Nationwide study of clinical and molecular features of hereditary non-polyposis colorectal cancer (HNPCC) in Latvia

Background: The mutational spectrum of mismatch repair (MMR) genes in the Baltic States has been reported to be quite similar to that in Poland; however during a country-wide study considerable differences in the population of Latvia were discovered. This study was undertaken to investigate the clinical and molecular features of HNPCC in Latvia. Materials and Methods: Family cancer histories were collected, from January 2000 until October 2003, for 702 consecutive hospital based colorectal cancer (CRC) cases. In families suspected of having a history consistent with hereditary non-polyposis colorectal cancer (HNPCC), DNA testing for MLH1, MSH2 and MSH6 genes was performed. Immunohistochemical examination of the normal and the cancer tissue from large bowel tumors was undertaken for MSH2 and MSH6 protein expression in 182 out of 702 (26%) of the cases. Results: Among the 702 CRC patients only 1 (0.14%) fulfilled the Amsterdam criteria. Thirteen (1.9%) cases matched the criteria for suspected HNPCC and 10 (1.4%) cases matched the late onset HNPCC criteria. Altogether in 7 out of 702 (1%) cases MMR gene mutations were detected: 2 in MLH1, 3 in MSH2 and 2 in MSH6 gene. Only one out of the seven mutations was registered in the Human Genome Mutation Database and the ICG (International Collaborational Group)-HNPCC mutation data base. Negative MSH2 and MSH6 protein expression was detected in 4 (2.2%) and 18 out of 182 (9.9%) cases respectively. Conclusion: The role of the classical Amsterdam criteria in diagnosing HNPCC in CRC patients from Latvia is very limited and diagnostic criteria for suspected HNPCC are the most effective. The frequency of constitutional mutations within the MMR genes is 1% of all newly diagnosed CRC cases and the spectrum of mutations is potentially characteristic.Peer reviewe

Ovarian cancer risk in Polish BRCA1 mutation carriers is not associated with the prohibitin 3' untranslated region polymorphism

<p>Abstract</p> <p>Background</p> <p>The variable penetrance of ovarian cancer in <it>BRCA1 </it>mutation carriers suggests that other genetic or environmental factors modify disease risk. The C to T transition in the 3' untranslated region of the prohibitin (<it>PHB</it>) gene alters mRNA function and has recently been shown to be associated with hereditary breast cancer risk in Polish women harbouring <it>BRCA1 </it>mutations.</p> <p>Methods</p> <p>To investigate whether the <it>PHB </it>3'UTR polymorphism also modifies hereditary ovarian cancer risk, we performed a case-control study among Polish women carrying one of the three common founder mutations (5382insC, 300 T > G, 4154delA) including 127 ovarian cases and 127 unaffected controls who had both breasts and ovaries intact. Controls were matched to cases by year of birth and <it>BRCA1 </it>mutation. Genotyping analysis was performed using PCR-based restriction fragment length polymorphism analysis. Odds ratios (OR) were calculated using conditional and penalized univariable and multivariable logistic regression.</p> <p>Results</p> <p>A comparison of the genotype frequencies between cases and controls revealed no association of the <it>PHB </it>3'UTR _CT+TT genotypes with ovarian cancer risk (OR_adj1.34; 95% CI, 0.59–3.11).</p> <p>Conclusion</p> <p>Our data suggest that the <it>PHB </it>3'UTR polymorphism does not modify ovarian cancer risk in women carrying one of the three Polish <it>BRCA1 </it>founder mutations.</p

First recurrent large genomic rearrangement in the BRCA1 gene found in Poland

Mutation in the <i>BRCA1</i> gene increases the risk of the person developing breast and/or ovarian cancer. The prevalence and spectrum of large genomic rearrangements (LGRs) varies considerably among different tested populations. In our previous study we described three LGRs in <i>BRCA1</i> (exons 13-19, exon 17 and exon 22) in Polish families at high risk of breast and ovarian cancer. In this study we analyzed a group of 550 unselected women with ovarian cancer for the three previously identified LGRs. We used a rapid, single-step and closed-tube method: high-resolution melting analysis (HRMA). In this group of unrelated patients diagnosed with ovarian cancer we found three cases with the same deletions of exon 22. This is the first recurrent large deletion in <i>BRCA1</i> found in Poland. We conclude that screening for the exon 22 deletion in <i>BRCA1</i> should be included in the Polish <i>BRCA1</i> genetic testing panel and possibly extended into other Slavic populations

The VEGF_936_C > T 3 ' UTR polymorphism reduces BRCA1-associated breast cancer risk in Polish women

The vascular endothelial growth factor (VEGF) plays a crucial role in the initiation of angiogenesis, which is an important stage in tumor development. A functional 936_C>T polymorphism in the VEGF gene and its association with sporadic breast cancer risk has been analyzed in various studies yielding conflicting results. To analyze the role of this polymorphism in modifying hereditary breast and ovarian cancer risks, we conducted a case-control study and genotyped 755 Polish BRCA1 carriers, including 319 breast cancer cases, 146 ovarian cancer cases, and 290 unaffected controls. The results revealed an association of the CT + TT genotypes with a reduced breast cancer risk (ORadj 0.63, 95% CI, 0.41-0.98; ORclustered 0.63, 95% CI, 0.48-0.83), and a potential effect on ovarian cancer risk (ORadj 0.62, 95% CI, 0.33-1.18; ORclustered 0.62, 95% CI, 0.47-0.83). Thus, the 936_C>T polymorphism appears to modify disease risks in BRCA1 carriers

Low prevalence of CDKN2A/ARF mutations among early-onset cancers of breast, pancreas and malignant melanoma in Poland

In this report the contribution of CDKN2A/ARF germline mutations to early-onset cancers of the breast, pancreas and malignant melanoma was examined. We screened 66 women with breast cancer diagnosed at age 30 and below, 72 melanoma patients with the median age at diagnosis ≤40 years and 51 pancreatic cancer patients diagnosed under the age of 50 years. In the total set of 189 patients we found a novel change Pro48Arg (nt 143 c>g), a novel intronic change IVS1+36 g>c and two common variants A148T and IVS3+29 c>g. The results of this study revealed a paucity of mutations in CDKN2A/ARF suggesting that in the Polish population this gene does not contribute significantly to early-onset breast cancer, pancreatic cancer and malignant melanoma

Exploring the Link Between Germline and Somatic Genetic Alterations in Breast Carcinogenesis

Recent genome-wide association studies (GWASs) have identified candidate genes contributing to cancer risk through low-penetrance mutations. Many of these genes were unexpected and, intriguingly, included well-known players in carcinogenesis at the somatic level. To assess the hypothesis of a germline-somatic link in carcinogenesis, we evaluated the distribution of somatic gene labels within the ordered results of a breast cancer risk GWAS. This analysis suggested frequent influence on risk of genetic variation in loci encoding for "driver kinases" (i.e., kinases encoded by genes that showed higher somatic mutation rates than expected by chance and, therefore, whose deregulation may contribute to cancer development and/or progression). Assessment of these predictions using a population-based case-control study in Poland replicated the association for rs3732568 in EPHB1 (odds ratio (OR) = 0.79; 95% confidence interval (CI): 0.63-0.98; P-trend = 0.031). Analyses by early age at diagnosis and by estrogen receptor alpha (ER alpha) tumor status indicated potential associations for rs6852678 in CDKL2 (OR = 0.32, 95% CI: 0.10-1.00; P-recessive = 0.044) and rs10878640 in DYRK2 (OR = 2.39, 95% CI: 1.32-4.30; P-dominant = 0.003), and for rs12765929, rs9836340, rs4707795 in BMPR1A, EPHA3 and EPHA7, respectively (ER alpha tumor status P-interaction<0.05). The identification of three novel candidates as EPH receptor genes might indicate a link between perturbed compartmentalization of early neoplastic lesions and breast cancer risk and progression. Together, these data may lay the foundations for replication in additional populations and could potentially increase our knowledge of the underlying molecular mechanisms of breast carcinogenesis

Exploring the Link Between Germline and Somatic Genetic Alterations in Breast Carcinogenesis

Recent genome-wide association studies (GWASs) have identified candidate genes contributing to cancer risk through low-penetrance mutations. Many of these genes were unexpected and, intriguingly, included well-known players in carcinogenesis at the somatic level. To assess the hypothesis of a germline-somatic link in carcinogenesis, we evaluated the distribution of somatic gene labels within the ordered results of a breast cancer risk GWAS. This analysis suggested frequent influence on risk of genetic variation in loci encoding for "driver kinases" (i.e., kinases encoded by genes that showed higher somatic mutation rates than expected by chance and, therefore, whose deregulation may contribute to cancer development and/or progression). Assessment of these predictions using a population-based case-control study in Poland replicated the association for rs3732568 in EPHB1 (odds ratio (OR) = 0.79; 95% confidence interval (CI): 0.63-0.98; P-trend = 0.031). Analyses by early age at diagnosis and by estrogen receptor alpha (ER alpha) tumor status indicated potential associations for rs6852678 in CDKL2 (OR = 0.32, 95% CI: 0.10-1.00; P-recessive = 0.044) and rs10878640 in DYRK2 (OR = 2.39, 95% CI: 1.32-4.30; P-dominant = 0.003), and for rs12765929, rs9836340, rs4707795 in BMPR1A, EPHA3 and EPHA7, respectively (ER alpha tumor status P-interaction<0.05). The identification of three novel candidates as EPH receptor genes might indicate a link between perturbed compartmentalization of early neoplastic lesions and breast cancer risk and progression. Together, these data may lay the foundations for replication in additional populations and could potentially increase our knowledge of the underlying molecular mechanisms of breast carcinogenesis

Founder mutations for early onset melanoma as revealed by whole exome sequencing suggests that this is not associated with the increasing incidence of melanoma in Poland

Purpose: Germline mutations within melanoma susceptibility genes are present only in minority of melanoma patients and it is expected that additional genes will be discovered with next generation sequence technology and whole-exome sequencing (WES). Materials and Methods: Herein we performed WES on a cohort of 96 unrelated Polish patients with melanoma diagnosed under the age of 40 years who all screened negative for the presence of CDKN2A-variants. A replication study using a set of 1,200 melanoma patient DNA samples and similarly large series of healthy controls was undertaken. Results: We selected 21 potentially deleterious variants in 20 genes (VRK1, MYCT1, DNAH14, CASC3, MS4A12, PRC1, WWOX, CARD6, EXO5, CASC3, CASP8AP2, STK33, SAMD11, CNDP2, CPNE1, EFCAB6, CABLES1, LEKR1, NUDT17, and RRP15), which were identified by WES and confirmed by Sanger sequencing for an association study. Evaluation of the allele distribution among carriers and their relatives in available family trios revealed that these variants were unlikely to account for many familial cases of melanoma. Replication study revealed no statistically significant differences between cases and controls. Conclusion: Although most of the changes seemed to be neutral we could not exclude an association between variants in VRK1, CREB3L3, EXO5, and STK33 with melanoma risk.</p

On the origin and diffusion of BRCA1 c.5266dupC (5382insC) in European populations

The BRCA1 mutation c.5266dupC was originally described as a founder mutation in the Ashkenazi Jewish (AJ) population. However, this mutation is also present at appreciable frequency in several European countries, which raises intriguing questions about the origins of the mutation. We genotyped 245 carrier families from 14 different population groups (Russian, Latvian, Ukrainian, Czech, Slovak, Polish, Danish, Dutch, French, German, Italian, Greek, Brazilian and AJ) for seven microsatellite markers and confirmed that all mutation carriers share a common haplotype from a single founder individual. Using a maximum likelihood method that allows for both recombination and mutational events of marker loci, we estimated that the mutation arose some 1800 years ago in either Scandinavia or what is now northern Russia and subsequently spread to the various populations we genotyped during the following centuries, including the AJ population. Age estimates and the molecular evolution profile of the most common linked haplotype in the carrier populations studied further suggest that c.5266dupC likely entered the AJ gene pool in Poland approximately 400–500 years ago. Our results illustrate that (1) BRCA1 c.5266dupC originated from a single common ancestor and was a common European mutation long before becoming an AJ founder mutation and (2) the mutation is likely present in many additional European countries where genetic screening of BRCA1 may not yet be common practice