Association of SULT1A1 Arg²¹³His polymorphism with male breast cancer risk: results from a multicenter study in Italy.

Male breast cancer (MBC) is rare and poorly understood. Like female breast cancer (FBC), MBCs are highly sensitive to hormonal changes, and hyperestrogenism, specifically, represents a major risk factor for MBC. MBC is considered similar to late-onset, post-menopausal estrogen/progesteron receptors positive FBC (ER+/PR+). Sulfotransferase 1A1 (SULT1A1) is an enzyme involved in the metabolism of estrogens. Recently, SULT1A1 common functional polymorphism Arg(213)His (638G>A) variant has been found to be associated with increased breast cancer (BC) risk, particularly in post-menopausal women. For this reason, we decided to explore whether SULT1A1 Arg(213)His could exert an effect on MBC development. The primary aim of this study was to evaluate the influence of the SULT1A1 Arg(213)His polymorphism on MBC risk. The secondary aim was to investigate possible associations with relevant clinical-pathologic features of MBC. A total of 394 MBC cases and 786 healthy male controls were genotyped for SULT1A1 Arg(213)His polymorphism by PCR-RFLP and high-resolution melting analysis. All MBC cases were characterized for relevant clinical-pathologic features. A significant difference in the distribution of SULT1A1 Arg(213)His genotypes was found between MBC cases and controls (P < 0.0001). The analysis of genotype-specific risk showed a significant increased MBC risk in individuals with G/A (OR 1.97, 95% CI 1.50-2.59; P < 0.0001) and A/A (OR 3.09, 95% CI 1.83-5.23; P < 0.0001) genotypes in comparison to wild-type genotype, under co-dominant model. A significant association between SULT1A1 risk genotypes and HER2 status emerged. Results indicate that SULT1A1 Arg(213)His may act as a low-penetrance risk allele for developing MBC and could be associated with a specific tumor subtype associated with HER2 overexpression.

Risk of desmoid tumours after open and laparoscopic colectomy in patients with familial adenomatous polyposis.

BACKGROUND: Desmoid tumour (DT) is a main cause of death after prophylactic colectomy in patients with familial adenomatous polyposis (FAP). The purpose of this study was to evaluate the impact of prophylactic laparoscopic colectomy on the risk of developing DT in patients with FAP. METHODS: The database of a single institution was reviewed. Patients with classical FAP with defined genotype who underwent either open or laparoscopic colectomy between 1947 and 2011 were included in the study. The impact of various demographic and clinical features on the risk of developing DT was assessed. RESULTS: A total of 672 patients underwent prophylactic colectomy: 602 by an open and 70 by a laparoscopic approach. With a median (range) follow-up of 132 (0-516) months in the open group and 60 (12-108) months in the laparoscopic group, 98 patients (16·3 per cent) developed DT after an open procedure compared with three (4 per cent) following laparoscopic surgery. The estimated cumulative risk of developing DT at 5 years after surgery was 13·0 per cent in the open group and 4 per cent in the laparoscopic group (P = 0·042). In multivariable analysis, female sex (hazard ratio (HR) 2·18, 95 per cent confidence interval 1·40 to 3·39), adenomatous polyposis coli mutation distal to codon 1400 (HR 3·85, 1·90 to 7·80), proctocolectomy (HR 1·67, 1·06 to 2·61), open colectomy (HR 6·84, 1·96 to 23·98) and year of surgery (HR 1·04, 1·01 to 1·07) were independent risk factors for the diagnosis of DT after prophylactic surgery. CONCLUSION: Laparoscopic surgery decreased the risk of DT after prophylactic colectomy in patients with FAP.

Performance of BOADICEA and BRCAPRO genetic models and of empirical criteria based on cancer family history for predicting BRCA mutation carrier probabilities: a retrospective study in a sample of Italian cancer genetics clinics.

PURPOSE: To evaluate in current practice the performance of BOADICEA and BRCAPRO risk models and empirical criteria based on cancer family history for the selection of individuals for BRCA genetic testing. PATIENTS AND METHODS: The probability of BRCA mutation according to the three tools was retrospectively estimated in 918 index cases consecutively undergone BRCA testing at 15 Italian cancer genetics clinics between 2006 and 2008. RESULTS: 179 of 918 cases (19.5%) carried BRCA mutations. With the strict use of the criteria based on cancer family history 173 BRCA (21.9%) mutations would have been detected in 789 individuals. At the commonly used 10% threshold of BRCA mutation carrier probability, the genetic models showed a similar performance [PPV (38% and 37%), sensitivity (76% and 77%) and specificity (70% and 69%)]. Their strict use would have avoided around 60% of the tests but would have missed approximately 1 every 4 carriers. CONCLUSION: Our data highlight the complexity of BRCA testing referral in routine practice and question the strict use of genetic models for BRCA risk assessment.

The Italian National External quality assessment program in molecular genetic testing: results of the VII round (2010-2011).

Since 2001 the Istituto Superiore di Sanità established a quality assurance programme for molecular genetic testing that covers four pathologies: Cystic Fibrosis (CF), Beta Thalassemia (BT), Fragile X Syndrome (FX), and Familial Adenomatous Polyposis Coli (APC). Since 2009 this activity is an institutional activity and participation is open to both public and private laboratories. Seven rounds have been performed until now and the eighth is in progress. Laboratories receive 4 DNA samples with mock clinical indications. They analyze the samples using their routine procedures. A panel of assessors review the raw data and the reports; all data are managed through a web utility. In 2010 the number of participants was 43, 17, 15, 5 for CF, BT, FX, APC schemes respectively. Genotyping results were correct in 96%, 98.5%, 100%, and 100% of CF, BT, FX, and APC samples, respectively. Interpretation was correct in 74%, 91%, 88%, and 60% of CF, BT, FX, and APC reports, respectively; however in most of them it was not complete but a referral to genetic counseling was given. Reports were satisfactory in more than 60% of samples in all schemes. This work presents the 2010 results in detail comparing our data with those from other European schemes.

Association of low-penetrance alleles with male breast cancer risk and clinicopathological characteristics: results from a multicenter study in Italy.

It is well-known that male breast cancer (MBC) susceptibility is mainly due to high-penetrance BRCA1/2 mutations. Here, we investigated whether common low-penetrance breast cancer (BC) susceptibility alleles may influence MBC risk in Italian population and whether variant alleles may be associated with specific clinicopathological features of MBCs. In the frame of the Italian Multicenter Study on MBC, we genotyped 413 MBCs and 745 age-matched male controls at 9 SNPs annotating known BC susceptibility loci. By multivariate logistic regression models, we found a significant increased MBC risk for 3 SNPs, in particular, with codominant models, for rs2046210/ESR1 (OR = 1.71; 95 % CI: 1.43-2.05; p = 0.0001), rs3803662/TOX3 (OR = 1.59; 95 % CI: 1.32-1.92; p = 0.0001), and rs2981582/FGFR2 (OR = 1.26; 95 % CI: 1.05-1.50; p = 0.013). Furthermore, we showed that the prevalence of the risk genotypes of ESR1 tended to be higher in ER- tumors (p = 0.062). In a case-case multivariate analysis, a statistically significant association between ESR1 and ER- tumors was found (OR = 1.88; 95 % CI: 1.03-3.49; p = 0.039). Overall, our data, based on a large and well-characterized MBC series, support the hypothesis that common low-penetrance BC susceptibility alleles play a role in MBC susceptibility and, interestingly, indicate that ESR1 is associated with a distinct tumor subtype defined by ER-negative status.

Unclassified variants in BRCA genes: guidelines for interpretation.

In the last few years, several studies have focused on the interpretation of unclassified variants (UVs) of BRCA1 and BRCA2 genes. Analysis of UVs through a unique approach is not sufficient to understand their role in the development of tumors. Thus, it is clear that assembling results from different sources (genetic and epidemiological data, histopathological features, and in vitro and in silico analyses) represents a powerful way to classify such variants. Building reliable integrated models for UV classification requires the joining of many working groups to collaborative consortia, allowing data exchange and improvements of methods. This will lead to improvement in the predictivity of gene testing in BRCA1 and BRCA2 and, consequently, to an increase in the number of families that can be correctly classified as linked or unlinked to these genes, allowing more accurate genetic counseling and clinical management.

Oral contraceptive use and breast or ovarian cancer risk in BRCA1/2 carriers: a meta-analysis.

BACKGROUND: Women with BRCA1 or BRCA2 mutations are at increased risk of breast and ovarian cancer. Oral contraceptives (OC) use has been associated with a reduction in ovarian cancer risk and with a moderately increased breast cancer risk, which tends to level off in the few years after stopping. The association between oral contraceptive and BRCA1 or BRCA2 gene mutations carriers is unclear. METHODS: We performed a comprehensive literature search updated to March 2010 of studies on the associations between OC users and breast or ovarian cancer for ascertained BRCA1/2 carriers. We obtained summary risk estimated for ever OC users, for duration of use and time since stopping. RESULTS: A total of 2855 breast cancer cases and 1503 ovarian cancer cases, carrying an ascertained BRCA1/2 mutation, were included in our meta-analyses, based on overall 18 studies. Use of OC was associated with a significant reduced risk of ovarian cancer for BRCA1/2 carriers (summary relative risk (SRR)=0.50; 95% confidence interval (CI), 0.33-0.75). We also observed a significant 36% risk reduction for each additional 10 years of OC use (SRR: 0.64; 95% CI, 0.53-0.78; P trend<0.01). We found no evidence of a significant association between OC and breast cancer risk in carriers (SRR: 1.13; 95% CI, 0.88-1.45) and with duration of use. OC formulations used before 1975 were associated with a significant increased risk of breast cancer (SRR: 1.47; 95% 1.06, 2.04), but no evidence of a significant association was found with use of more recent formulations (SRR: 1.17; 95% 0.74, 1.86). CONCLUSIONS: OC users carrying an ascertained BRCA1/2 mutation have a reduced risk of ovarian cancer, proportional to the duration of use. There is no evidence that recent OC formulations increase breast cancer risk in carriers.

COGENT (COlorectal cancer GENeTics): an international consortium to study the role of polymorphic variation on the risk of colorectal cancer.

It is now recognised that a part of the inherited risk of colorectal cancer (CRC) can be explained by the co-inheritance of low-penetrance genetic variants. The accumulated experience to date in identifying these variants has served to highlight difficulties in conducting statistically and methodologically rigorous studies and follow-up analyses. The COGENT (COlorectal cancer GENeTics) consortium includes 20 research groups in Europe, Australia, the Americas, China and Japan. The overarching goal of COGENT is to identify and characterise low-penetrance susceptibility variants for CRC through association-based analyses. In this study, we review the rationale for identifying low-penetrance variants for CRC and our proposed strategy for establishing COGENT.

Microscale modelling simulations for the site characterization of air quality stations in an urban environment.

The presence of natural or artificial barriers placed near the air quality measuring stations located in an urban environment poses some problems in the assessment of their siting and significance. The atmospheric flow distortion induced by these structures can create situations that affect the concentration levels of measured pollutants. A modelling study at microscale of the pollutant dispersion in an urban environment has been performed to quantify these possible effects on measurements. The target domain is located in a central section of the city of Turin (northern Italy) around via della Consolata, near the location of an existing station of the regional monitoring network. The study involved the use of the modelling system Micro-Swift-Spray, which takes into account the presence of complex topographical barriers, including street canyons and squares surrounded by buildings. Two entire days have been simulated, to characterise both a critical and a more standard condition, with reconstruction of average flow, turbulence and hourly ground-level pollutant concentrations. Contributions from both traffic and building-heating sources have been considered and a comparison with measured concentrations has been performed to verify the representativeness of the measuring station with respect to both average conditions and spatial variability inside the considered region, otherwise very difficult to asses through a single and isolated measuring point.

The TP53 Arg72Pro and MDM2 309G>T polymorphisms are not associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: The TP53 pathway, in which TP53 and its negative regulator MDM2 are the central elements, has an important role in carcinogenesis, particularly in BRCA1- and BRCA2-mediated carcinogenesis. A single nucleotide polymorphism (SNP) in the promoter region of MDM2 (309T>G, rs2279744) and a coding SNP of TP53 (Arg72Pro, rs1042522) have been shown to be of functional significance. METHODS: To investigate whether these SNPs modify breast cancer risk for BRCA1 and BRCA2 mutation carriers, we pooled genotype data on the TP53 Arg72Pro SNP in 7011 mutation carriers and on the MDM2 309T>G SNP in 2222 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Data were analysed using a Cox proportional hazards model within a retrospective likelihood framework. RESULTS: No association was found between these SNPs and breast cancer risk for BRCA1 (TP53: per-allele hazard ratio (HR)=1.01, 95% confidence interval (CI): 0.93-1.10, P(trend)=0.77; MDM2: HR=0.96, 95%CI: 0.84-1.09, P(trend)=0.54) or for BRCA2 mutation carriers (TP53: HR=0.99, 95%CI: 0.87-1.12, P(trend)=0.83; MDM2: HR=0.98, 95%CI: 0.80-1.21, P(trend)=0.88). We also evaluated the potential combined effects of both SNPs on breast cancer risk, however, none of their combined genotypes showed any evidence of association. CONCLUSION: There was no evidence that TP53 Arg72Pro or MDM2 309T>G, either singly or in combination, influence breast cancer risk in BRCA1 or BRCA2 mutation carriers.

An evaluation of the polymorphisms Ins16bp and Arg72Pro in p53 as breast cancer risk modifiers in BRCA1 and BRCA2 mutation carriers.

The close functional relationship between p53 and the breast cancer susceptibility genes BRCA1 and BRCA2 has promoted the investigation of various polymorphisms in the p53 gene as possible risk modifiers in BRCA1/2 mutation carriers. Specifically, two polymorphisms in p53, c.97-147ins16bp and p.Arg72Pro have been analysed as putative breast cancer susceptibility variants, and it has been recently reported that a p53 haplotype combining the absence of the 16-bp insertion and the presence of proline at codon 72 (No Ins-72Pro) was associated with an earlier age at the onset of the first primary tumour in BRCA2 mutation carriers in the Spanish population. In this study, we have evaluated this association in a series of 2932 BRCA1/2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2.

Functional inactivation of the WTX gene is not a frequent event in Wilms' tumors.

For many years the precise genetic etiology of the majority of Wilms' tumors has remained unexplained. Recently, the WTX gene, mapped to chromosome Xq11.1, has been reported to be lost or mutated in approximately one-third of Wilms' tumors. Moreover, in female cases, the somatically inactivated alleles were found to invariantly derive from the active chromosome X. Consequently, WTX has been proposed as a 'one-hit' tumor suppressor gene. To provide further insights on the contribution of WTX to the development of the disease, we have examined 102 Wilms' tumors, obtained from 43 male and 57 female patients. Quantitative PCR analyses detected WTX deletions in 5 of 45 (11%) tumors from males, whereas loss of heterozygosity at WTX-linked microsatellites was observed in 9 tumors from 50 informative females (19%). However, in the latter group, using a combination of HUMARA assay and bisulfite-modified DNA sequencing, we found that the deletion affected the active chromosome X only in two cases (4%). Sequence analyses detected an inactivating somatic mutation of WTX in a single tumor, in which a strongly reduced expression of the mutant allele respect to the wild-type allele was observed, a finding not consistent with its localization on the active chromosome X. Overall, a functional somatic nullizygosity of the WTX gene was ascertained only in seven of the Wilms' tumors included in the study (approximately 7%). Our findings indicate that previously reported estimates on the proportion of Wilms' tumors due to WTX alterations should be reconsidered.

The BOADICEA model of genetic susceptibility to breast and ovarian cancers: updates and extensions.

Multiple genetic loci confer susceptibility to breast and ovarian cancers. We have previously developed a model (BOADICEA) under which susceptibility to breast cancer is explained by mutations in BRCA1 and BRCA2, as well as by the joint multiplicative effects of many genes (polygenic component). We have now updated BOADICEA using additional family data from two UK population-based studies of breast cancer and family data from BRCA1 and BRCA2 carriers identified by 22 population-based studies of breast or ovarian cancer. The combined data set includes 2785 families (301 BRCA1 positive and 236 BRCA2 positive). Incidences were smoothed using locally weighted regression techniques to avoid large variations between adjacent intervals. A birth cohort effect on the cancer risks was implemented, whereby each individual was assumed to develop cancer according to calendar period-specific incidences. The fitted model predicts that the average breast cancer risks in carriers increase in more recent birth cohorts. For example, the average cumulative breast cancer risk to age 70 years among BRCA1 carriers is 50% for women born in 1920-1929 and 58% among women born after 1950. The model was further extended to take into account the risks of male breast, prostate and pancreatic cancer, and to allow for the risk of multiple cancers. BOADICEA can be used to predict carrier probabilities and cancer risks to individuals with any family history, and has been implemented in a user-friendly Web-based program (http://www.srl.cam.ac.uk/genepi/boadicea/boadicea_home.html).

Reconstructing the genealogy of a BRCA1 founder mutation by phylogenetic analysis.

Estimating the age of founder mutations may contribute to improve our knowledge of population genetics and evolutionary history of diseases. Previous haplotype analysis suggested that the BRCA1*1499insA mutation was a founder allele, probably originated in Tuscany (Italy). Here, we collected additional pedigrees carrying this mutation, and applied a phylogenetic method for estimating mutation age. A chromosome segment of about 25 cM, including 37 short tandem repeats (STRs) on both sides of the BRCA1 gene (DeCode map), was typed in 50 subjects (28 mutation carriers) from 14 unrelated families. The time to the most recent common ancestor (MRCA) of the mutation carriers was estimated by the length of the shared haplotype between all possible pairs of individuals. A function relating the length of the shared haplotype to the time to the MRCA was obtained by a computer simulation. This approach gives results comparable with those of other existing mutation-dating methods, but does not depend explicitly on population-specific parameters such as allele frequencies, provides narrower confidence intervals (CI), and allows one to build an extended genealogical tree of all mutation carriers. The 1499insA mutation shared by the investigated subjects was estimated to be present in an individual living about 30 generations ago (95% CL 22-56), or 750 years (95% CL 550-1,400).

Methyl group metabolism gene polymorphisms as modifier of breast cancer risk in Italian BRCA1/2 carriers.

BRCA1 and 2 are major cancer susceptibility genes but their penetrance is highly variable. The folate metabolism plays an important role in DNA methylation and its alterated metabolism is associated with cancer risk. The role of allele variants 677T and 1298C (MTHFR gene) and 2756G (MS gene) has been investigated as potentially modifying factors of BRCA gene penetrance, evaluated as age at first diagnosis of cancer, in 484 BRCA1/BRCA2 carriers and in 108 sporadic breast cancer cases as a control group. The genotype analysis has been performed by means of PCR/RFLP's. The analysis of association between a particular genotype and disease risk was performed using Cox Regression with time to breast or ovarian cancer onset as the end-point. The presence of 677T allele confers an increased risk of breast cancer in BRCA1 carriers (P = 0.007) and the presence of 1298C allele confers an increased risk of breast cancer in sporadic cases (P = 0.015).

Breast and ovarian cancer risks to carriers of the BRCA1 5382insC and 185delAG and BRCA2 6174delT mutations: a combined analysis of 22 population based studies.

A recent report estimated the breast cancer risks in carriers of the three Ashkenazi founder mutations to be higher than previously published estimates derived from population based studies. In an attempt to confirm this, the breast and ovarian cancer risks associated with the three Ashkenazi founder mutations were estimated using families included in a previous meta-analysis of populatrion based studies. The estimated breast cancer risks for each of the founder BRCA1 and BRCA2 mutations were similar to the corresponding estimates based on all BRCA1 or BRCA2 mutations in the meta-analysis. These estimates appear to be consistent with the observed prevalence of the mutations in the Ashkenazi Jewish population.

Classification of BRCA1 missense variants of unknown clinical significance.

BACKGROUND: BRCA1 is a tumour suppressor with pleiotropic actions. Germline mutations in BRCA1 are responsible for a large proportion of breast-ovarian cancer families. Several missense variants have been identified throughout the gene but because of lack of information about their impact on the function of BRCA1, predictive testing is not always informative. Classification of missense variants into deleterious/high risk or neutral/low clinical significance is essential to identify individuals at risk. OBJECTIVE: To investigate a panel of missense variants. METHODS AND RESULTS: The panel was investigated in a comprehensive framework that included (1) a functional assay based on transcription activation; (2) segregation analysis and a method of using incomplete pedigree data to calculate the odds of causality; (3) a method based on interspecific sequence variation. It was shown that the transcriptional activation assay could be used as a test to characterise mutations in the carboxy-terminus region of BRCA1 encompassing residues 1396-1863. Thirteen missense variants (H1402Y, L1407P, H1421Y, S1512I, M1628T, M1628V, T1685I, G1706A, T1720A, A1752P, G1788V, V1809F, and W1837R) were specifically investigated. CONCLUSIONS: While individual classification schemes for BRCA1 alleles still present limitations, a combination of several methods provides a more powerful way of identifying variants that are causally linked to a high risk of breast and ovarian cancer. The framework presented here brings these variants nearer to clinical applicability.