Genetic variation in genes interacting with BRCA1/2 and risk of breast cancer in the Cypriot population.

Inability to correctly repair DNA damage is known to play a role in the development of breast cancer. Single nucleotide polymorphisms (SNPs) of DNA repair genes have been identified, which modify the DNA repair capacity, which in turn may affect the risk of developing breast cancer. To assess whether alterations in DNA repair genes contribute to breast cancer, we genotyped 62 SNPs in 29 genes in 1,109 Cypriot women with breast cancer and 1,177 age-matched healthy controls. Five SNPs were associated with breast cancer. SNPs rs13312840 and rs769416 in the NBS1 gene were associated with a decrease in breast cancer risk (OR TT vs. TC/CC = 0.58; 95% CI, 0.37-0.92; P = 0.019 and OR GG vs. GT/TT = 0.23, 95% CI 0.06-0.85, P = 0.017, respectively). The variant allele of MRE11A rs556477 was also associated with a reduced risk of developing the disease (OR AA vs. AG/GG = 0.76; 95% CI, 0.64-0.91; P = 0.0022). MUS81 rs545500 and PBOV1 rs6927706 SNPs were associated with an increased risk of developing breast cancer (OR GG vs. GC/CC = 1.21, 95% CI, 1.02-1.45; P = 0.031; OR AA vs. AG/GG = 1.53, 95% CI, 1.07-2.18; P = 0.019, respectively). Finally, haplotype-based tests identified significant associations between specific haplotypes in MRE11A and NBS1 genes and breast cancer risk. Further large-scale studies are needed to confirm these results.

An investigation of breast cancer risk factors in Cyprus: a case control study.

BACKGROUND: Breast cancer is the most common form of malignancy affecting women worldwide. It is also the leading cancer in females in Cyprus, with approximately 400 new cases diagnosed annually. It is well recognized that genetic variation as well as environmental factors modulate breast cancer risk. The main aim of this study was to assess the strength of associations between recognized risk factors and breast cancer among Cypriot women. This is the first epidemiological investigation on risk factors of breast cancer among the Cypriot female population. METHODS: We carried out a case-control study, involving 1,109 breast cancer patients and a group of 1,177 controls who were recruited while participating in the National screening programme for breast cancer. Information on demographic characteristics and potential risk factors were collected from both groups during a standardized interview. Logistic regression analysis was used to assess the strength of the association between each risk factor and breast cancer risk, before and after adjusting for the possible confounding effect of other factors. RESULTS: In multivariable models, family history of breast cancer (OR 1.64, 95% CI 1.23, 2.19) was the strongest predictor of breast cancer risk in the Cypriot population. Late menarche (OR 0.64, 95% CI 0.45, 0.92 among women reaching menarche after the age of 15 vs. before the age of 12) and breastfeeding (OR 0.74, 95% CI 0.59, 0.92) exhibited a strong protective effect. In the case of breastfeeding, the observed effect appeared stronger than the effect of pregnancy alone. Surprisingly, we also observed an inverse association between hormone replacement therapy (HRT) although this may be a product of the retrospective nature of this study. CONCLUSION: Overall the findings of our study corroborate with the results of previous investigations on descriptive epidemiology of risk factors for breast cancer. This investigation provides important background information for designing detailed studies that aim to improve our understanding of the epidemiology of breast cancer in the Cypriot population, including the study of gene-environment interactions. Furthermore, our study provides the first scientific evidence for formulating targeted campaigns for prevention and early diagnosis of breast cancer in Cyprus.

DNA-repair genetic polymorphisms and risk of breast cancer in Cyprus.

The DNA repair pathway is known to play a role in the etiology of breast cancer. A number of studies have demonstrated that common germline variants in genes involved in the DNA repair pathway influence breast cancer risk. To assess whether alterations in DNA repair genes contribute to breast cancer, we genotyped 12 single nucleotide polymorphisms (SNPs) in 1,109 Cypriot women with breast cancer and 1,177 age-matched healthy controls. We found significant associations with breast cancer for SNPs in the BRCA2 and MRE11A genes. Carriers of the BRCA2 rs1799944 variant (991 Asp) were found to have an increased risk of breast cancer (OR = 1.41, 95% CI 1.08-1.83, P = 0.01) with P (trend) = 0.0076. Homozygous carriers of the MRE11A rs601341 A allele had an increased risk of breast cancer (OR = 1.36, 95% CI 1.08-1.71, P = 0.009) with P (trend) = 0.0087. This study suggests that genetic variants in BRCA2 and MRE11A are associated with breast cancer risk.

Genetic polymorphisms in the DNA repair genes XRCC1, XRCC2 and XRCC3 and risk of breast cancer in Cyprus.

Population-based studies have reported significant associations between specific genetic polymorphisms and breast cancer susceptibility. A number of studies have demonstrated that common variants of genes involved in the DNA repair pathway act as low penetrance breast cancer susceptibility alleles. We aimed to investigate the association of single nucleotide polymorphisms (SNPs) in the DNA repair genes XRCC1, XRCC2 and XRCC3 and breast cancer in MASTOS, a population-based case-control study of 1,109 Cypriot women with breast cancer diagnosed between 40 and 70 years and 1,177 age-matched healthy controls. Five coding SNPs were genotyped including rs1799782, rs25489 and rs25487 in XRCC1, rs3218536 in XRCC2 and rs861539 in XRCC3. Homozygous XRCC1 280His carriers had an increased risk of breast cancer (odds ratio 4.68; 95% CI 1.01-21.7; P = 0.03). The XRCC2 188His allele was associated with a marginal protective effect for breast cancer (odds ratio 0.79; 95% CI 0.62-1.00; P = 0.05). No significant associations were observed between the other three SNPs and breast cancer. This study suggests that genetic variation in SNPs in XRCC1 and XRCC2 genes may influence breast cancer susceptibility.

Incidence of thin basement membrane nephropathy in 990 consecutive renal biopsies examined with electron microscopy.

Thin basement membrane nephropathy is one of the main causes of hematuria in both children and adults. It is often associated with a family history and its true incidence is unknown. Accurate diagnosis of thin basement membrane nephropathy relies on the presence of attenuated glomerular basement membranes, a finding that can be appreciated only by examination in the electron microscope. In Cyprus the department of electron microscopy has received 990 consecutive renal biopsies for diagnosis. The aim of this study is to define the incidence of thin basement membrane nephropathy in this population sample based on the results of electron microscopy.