Influence of family history on risk of second primary cancers and survival in patients with squamous cell skin cancer

Summary Background Patients with squamous cell skin cancer (SCC) have an excellent prognosis but second primary cancers (SPCs) weaken survival prospects. Family history is a known risk factor for cancer but whether it is a risk factor for SPC in patients with SCC is not known. Objectives To quantify the risk of family history on SPCs in patients with SCC and estimate survival probabilities of patients with SPCs depending on family history. Methods With 13 945 histologically verified SCCs, relative risks (RRs) were estimated for family history using a generalized regression model. For survival analysis, hazard ratios (HRs) were assessed using a multivariable Cox proportional-hazards model. Results Family history of invasive SCC increased risk of second invasive SCC [RR = 42·92, 95% confidence interval (CI) 33·69?50·32] compared with risk without family history (RR 19·12, 95% CI 17·88?21·08). Family history of any nonskin cancer in invasive SCC increased risk of the same cancers to be diagnosed as SPC (RRFH = 1·48, 95% CI 1·35?1·61 vs. RRno FH = 1·40, 95% CI 1·32?1·48); significant increases were observed for seven different nonskin cancers. Most results were replicated for in situ SCC. SPC was deleterious for survival irrespective of family history; HR for patients with SPC was 4·28 (95% CI 3·83?4·72) vs. those without SPC (1·04). Conclusions Family history of nonskin cancer was associated with approximately a doubling of risk for SPCs in patients with SCC. SPC increases the death rate in patients with SCC 3?4 times, irrespective of family history. Taking family history into account at SCC diagnosis may help prevention or early detection of SPCs. What's already known about this topic? Second primary cancers (SPCs) are frequently diagnosed in patients with invasive and in situ squamous cell carcinoma (SCC); some epidemiological studies suggest a link to immune dysfunction. Family history of cancer is a risk factor for practically all first primary cancers but whether it also influences risk of SPCs in patients with SCC is not known. The possible influence of family history on survival in patients with SCC remains to be established.Peer reviewe

A gene-wide investigation on polymorphisms in the taste receptor 2R14 (TAS2R14) and susceptibility to colorectal cancer

Background: Molecular sensing in the gastro-intestinal (GI) tract is responsible for the detection of ingested harmful drugs and toxins, thereby genetic polymorphisms affecting the capability of initiating these responses may be critical for the subsequent efficiency of the gut in eliminating possible threats to the organism. Although these fundamental control systems have been known for long time, the initial molecular recognition events that sense the chemical composition of the luminal contents of the GI tract have remained elusive. TAS2R14 is one of the better characterized members of the taste receptor family and has several polymorphic variants. Several substances that have been shown to activate TAS2R14 are powerful toxic and carcinogenic agents. Methods: Using a tagging approach we investigated all the common genetic variation of the gene region in relation to colon cancer risk with a case-control study design. This is, at the best of our knowledge also the first report on the allele frequencies of the gene in the Caucasian population. Results: We found no evidence of statistically significant associations between polymorphisms in the TAS2R14 gene and colon cancer risk. Conclusion: In conclusion we can confidently exclude a major role for common polymorphisms of the TAS2R14 gene in colorectal cancer risk in this population, although in this report we had insufficient statistical power to completely exclude the possibility that rare variants of the TAS2R14 might be involved in colorectal cancer risk

Runs of homozygosity and inbreeding in thyroid cancer

BACKGROUND: Genome-wide association studies (GWASs) have identified several single-nucleotide polymorphisms (SNPs) influencing the risk of thyroid cancer (TC). Most cancer predisposition genes identified through GWASs function in a co-dominant manner, and studies have not found evidence for recessively functioning disease loci in TC. Our study examines whether homozygosity is associated with an increased risk of TC and searches for novel recessively acting disease loci. METHODS: Data from a previously conducted GWAS were used for the estimation of the proportion of phenotypic variance explained by all common SNPs, the detection of runs of homozygosity (ROH) and the determination of inbreeding to unravel their influence on TC. RESULTS: Inbreeding coefficients were significantly higher among cases than controls. Association on a SNP-by-SNP basis was controlled by using the false discovery rate at a level of q* < 0.05, with 34 SNPs representing true differences in homozygosity between cases and controls. The average size, the number and total length of ROHs per person were significantly higher in cases than in controls. A total of 16 recurrent ROHs of rather short length were identified although their association with TC risk was not significant at a genome-wide level. Several recurrent ROHs harbor genes associated with risk of TC. All of the ROHs showed significant evidence for natural selection (iHS, Fst, Fay and Wu's H). CONCLUSIONS: Our results support the existence of recessive alleles in TC susceptibility. Although regions of homozygosity were rather small, it might be possible that variants within these ROHs affect TC risk and may function in a recessive manner

Search for multiple myeloma risk factors using Mendelian randomization.

The etiology of multiple myeloma (MM) is poorly understood. Summary data from genome-wide association studies (GWASs) of multiple phenotypes can be exploited in a Mendelian randomization (MR) phenome-wide association study (PheWAS) to search for factors influencing MM risk. We performed an MR-PheWAS analyzing 249 phenotypes, proxied by 10 225 genetic variants, and summary genetic data from a GWAS of 7717 MM cases and 29 304 controls. Odds ratios (ORs) per 1 standard deviation increase in each phenotype were estimated under an inverse variance weighted random effects model. A Bonferroni-corrected threshold of P = 2 × 10-4 was considered significant, whereas P < .05 was considered suggestive of an association. Although no significant associations with MM risk were observed among the 249 phenotypes, 28 phenotypes showed evidence suggestive of association, including increased levels of serum vitamin B6 and blood carnitine (P = 1.1 × 10-3) with greater MM risk and ω-3 fatty acids (P = 5.4 × 10-4) with reduced MM risk. A suggestive association between increased telomere length and reduced MM risk was also noted; however, this association was primarily driven by the previously identified risk variant rs10936599 at 3q26 (TERC). Although not statistically significant, increased body mass index was associated with increased risk (OR, 1.10; 95% confidence interval, 0.99-1.22), supporting findings from a previous meta-analysis of prospective observational studies. Our study did not provide evidence supporting any modifiable factors examined as having a major influence on MM risk; however, it provides insight into factors for which the evidence has previously been mixed

Germline variants of CYBA and TRPM4 predispose to familial colorectal cancer

Simple Summary Whole-genome sequencing and bioinformatics analysis on unique colorectal cancer families revealed two attractive candidate predisposition genes, CYBA and TRPM4, each with a loss-of-function variant. Supported by our functional studies, we suggest that the two gene defects mechanistically involve intestinal barrier integrity through reactive oxygen species and mucus biology, which converges in chronic bowel inflammation, a known risk factor for colorectal cancer. Abstract Familial colorectal cancer (CRC) is only partially explained by known germline predisposing genes. We performed whole-genome sequencing in 15 Polish families of many affected individuals, without mutations in known CRC predisposing genes. We focused on loss-of-function variants and functionally characterized them. We identified a frameshift variant in the CYBA gene (c.246delC) in one family and a splice site variant in the TRPM4 gene (c.25–1 G > T) in another family. While both variants were absent or extremely rare in gene variant databases, we identified four additional Polish familial CRC cases and two healthy elderly individuals with the CYBA variant (odds ratio 2.46, 95% confidence interval 0.48–12.69). Both variants led to a premature stop codon and to a truncated protein. Functional characterization of the variants showed that knockdown of CYBA or TRPM4 depressed generation of reactive oxygen species (ROS) in LS174T and HT-29 cell lines. Knockdown of TRPM4 resulted in decreased MUC2 protein production. CYBA encodes a component in the NADPH oxidase system which generates ROS and controls, e.g., bacterial colonization in the gut. Germline CYBA variants are associated with early onset inflammatory bowel disease, supported with experimental evidence on loss of intestinal mucus barrier function due to ROS deficiency. TRPM4 encodes a calcium-activated ion channel, which, in a human colonic cancer cell line, controls calcium-mediated secretion of MUC2, a major component of intestinal mucus barrier. We suggest that the gene defects in CYBA and TRPM4 mechanistically involve intestinal barrier integrity through ROS and mucus biology, which converges in chronic bowel inflammation

Mutation analysis of CBP and PCAF reveals rare inactivating mutations in cancer cell lines but not in primary tumours

In this study we screened the histone acetyltransferases CBP and PCAF for mutations in human epithelial cancer cell lines and primary tumours. We identified two CBP truncations (both in cell lines), seven PCAF missense variants and four CBP intronic microdeletions. These data suggest that neither gene is commonly inactivated in human epithelial cancers

The ‘Common Disease-Common Variant’ Hypothesis and Familial Risks

The recent large genotyping studies have identified a new repertoire of disease susceptibility loci of unknown function, characterized by high allele frequencies and low relative risks, lending support to the common disease-common variant (CDCV) hypothesis. The variants explain a much larger proportion of the disease etiology, measured by the population attributable fraction, than of the familial risk. We show here that if the identified polymorphisms were markers of rarer functional alleles they would explain a much larger proportion of the familial risk. For example, in a plausible scenario where the marker is 10 times more common than the causative allele, the excess familial risk of the causative allele is over 10 times higher than that of the marker allele. However, the population attributable fractions of the two alleles are equal. The penetrance mode of the causative locus may be very difficult to deduce from the apparent penetrance mode of the marker locus

Consensus Pathways Implicated in Prognosis of Colorectal Cancer Identified Through Systematic Enrichment Analysis of Gene Expression Profiling Studies

Background: A large number of gene expression profiling (GEP) studies on prognosis of colorectal cancer (CRC) has been performed, but no reliable gene signature for prediction of CRC prognosis has been found. Bioinformatic enrichment tools are a powerful approach to identify biological processes in high-throughput data analysis. Principal Findings: We have for the first time collected the results from the 23 so far published independent GEP studies on CRC prognosis. In these 23 studies, 1475 unique, mapped genes were identified, from which 124 (8.4%) were reported in at least two studies, with 54 of them showing consisting direction in expression change between the single studies. Using these data, we attempted to overcome the lack of reproducibility observed in the genes reported in individual GEP studies by carrying out a pathway-based enrichment analysis. We used up to ten tools for overrepresentation analysis of Gene Ontology (GO) categories or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in each of the three gene lists (1475, 124 and 54 genes). This strategy, based on testing multiple tools, allowed us to identify the oxidative phosphorylation chain and the extracellular matrix receptor interaction categories, as well as a general category related to cell proliferation and apoptosis, as the only significantly and consistently overrepresented pathways in the three gene lists, which were reported by several enrichment tools. Conclusions: Our pathway-based enrichment analysis of 23 independent gene expression profiling studies on prognosis of CRC identified significantly and consistently overrepresented prognostic categories for CRC. These overrepresented categories have been functionally clearly related with cancer progression, and deserve further investigation