carcinomas in all tumors (P < 0.0001), in the basal-like group (P = 0.0086), TN (P = 0.0015), and non-basal-like groups (P = 0.016) but not in the non-TN group. Among BRCA1-associated BCs, low PARP-1 expression was found in 18.5% of all cases, 18.9% of basal-like and 21% of TN cancers. Among BRCA1-non-related tumors, low PARP-1 expression was found in 8.8% of all cases, 3.1% of basal-like, and 2.7% of TN cancers. PARP-1 expression is significantly associated with BRCA1 status in basal-like and TN BCs. The assessment of PARP-1 expression in tumor samples may improve the selection of BC patients for PARP inhibitor therapy.

The 10-year survival rate among women with breast cancer and a BRCA1 mutation is similar to that of patients without a BRCA1 mutation. Among women with a BRCA1 mutation, survival was much improved after oophorectomy.

CHEK2 is a tumor suppressor gene whose functions are central to the induction of cell cycle arrest and apoptosis following DNA damage. Mutations in CHEK2 have been associated with cancers at many sites, including breast and prostate cancers, but the relationship between CHEK2 and gastric cancer has not been extensively studied. In Poland, there are four known founder alleles of CHEK2; three alleles are protein truncating (1100delC, IVS2G>A, del5395) and the other is a missense variant (I157T). We examined the frequencies of four Polish founder mutations in the CHEK2 gene in 658 unselected gastric cancer patients, in 154 familial gastric cancer patients and in 8,302 controls. A CHEK2 mutation was seen in 57 of 658 (8.7 %) unselected patients with gastric cancer compared to 480 of 8,302 (5.8 %) controls (OR 1.6, p = 0.004). A CHEK2 mutation was present in 19 of 154 (12.3 %) familial cases (OR = 2.3, p = 0.001). The odds ratio for early onset (<50 years) gastric cancer was higher (2.1, p = 0.01), than for cases diagnosed at age of 50 or above (OR 1.4, p = 0.05). Truncating mutations of CHEK2 were associated with higher risk (OR = 2.1, p = 0.02) than the missense mutation I157T (OR = 1.4, p = 0.04). CHEK2 mutations predispose to gastric cancer, in particular to young-onset cases.