BackgroundLynch syndrome (LS) is a hereditary condition that increases the risk for endometrial and other cancers. The identification of endometrial cancer (EC) patients with LS has the potential to influence life-saving interventions. We aimed to study the prevalence of LS among EC patients in our population.MethodsUniversal screening for LS was applied for a consecutive series EC. Tumor testing using microsatellite instability (MSI), immunohistochemistry (IHC) for mismatch-repair (MMR) protein expression and MLH1-methylation analysis, when required, was used to select LS-suspicious cases. Sequencing of corresponding MMR genes was performed.ResultsOne hundred and seventy-three EC (average age, 63 years) were screened. Sixty-one patients (35%) had abnormal IHC or MSI results. After MLH1 methylation analysis, 27 cases were considered suspicious of LS. From these, 22 were contacted and referred for genetic counseling. Nineteen pursued genetic testing and eight were diagnosed of LS. Mutations were more frequent in younger patients (<50 yrs). Three cases had either intact IHC or MSS and reinforce the need of implement the EC screening with both techniques.ConclusionThe prevalence of LS among EC patients was 4.6% (8/173); with a predictive frequency of 6.6% in the Spanish population. Universal screening of EC for LS is recommended.

Identification of genes associated with hereditary cancers facilitates management of patients with family histories of cancer. We performed exome sequencing of DNA from 3 individuals from a family with colorectal cancer who met the Amsterdam criteria for risk of hereditary nonpolyposis colorectal cancer. These individuals had mismatch repair-proficient tumors and each carried nonsense variant in the FANCD2/FANCI-associated nuclease 1 gene (FAN1), which encodes a nuclease involved in DNA inter-strand cross-link repair. We sequenced FAN1 in 176 additional families with histories of colorectal cancer and performed in vitro functional analyses of the mutant forms of FAN1 identified. We detected FAN1 mutations in approximately 3% of families who met the Amsterdam criteria and had mismatch repair-proficient cancers with no previously associated mutations. These findings link colorectal cancer predisposition to the Fanconi anemia DNA repair pathway, supporting the connection between genome integrity and cancer risk.

The standard genetic test for Lynch syndrome (LS) frequently reveals an absence of pathogenic mutations in DNA mismatch repair genes known to be associated with LS. It was recently shown that germ line deletions in the last exons of EPCAM are involved in the etiology of LS. The aim of this study was to evaluate the prevalence of EPCAM deletions in a Spanish population and the clinical implications of deletion. Probands from 501 families suspected of having LS were enrolled in the study. Twenty-five cases with MSH2 loss were identified: 10 had mutations of MSH2, five had mutations of MSH6 , and 10 did not show MSH2/MSH6 mutations. These 25 cases were analyzed for EPCAM deletions using multiplex ligation-dependent probe amplification , and deletions were mapped using long-range PCR analysis. One subject with no MSH2/MSH6 mutations had a large deletion in the EPCAM locus that extended for 8.7 kb and included exons 8 and 9. The tumor exhibited MSH2 promoter hypermethylation. EPCAM deletion analysis followed by MSH2 methylation testing of the tumor is a fast low-cost procedure that can be used to identify mutations that cause LS. We propose that this procedure be incorporated into clinical genetic analysis strategies and present a decision-support flow diagram for the diagnosis of

Lynch syndrome (LS) is a common cause of hereditary colorectal cancer (CRC). Some CRC patients develop mismatch repair deficiency without germline pathogenic mutation, known as Lynch-like syndrome (LLS). We compared the risk of CRC in first-degree relatives (FDRs) in LLS and LS patients. LLS was diagnosed when tumors showed immunohistochemical loss of MSH2, MSH6, and PMS2; or loss of MLH1 with BRAF wild type; and/or no MLH1 methylation and absence of pathogenic mutation in these genes. CRC and other LS-related neoplasms were followed in patients diagnosed with LS and LLS and among their FDRs. Standardized incidence ratios (SIRs) were calculated for CRC and other neoplasms associated with LS among FDRs of LS and LLS patients. In total, 205 LS (1205 FDRs) and 131 LLS families (698 FDRs) had complete pedigrees. FDRs of patients with LLS had a high incidence of CRC (SIR, 2.08; 95% confidence interval (CI), 1.56–2.71), which was significantly lower than that in FDRs of patients with LS (SIR, 4.25; 95% CI, 3.67–4.90; p < 0.001). The risk of developing other neoplasms associated with LS also increased among FDR of LLS patients (SIR, 2.04; 95% CI, 1.44–2.80) but was lower than that among FDR of patients with LS (SIR, 5.01, 95% CI, 4.26–5.84; p < 0.001). FDRs with LLS have an increased risk of developing CRC as well as LS-related neoplasms, although this risk is lower than that of families with LS. Thus, their management should take into account this increased risk.

Purpose Germline mutations in BRCA1 and/or BRCA2 genes (gBRCA1/2m) are associated with an increased risk of breast cancer (BC) and ovarian cancer (OC). The aim of this study was to estimate the efficiency of providing germline BRCA1/2 testing to high-grade epithelial ovarian cancer (HGEOC) patients without family history of OC or BC and the subsequent testing and management of their relatives with gBRCA1/2m in Spain. Methods/patients Incident HGEOC patients without family history of OC or BC who were gBRCA1/2m carriers and their relatives were simulated in a 50-year time horizon. The study compared two scenarios: BRCA1/2 testing vs no testing, using the perspective of the Spanish National Health Service. Cancer risk among gBRCA1/2m carriers was estimated based on their age and whether they had undergone risk-reducing surgeries. Direct healthcare costs and utilities of patients who developed EOC and BC were also included. A probabilistic sensitivity analysis (PSA) with 5 thousand simulations was developed considering ± 25% of the base-case value. Results The BRCA1/2-testing scenario amounted to €13,437,897.43 while the no-testing scenario amounted to €12,053,291.17. It was estimated that the screening test improved the quality of life among the patients' relatives by 43.8 quality-adjusted life years (QALYs). The incremental cost-utility ratio (ICUR) was €31,621.33/QALY in the base case. The PSA showed that 89.12% of the simulations were below the €50,000/QALY threshold. Conclusion Providing this screening test to HGEOC patients and their relatives is cost-effective and it allows one to identify a target population with high risk of cancer to provide effective prevention strategies.

Our results suggest a negligible prevalence of MLH1 constitutional epimutations in unselected cases of CRC. Therefore, MLH1 constitutional epimutation analysis should be conducted only for patients who fulfil the rBG and who lack MLH1 expression with methylated MLH1.

Genetic mutations have been identified as the cause of inherited cancer risk in some colon cancer; these mutations are estimated to account for only 5-6 % of colorectal cancer (CRC) cases overall. Up to 25-30 % of patients have a family history of CRC that suggests a hereditary component, common exposures among family members, or a combination of both. Cancers in people with a hereditary predisposition typically occur at an earlier age than in sporadic cases. A predisposition to CRC may include a predisposition to other cancers, such as endometrial cancer. We describe genetics, current diagnosis and management of CRC hereditary syndromes pointing to a multidisciplinary approach to achieve the best results in patients and family outcomes.

Mutational processes in germline and in somatic cells are vastly different, and it remains unclear how the same genetic background affects somatic and transmissible mutations. Here, we estimate the impact of a germline pathogenic variant in the exonuclease domain of polymerase delta (Polδ) on somatic and germline mutational processes and cancer development. In germline cells and in non-cancer somatic cells, the POLD1 L474P variant only slightly increases the mutation burden, contributing to ∼11.8% and ∼14.7% of mutations respectively, although it strongly distorts the mutational spectra. By contrast, tumors developed by carriers of germline pathogenic variants in POLD1 harbor a DNA rearrangement that results in a homozygous state of the pathogenic variant, leading to an extremely high mutation rate. Thus, Polδ proofreading dysfunction has a recessive effect on mutation rate, with mutations in both POLD1 alleles leading to a dramatic rate of mutation accumulation and cancer development. These results clarify the link between the effect of POLD1 mutator variants on germline and somatic replication, and, together with previous findings, illustrate the important differences in disruption of replication fidelity caused by mutations in main replicative polymerases.