Modification of cancer risks in offspring by sibling and parental cancers from 2,112,616 nuclear families

Advancing GCT Management: A Review of miR-371a-3p and Other miRNAs in Comparison to Traditional Serum Tumor Markers

MicroRNAs, short non-protein coding RNAs, are overexpressed in GCTs. Circulating levels of germ cell tumor (GCT)-associated miRNAs, such as miR-371a-3p, can be utilized as efficient and cost-effective alternatives in diagnosing and managing patients presenting with GCTs. This quality of miRNAs has demonstrated favorable performance characteristics as a reliable blood-based biomarker with high diagnostic accuracy compared to current serum tumor markers (STMs), including α-fetoprotein (AFP), beta human chorionic gonadotropin (β-hCG), and lactate dehydrogenase (LDH). The conventional STMs exhibit limited specificity and sensitivity. Potential clinical implications of miRNAs include impact on de-escalating or intensifying treatment, detecting recurrence at earlier stages, and lessening the necessity of cross-sectional imaging or invasive tissue biopsy for non-teratomatous GCTs. Here, we also highlight the outstanding issues that must be addressed prior to clinical implementation. Standards for measuring circulating miRNAs and determining ideal cutoff values are essential for integration into current clinical guidelines.

Role of telomere length in human carcinogenesis (Review)

Cancer is considered the most important clinical, social and economic issue regarding cause‑specific disability‑adjusted life years among all human pathologies. Exogenous, endogenous and individual factors, including genetic predisposition, participate in cancer triggering. Telomeres are specific DNA structures positioned at the end of chromosomes and consist of repetitive nucleotide sequences, which, together with shelterin proteins, facilitate the maintenance of chromosome stability, while protecting them from genomic erosion. Even though the connection between telomere status and carcinogenesis has been identified, the absence of a universal or even a cancer‑specific trend renders consent even more complex. It is indicative that both short and long telomere lengths have been associated with a high risk of cancer incidence. When evaluating risk associations between cancer and telomere length, a disparity appears to emerge. Even though shorter telomeres have been adopted as a marker of poorer health status and an older biological age, longer telomeres due to increased cell growth potential are associated with the acquirement of cancer‑initiating somatic mutations. Therefore, the present review aimed to comprehensively present the multifaceted pattern of telomere length and cancer incidence association.

Thyroid Carcinoma: A Review for 25 Years of Environmental Risk Factors Studies

Environmental factors are established contributors to thyroid carcinomas. Due to their known ability to cause cancer, exposure to several organic and inorganic chemical toxicants and radiation from nuclear weapons, fallout, or medical radiation poses a threat to global public health. Halogenated substances like organochlorines and pesticides can interfere with thyroid function. Like phthalates and bisphenolates, polychlorinated biphenyls and their metabolites, along with polybrominated diethyl ethers, impact thyroid hormones biosynthesis, transport, binding to target organs, and impair thyroid function. A deeper understanding of environmental exposure is crucial for managing and preventing thyroid cancer. This review aims to investigate the relationship between environmental factors and the development of thyroid cancer.

Sex-specific familial aggregation of cancers in Finland

Despite the fact that the effect of sex on the occurrence of cancers has been studied extensively, it remains unclear whether sex modifies familial aggregation of cancers. We explored sex-specific familial aggregation of cancers in a large population-based historical cohort study. We combined cancer and population registry data, inferring familial relationships from birth municipality-surname-sex (MNS) combinations. Our data consisted of 391,529 incident primary cancers in 377,210 individuals with 319,872 different MNS combinations. Cumulative sex-specific numbers of cancers were compared to expected cumulative incidence. Familial cancer risks were similar between the sexes in our population-wide analysis. Families with concordant cancer in both sexes exhibited similar sex-specific cancer risks. However, some families had exceptionally high sex-specific cumulative cancer incidence. We identified six families with exceptionally strong aggregation in males: three families with thyroid cancer (ratio between observed and expected incidence 184.6; 95% credible interval (95% CI) 33.1–1012.7, 173.4 (95% CI 65.4–374.3), and 161.4 (95% CI 29.6–785.7), one with stomach (ratio 14.4 (95% CI 6.9–37.2)), colon (ratio 15.5 (95% CI 5.7–56.3)) cancers and one with chronic lymphocytic leukaemia (ratio 33.5 (95% CI 17.2–207.6)). Our results imply that familial aggregation of cancers shows no sex-specific preference. However, the atypical sex-specific aggregation of stomach cancer, colon cancer, thyroid cancer and chronic lymphocytic leukaemia in certain families is difficult to fully explain with present knowledge of possible causes, and could yield useful knowledge if explored further.

Genetic susceptibility to hereditary non-medullary thyroid cancer

Non-medullary thyroid cancer (NMTC) is the most common type of thyroid cancer. With the increasing incidence of NMTC in recent years, the familial form of the disease has also become more common than previously reported, accounting for 5-15% of NMTC cases. Familial NMTC is further classified as non-syndromic and the less common syndromic FNMTC. Although syndromic NMTC has well-known genetic risk factors, the gene(s) responsible for the vast majority of non-syndromic FNMTC cases are yet to be identified. To date, several candidate genes have been identified as susceptibility genes in hereditary NMTC. This review summarizes genetic predisposition to non-medullary thyroid cancer and expands on the role of genetic variants in thyroid cancer tumorigenesis and the level of penetrance of NMTC-susceptibility genes.

PREDICTION OF HEREDITARY CANCERS USING NEURAL NETWORKS

Family history is a major risk factor for many types of cancer. Mendelian risk prediction models translate family histories into cancer risk predictions, based on knowledge of cancer susceptibility genes. These models are widely used in clinical practice to help identify high-risk individuals. Mendelian models leverage the entire family history, but they rely on many assumptions about cancer susceptibility genes that are either unrealistic or challenging to validate, due to low mutation prevalence. Training more flexible models, such as neural networks, on large databases of pedigrees can potentially lead to accuracy gains. In this paper we develop a framework to apply neural networks to family history data and investigate their ability to learn inherited susceptibility to cancer. While there is an extensive literature on neural networks and their state-of-the-art performance in many tasks, there is little work applying them to family history data. We propose adaptations of fully-connected neural networks and convolutional neural networks to pedigrees. In data simulated under Mendelian inheritance, we demonstrate that our proposed neural network models are able to achieve nearly optimal prediction performance. Moreover, when the observed family history includes misreported cancer diagnoses, neural networks are able to outperform the Mendelian BRCAPRO model embedding the correct inheritance laws. Using a large dataset of over 200,000 family histories, the Risk Service cohort, we train prediction models for future risk of breast cancer. We validate the models using data from the Cancer Genetics Network.

CNV Hotspots in Testicular Seminoma Tissue and Seminal Plasma

Seminoma (SE) is the most frequent type of testicular tumour, affecting predominantly young men. Early detection and diagnosis of SE could significantly improve life quality and reproductive health after diagnosis and treatment. Copy number variation (CNV) has already been associated with various cancers as well as SE. In this study, we selected four genes (MAGEC2, NANOG, RASSF1A, and KITLG) for CNV analysis in genomic DNA (gDNA), which are located on chromosomes susceptible to gains, and whose aberrant expression was already detected in SE. Furthermore, CNV was analysed in cell-free DNA (cfDNA) from seminal plasma. Analysis was performed by droplet digital polymerase chain reaction (ddPCR) on gDNA from SE and nonmalignant testicular tissue. Seminal plasma cfDNA from SE patients before and after surgery was analysed, as well as from healthy volunteers. The CNV hotspot in gDNA from SE tissue was detected for the first time in all analysed genes, and for two genes, NANOG and KITLG it was reflected in cfDNA from seminal plasma. Although clinical value is yet to be determined, presented data emphasize a potential use of CNV as a potential SE biomarker from a liquid biopsy.

Identification of Genetic Risk Factors for Familial Urinary Bladder Cancer: An Exome Sequencing Study

PURPOSE

Previous studies have shown an approximately two-fold elevation in the relative risk of urinary bladder cancer (UBC) among people with a family history that could not be entirely explained by shared environmental exposures, thus suggesting a genetic component in its predisposition. Multiple genome-wide association studies and recent gene panel sequencing studies identified several genetic loci that are associated with UBC risk; however, the list of UBC-associated variants and genes is incomplete.

MATERIALS AND METHODS

We exome sequenced eight patients from three multiplex UBC pedigrees and a group of 77 unrelated familial UBC cases matched to 241 cancer-free controls. In addition, we examined pathogenic germline variation in 444 candidate genes in 392 The Cancer Genome Atlas UBC cases.

RESULTS

In the pedigrees, segregating variants were family-specific although the identified genes clustered in common pathways, most notably DNA repair (MLH1 and MSH2) and cellular metabolism (IDH1 and ME1). In the familial UBC group, the proportion of pathogenic and likely pathogenic variants was significantly higher in cases compared with controls (P = .003). Pathogenic and likely pathogenic variant load was also significantly increased in genes involved in cilia biogenesis (P = .001). In addition, a pathogenic variant in CHEK2 (NM_007194.4:c.1100del; p.T367Mfs*15) was over-represented in cases (variant frequency = 2.6%; 95% CI, 0.71 to 6.52) compared with controls (variant frequency = 0.21%; 95% CI, 0.01 to 1.15), but was not statistically significant.

CONCLUSION

These results point to a complex polygenic predisposition to UBC. Despite heterogeneity, the genes cluster in several biologically relevant pathways and processes, for example, DNA repair, cilia biogenesis, and cellular metabolism. Larger studies are required to determine the importance of CHEK2 in UBC etiology.

Genetics of prostate cancer and its utility in treatment and screening

Prostate cancer heritability is attributed to a combination of rare, moderate to highly penetrant genetic variants as well as commonly occurring variants conferring modest risks [single nucleotide polymorphisms (SNPs)]. Some of the former type of variants (e.g., BRCA2 mutations) predispose particularly to aggressive prostate cancer and confer poorer prognoses compared to men who do not carry mutations. Molecularly targeted treatments such as PARP inhibitors have improved outcomes in men carrying somatic and/or germline DNA repair gene mutations. Ongoing clinical trials are exploring other molecular targeted approaches based on prostate cancer somatic alterations. Genome wide association studies have identified >250 loci that associate with prostate cancer risk. Multi-ancestry analyses have identified shared as well as population specific risk SNPs. Prostate cancer risk SNPs can be used to estimate a polygenic risk score (PRS) to determine an individual's genetic risk of prostate cancer. The odds ratio of prostate cancer development in men whose PRS lies in the top 1% of the risk profile ranges from 9 to 11. Ongoing studies are investigating the utility of a prostate cancer PRS to target population screening to those at highest risk. With the advent of personalized medicine and development of DNA sequencing technologies, access to clinical genetic testing is increasing, and oncology guidelines from bodies such as NCCN and ESMO have been updated to provide criteria for germline testing of "at risk" healthy men as well as those with prostate cancer. Both germline and somatic prostate cancer research have significantly evolved in the past decade and will lead to further development of precision medicine approaches to prostate cancer treatment as well as potentially developing precision population screening models.

Familial Risks and Proportions Describing Population Landscape of Familial Cancer

Simple Summary

Familial cancer can be defined through the occurrence of the same cancer in two or more family members. Hereditary cancer is a narrower definition of high-risk familial aggregation through identified predisposing genes. The absence of correlation between spouses for risk of most cancers, particularly those not related to tobacco smoking or solar exposure, suggests that familial cancers are mainly due to genetic causes. The aim of the present study was to define the frequency and increased risk for familial cancer. Data on 31 of the most common cancers were obtained from the Swedish Family-Cancer Database and familial relative risks (SIRs) were estimated between persons with or without family history of the same cancer in first-degree relatives. Practically all cancers showed a familial risk, with an SIR most commonly around two, or a doubling of the risk because of family history.

Abstract

Background: Familial cancer can be defined through the occurrence of the same cancer in two or more family members. We describe a nationwide landscape of familial cancer, including its frequency and the risk that it conveys, by using the largest family database in the world with complete family structures and medically confirmed cancers. Patients/methods: We employed standardized incidence ratios (SIRs) to estimate familial risks for concordant cancer among first-degree relatives using the Swedish Cancer Registry from years 1958 through 2016. Results: Cancer risks in a 20–84 year old population conferred by affected parents or siblings were about two-fold compared to the risk for individuals with unaffected relatives. For small intestinal, testicular, thyroid and bone cancers and Hodgkin disease, risks were higher, five-to-eight-fold. Novel familial associations included adult bone, lip, pharyngeal, and connective tissue cancers. Familial cancers were found in 13.2% of families with cancer; for prostate cancer, the proportion was 26.4%. High-risk families accounted for 6.6% of all cancer families. Discussion/Conclusion: High-risk family history should be exceedingly considered for management, including targeted genetic testing. For the major proportion of familial clustering, where genetic testing may not be feasible, medical and behavioral intervention should be indicated for the patient and their family members, including screening recommendations and avoidance of carcinogenic exposure.

Germ-line mutations in WDR77 predispose to familial papillary thyroid cancer

The inheritance of predisposition to nonsyndromic familial nonmedullary thyroid cancer (FNMTC) remains unclear. Here, we report six individuals with papillary thyroid cancer (PTC) in two unrelated nonsyndromic FNMTC families. Whole-exome sequencing revealed two germ-line loss-of-function variants occurring within a 28-bp fragment of WDR77, which encodes a core member of a transmethylase complex formed with the protein arginine methyltransferase PRMT5 that is responsible for histone H4 arginine 3 dimethylation (H4R3me2) in frogs and mammals. To date, the association of WDR77 with susceptibility to cancer in humans is unknown. A very rare heterozygous missense mutation (R198H) in WDR77 exon 6 was identified in one family of three affected siblings. A heterozygous splice-site mutation (c.619+1G > C) at the 5' end of intron 6 is present in three affected members from another family. The R198H variant impairs the interaction of WDR77 with PRMT5, and the splice-site mutation causes exon 6 skipping and results in a marked decrease in mutant messenger RNA, accompanied by obviously reduced H4R3me2 levels in mutation carriers. Knockdown of WDR77 results in increased growth of thyroid cancer cells. Whole-transcriptome analysis of WDR77 mutant patient-derived thyroid tissue showed changes in pathways enriched in the processes of cell cycle promotion and apoptosis inhibition. In summary, we report WDR77 mutations predisposing patients to nonsyndromic familial PTC and link germ-line WDR77 variants to human malignant disease.

Associations of genetically predicted circulating insulin-like growth factor-1 and insulin-like growth factor binding protein-3 with bladder cancer risk

Insulin-like growth factors (IGF) play important roles in carcinogenesis. The associations of circulating IGF-1 and insulin-like growth factor-binding protein-3 (IGFBP-3) with the risks of bladder cancer remain unclear. In this large case control study of 2011 bladder cancer cases and 2369 heathy controls, we assessed the associations of circulating IGF-1 and IGFBP-3 with bladder cancer risks using a Mendelian randomization approach, which uses genetic variants as instruments to study causal relationship between risk factors and diseases. We first constructed a weighted genetic risk score (GRS) predictive of circulating IGF-1 and IGFBP-3 using 413 genome-wide association study-identified single nucleotide polymorphisms (SNPs) associated with IGF-1 and four SNPs with IGFBP-3, respectively. We found that higher GRS for IGF-1 was associated with a significantly reduced bladder cancer risk (odds ratio [OR] = 0.66 per SD increase, 95% confidence interval [CI], 0.54-0.82, p < 0.001). We then used a summary statistics-based MR method, inverse-variance weighting (IVW), and found a similar risk estimate (OR = 0.67 per SD increase, 95% CI = 0.54-0.83, p < 0.001). When we categorized individuals into high and low IGF-1 groups using the median GRS value in the controls, the high GRS group had a 21% reduced bladder cancer risk (OR = 0.79, 95% CI = 0.70-0.89) compared to the low GRS group. Genetically predicted circulating IGFBP-3 was not associated with bladder cancer risk. In conclusion, our data demonstrated for the first time a strong inverse relationship between circulating IGF-1 level and bladder cancer risk.

Are there monogenic hereditary forms of bladder cancer or only genetic susceptibilities?

Bladder cancer (BC) is the most common cancer involving the urinary system and the ninth most common cancer worldwide. Tobacco smoking is the most important environmental risk factor of BC. Several single nucleotide polymorphisms have been validated by genome-wide association studies as genetic risk factors for BC. However, the identification of DNA mismatch-repair genes, including MSH2 in Lynch syndrome and MUTYH in MUTYH-associated polyposis, raises the possibility of monogenic hereditary forms of BC. Moreover, other genetic mutations may play a key role in familial and hereditary transmissions of BC. Therefore, the aim of this review is to focus on the major hereditary syndromes involved in the development of BC and to report BC genetic susceptibilities established with genome-wide significance level.

Genetic predisposition to prostate cancer: an update

Improvements in DNA sequencing technology and discoveries made by large scale genome-wide association studies have led to enormous insight into the role of genetic variation in prostate cancer risk. High-risk prostate cancer risk predisposition genes exist in addition to common germline variants conferring low-moderate risk, which together account for over a third of familial prostate cancer risk. Identifying men with additional risk factors such as genetic variants or a positive family history is of clinical importance, as men with such risk factors have a higher incidence of prostate cancer with some evidence to suggest diagnosis at a younger age and poorer outcomes. The medical community remains in disagreement on the benefits of a population prostate cancer screening programme reliant on PSA testing. A reduction in mortality has been demonstrated in many studies, but at the cost of significant amounts of overdiagnosis and overtreatment. Developing targeted screening strategies for high-risk men is currently the subject of investigation in a number of prospective studies. At present, approximately 38% of the familial risk of PrCa can be explained based on published SNPs, with men in the top 1% of the risk profile having a 5.71-fold increase in risk of developing cancer compared with controls. With approximately 170 prostate cancer susceptibility loci now identified in European populations, there is scope to explore the clinical utility of genetic testing and genetic-risk scores in prostate cancer screening and risk stratification, with such data in non-European populations eagerly awaited. This review will focus on both the rare and common germline genetic variation involved in hereditary and familial prostate cancer, and discuss ongoing research in exploring the role of targeted screening in this high-risk group of men.

Precision Prevention: The Current State and Future of Genomically Guided Cancer Prevention

The identification of cancer-predisposing germline variants has potentially substantial clinical impact for patients and their families. Although management guidelines have been proposed for some genes, guidelines for other genes are lacking. This review focuses on the current surveillance and management guidelines for the most common hereditary cancer syndromes and discusses some of the most pivotal studies supporting the available guidelines. We also highlight the gaps in the identification of germline carriers, the cascade testing of at-risk relatives, and the challenges impeding the proper follow-up and optimal management of pathogenic germline carriers. The anticipated surge in the number of identified germline carriers, deficient management guidelines, poor cascade testing uptake, and long-term follow-up necessitate the development of multidisciplinary clinics as an obligatory step toward the improvement of cancer prevention.

Familial testicular germ cell tumors in two brothers

INTRODUCTION

Two percent of testicular germ cell tumors occur in family clusters. Here, we report metachronous testicular germ cell tumors in two brothers.

CASE PRESENTATION

An elder brother was diagnosed at the age of 30 years old and the pathological diagnosis was mixed testicular germ cell tumor. A tumor in the younger brother was suspected during testicular self-examination. It was confirmed by ultrasound examination at the age of 30 years old, 3 years and 6 months after the diagnosis of the testicular tumor in elder brother. The pathological diagnosis was pure seminoma. Both brothers had stage 1 testicular germ cell tumors and no recurrence was observed during the follow-up period of 4 years and 4 months and 10 months, respectively.

CONCLUSION

Various histological types of tumor can occur in members of one family. Besides genetic predisposition, shared diet, environmental exposure and other factors can contribute to the familial testicular cancer. Testicular self-examination is recommended for family members of a person with testicular germ cell tumor.

Linking population-based registries to identify familial cancer risk in childhood cancer

BACKGROUND

Linked population-based registries provide a unique source for identification of new family cancer syndromes and for elucidating risk of early-onset cancer in close relatives of cancer patients.

METHODS

Using the Finnish Cancer Registry, we identified 9078 probands who had been diagnosed with cancer at <21 years of age between 1970 and 2012. Siblings, offspring, parents, nephews, and nieces of probands were identified from the Population Registry. Childhood and young adult (ChYA) cancer diagnoses (age 0-39 years) in relatives were identified by linking to the Finnish Cancer Registry. The relative risk of ChYA cancer in family members of probands was estimated using standardized incidence ratios (SIRs).

RESULTS

Among 58,010 family members of the 9078 probands, 363 ChYA cancers were diagnosed, 324 of which were expected (SIR, 1.12; 95% CI, 1.01-1.24). The risk of ChYA cancer was elevated both in offspring (SIR, 2.25; 95% CI, 1.51-3.24) and in siblings (SIR, 1.17; 95% CI, 1.01-1.36). Offspring of probands with retinoblastoma were at highest risk (SIR, 75.85; 95% CI, 32.75-149.45); risks were also elevated for siblings of probands with lymphoma (SIR, 1.62; 95% CI, 1.14-2.25). Known cancer predisposition syndromes were observed in 29 (66%) of 44 sibling pairs with cancers diagnosed at <21 years of age and in 20% of the 135 families with a childhood cancer proband whose sibling was diagnosed with a young adult malignancy.

CONCLUSION

Linked population-based registry data indicate a modestly increased risk of ChYA in relatives of children with cancer. Some of the observed cancer clusters in the cohort suggest novel patterns and familial cancer syndromes.

Assessing thyroid cancer risk using polygenic risk scores

Genome-wide association studies (GWASs) have identified at least 10 single-nucleotide polymorphisms (SNPs) associated with papillary thyroid cancer (PTC) risk. Most of these SNPs are common variants with small to moderate effect sizes. Here we assessed the combined genetic effects of these variants on PTC risk by using summarized GWAS results to build polygenic risk score (PRS) models in three PTC study groups from Ohio (1,544 patients and 1,593 controls), Iceland (723 patients and 129,556 controls), and the United Kingdom (534 patients and 407,945 controls). A PRS based on the 10 established PTC SNPs showed a stronger predictive power compared with the clinical factors model, with a minimum increase of area under the receiver-operating curve of 5.4 percentage points (P ≤ 1.0 × 10^-9). Adding an extended PRS based on 592,475 common variants did not significantly improve the prediction power compared with the 10-SNP model, suggesting that most of the remaining undiscovered genetic risk in thyroid cancer is due to rare, moderate- to high-penetrance variants rather than to common low-penetrance variants. Based on the 10-SNP PRS, individuals in the top decile group of PRSs have a close to sevenfold greater risk (95% CI, 5.4-8.8) compared with the bottom decile group. In conclusion, PRSs based on a small number of common germline variants emphasize the importance of heritable low-penetrance markers in PTC.

Variants in LRRC34 reveal distinct mechanisms for predisposition to papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) demonstrates high heritability and a low somatic mutation burden relative to other cancers. Therefore, the genetic risk predisposing to PTC is likely due to a combination of low penetrance variants. A recent genome-wide association study revealed the association of PTC with a missense variant, rs6793295, at 3q26 in a gene called Leucine Repeat Rich Containing 34 (LRRC34).

METHODS

We report the mechanisms of PTC risk at 3q26 using a combination of overexpression, mass spectroscopy, knockdown, transcriptome profiling, migration assays and genetic analysis.

RESULTS

We observed differential binding of wild-type and missense LRRC34 to RANBP1. Overexpression of missense LRRC34 reduced RanGTP levels and increased apoptosis. We also identified a second linkage disequilibrium (LD) block upstream of LRRC34 containing regulatory variants with allele-specific expression. Transcriptome profiling of LRRC34 knockdown cells showed changes in genes involved with cellular movement. LRRC34 knockdown reduced the migration of thyroid cancer cell lines. Lastly, we assessed the relative contribution of PTC risk from each locus using haplotype analysis.

CONCLUSIONS

Our study demonstrates two separate mechanisms, one in G protein signalling and the other in transcriptional control, dictating PTC risk at 3q26 using both biochemical and genetic techniques.

Glycan Analysis as Biomarkers for Testicular Cancer

The U.S. Preventive Services Task Force does not recommend routine screening for testicular cancer (TC) in asymptomatic men, essentially because serological testicular cancer (TC) biomarkers are not reliable. The main reason is that two of the most important TC biomarkers, α-fetoprotein (AFP) and human chorionic gonadotropin (hCG), are not produced solely due to TC. Moreover, up to 40% of patients with TC do not have elevated serological biomarkers, which is why serial imaging with CT is the chief means of monitoring progress. On the other hand, exposure to radiation can lead to an increased risk of secondary malignancies. This review provides the first comprehensive account of the applicability of protein glycoprofiling as a promising biomarker for TC with applications in disease diagnostics, monitoring and recurrence evaluation. The review first deals with the description and classification of TC. Secondly, the limitations of current TC biomarkers such as hCG, AFP and lactate dehydrogenase are provided together with an extensive overview of the glycosylation of hCG and AFP related to TC. The final part of the review summarises the potential of glycan changes on either hCG and AFP as TC biomarkers for diagnostics and prognostics purposes, and for disease recurrence evaluation. Finally, an analysis of glycans in serum and tissues as TC biomarkers is also provided.

Identification of Rare Variants Predisposing to Thyroid Cancer

Background: Familial non-medullary thyroid cancer (NMTC) accounts for a relatively small proportion of thyroid cancer cases, but it displays strong genetic predisposition. So far, only a few NMTC susceptible genes and low-penetrance variants contributing to NMTC have been described. This study aimed to identify rare germline variants that may predispose individuals to NMTC by sequencing a cohort of 17 NMTC families. Methods: Whole-genome sequencing and genome-wide linkage analysis were performed in 17 NMTC families. MendelScan and BasePlayer were applied to screen germline variants followed by customized filtering. The remaining candidate variants were subsequently validated by Sanger sequencing. A panel of 277 known cancer predisposition genes was also screened in these families. Results: A total of 41 rare coding candidate variants in 40 genes identified by whole-genome sequencing are reported, including 24 missense, five frameshift, five splice change, and seven nonsense variants. Sanger sequencing confirmed all 41 rare variants and proved their co-segregation with NMTC in the extended pedigrees. In silico functional analysis of the candidate genes using Ingenuity Pathway Analysis showed that cancer was the top category of "Diseases and Disorders." Additionally, a targeted search displayed six variants in known cancer predisposition genes, including one frameshift variant and five missense variants. Conclusions: The data identify rare germline variants that may play important roles in NMTC predisposition. It is proposed that in future research including functional characterization, these variants and genes be considered primary candidates for thyroid cancer predisposition.

Familial aggregation of early-onset cancers

This registry‐linkage study evaluates familial aggregation of cancer among relatives of a population‐based series of early‐onset (≤40 years) cancer patients in Finland. A cohort of 376,762 relatives of early‐onset cancer patients diagnosed between 1970 and 2012 in 40,538 families was identified. Familial aggregation of early‐onset breast, colorectal, brain and other central nervous system (CNS) cancer and melanoma was explored by standardized incidence ratios (SIR), stratified by relatedness. Gender‐, age‐ and period‐specific population cancer incidences were used as reference. Cumulative risks for siblings and offspring of the proband up to age ≤40 years were also estimated. Almost all early‐onset cancers were sporadic (98% or more). Among first‐degree relatives, SIR was largest in colorectal cancer (14, 95% confidence interval 9.72–18), and lowest in melanoma (1.93, 1.05–3.23). Highest relative‐specific SIRs were observed for siblings in families, where also parent had concordant cancer, 90 (43–165) for colorectal cancer and 29 (11–64) for CNS cancer. In spouses, all SIRs were at population level. Cumulative risk of colorectal cancer by age 41 was 0.98% in siblings and 0.10% in population, while in breast cancer the corresponding risks were 2.05% and 0.56%. In conclusion, early‐onset cancers are mainly sporadic. Findings support high familial aggregation in early‐onset colorectal and CNS cancers. Familial aggregation in multiplex families with CNS cancers was mainly attributed to neurofibromatosis and in colorectal cancer to FAP‐ and HNPCC‐syndromes. The pattern of familial aggregation of early‐onset breast cancer could be seen to support very early exposure to environmental factors and/or rare genetic factors.

What's new?

The tendency for certain cancer types to cluster in families generally is explained by shared environmental exposures or inherited mutations. In particular, early‐onset cancer, diagnosed between ages 0 and 40, is considered indicative of familial factors. Here, investigation of cancer risk among more than 376,760 relatives of probands, or individuals with early‐onset cancer, shows that the likelihood of early‐onset cancer affecting even just one other relative in addition to the proband is exceedingly rare. Nearly all early‐onset cancers in the study population were sporadic. Estimated cumulative risks observed for specific cancers may prove useful in the context of genetic counseling.

Testicular cancer

Testicular cancer is the most common malignancy among men between 14 and 44 years of age, and its incidence has risen over the past two decades in Western countries. Both genetic and environmental factors contribute to the development of testicular cancer, for which cryptorchidism is the most common risk factor. Progress has been made in our understanding of the disease since the initial description of carcinoma in situ of the testis in 1972 (now referred to as germ cell neoplasia in situ), which has led to improved treatment options. The combination of surgery and cisplatin-based chemotherapy has resulted in a cure rate of >90% in patients with testicular cancer, although some patients become refractory to chemotherapy or have a late relapse; an improved understanding of the molecular determinants underlying tumour sensitivity and resistance may lead to the development of novel therapies for these patients. This Primer provides an overview of the biology, epidemiology, diagnosis and current treatment guidelines for testicular cancer, with a focus on germ cell tumours. We also outline areas for future research and what to expect in the next decade for testicular cancer.

Family history of colorectal cancer in first-degree relatives and metachronous colorectal adenoma

OBJECTIVES

Little is known about the relationship between having a first-degree relative (FDR) with colorectal cancer (CRC) and risk for metachronous colorectal adenoma (CRA) following polypectomy.

METHODS

We pooled data from seven prospective studies of 7697 patients with previously resected CRAs to quantify the relationship between having a FDR with CRC and risk for metachronous adenoma.

RESULTS

Compared with having no family history of CRC, a positive family history in any FDR was significantly associated with increased odds of developing any metachronous CRA (OR = 1.14; 95% CI = 1.01-1.29). Higher odds of CRA were observed among individuals with an affected mother (OR = 1.27; 95% CI = 1.05-1.53) or sibling (OR = 1.34; 95% CI = 1.11-1.62) as compared with those without, whereas no association was shown for individuals with an affected father. Odds of having a metachronous CRA increased with number of affected FDRs, with ORs (95% CIs) of 1.07 (0.93-1.23) for one relative and 1.39 (1.02-1.91) for two or more. Younger age of diagnosis of a sibling was associated with higher odds of metachronous CRA, with ORs (95% CIs) of 1.66 (1.08-2.56) for diagnosis at <54 years; 1.34 (0.89-2.03) for 55-64 years; and 1.10 (0.70-1.72) for >65 years (p-trend = 0.008). Although limited by sample size, results for advanced metachronous CRA were similar to those for any metachronous CRA.

CONCLUSIONS

A family history of CRC is related to a modestly increased odds of metachronous CRA. Future research should explore whether having a FDR with CRC, particularly at a young age, should have a role in risk stratification for surveillance colonoscopy.

Can a gastric cancer risk survey identify high-risk patients for endoscopic screening? A pilot study

BACKGROUND

A questionnaire that distinguishes how variability in gastric cancer prevalence is associated with ethnicity/birth country/immigration/cultural diet along with known risk factors may improve targeting populations for gastric cancer screening in the United States.

METHODS

Existing literature was used to identify the item pool. Cluster analysis, focus groups, and cognitive interviewing were used to reduce collinear items and refine the questionnaire. Logistic regression analysis was used to determine which items distinguished gastric cancer cases from the primary care and community controls.

RESULTS

The results of analysis of data from 40 cases and 100 controls (primary care = 47; community = 53) were used to reduce the 227 item pool to 12 items. After ranking these variables using model bootstrapping, a logistic regression model using the highest ranked eight variables was chosen as the final model. Older age, foreign nativity, daily consumption of cultural food at ages 15-18, less than high-school education, and greater acculturation were significantly associated with being a gastric cancer case compared with the controls.

CONCLUSIONS

An eight-item survey that addresses gastric cancer risk factors, ethnicity, cultural habits, and immigration patterns has potential to identify high-risk persons from multicultural areas within the US, who might benefit from endoscopic screening for gastric cancer.

Inherited forms of bladder cancer: a review of Lynch syndrome and other inherited conditions

Environmental factors that play a role in the urothelial carcinogenesis have been well characterized. Current research is continuously exploring potential heritable forms of bladder cancer. Lynch syndrome is a well-known inheritable disease that increases the risk for a variety of cancers, including urothelial carcinomas. Screening of patients with known Lynch syndrome is important to evaluate for development of new primary tumors. Further study may provide more information on what level of follow-up each patient needs. Recent data suggest that mismatch repair mutations confer a greater risk for urothelial cancer. Additional large patient series as well as advancement of molecular testing may provide triage for Lynch syndrome patients in regards to the frequency and type of screening best suited for individual patient.

Non-BRCA familial breast cancer: review of reported pathology and molecular findings

The majority of women evaluated for a clinical concern of possible hereditary breast cancer syndromes have no identified pathogenic variants in genes predisposing them to breast cancer. Non-BRCA1- or BRCA2-related familial breast cancer, also called 'BRCAX', thus comprises a sizeable proportion of familial breast cancer but it is poorly understood. In this study, we reviewed 14 studies on histopathology and molecular studies of BRCAX to determine if there were differences between 'sporadic' breast cancers and compared to cancers arising in women harbouring variants in known cancer predisposition genes. Across available literature, there was inconsistency on inclusion and exclusion criteria, reported parameters, and use of controls. Cohorts were small, and while several studies reported findings that appeared to distinguish the BRCAX cases from sporadic and/or gene-positive controls, no findings were reported in more than one study. To determine whether the BRCAX families might still contain important genetic subsets awaiting discovery will require prospective ascertainment of a large number of women with familial breast cancer who are screened for all currently established predisposition genes, whose tumours are assessed for multiple parameters in a uniform manner, and in which controls (BRCA1/2+ and non-familial 'sporadic' cases) are collected from the same population.

Estimation of heritability for nine common cancers using data from genome-wide association studies in Chinese population

The familial aggregation indicated the inheritance of cancer risk. Recent genome-wide association studies (GWASs) have identified a number of common single-nucleotide polymorphisms (SNPs). Following heritability analyses have shown that SNPs could explain a moderate amount of variance for different cancer phenotypes among Caucasians. However, little information was available in Chinese population. We performed a genome-wide complex trait analysis for common cancers at nine anatomical sites in Chinese population (14,629 cancer cases vs. 17,554 controls) and estimated the heritability of these cancers based on the common SNPs. We found that common SNPs explained certain amount of heritability with significance for all nine cancer sites: gastric cancer (20.26%), esophageal squamous cell carcinoma (19.86%), colorectal cancer (16.30%), lung cancer (LC) (15.17%), and epithelial ovarian cancer (13.31%), and a similar heritability around 10% for hepatitis B virus-related hepatocellular carcinoma, prostate cancer, breast cancer and nasopharyngeal carcinoma. We found that nearly or less than 25% change was shown when removing the regions expanding 250 kb or 500 kb upward and downward of the GWAS-reported SNPs. We also found strong linear correlations between variance partitioned by each chromosome and chromosomal length only for LC (R2  = 0.641, p = 0.001) and esophageal squamous cell cancer (R2  = 0.633, p = 0.002), which implied us the complex heterogeneity of cancers. These results indicate polygenic genetic architecture of the nine common cancers in Chinese population. Further efforts should be made to discover the hidden heritability of different cancer types among Chinese.

Inherited Forms of Renal Cell Carcinoma

It is estimated that up to 2% of renal cell cancer (RCC) clusters in families. Several forms of hereditary RCC have been characterized with specific clinical, histopathological, and genetic features. The most common of these is von Hippel-Lindau (VHL) disease caused by mutations in the VHL gene and predisposing to clear cell RCC. Predisposition to papillary RCC is present in hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary papillary renal cell carcinoma (HPRC). Identification of the genetic defects causing these diseases has enlightened the molecular pathogenesis of RCC, and moreover, provided means to improve patient management. Genetic testing enables early diagnosis of the disease, after which individuals at-risk can be guided to regular surveillance. Screening facilitates detection of presymptomatic early tumors broadening treatment options and potentially improving prognosis. Thus, identification of individuals with inherited cancer susceptibility is important as special management of these patients improves disease outcome. The purpose of this review is to provide clues for identification and management of hereditary renal cancer patients in clinical practice.

ENDOCRINE TUMOURS: Advances in the molecular pathogenesis of thyroid cancer: lessons from the cancer genome

Thyroid cancer is the most common endocrine malignancy giving rise to one of the most indolent solid cancers, but also one of the most lethal. In recent years, systematic studies of the cancer genome, most importantly those derived from The Cancer Genome Altas (TCGA), have catalogued aberrations in the DNA, chromatin, and RNA of the genomes of thousands of tumors relative to matched normal cellular genomes and have analyzed their epigenetic and protein consequences. Cancer genomics is therefore providing new information on cancer development and behavior, as well as new insights into genetic alterations and molecular pathways. From this genomic perspective, we will review the main advances concerning some essential aspects of the molecular pathogenesis of thyroid cancer such as mutational mechanisms, new cancer genes implicated in tumor initiation and progression, the role of non-coding RNA, and the advent of new susceptibility genes in thyroid cancer predisposition. This look across these genomic and cellular alterations results in the reshaping of the multistep development of thyroid tumors and offers new tools and opportunities for further research and clinical development of novel treatment strategies.

Papillary Thyroid Carcinoma: Association Between Germline DNA Variant Markers and Clinical Parameters

BACKGROUND

Papillary thyroid cancer (PTC) is reported to be highly heritable in epidemiological studies. Genome-wide association studies (GWAS) have uncovered several variants associated with PTC predisposition. It remains unknown whether these variants might contribute to better clinical stratification of PTC patients.

METHODS

In order to assess the usefulness of germline genetic analyses in the management of PTC patients, the genotypes of five variants (rs965513, rs944289, rs116909374, rs2439302, and rs966423) were determined in 1216 PTC patients and 1416 controls. Additionally, the expression of seven genes located close to GWAS variants (PTCSC3, MBIP, NKX2-1, FOXE1, DIRC3, PTCSC2, and NRG1) were measured in 73 PTC paired tumor/normal tissues, respectively. Next, the association was analyzed between the genotypes of the germline variants and the levels of gene expression with clinical/pathological features such as age, sex, TNM staging, multifocality status, extrathyroidal expansion, and MACIS score.

RESULTS

The risk allele of rs965513 was associated with larger tumor size (p = 0.025) and extrathyroidal expansion (odd ratio [OR] = 1.29, p = 0.045). The variant rs2439302 showed association with lymph node metastasis (OR = 1.24, p = 0.016), and multifocality status of the tumor (OR = 1.24, p = 0.012). The expression of MBIP was associated with T stage (p = 0.010). MBIP and PTCSC3 displayed lower expression in PTC tissue in males than in females (p = 0.025 and p = 0.036, respectively). NKX2-1 displayed lower expression in patients with N1 stage (p = 0.040).

CONCLUSIONS

The studied germline risk alleles predisposing to PTC were associated with a more aggressive course of the disease reflected by larger tumor diameter, higher multifocality rate, and more advanced N stage at the time of diagnosis. These results show that germline variants not only predispose to PTC but also might impact its clinical course. However, these associations were only moderate, and further large multi-ethnic studies are required to evaluate the usefulness of these germline variants in the clinical stratification of PTC patients.

Genome-Wide Association Study of Bladder Cancer in a Chinese Cohort Reveals a New Susceptibility Locus at 5q12.3

Genome-wide association studies (GWAS) of bladder cancer have identified a number of susceptibility loci in European populations but have yet to uncover the genetic determinants underlying bladder cancer incidence among other ethnicities. Therefore, we performed the first GWAS in a Chinese cohort comprising 3,406 cases of bladder cancer and 4,645 controls. We identified a new susceptibility locus for bladder cancer at 5q12.3, located in the intron of CWC27 (rs2042329), that was significantly associated with disease risk (OR = 1.40; P = 4.61 × 10(-11)). However, rs2042329 was not associated with bladder cancer risk in patients of European descent. The rs2042329 risk allele was also related to significantly increased expression levels of CWC27 mRNA and protein in bladder cancer tissues from Chinese patients. Additional functional analyses suggested that CWC27 played an oncogenic role in bladder cancer by inducing cell proliferation and suppressing apoptosis. In conclusion, the identification of a risk-associated locus at 5q12.3 provides new insights into the inherited susceptibility to bladder cancer in Chinese populations and may help to identify high-risk individuals. Cancer Res; 76(11); 3277-84. ©2016 AACR.

Identification of a novel susceptibility locus at 13q34 and refinement of the 20p12.2 region as a multi-signal locus associated with bladder cancer risk in individuals of European ancestry

Candidate gene and genome-wide association studies (GWAS) have identified 15 independent genomic regions associated with bladder cancer risk. In search for additional susceptibility variants, we followed up on four promising single-nucleotide polymorphisms (SNPs) that had not achieved genome-wide significance in 6911 cases and 11 814 controls (rs6104690, rs4510656, rs5003154 and rs4907479, P < 1 × 10(-6)), using additional data from existing GWAS datasets and targeted genotyping for studies that did not have GWAS data. In a combined analysis, which included data on up to 15 058 cases and 286 270 controls, two SNPs achieved genome-wide statistical significance: rs6104690 in a gene desert at 20p12.2 (P = 2.19 × 10(-11)) and rs4907479 within the MCF2L gene at 13q34 (P = 3.3 × 10(-10)). Imputation and fine-mapping analyses were performed in these two regions for a subset of 5551 bladder cancer cases and 10 242 controls. Analyses at the 13q34 region suggest a single signal marked by rs4907479. In contrast, we detected two signals in the 20p12.2 region-the first signal is marked by rs6104690, and the second signal is marked by two moderately correlated SNPs (r(2) = 0.53), rs6108803 and the previously reported rs62185668. The second 20p12.2 signal is more strongly associated with the risk of muscle-invasive (T2-T4 stage) compared with non-muscle-invasive (Ta, T1 stage) bladder cancer (case-case P ≤ 0.02 for both rs62185668 and rs6108803). Functional analyses are needed to explore the biological mechanisms underlying these novel genetic associations with risk for bladder cancer.

BRAF-Activated Long Noncoding RNA Modulates Papillary Thyroid Carcinoma Cell Proliferation through Regulating Thyroid Stimulating Hormone Receptor

PURPOSE

The importance of long noncoding RNAs (lncRNAs) in tumorigenesis has recently been demonstrated. However, the role of lncRNAs in development of thyroid cancer remains largely unknown.

MATERIALS AND METHODS

Using quantitative reverse transcription polymerase chain reaction, expression of three lncRNAs, including BRAF-activated long noncoding RNA (BANCR), papillary thyroid cancer susceptibility candidate 3 (PTCSC3), and noncoding RNA associated with mitogen-activated protein kinase pathway and growth arrest (NAMA), was investigated in the current study.

RESULTS

Of the three lncRNAs (BANCR, PTCSC3, and NAMA), expression of BANCR was significantly up-regulated while PTCSC3 and NAMA were significantly down-regulated in papillary thyroid carcinoma (PTC) compared to that in normal tissue. BANCR-knockdown in a PTC-derived cell line (IHH-4) resulted in significant suppression of thyroid stimulating hormone receptor (TSHR). BANCR-knockdown also led to inhibition of cell growth and cell cycle arrest at G0/G1 phase through down-regulation of cyclin D1. In addition, BANCR was enriched by polycomb enhancer of zeste homolog 2 (EZH2), and silencing BANCR led to decreased chromatin recruitment of EZH2, which resulted significantly reduced expression of TSHR.

CONCLUSION

These findings indicate that BANCR may contribute to the tumorigenesis of PTC through regulation of cyclin D1 and TSHR.

A germline mutation in SRRM2, a splicing factor gene, is implicated in papillary thyroid carcinoma predisposition

Papillary thyroid carcinoma (PTC) displays strong but so far largely uncharacterized heritability. Here we studied genetic predisposition in a family with six affected individuals. We genotyped all available family members and conducted whole exome sequencing of blood DNA from two affected individuals. Haplotype analysis and other genetic criteria narrowed our list of candidates to a germline variant in the serine/arginine repetitive matrix 2 gene (SRRM2). This heterozygous variant, c.1037C > T (Ser346Phe or S346F; rs149019598) cosegregated with PTC in the family. It was not found in 138 other PTC families. It was found in 7/1,170 sporadic PTC cases and in 0/1,404 controls (p = 0.004). The encoded protein SRRM2 (also called SRm300) is part of the RNA splicing machinery. To evaluate the possibility that the S346F missense mutation affects alternative splicing, we compared RNA-Seq data in leukocytes from three mutation carriers and three controls. Significant differences in alternative splicing were identified for 1,642 exons, of which a subset of 7 exons was verified experimentally. The results confirmed a higher ratio of inclusion of exons in mutation carriers. These data suggest that the S346F mutation in SRRM2 predisposes to PTC by affecting alternative splicing of unidentified downstream target genes.

Multiple functional variants in long-range enhancer elements contribute to the risk of SNP rs965513 in thyroid cancer

The [A] allele of SNP rs965513 in 9q22 has been consistently shown to be highly associated with increased papillary thyroid cancer (PTC) risk with an odds ratio of ∼1.8 as determined by genome-wide association studies, yet the molecular mechanisms remain poorly understood. Previously, we noted that the expression of two genes in the region, forkhead box E1 (FOXE1) and PTC susceptibility candidate 2 (PTCSC2), is regulated by rs965513 in unaffected thyroid tissue, but the underlying mechanisms were not elucidated. Here, we fine-mapped the 9q22 region in PTC and controls and detected an ∼33-kb linkage disequilibrium block (containing the lead SNP rs965513) that significantly associates with PTC risk. Chromatin characteristics and regulatory element signatures in this block disclosed at least three regulatory elements functioning as enhancers. These enhancers harbor at least four SNPs (rs7864322, rs12352658, rs7847449, and rs10759944) that serve as functional variants. The variant genotypes are associated with differential enhancer activities and/or transcription factor binding activities. Using the chromosome conformation capture methodology, long-range looping interactions of these elements with the promoter region shared by FOXE1 and PTCSC2 in a human papillary thyroid carcinoma cell line (KTC-1) and unaffected thyroid tissue were found. Our results suggest that multiple variants coinherited with the lead SNP and located in long-range enhancers are involved in the transcriptional regulation of FOXE1 and PTCSC2 expression. These results explain the mechanism by which the risk allele of rs965513 predisposes to thyroid cancer.

Nontesticular cancers in relatives of testicular germ cell tumor (TGCT) patients from multiple-case TGCT families

Testicular germ cell tumors (TGCT) exhibit striking familial aggregation that remains incompletely explained. To improve the phenotypic definition of familial TGCT (FTGCT), we studied an international cohort of multiple-case TGCT families to determine whether first-degree relatives of FTGCT cases are at increased risk of other types of cancer. We identified 1041 first-degree relatives of TGCT cases in 66 multiple-case TGCT families from Norway and 64 from the United States (combined follow-up of 31,556 person-years). We collected data on all cancers (except nonmelanoma skin cancers) reported by the family informant in these relatives, and we attempted to verify all reported cancer diagnoses through medical or cancer registry records. We calculated observed-to-expected (O/E) standardized incidence ratios, together with 95% confidence intervals (CI), for invasive cancers other than TGCT. We found no increase in risk of cancer overall (Norway O/E = 0.8; 95% CI: 0.6–1.1 and United States O/E = 0.9; 95% CI: 0.7–1.3). Site-specific analyses pooled across the two countries revealed a leukemia excess (O/E = 6.5; 95% CI: 3.0–12.3), deficit of female breast cancer (O/E = 0.0; 95% CI: 0.0–0.6) and increased risk of soft tissue sarcoma (O/E = 7.2; 95% CI: 2.0–18.4); in all instances, these results were based on small case numbers and statistically significant only in Norway. While limited by sample size and potential issues relating to completeness of cancer reporting, this study in multiple-case TGCT families does not support the hypothesis that cancers other than testis cancer contribute to the FTGCT phenotype.

CHEK2 mutations and the risk of papillary thyroid cancer

Mutations in the cell cycle checkpoint kinase 2 (CHEK2) tumor suppressor gene are associated with multi-organ cancer susceptibility including cancers of the breast and prostate. A genetic association between thyroid and breast cancer has been suggested, however little is known about the determinants of this association. To characterize the association of CHEK2 mutations with thyroid cancer, we genotyped 468 unselected patients with papillary thyroid cancer and 468 (matched) cancer-free controls for four founder mutations of CHEK2 (1100delC, IVS2 + 1G>A, del5395 and I157T). We compared the family histories reported by patients with a CHEK2 mutation to those of non-carriers. A CHEK2 mutation was seen in 73 of 468 (15.6%) unselected patients with papillary thyroid cancer, compared to 28 of 460 (6.0%) age- and sex-matched controls (OR 3.3; p < 0.0001). A truncating mutation (IVS2 + 1G>A, 1100delC or del5395) was associated with a higher risk of thyroid cancer (OR = 5.7; p = 0.006), than was the missense mutation I157T (OR = 2.8; p = 0.0001). CHEK2 mutation carriers reported a family history of breast cancer 2.2 times more commonly than non-carriers (16.4% vs.8.1%; p = 0.05). A CHEK2 mutation was found in seven of 11 women (63%) with multiple primary cancers of the breast and thyroid (OR = 10; p = 0.0004). These results suggest that CHEK2 mutations predispose to thyroid cancer, familial aggregations of breast and thyroid cancer and to double primary cancers of the breast and thyroid.

International patterns and trends in testicular cancer incidence, overall and by histologic subtype, 1973-2007

Incidence rates of testicular cancer in Northern European and North American countries have been widely reported, whereas rates in other populations, such as Eastern Europe, Central/South America, Asia, and Africa, have been less frequently evaluated. We examined testicular cancer incidence rates overall and by histologic type by calendar time and birth cohort for selected global populations 1973-2007. Age-standardized incidence rates over succeeding 5-year periods were calculated from volumes 4-9 of Cancer Incidence in Five Continents electronic database (CI5plus) and the newly released CI5X (volume 10) database. Annual percent change over the 35-year period was calculated using weighted least squares regression. Age-period-cohort analyses were performed and observed rates and fitted rate ratios presented by birth cohort. Incidence rates of testicular cancer increased between 1973-1977 and 2003-2007 in most populations evaluated worldwide. Of note, incidence rates in Eastern European countries rose rapidly and approached rates in Northern European countries. Rates in Central and South America also increased and are now intermediate to the high rates among men of European ancestry and low rates among men of Asian or African descent. Some heterogeneity in the trends in seminoma and nonseminoma were observed in Denmark, the United Kingdom, and among US whites, particularly in recent generations, with rapid and uniform increases in the incidence of both histologic types in Slovakia. Reasons for the rising incidence rates among European and American populations remain unexplained; however, changing distributions in the prevalence of risk factors for testicular cancer cannot be ruled out.

Genetic predisposition to papillary thyroid carcinoma: involvement of FOXE1, TSHR, and a novel lincRNA gene, PTCSC2

CONTEXT

By genome-wide association studies, the risk allele [A] of SNP rs965513 predisposes strongly to papillary thyroid carcinoma (PTC). It is located in a gene-poor region of 9q22, some 60 kb from the FOXE1 gene. The underlying mechanisms remain to be discovered.

OBJECTIVE

Our objective was to identify novel transcripts in the 9q22 locus and correlate gene expression levels with the genotypes of rs965513.

DESIGN

We performed 3' and 5' rapid amplification of cDNA ends and RT-PCR to detect novel transcripts. One novel transcript was forcibly expressed in a cell line followed by gene expression array analysis. We genotyped rs965513 from PTC patients and measured gene expression levels by real-time RT-PCR in unaffected thyroid tissue and matched tumor.

SETTING

This was a laboratory-based study using cells from clinical tissue samples and a cancer cell line.

MAIN OUTCOME MEASURES

We detected previously uncharacterized transcripts and evaluated the gene expression levels and the correlation with the risk allele of rs965513, age, gender, chronic lymphocyte thyroiditis (CLT), and TSH levels.

RESULTS

We found a novel long intergenic noncoding RNA gene and named it papillary thyroid cancer susceptibility candidate 2 (PTCSC2). Transcripts of PTCSC2 are down-regulated in PTC tumors. The risk allele [A] of rs965513 was significantly associated with low expression of unspliced PTCSC2, FOXE1, and TSHR in unaffected thyroid tissue. We also observed a significant association of age and CLT with PTCSC2 unspliced transcript levels. The correlation between the rs965513 genotype and the PTCSC2 unspliced transcript levels remained significant after adjusting for age, gender, and CLT. Forced expression of PTCSC2 in the BCPAP cell line affected the expression of a subset of noncoding and coding transcripts with enrichment of genes functionally involved in cell cycle and cancer.

CONCLUSIONS

Our data suggest a role for PTCSC2, FOXE1, and TSHR in the predisposition to PTC.

Pathway-based analysis of GWAs data identifies association of sex determination genes with susceptibility to testicular germ cell tumors

Genome-wide association (GWA) studies of testicular germ cell tumor (TGCT) have identified 18 susceptibility loci, some containing genes encoding proteins important in male germ cell development. Deletions of one of these genes, DMRT1, lead to male-to-female sex reversal and are associated with development of gonadoblastoma. To further explore genetic association with TGCT, we undertook a pathway-based analysis of SNP marker associations in the Penn GWAs (349 TGCT cases and 919 controls). We analyzed a custom-built sex determination gene set consisting of 32 genes using three different methods of pathway-based analysis. The sex determination gene set ranked highly compared with canonical gene sets, and it was associated with TGCT (FDRG = 2.28 × 10(-5), FDRM = 0.014 and FDRI = 0.008 for Gene Set Analysis-SNP (GSA-SNP), Meta-Analysis Gene Set Enrichment of Variant Associations (MAGENTA) and Improved Gene Set Enrichment Analysis for Genome-wide Association Study (i-GSEA4GWAS) analysis, respectively). The association remained after removal of DMRT1 from the gene set (FDRG = 0.0002, FDRM = 0.055 and FDRI = 0.009). Using data from the NCI GWA scan (582 TGCT cases and 1056 controls) and UK scan (986 TGCT cases and 4946 controls), we replicated these findings (NCI: FDRG = 0.006, FDRM = 0.014, FDRI = 0.033, and UK: FDRG = 1.04 × 10(-6), FDRM = 0.016, FDRI = 0.025). After removal of DMRT1 from the gene set, the sex determination gene set remains associated with TGCT in the NCI (FDRG = 0.039, FDRM = 0.050 and FDRI = 0.055) and UK scans (FDRG = 3.00 × 10(-5), FDRM = 0.056 and FDRI = 0.044). With the exception of DMRT1, genes in the sex determination gene set have not previously been identified as TGCT susceptibility loci in these GWA scans, demonstrating the complementary nature of a pathway-based approach for genome-wide analysis of TGCT.

Genetic predisposition for nonmedullary thyroid cancer

Nonmedullary thyroid cancer (NMTC) can be sporadic or can occur as a component cancer as part of several well-described hereditary cancer syndromes. NMTC, particularly papillary thyroid cancer, also can occur by itself in families and is often termed familial NMTC or familial papillary thyroid cancer. The occurrence of NMTC in families, along with extensive population-based evidence from patients with sporadic thyroid cancer, together suggest that NMTC has a strong genetic component, only a small proportion of which has been characterized to date. Advances in genetic and genomic technology have rapidly advanced our understanding of the complex nature of NMTC susceptibility, although much remains to be explained. Herein, we describe the current state of knowledge, starting with a brief review of hereditary syndromic causes and moving on to describe recent data using modern genomic approaches to identifying genes involved in the predisposition to NMTC.

Genome-wide association study yields variants at 20p12.2 that associate with urinary bladder cancer

Genome-wide association studies (GWAS) of urinary bladder cancer (UBC) have yielded common variants at 12 loci that associate with risk of the disease. We report here the results of a GWAS of UBC including 1670 UBC cases and 90 180 controls, followed by replication analysis in additional 5266 UBC cases and 10 456 controls. We tested a dataset containing 34.2 million variants, generated by imputation based on whole-genome sequencing of 2230 Icelanders. Several correlated variants at 20p12, represented by rs62185668, show genome-wide significant association with UBC after combining discovery and replication results (OR = 1.19, P = 1.5 × 10(-11) for rs62185668-A, minor allele frequency = 23.6%). The variants are located in a non-coding region approximately 300 kb upstream from the JAG1 gene, an important component of the Notch signaling pathways that may be oncogenic or tumor suppressive in several forms of cancer. Our results add to the growing number of UBC risk variants discovered through GWAS.

Patterns of changing cancer risks with time since diagnosis of a sibling

Family history is a well-known risk factor for many cancers. However, it is important to know if/how the familial risk of cancer changes over time. For each of four major cancers (colorectal, breast, prostate and melanoma), we identified siblings of cancer patients (case siblings) and siblings of matched cancer-free controls sampled from Swedish population-based registers. Effects of age and time since diagnosis on sibling risks were examined using Poisson regression and presented graphically as smoothed hazard ratios (HRs). Screening effects were investigated by comparing hazards before/after the introduction of mammography for breast cancer and prostate-specific antigen (PSA) testing for prostate cancer. Case siblings had higher cancer incidence than control siblings for all cancers at all ages, with overall incidence rate ratios (IRRs) of 2.41 (95% confidence interval 2.14-2.71) for colorectal cancer, 2.37 (2.24-2.52) for breast cancer, 3.69 (3.46-3.93) for prostate cancer and 3.20 (2.72-3.76) for melanoma. Risks were highest in siblings who were young when the first cancer was diagnosed in the family, with siblings aged 30-40 having IRR 9.05 (3.03-27.00) for colorectal cancer and 4.30 (2.87-6.45) for breast cancer. Smoothed HRs remained fairly constant for up to 20 years except for prostate cancer, where the HR decreased steeply during the first few years. After introduction of PSA testing, men had higher incidence of prostate cancer shortly after diagnosis in a brother, but no such screening effect was found for breast cancer. Our findings can help inform the screening and counseling of family members of cancer patients.

An oncofetal and developmental perspective on testicular germ cell cancer

Germ cell tumors (GCTs) represent a diverse group of tumors presumably originating from (early fetal) developing germ cells. Most frequent are the testicular germ cell cancers (TGCC). Overall, TGCC is the most frequent malignancy in Caucasian males (20-40 years) and remains an important cause of (treatment related) mortality in these young men. The strong association between the phenotype of TGCC stem cell components and their totipotent ancestor (fetal primordial germ cell or gonocyte) makes these tumors highly relevant from an onco-fetal point of view. This review subsequently discusses the evidence for the early embryonic origin of TGCCs, followed by an overview of the crucial association between TGCC pathogenesis, genetics, environmental exposure and the (fetal) testicular micro-environment (genvironment). This culminates in an evaluation of three genvironmentally modulated hallmarks of TGCC directly related to the oncofetal pathogenesis of TGCC: (1) maintenance of pluripotency, (2) cell cycle control/cisplatin sensitivity and (3) regulation of proliferation/migration/apoptosis by KIT-KITL mediated receptor tyrosine kinase signaling. Briefly, TGCC exhibit identifiable stem cell components (seminoma and embryonal carcinoma) and progenitors that show large and consistent similarities to primordial/embryonic germ cells, their presumed totipotent cells of origin. TGCC pathogenesis depends crucially on a complex interaction of genetic and (micro-)environmental, i.e. genvironmental risk factors that have only been partly elucidated despite significant effort. TGCC stem cell components also show a high degree of similarity with embryonic stem/germ cells (ES) in the regulation of pluripotency and cell cycle control, directly related to their exquisite sensitivity to DNA damaging agents (e.g. cisplatin). Of note, (ES specific) micro-RNAs play a pivotal role in the crossover between cell cycle control, pluripotency and chemosensitivity. Moreover, multiple consistent observations reported TGCC to be associated with KIT-KITL mediated receptor tyrosine kinase signaling, a pathway crucially implicated in proliferation, migration and survival during embryogenesis including germ cell development. In conclusion, TGCCs are a fascinating model for onco-fetal developmental processes especially with regard to studying cell cycle control, pluripotency maintenance and KIT-KITL signaling. The knowledge presented here contributes to better understanding of the molecular characteristics of TGCC pathogenesis, translating to identification of at risk individuals and enhanced quality of care for TGCC patients (diagnosis, treatment and follow-up).

Adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy, often with an unfavorable prognosis. Here we summarize the knowledge about diagnosis, epidemiology, pathophysiology, and therapy of ACC. Over recent years, multidisciplinary clinics have formed and the first international treatment trials have been conducted. This review focuses on evidence gained from recent basic science and clinical research and provides perspectives from the experience of a large multidisciplinary clinic dedicated to the care of patients with ACC.

Does risk of endometrial cancer for women without a germline mutation in a DNA mismatch repair gene depend on family history of endometrial cancer or colorectal cancer?

OBJECTIVE

To determine whether risk of endometrial cancer for women without a germline mutation in a DNA mismatch repair (MMR) gene depends on family history of endometrial or colorectal cancer.

METHODS

We retrospectively followed a cohort of 79,166 women who were recruited to the Colon Cancer Family Registry, after exclusion of women who were relatives of a carrier of a MMR gene mutation. The Kaplan-Meier failure method was used to estimate the cumulative risk of endometrial cancer. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for association between family history of endometrial or colorectal cancer and risk of endometrial cancer.

RESULTS

A total of 628 endometrial cancer cases were observed, with mean age at diagnosis of 54.4 (standard deviation: 15.7) years. The cumulative risk of endometrial cancer to age 70 years was estimated to be 0.94% (95% CI 0.83-1.05) for women with no family history of endometrial cancer, and 3.80% (95% CI 2.75-4.98) for women with at least one first- or second-degree relative with endometrial cancer. Compared with women without family history, we found an increased risk of endometrial cancer for women with at least one first- or second-degree relative with endometrial cancer (HR 3.66, 95% CI 2.63-5.08), and for women with one first-degree relative with colorectal cancer diagnosed at age <50 years (HR 1.48, 95% CI 1.15-1.91).

CONCLUSION

An increased risk of endometrial cancer is associated with a family history of endometrial cancer or early-onset colorectal cancer for women without a MMR gene mutation, indicating for potential underlying genetic and environmental factors shared by colorectal and endometrial cancers other than caused by MMR gene mutations.