A comprehensive survey of cancer risks in extended families

Describing patterns of familial cancer risk in subfertile men using population pedigree data

STUDY QUESTION

Can we simultaneously assess risk for multiple cancers to identify familial multicancer patterns in families of azoospermic and severely oligozoospermic men?

SUMMARY ANSWER

Distinct familial cancer patterns were observed in the azoospermia and severe oligozoospermia cohorts, suggesting heterogeneity in familial cancer risk by both type of subfertility and within subfertility type.

WHAT IS KNOWN ALREADY

Subfertile men and their relatives show increased risk for certain cancers including testicular, thyroid, and pediatric.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort of subfertile men (N = 786) was identified and matched to fertile population controls (N = 5674). Family members out to third-degree relatives were identified for both subfertile men and fertile population controls (N = 337 754). The study period was 1966-2017. Individuals were censored at death or loss to follow-up, loss to follow-up occurred if they left Utah during the study period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Azoospermic (0 × 106/mL) and severely oligozoospermic (<1.5 × 106/mL) men were identified in the Subfertility Health and Assisted Reproduction and the Environment cohort (SHARE). Subfertile men were age- and sex-matched 5:1 to fertile population controls and family members out to third-degree relatives were identified using the Utah Population Database (UPDB). Cancer diagnoses were identified through the Utah Cancer Registry. Families containing ≥10 members with ≥1 year of follow-up 1966-2017 were included (azoospermic: N = 426 families, 21 361 individuals; oligozoospermic: N = 360 families, 18 818 individuals). Unsupervised clustering based on standardized incidence ratios for 34 cancer phenotypes in the families was used to identify familial multicancer patterns; azoospermia and severe oligospermia families were assessed separately.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to control families, significant increases in cancer risks were observed in the azoospermia cohort for five cancer types: bone and joint cancers hazard ratio (HR) = 2.56 (95% CI = 1.48-4.42), soft tissue cancers HR = 1.56 (95% CI = 1.01-2.39), uterine cancers HR = 1.27 (95% CI = 1.03-1.56), Hodgkin lymphomas HR = 1.60 (95% CI = 1.07-2.39), and thyroid cancer HR = 1.54 (95% CI = 1.21-1.97). Among severe oligozoospermia families, increased risk was seen for three cancer types: colon cancer HR = 1.16 (95% CI = 1.01-1.32), bone and joint cancers HR = 2.43 (95% CI = 1.30-4.54), and testis cancer HR = 2.34 (95% CI = 1.60-3.42) along with a significant decrease in esophageal cancer risk HR = 0.39 (95% CI = 0.16-0.97). Thirteen clusters of familial multicancer patterns were identified in families of azoospermic men, 66% of families in the azoospermia cohort showed population-level cancer risks, however, the remaining 12 clusters showed elevated risk for 2-7 cancer types. Several of the clusters with elevated cancer risks also showed increased odds of cancer diagnoses at young ages with six clusters showing increased odds of adolescent and young adult (AYA) diagnosis [odds ratio (OR) = 1.96-2.88] and two clusters showing increased odds of pediatric cancer diagnosis (OR = 3.64-12.63). Within the severe oligozoospermia cohort, 12 distinct familial multicancer clusters were identified. All 12 clusters showed elevated risk for 1-3 cancer types. An increase in odds of cancer diagnoses at young ages was also seen in five of the severe oligozoospermia familial multicancer clusters, three clusters showed increased odds of AYA diagnosis (OR = 2.19-2.78) with an additional two clusters showing increased odds of a pediatric diagnosis (OR = 3.84-9.32).

LIMITATIONS, REASONS FOR CAUTION

Although this study has many strengths, including population data for family structure, cancer diagnoses and subfertility, there are limitations. First, semen measures are not available for the sample of fertile men. Second, there is no information on medical comorbidities or lifestyle risk factors such as smoking status, BMI, or environmental exposures. Third, all of the subfertile men included in this study were seen at a fertility clinic for evaluation. These men were therefore a subset of the overall population experiencing fertility problems and likely represent those with the socioeconomic means for evaluation by a physician.

WIDER IMPLICATIONS OF THE FINDINGS

This analysis leveraged unique population-level data resources, SHARE and the UPDB, to describe novel multicancer clusters among the families of azoospermic and severely oligozoospermic men. Distinct overall multicancer risk and familial multicancer patterns were observed in the azoospermia and severe oligozoospermia cohorts, suggesting heterogeneity in cancer risk by type of subfertility and within subfertility type. Describing families with similar cancer risk patterns provides a new avenue to increase homogeneity for focused gene discovery and environmental risk factor studies. Such discoveries will lead to more accurate risk predictions and improved counseling for patients and their families.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by GEMS: Genomic approach to connecting Elevated germline Mutation rates with male infertility and Somatic health (Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): R01 HD106112). The authors have no conflicts of interest relevant to this work.

TRIAL REGISTRATION NUMBER

N/A.

A Systematic Review on Clinico-Aetiopathological Trends of Nasopharyngeal Cancer in Asia

BACKGROUND

Nasopharyngeal cancer (NPC) is a type of malignancy that is highly prevalent in Asian countries. Therefore, an understanding between NPC epidemiological trend, the clinico-pathological and aetiological profiles are needed. This systematic review focuses on asian countries demographic and clinico-pathological presentation reported in 9982 NPC cases diagnosed from the year 2010 to 2021.

METHODOLOGY

Data were extracted from databases, such as PubMed, Springer Link, Science Direct, Google Scholar and general search engines, by using pre-determined keywords (e.g. clinico-pathological data, age, sex, tumour stage, nasopharyngeal cancer, nasopharyngeal carcinoma, naso-pharynx and cancer in Asia).

RESULTS AND CONCLUSION

Findings from our systematic review shows that from 2010 to 2021, males in age range below 50 years old are at a higher risk of developing NPC in Asia. NPC is mostly diagnosed at advanced stage in Asia, which is likely due to the deep-seated location of the cancer. Type III NPC and EBV proteins (EBNA1 and LMP2A) are frequently associated with reported EBV-positive NPC cases in Asian countries. Meanwhile, NPC type I, II, and III are associated with EBV-negative NPC cases in Asia. Human leucocyte antigen (HLA) alleles (A2, B27, and B46) are frequently present in reported EBV-negative NPC cases in Asia. In Asia, males below 50 years old are more prone to NPC and often diagnosed at late stage. EBV-positive and EBV-negative NPC in Asia have unique histological profiles. Systemic approach of this study may help to provide better knowledge on reported NPC cases especially on the risk factors and clinical presentation focusing in Asian countries.

Mutual association between family history of gastric and colorectal cancer and risk of gastric and colorectal cancer

BACKGROUND AND AIM

We evaluated the associations between gastric cancer (GC) family history (FH) and colorectal cancer (CRC) risk and between CRC FH and GC/gastric adenoma risk.

METHODS

We used data of participants who underwent national cancer screening between 2013 and 2014. Participants with GC or CRC FH in first-degree relatives (n = 1 172 750) and those without cancer FH (n = 3 518 250) were matched 1:3 by age and gender.

RESULTS

Of the 1 172 750 participants with a FH, 871 104, 264 040, and 37 606 had FHs of only GC, only CRC, and both GC and CRC, respectively. The median follow-up time was 4.8 years. GC and CRC FHs were associated with increased GC and CRC risks, respectively. GC FH was associated with CRC risk (adjusted hazard ratio 1.05; 95% confidence interval [CI] 1.01-1.10), whereas CRC FH was not associated with the risk of GC or gastric adenoma. However, gastric adenoma risk increased 1.62-fold (95% CI 1.40-1.87) in participants with FHs of both GC and CRC, demonstrating a significant difference with the 1.39-fold (95% CI 1.34-1.44) increase in participants with only GC FH. Furthermore, GC risk increased by 5.32 times (95% CI 1.74-16.24) in participants with FHs of both GC and CRC in both parents and siblings.

CONCLUSIONS

GC FH was significantly associated with a 5% increase in CRC risk. Although CRC FH did not increase GC risk, FH of both GC and CRC further increased the risk of gastric adenoma. FHs of GC and CRC may affect each other's neoplastic lesion risk.

Additive pre-diagnostic and diagnostic value of routine blood-based biomarkers in the detection of colorectal cancer in the UK Biobank cohort

Survival rates from colorectal cancer (CRC) are drastically higher if the disease is detected and treated earlier. Current screening guidelines involve stool-based tests and colonoscopies, whose acceptability and uptake remains low. Routinely collected blood-based biomarkers may offer a low-cost alternative or aid for detecting CRC. Here we aimed to evaluate the pre-diagnostic and diagnostic value of a wide-range of multimodal biomarkers in the UK Biobank dataset, including sociodemographic, lifestyle, medical, physical, and blood and urine-based measures in detecting CRC. We performed a Cox proportional hazard and a tree-boosting model alongside feature selection methods to determine optimal combination of biomarkers. In addition to the modifiable lifestyle factors of obesity, alcohol consumption and cardiovascular health, we showed that blood-based biomarkers that capture the immune response, lipid profile, liver and kidney function are associated with CRC risk. Following feature selection, the final Cox and tree-boosting models achieved a C-index of 0.67 and an AUC of 0.76 respectively. We show that blood-based biomarkers collected in routine examinations are sensitive to preclinical and clinical CRC. They may provide an additive value and improve diagnostic accuracy of current screening tools at no additional cost and help reduce burden on the healthcare system.

Multiple primary melanoma in association with other personal and familial cancers

BACKGROUND

Multiple primary melanoma (MPM) is known to be associated with familial melanoma. However, the association between MPM and other personal and familial cancers is not well documented. The objective of this study was to evaluate the association between MPM and personal history of other cancers or cancer history among first-degree relatives (FDRs).

METHODS

We performed a retrospective case-control study including cases with gender-matched MPM and single primary melanoma (SPM) at a 1:2 ratio from the University of Pittsburgh Cancer Institute Melanoma Center Biological Sample and Nevus Bank. The associations between MPM and other cancers were evaluated using univariable and multivariable logistic regression models.

RESULTS

In total, 378 patients (44.2% men; median age 52 years) were enrolled, including 252 with SPM and 126 with MPM. In comparison to patients with SPM, patients with MPM were more likely to have squamous cell carcinoma (odds ratio [OR] 1.95, 95% confidence interval [CI] 1.001-3.79, p = 0.047) and prostate cancer (OR 2.72, 95% CI 1.07-7.01, p = 0.034). FDRs of patients with MPM had higher prevalence of melanoma (OR 2.37, 95% CI 1.31-4.28, p = 0.004) and prostate cancer (OR 2.92, 95% CI 1.47-6.14, p = 0.002) but not other cancers. In multivariable analysis, the association remained significant between MPM and squamous cell carcinoma (OR 2.18, 95% CI 1.08-4.39, p = 0.028), prostate cancer (OR 2.85, 95% CI 1.09-7.54, p = 0.032), FDR history of melanoma (OR 2.37, 95% CI 1.31-4.29, p = 0.004), and FDR history of prostate cancer (OR 3.26, 95% CI 1.59-6.83, p = 0.001).

CONCLUSIONS

Patients with MPM have a higher prevalence of personal and FDR histories of nonmelanoma skin cancers and prostate cancer.

Evidence for excess familial clustering of Post Traumatic Stress Disorder in the US Veterans Genealogy resource

A genealogy of the United States has been record-linked to National Veteran's Health Administration (VHA) patient data to allow non-identifiable analysis of familial clustering. This genealogy, including over 70 million individuals linked to over 1 million VHA patients, is the largest such combined resource reported. Analysis of familial clustering among VHA patients diagnosed with Post Traumatic Stress Disorder (PTSD) allowed a test of the hypothesis of an inherited contribution to PTSD. PTSD is associated strongly with military service and extended familial clustering data have not previously been presented. PTSD-affected VHA patients with genealogy data were identified by presence of an ICD diagnosis code in the VHA medical record in at least 2 different years. The Genealogical Index of Familiality (GIF) method was used to compare the average relatedness of VHA patients diagnosed with PTSD with their expected average relatedness, estimated from randomly selected sets of matched linked VHA patient controls. Relative risks for PTSD were estimated in first-, second-, and third-degree relatives of PTSD patients who were also VHA patients, using sex and age-matched rates for PTSD estimated from all linked VHA patients. Significant excess pairwise relatedness, and significantly elevated risk for PTSD in first-, second-, and third-degree relatives was observed; multiple high-risk extended PTSD pedigrees were identified. The analysis provides evidence for excess familial clustering of PTSD and identified high-risk PTSD pedigrees. These results support an inherited contribution to PTSD predisposition and identify a powerful resource of high-risk PTSD pedigrees for predisposition gene identification.

Family History of Cancer is associated with poorer prognosis in Oral Squamous Cell Carcinoma

OBJECTIVE

The purpose of this study was to investigate the prognostic value of the family history of cancer (FHC) in predicting survival and clinicopathological features in oral squamous cell carcinoma (OSCC) patients.

MATERIALS AND METHODS

This single-institution study utilized data from 610 patients undergoing surgery from 2014 to 2020 that was prospectively collected and cataloged for research purposes. All patients underwent standard surgery with/without radiotherapy or chemoradiotherapy. We statistically evaluated whether FHC was associated with changes in disease-free survival (DFS) and disease-specific survival (DSS).

RESULTS

Among 610 patients, 141 (23.1%) reported a family history of cancer. The distribution of clinicopathological characteristics was balanced between FHC-positive and FHC-negative OSCC patients. FHC-positive patients had decreased DFS (P=0.005) and DSS (P=0.018) compared to FHC-negative patients.

CONCLUSIONS

FHC-positive OSCC patients have a poorer prognosis. FHC positivity is an independent predictor of negative outcomes based on DFS and DSS. FHC should be a consideration in screening, evaluating, counseling, and treating OSCC patients.

Gene Mutations Associated With Clinical Characteristics in the Tumors of Patients With Breast Cancer

Background

Clinical characteristics including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) are important biomarkers in the treatment of breast cancer, but how genomic mutations affect their status is rarely studied. This study aimed at finding genomic mutations associated with these clinical characteristics.

Methods

There were 160 patients with breast cancer enrolled in this study. Samples from those patients were used for next-generation sequencing, targeting a panel of 624 pan-cancer genes. Short nucleotide mutations, copy number variations, and gene fusions were identified for each sample. Fisher’s exact test compared each pair of genes. A similarity score was constructed with the resulting P-values. Genes were clustered with the similarity scores. The identified gene clusters were compared to the status of clinical characteristics including ER, PR, HER2, and a family history of cancer (FH) in terms of the mutations in patients.

Results

Gene-by-gene analysis found that CCND1 mutations were positively correlated with ER status while ERBB2 and CDK12 mutations were positively correlated with HER2 status. Mutation-based clustering identified four gene clusters. Gene cluster 1 (ADGRA2, ZNF703, FGFR1, KAT6A, and POLB) was significantly associated with PR status; gene cluster 2 (COL1A1, AXIN2, ZNF217, GNAS, and BRIP1) and gene cluster 3 (FGF3, FGF4, FGF19, and CCND1) were significantly associated with ER status; gene cluster 2 was also negatively associated with a family history of cancer; and gene cluster 4 was significantly negatively associated with age. Patients were classified into four corresponding groups. Patient groups 1, 2, 3, and 4 had 24.1%, 36.5%, 38.7%, and 41.3% of patients with an FDA-recognized biomarker predictive of response to an FDA-approved drug, respectively.

Conclusion

This study identified genomic mutations positively associated with ER and PR status. These findings not only revealed candidate genes in ER and PR status maintenance but also provided potential treatment targets for patients with endocrine therapy resistance.

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.

Population Screening for Inherited Predisposition to Breast and Ovarian Cancer

The discovery of genes underlying inherited predisposition to breast and ovarian cancer has revolutionized the ability to identify women at high risk for these diseases before they become affected. Women who are carriers of deleterious variants in these genes can undertake surveillance and prevention measures that have been shown to reduce morbidity and mortality. However, under current strategies, the vast majority of women carriers remain undetected until they become affected. In this review, we show that universal testing, particularly of the BRCA1 and BRCA2 genes, fulfills classical disease screening criteria. This is especially true for BRCA1 and BRCA2 in Ashkenazi Jews but is translatable to all populations and may include additional genes. Utilizing genetic information for large-scale precision prevention requires a paradigmatic shift in health-care delivery. To address this need, we propose a direct-to-patient model, which is increasingly pertinent for fulfilling the promise of utilizing personal genomic information for disease prevention.

Harnessing Population Pedigree Data and Machine Learning Methods to Identify Patterns of Familial Bladder Cancer Risk

BACKGROUND

Relatives of patients with bladder cancer have been shown to be at increased risk for kidney, lung, thyroid, and cervical cancer after correcting for smoking-related behaviors that may concentrate in some families. We demonstrate a novel approach to simultaneously assess risks for multiple cancers to identify distinct multicancer configurations (multiple different cancer types that cluster in relatives) surrounding patients with familial bladder cancer.

METHODS

This study takes advantage of a unique population-level data resource, the Utah Population Database (UPDB), containing vast genealogy and statewide cancer data. Familial risk is measured using standardized incidence risk (SIR) ratios that account for sex, age, birth cohort, and person-years of the pedigree members.

RESULTS

We identify 1,023 families with a significantly higher bladder cancer rate than population controls (familial bladder cancer). Familial SIRs are then calculated across 25 cancer types, and a weighted Gower distance with K-medoids clustering is used to identify familial multicancer configurations (FMC). We found five FMCs, each exhibiting a different pattern of cancer aggregation. Of the 25 cancer types studied, kidney and prostate cancers were most commonly enriched in the familial bladder cancer clusters. Laryngeal, lung, stomach, acute lymphocytic leukemia, Hodgkin disease, soft-tissue carcinoma, esophageal, breast, lung, uterine, thyroid, and melanoma cancers were the other cancer types with increased incidence in familial bladder cancer families.

CONCLUSIONS

This study identified five familial bladder cancer FMCs showing unique risk patterns for cancers of other organs, suggesting phenotypic heterogeneity familial bladder cancer.

IMPACT

FMC configurations could permit better definitions of cancer phenotypes (subtypes or multicancer) for gene discovery and environmental risk factor studies.

Genetic Variants Implicate Dual Oxidase-2 in Familial and Sporadic Nonmedullary Thyroid Cancer

Highly penetrant hereditary thyroid cancer manifests as familial nonmedullary thyroid cancer (FNMTC), whereas low-penetrance hereditary thyroid cancer manifests as sporadic disease and is associated with common polymorphisms, including rs965513[A]. Whole-exome sequencing of an FNMTC kindred identified a novel Y1203H germline dual oxidase-2 (DUOX2) mutation. DUOX2_Y1203H is enzymatically active, with increased production of reactive oxygen species. Furthermore, patients with sporadic thyroid cancer homozygous for rs965513[A] demonstrated higher DUOX2 expression than heterozygous rs965513[A/G] or homozygous rs965513[A]-negative patients. These data suggest that dysregulated hydrogen peroxide metabolism is a common mechanism by which high- and low-penetrance genetic factors increase thyroid cancer risk. SIGNIFICANCE: This study provides novel insights into the genetic and molecular mechanisms underlying familial and sporadic thyroid cancers.

Population-Based Relative Risks for Lung Cancer Based on Complete Family History of Lung Cancer

INTRODUCTION

Published risk estimates for diagnosis of lung cancer based on family history are typically focused on close relatives, rather than a more diverse or complete family history. This study provides estimates of relative risk (RR) for lung cancer based on comprehensive family history data obtained from a statewide cancer registry linked to a high-quality genealogy data resource that is extensive and deep. The risk estimates presented avoid common recall, recruitment, ascertainment biases, and are based on an individual's (proband's) lung cancer family history constellation (pattern of lung cancer affected relatives); numerous constellations are explored.

METHODS

We used a population-based genealogic resource linked to a statewide electronic Surveillance Epidemiology and End Results program cancer registry to estimate RR for lung cancer for an individual based on their lung cancer family history. The family history data available for a proband included degree of relationship (first- to third-degree), paternal or maternal family lung cancer history, number of lung cancer-affected relatives, and age at diagnosis of affected relatives. More than 1.3 million probands with specific constellations of lung cancer were analyzed. To estimate RRs for lung cancer, the observed number of lung cancer cases among probands with a specific family history constellation was compared to the expected number using internal cohort-specific rates.

RESULTS

A total of 5048 lung cancer cases were identified. Significantly elevated RR was observed for any number of lung cancer-affected relatives among first-, second-, or third-degree relatives. RRs for lung cancer were significantly elevated for each additional lung cancer first-degree relative (FDR) ranging from RR = 2.57 (confidence interval [CI] 95%: 2.39, 2.76) for 1 or more FDR to RR = 4.24 (CI 95%: 1.56, 9.23) for 3 or more FDRs affected. In an absence of FDR family history, increased risk for lung cancer was significant for increasing numbers of affected second-degree relatives (SDRs) ranging from 1.41 (CI 95%: 1.30, 1.52) for 1 or more SDRs to 4.76 (CI 95%: 1.55, 11.11) for 4 or more SDRs. In the absence of affected FDRs and SDRs, there were significantly increased risks based on lung cancer-affected third-degree relatives (TDRs) ranging from 1.18 (CI 95%: 1.11, 1.24) for 1 or more affected TDRs to 1.55 (CI 95%: 1.03, 2.24) for 4 or more affected TDRs. RRs were significantly increased with earlier age at diagnosis of a FDR, and equivalent risks for maternal compared to paternal history were observed.

CONCLUSIONS

This study provides population-based estimates of lung cancer risk based on a proband's complete family history (lung cancer constellation). Many individuals at two to five or more times increased risk for lung cancer are identified. Estimates of RR for lung cancer based on family history are arguably relevant clinically. The constellation RR estimates presented could serve in individual decision-making to direct resource use for lung cancer screening, and could be pivotal in decision-making for screening, treatment, and post-treatment surveillance.

Elevated IgM and abnormal free light chain ratio are increased in relatives from high-risk chronic lymphocytic leukemia pedigrees

Abnormal serum immunoglobulin (Ig) free light chains (FLC) are established biomarkers of early disease in multiple B-cell lymphoid malignancies, including chronic lymphocytic leukemia (CLL). Heavy chains have also been shown to be biomarkers in plasma cell disorders. An unanswered question is whether these Ig biomarkers are heritable, i.e., influenced by germline factors. CLL is heritable but highly heterogeneous. Heritable biomarkers could elucidate steps of disease pathogenesis that are affected by germline factors, and may help partition heterogeneity and identify genetic pleiotropies across malignancies. Relatives in CLL pedigrees present an opportunity to identify heritable biomarkers. We compared FLCs and heavy chains between relatives in 23 high-risk CLL pedigrees and population controls. Elevated IgM (eIgM) and abnormal FLC (aFLC) ratio was significantly increased in relatives, suggesting that these Ig biomarkers are heritable and could offer risk stratification in pedigree relatives. Within high-risk CLL pedigrees, B-cell lymphoid malignancies were five times more prevalent in close relatives of individuals with eIgM, prostate cancer was three times more prevalent in relatives of individuals with aFLC, and monoclonal B-cell lymphocytosis increased surrounding individuals with normal Ig levels. These different clustering patterns suggest Ig biomarkers have the potential to partition genetic heterogeneity in CLL and provide insight into distinct heritable pleiotropies associated with CLL.

Familial Associations of Colon and Rectal Cancers With Other Cancers

BACKGROUND

Many studies have indicated that colon and rectal cancers differ in etiology and histology.

OBJECTIVE

The aim of this study was to investigate whether the associations of colon and rectal cancers with any other (discordant) cancer were site specific.

DESIGN

A novel approach was implemented in which cancer risks were analyzed in families with increasing numbers of family members diagnosed with defined cancers. The novel assumption was that, for a true familial association, the risk should increase by the number of affected family members. In separate analyses, familial risks were calculated after the exclusion of putative families with hereditary nonpolyposis colorectal cancer.

SETTINGS

The study was conducted using the Swedish Family-Cancer Database.

MAIN OUTCOME MEASURES

The outcome measure was relative risk.

RESULTS

Relative risks of colorectal cancer and colon cancer were higher when family members were diagnosed with colon cancer than when family members were diagnosed with rectal cancer (incidence rate ratio for colorectal: 1.82 (95% CI, 1.74-1.90) vs 1.61 (95% CI, 1.51-1.71); incidence rate ratio for colon: 1.92 (95% CI, 1.83-2.02) vs 1.56 (95% CI, 1.45-1.69)). Relative risks for 10 discordant cancers were increased in colon or rectal cancer families, whereas none of the relative risks differed significantly between colon and rectal cancers. After deleting hereditary nonpolyposis colorectal cancer families, the relative risks of endometrial and ovarian cancers were no longer significant.

LIMITATIONS

Genetic data are unavailable in the database.

CONCLUSIONS

Our results suggested that familial risks for colon cancer were higher than risks for rectal cancer in families of patients with colorectal cancer and colon cancer. The relationships of lung cancer and nervous system cancer with colorectal cancer were site specific. The associations of colon and rectal cancers with lung cancer, myeloma, and cancer of unknown primary appeared not to point out known syndromes and may suggest involvement of a novel predisposition. See Video Abstract at http://links.lww.com/DCR/A791.

A Nonsynonymous Variant in the GOLM1 Gene in Cutaneous Malignant Melanoma

Background

Statistically significant linkage of melanoma to chromosome 9q21 was previously reported in a Danish pedigree resource and independently confirmed in Utah high-risk pedigrees, indicating strong evidence that this region contains a melanoma predisposition gene.

Methods

Whole-exome sequencing of pairs of related melanoma case subjects from two pedigrees with evidence of 9q21 linkage was performed to identify the responsible predisposition gene. Candidate variants were tested for association with melanoma in an independent set of 454 unrelated familial melanoma case subjects and 396 unrelated cancer-free control subjects from Utah, and 1534 melanoma case subjects and 1146 noncancer control subjects from Texas (MD Anderson) via a two-sided Fisher exact test.

Results

A rare nonsynonymous variant in Golgi Membrane Protein 1 (GOLM1), rs149739829, shared in two hypothesized predisposition carriers in one linked pedigree was observed. Segregation of this variant in additional affected relatives of the index carriers was confirmed. A statistically significant excess of carriers of the variant was observed among Utah case subjects and control subjects (odds ratio [OR] = 9.81, 95% confidence interval [CI] = 8.35 to 11.26, P < .001) and statistically significantly confirmed in Texas case subjects and control subjects (OR = 2.45, 95% CI = 1.65 to 3.25, P = .02).

Conclusion

These findings support GOLM1 as a candidate melanoma predisposition gene.

Familial risks of ovarian cancer by age at diagnosis, proband type and histology

Ovarian cancer is a heterogeneous disease. Data regarding familial risks for specific proband, age at diagnosis and histology are limited. Such data can assist genetic counseling and help elucidate etiologic differences among various histologic types of ovarian malignancies. By using the Swedish Family-Cancer Database, we calculated relative risks (RRs) for detailed family histories using a two-way comparison, which implied e.g. estimation of RRs for overall ovarian cancer when family history was histology-specific ovarian cancer, and conversely, RRs for histology-specific ovarian cancer when family history was overall ovarian cancer. In families of only mother, only sisters or both mother and sisters diagnosed with ovarian cancer, cancer risks for ovary were 2.40, 2.59 and 10.40, respectively; and were higher for cases diagnosed before the age of 50 years. All histological types showed a familial risk in two-way analyses, except mucinous and sex cord-stromal tumors. RRs for concordant histology were found for serous (2.47), endometrioid (3.59) and mucinous ovarian cancers (6.91). Concordant familial risks were highest for mucinous cancer; for others, some discordant associations, such as endometrioid-undifferentiated (9.27) and serous-undifferentiated (4.80), showed the highest RRs. Familial risks are high for early-onset patients and for those with multiple affected relatives. Sharing of different histological types of ovarian cancer is likely an indication of the complexity of the underlying mechanisms.

Familial Ovarian Cancer Clusters with Other Cancers

Familial risk of ovarian cancer is well-established but whether ovarian cancer clusters with other cancers and the clusters differ by histology remains uncertain. Using data from the Swedish Family-Cancer Database, we explored familial associations of ovarian cancer with other cancers with a novel approach; relative risk for (histology-specific) ovarian cancer was estimated in families with patients affected by other cancers, and conversely, risks for other cancers in families with (histology-specific) ovarian cancer patients. Eight discordant cancers were associated with ovarian cancer risk, of which family history of breast cancer showed a dose-response (P-trend <0.0001). Conversely, risks of eight types of cancer increased in families with ovarian cancer patients, and dose-responses were shown for risks of liver (P-trend = 0.0083) and breast cancers (P-trend <0.0001) and cancer of unknown primary (P-trend = 0.0157). Some cancers were only associated with histology-specific ovarian cancers, e.g. endometrial cancer was only associated with endometrioid type but with highest significance. Novel associations with virus-linked cancers of the nose and male and female genitals were found. The results suggest that ovarian cancer shares susceptibility with a number of other cancers. This might alert genetic counselors and challenge approaches for gene and gene-environment identification.

A population-based description of familial clustering of Hirschsprung disease

BACKGROUND

Familial recurrence of Hirschsprung disease (HSCR) is well documented, and risk estimates for relatives have been reported from various populations. We describe the familial clustering of HSCR cases using well-established unbiased familial aggregation techniques within the context of a population genealogy.

METHODS

Patients included 264 HSCR cases identified using ICD-9 diagnosis coding from the two largest healthcare providers in Utah who also had linked genealogy data. The GIF statistic was used to identify excess familial clustering by comparing average relatedness of cases to matched controls. In addition, relative risks (RRs) of HSCR in relatives of cases were estimated using age-, sex- and birthplace-matched disease rates, and for several diseases frequently associated with HSCR (Down syndrome, multiple endocrine neoplasia IIa, central hypoventilation syndrome, Bardet-Biedl syndrome, ventricular and atrial septal defect).

RESULTS

Significant excess relatedness was observed for all HSCRs (p<1e^-3). Significant RRs for HSCR were observed for first-, second-, and fourth-degree relatives of cases (RR=12.0, 10.0, and 4.6, respectively). Significant elevated risks of Down syndrome, Bardet-Biedl syndrome, and atrial and ventricular septal defects were observed for HSCR cases.

CONCLUSION

This population-based survey of HSCR provides confirmation of a genetic contribution to HSCR disease and presents unbiased risk estimates that may have clinical value in predicting recurrence.

LEVEL OF EVIDENCE RATING

Prognosis study, level II.

Genetic Contribution to Nonsquamous, Non-Small Cell Lung Cancer in Nonsmokers

INTRODUCTION

Lung carcinogenesis is strongly influenced by environmental and heritable factors. The genetic contribution to the different histologic subtypes is unknown.

METHODS

A population-based computerized genealogy resource linked to a statewide cancer registry of lung cancer cases (N = 5408) was analyzed to evaluate the heritable contribution to lung cancer histologic subtype in smokers (n = 1751) and nonsmokers (n = 818). Statistical methods were used to test for significant excess relatedness of lung cancer cases.

RESULTS

Significant excess distant relatedness was observed for all lung cancer histologic subgroups analyzed except for the SCLC subset (p = 0.213). When histologic subsets of smokers and nonsmokers with lung cancer were considered, excess relatedness was observed only in nonsmokers with NSCLC (n = 653 [p = 0.026]) and, in particular, in those nonsmokers with the nonsquamous histologic subtype (n = 561 [p = 0.036]). A total of 61 pedigrees demonstrating a significant excess risk of nonsquamous lung cancer in nonsmokers were identified, and an excess of cases in females was observed among the individuals with these high-risk pedigrees.

CONCLUSIONS

This analysis supports a genetic predisposition to lung cancer carcinogenesis in nonsmokers with nonsquamous NSCLC.

Cancer risk susceptibility loci in a Swedish population

A germline mutation in cancer predisposing genes is known to increase the risk of more than one tumor type. In order to find loci associated with many types of cancer, a genome-wide association study (GWAS) was conducted, and 3,555 Swedish cancer cases and 15,581 controls were analyzed for 226,883 SNPs. The study used haplotype analysis instead of single SNP analysis in order to find putative founder effects. Haplotype association studies identified seven risk loci associated with cancer risk, on chromosomes 1, 7, 11, 14, 16, 17 and 21. Four of the haplotypes, on chromosomes 7, 14, 16 and 17, were confirmed in Swedish familial cancer cases. It was possible to perform exome sequencing in one patient for each of those four loci. No clear disease-causing exonic mutation was found in any of the four loci. Some of the candidate loci hold several cancer genes, suggesting that the risk associated with one locus could involve more than one gene associated with cancer risk. In summary, this study identified seven novel candidate loci associated with cancer risk. It was also suggested that cancer risk at one locus could depend on multiple contributing risk mutations/genes.

Family history of gastric cancer is associated with the risk of colorectal neoplasia in Korean population

BACKGROUND

Family history of cancers at different sites except for colorectum has not been evaluated as a risk factor for colorectal neoplasia (CRN).

AIMS

To investigate CRN risk according to family history of cancers at 12 different sites, including stomach and colorectum.

METHODS

A cross-sectional study was performed on 139,497 asymptomatic Koreans who underwent colonoscopy as part of a health check-up.

RESULTS

The mean age of the study population was 41.6 and the prevalence of CRN was 16.3%. Multivariate analyses revealed that family histories of CRC (adjusted odds ratio; confidence interval, 1.26; 1.17-1.35) and gastric cancer (1.07; 1.01-1.13) were independent risk factors for CRN. Notably, the risk of CRN increased even more for participants with family histories of both CRC and gastric cancer (1.38; 1.12-1.70). Family history of CRC was associated with risk of CRN in participants aged both <50 and ≥50 years, whereas family history of gastric cancer was associated with risk of CRN in participants aged <50 years (1.22; 1.14-1.30), but not in participants aged ≥50 years (1.08; 0.99-1.18).

CONCLUSIONS

Family history of gastric cancer was an independent risk factor for CRN, especially in those aged <50years. Persons with family histories of gastric cancer and CRC, especially those with family histories of both, may need to begin colonoscopy earlier.

Familial associations of female breast cancer with other cancers

Familial risks of breast cancer (BC) are well established but whether BC clusters with other, i.e. discordant, cancers is less certain but of interest for the identification of common genetic and possible environmental factors contributing to a general cancer susceptibility. We apply a novel approach to search for familial associations of BC with other (discordant) cancers based on the Swedish Family-Cancer Database. Relative risks (RRs) were calculated for BC in families with increasing numbers of patients with discordant cancer X, and conversely, familial RRs for cancer X in families with increasing numbers of BC patients. Joint p-values were calculated from independent analyses. The total number of familial BCs was 12,266, 14.9% with one first-degree relative with BC and 1.2% with at least 2 affected relatives. Ovarian and prostate cancers showed the strongest associations with BC (p-value <10^-11 ). The p-value for melanoma was <10^-6 , for stomach and male colorectal cancer <2.5 × 10^-6 , for cancer of unknown primary <2.5 × 10^-5 and for lung cancer <5 × 10^-5 . Significance level <5 × 10^-4 was reached with pancreatic cancer. The remaining associations (p < 0.0025) included thyroid, endometrial, testicular, eye cancers (uveal melanoma), nervous system and endocrine tumors and non-Hodgkin lymphoma. The RR for BC increased by increasing numbers of patients with any cancer in family members and it reached 1.62 when three or more family members were affected. The results suggest that BC shares susceptibility with a number of other cancers. This might alert genetic counselors and challenge approaches for gene and gene-environment identification.

Genealogical Microdata and Their Significance for Social Science

Despite long-standing recognition of the importance of family background in shaping life outcomes, only recently have empirical studies in demography, stratification, and other areas begun to consider the influence of kin other than parents. These new studies reflect the increasing availability of genealogical microdata that provide information about ancestors and kin over three or more generations. These data sets, including family genealogies, linked vital registration records, population registers, longitudinal surveys, and other sources, are valuable resources for social research on family, population, and stratification in a multigenerational perspective. This article reviews relevant recent studies, introduces and presents examples of the most important sources of genealogical microdata, identifies key methodological issues in the construction and analysis of genealogical data, and suggests directions for future research.

Family history of cancer and the risk of bladder cancer: A case-control study from Italy

BACKGROUND

A family history of bladder cancer has been associated with the risk of bladder cancer, but quantification of the excess risk in different populations is still a relevant issue. Further, the role of a family history of other cancers on the risk of bladder cancer remains unclear.

METHODS

We analyzed data from an Italian case-control study, including 690 bladder cancer cases and 665 hospital controls. Odds ratios (ORs) were estimated through unconditional logistic regression models, adjusted for sex, age, study center, year of interview and further for education, smoking and sibling's number.

RESULTS

The OR for family history of bladder cancer was 2.13 (95% confidence intervals (95%CIs) 1.02-4.49) from the model with partial adjustment, and 1.99 (95%CI 0.91-4.32) after additional adjustment for smoking and siblings' number, based on 23 cases (3.3%) and 11 controls (1.7%) with a family history of bladder cancer. The fully adjusted OR was 3.77 when the relative was diagnosed at age below 65years. Smokers with a family history of bladder cancer had a four-fold increased risk compared to non-smokers without a family history. Bladder cancer risk was significantly increased among subjects with a family history of hemolymphopoietic cancers (OR=2.97, 95%CI 1.35-6.55). Family history of cancer at other sites showed no significant association with bladder cancer risk.

CONCLUSION

This study confirms an approximately two-fold increased risk of bladder cancer for family history of bladder cancer, and indicates a possible familial clustering of bladder cancer with cancers of the hemolymphopoietic system.

Risk of other Cancers in Families with Melanoma: Novel Familial Links

A family history of cutaneous melanoma (‘melanoma’) is a well-established risk factor for melanoma. However, less is known about the possible familial associations of melanoma with other discordant cancers. A risk for discordant cancer may provide useful information about shared genetic and environmental risk factors and it may be relevant background data in clinical genetic counseling. Using the Swedish Family-Cancer Database, we assessed the relative risk (RR) for any cancer in families with increasing numbers of first-degree relatives diagnosed with melanoma, including multiple melanoma, and in reverse order RR for melanoma in families of multiple discordant cancers. Close to 9% of melanoma was familial; among these 92% were in 2-case families and 8% in families with 3 cases or more. Cancers that were associated with melanoma, in at least two independent analyses, included breast, prostate, colorectal, skin and nervous system cancers. Other associations included cancer of unknown primary, acute myeloid leukemia/myelofibrosis and Waldenström macroglobulinemia/myeloma. Significant results, which appear biologically plausible, were also obtained for rare nasal melanoma and mesothelioma. Although small samples sizes and multiple comparisons were of concern, many of the above associations were internally consistent and provide new diverse leads for discordant familial association of melanoma.

Family history of cancer other than breast or ovarian cancer in first-degree relatives is associated with poor breast cancer prognosis

OBJECTIVE

Whether a first-degree family history of others cancers (FHOC) than breast or ovarian cancer (BOC) is associated with breast cancer prognosis remains unknown. Thus, the aim of the present study was to clarify this issue.

METHODS

Women who were diagnosed with invasive breast cancer at the Renmin Hospital of Wuhan University from 2010 to 2013 were included in the study. The demographic and clinicopathological characteristics of these patients were extracted. FHOC was considered positive for any patient who had a relative who had been diagnosed with cancer other than BOC. Disease-free survival (DFS) was calculated based on the date of diagnosis. DFS was analyzed using the Cox proportional hazards model.

RESULTS

A total of 434 breast cancer patients were included in this study. Among these patients, 61 (14.06%) had a positive FHOC in first-degree relatives. Patients with a positive FHOC tended to have HER2-positive breast cancer (p = 0.03). In the survival analysis, FHOC was associated with poor DFS in both univariate (HR = 2.21 (1.28-3.83), 95% CI: 1.28-3.83, p < 0.01) and multivariate (HR = 2.50, 95% CI: 1.24-5.04, p = 0.01) analyses, especially in patients with luminal A subtypes.

CONCLUSION

The results demonstrated an increased risk of recurrence in breast cancer patients with FHOC, especially in patients with luminal A subtype.

Concordant and discordant familial cancer: Familial risks, proportions and population impact

Relatives of cancer patients are at an increased risk of the same (concordant) cancer but whether they are at a risk for different (discordant) cancers is largely unknown - beyond well characterized hereditary cancer syndromes - but would be of major scientific and clinical interest. We therefore decided to resolve the issue by analyzing familial risks when family members were diagnosed with any discordant cancers. We compared the population impact of concordant to discordant familial cancer. The Swedish Family-Cancer Database (FCD) was used to calculate familial relative risks (RRs) for family members of cancer patients, for the 27 most common cancers. Population attributable fractions (PAFs) were estimated for concordant and discordant family histories. Discordant cancers in the family were detected as significant risk factors for the majority of cancers, although the corresponding RRs were modest compared to RRs for concordant cancers. Risks increased with the number of affected family members with the highest RRs for pancreatic (2.31), lung (1.69), kidney (1.98), nervous system (1.79) and thyroid cancers (3.28), when 5 or more family members were diagnosed with discordant cancers. For most cancers, the PAF for discordant family history exceeded that for concordant family history. Our findings suggest that there is an unspecific genetic predisposition to cancer with clinical consequences. We consider it unlikely that shared environmental risk factors could essentially contribute to the risks for diverse discordant cancers, which are likely driven by genetic predisposition. The identification of genes that moderately increase the risk for many cancers will be a challenge.

Familial Risk of Biliary Tract Cancers: A Population-Based Study in Utah

BACKGROUND AND OBJECTIVES

Biliary tract cancers (BTC) including, cholangiocarcinoma (CC) and gallbladder cancer (GBC), are rare and highly fatal malignancies. The etiology and inherited susceptibility of both malignancies are poorly understood. We quantified the risk of BTC in first-degree (FDR), second-degree (SDR), and first cousin (FC) relatives of individuals with BTC, stratified by tumor subsite.

METHODS

BTC diagnosed between 1980 and 2011 were identified from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. Age- and gender-matched BTC-free controls were selected to form the comparison group for determining BTC risk in relatives using Cox regression analysis.

RESULTS

Of the 1302 index patients diagnosed with BTC, 550 (42.2 %) were located in the gallbladder and 752 (57.8 %) were cholangiocarcinomas. There was no elevated risk of BTC (all subsites combined) in FDRs (HR 0.94, 95 % CI 0.29-3.0), SDRs (HR 0.25, 95 % CI 0.06-1.03), and FCs (HR 0.96, 95 % CI 0.61-1.51) of BTC cases compared to cancer-free controls. Similarly, no increased familial risk of GBC or CC was found in relatives of BTC patients stratified by tumor subsite compared to relatives of controls.

CONCLUSIONS

Relatives of BTC patients are not at an increased risk of GBC or CC in a statewide population. This suggests that biliary tract cancer risk is not associated with a familial predisposition and may be mitigated more strongly by environmental modifiers.

Family History of Cancer and Head and Neck Cancer Risk in a Chinese Population

BACKGROUND

The aim of this study was to investigate whether family history of cancer is associated with head and neck cancer risk in a Chinese population.

MATERIALS AND METHODS

This case-control study included 921 cases and 806 controls. Recruitment was from December 2010 to January 2015 in eight centers in East Asia. Controls were matched to cases with reference to sex, 5-year age group, ethnicity, and residence area at each of the centers.

RESULTS

We observed an increased risk of head and neck cancer due to first degree family history of head and neck cancer, but after adjustment for tobacco smoking, alcohol drinking and betel quid chewing the association was no longer apparent. The adjusted OR were 1.10 (95% CI=0.80-1.50) for family history of tobacco-related cancer and 0.96 (95%CI=0.75-1.24) for family history of any cancer with adjustment for tobacco, betel quid and alcohol habits. The ORs for having a first-degree relative with HNC were higher in all tobacco/ alcohol subgroups.

CONCLUSIONS

We did not observe a strong association between family history of head and neck cancer and head and neck cancer risk after taking into account lifestyle factors. Our study suggests that an increased risk due to family history of head and neck cancer may be due to shared risk factors. Further studies may be needed to assess the lifestyle factors of the relatives.

A population-based survey of risk for cancer in individuals diagnosed with myotonic dystrophy

INTRODUCTION

The risk of cancer in patients diagnosed with myotonic dystrophy (DM) is reported for the homogeneous Utah population.

METHODS

Clinical data accessed from the largest Utah healthcare providers have been record-linked to the Utah Population Database, a population-based resource also linked to the Utah Cancer Registry. Relative risks were estimated for 36 cancers of different types in 281 DM patients.

RESULTS

Testicular cancer (relative risk [RR] = 10.74; 95% confidence interval [CI], 1.91-38.79), endometrial cancer (RR = 6.98; 95% CI, 1.24-25.22), and non-Hodgkin lymphoma (RR = 4.25; 95% CI, 1.16-12.43) were all observed at significant excess in DM patients.

CONCLUSIONS

This study confirms an overall increased risk of cancer in DM. Individuals diagnosed with DM might benefit from risk counseling. Muscle Nerve 54: 783-785, 2016.

Population-based risks for cancer in patients with ALS

OBJECTIVE

To estimate the risks for cancer (overall and site-specific) in an amyotrophic lateral sclerosis (ALS) cohort.

METHODS

In this observational longitudinal study, ALS and cancer cases were identified in a computerized Utah genealogy database (Utah Population Database) linked to a statewide cancer registry and death certificates. Hazard ratios (HRs) were estimated as the ratio of observed to expected number of cancers. Site-specific rates for cancer were estimated within the Utah Population Database; sex, birth year (5-year range), and birth state (Utah or not) cohorts were used to estimate the expected number of cancers among ALS cases. To account for an overall shortened lifespan, Cox regression was used to include years at risk in estimation of cancer risks for ALS cases.

RESULTS

An overall decreased hazard (hazard ratio [HR] 0.80, p = 0.014, 95% confidence interval [CI] 0.66-0.96) was found for cancer of any site in 1,081 deceased patients with ALS. A decreased hazard was found for lung cancer (HR 0.23, p = 0.002, CI 0.05-0.63). An increased hazard was found for salivary (HR 5.27, p = 0.041, 95% CI 1.09-15.40) and testicular (HR 3.82, p = 0.042, 95% CI 1.06-9.62) cancers. A nonsignificant hazard was observed for cutaneous malignant melanoma (HR 1.62, p = 0.12, 95% CI 0.88-2.71) for which increased risk has previously been reported.

CONCLUSIONS

Using a unique population database, the overall risk of cancer of any site was found to be significantly reduced in cases with ALS, as was the risk of lung cancer. Significantly increased risk was observed for salivary and testicular cancers.

Determining the familial risk distribution of colorectal cancer: a data mining approach

This study was aimed to characterize the distribution of colorectal cancer risk using family history of cancers by data mining. Family histories for 10,066 colorectal cancer cases recruited to population cancer registries of the Colon Cancer Family Registry were analyzed using a data mining framework. A novel index was developed to quantify familial cancer aggregation. Artificial neural network was used to identify distinct categories of familial risk. Standardized incidence ratios (SIRs) and corresponding 95% confidence intervals (CIs) of colorectal cancer were calculated for each category. We identified five major, and 66 minor categories of familial risk for developing colorectal cancer. The distribution the major risk categories were: (1) 7% of families (SIR = 7.11; 95% CI 6.65-7.59) had a strong family history of colorectal cancer; (2) 13% of families (SIR = 2.94; 95% CI 2.78-3.10) had a moderate family history of colorectal cancer; (3) 11% of families (SIR = 1.23; 95% CI 1.12-1.36) had a strong family history of breast cancer and a weak family history of colorectal cancer; (4) 9 % of families (SIR = 1.06; 95 % CI 0.96-1.18) had strong family history of prostate cancer and weak family history of colorectal cancer; and (5) 60% of families (SIR = 0.61; 95% CI 0.57-0.65) had a weak family history of all cancers. There is a wide variation of colorectal cancer risk that can be categorized by family history of cancer, with a strong gradient of colorectal cancer risk between the highest and lowest risk categories. The risk of colorectal cancer for people with the highest risk category of family history (7% of the population) was 12-times that for people in the lowest risk category (60%) of the population. Data mining was proven an effective approach for gaining insight into the underlying cancer aggregation patterns and for categorizing familial risk of colorectal cancer.

Evidence for a heritable contribution to neuroendocrine tumors of the small intestine

Small intestinal neuroendocrine tumors (SI-NETs) are rare tumors arising from the enterochromaffin cells of the gut. Having a first-degree relative with a SI-NET has been shown to confer a substantial risk arising from shared environment and genetics. Heritable risk was examined using a computerized genealogy linked to historical statewide cancer data. A population-based analysis of the observed familial clustering of SI-NETs was performed to assess the genetic risk in distant relatives. A test for significant excess relatedness of 384 individuals with genealogy data and histologically confirmed SI-NETs was performed by comparing pairwise relatedness of cases to 1000 sets of matched controls. Overall significant excess pairwise relatedness was found for the 384 cases (P<0.001) and was still observed when closer than first cousin relationships were ignored (P=0.041). Relative risks (RRs) for SI-NETs were estimated as a ratio of observed to expected number of SI-NET cases among each relationship class. Siblings have a 13.4-fold (P<0.0001) and parents have a 6.5-fold (P=0.143) RR, suggesting both genetic and environmental influences. The risk extends out to third-degree relatives with a 2.3-fold RR (P=0.008). Metachronous cancers were also reported in 26% of the SI-NET cases demonstrating an increased RR of colon, bladder, non-Hodgkin lymphoma, melanoma, and prostate cancers. Although SI-NETs are rare, relatives of these cases are at a significantly elevated risk of developing a SI-NET due to heritable genetic factors. Definition of the genetic risk factors will be an important tool for earlier diagnosis and better outcomes for SI-NETs.

Risk of associated conditions in relatives of subjects with interstitial cystitis

OBJECTIVES

Urological chronic pelvic pain syndrome includes interstitial cystitis/painful bladder syndrome (IC/PBS), a chronic bladder pain condition of unknown etiology. Interstitial cystitis/painful bladder syndrome can co-occur with a number of associated conditions such as irritable bowel syndrome and fibromyalgia. The purpose of this study was to estimate the heritability of approximately 20 associated conditions in first-degree relatives (and if appropriate, second- and third-degree relatives) of patients with IC/PBS to identify shared genetic contributions for the disease combinations.

METHODS

We used the Utah Population Database, a unique population-based genealogical database that has been linked to electronic health records for the University of Utah Health Sciences Center back in 1994. Interstitial cystitis/painful bladder syndrome probands were identified by the International Classification of Diseases, Ninth Revision code for chronic interstitial cystitis and had genealogy information for 12 of their 14 immediate ancestors. We calculated excess risk of an associated condition in relatives of patients with IC/PBS using relative risk estimates.

RESULTS

We identified 248 IC/PBS probands. We found that 2 associated conditions, myalgia and myositis/unspecified (fibromyalgia) as well as constipation, were in significant excess in the patients with IC/PBS themselves, their first-degree relatives, and their second-degree relatives. The excess risk among relatives between IC/PBS and these associated conditions also held in the converse direction. Excess risk of IC/PBS was observed in the first- and second-degree relatives in probands with myalgia and myositis/unspecified (fibromyalgia) and in probands with constipation.

CONCLUSIONS

These results suggest that myalgia and myositis/unspecified (fibromyalgia) as well as constipation are likely to share underlying genetic factors with IC/PBS.

Evidence for a genetical contribution to non-smoking-related lung cancer

BACKGROUND

The majority of lung cancers are smoking-related, with environmental and genetical factors contributing. The interplay between environmental and genetical contributions in non-smoking-related lung cancers is less clear.

METHODS

We analysed a population-based computerised genealogy resource linked to a state-wide cancer registry of lung cancer cases (n=5544) for evidence of a genetical contribution to lung cancer predisposition in smoking (n=1747) and non-smoking cases (n=784). Statistical methods were used to test for significant excess relatedness of cases and estimate relative risk (RR) in close and distant relatives of lung cancer cases.

RESULTS

Significant excess relatedness was observed for all lung cancer cases (p<0.001) and for the subsets of smoking-related (p<0.001) and non-smoking-related (p<0.001) cases when all pairwise relationships were considered. Only the non-smoking-related subset of cases showed significant excess relatedness when close relationships were ignored (p=0.020). First-degree, second-degree, and fourth-degree relatives of non-smoking-related lung cancer cases had significantly elevated RR. An even higher elevated RR was observed for first-degree, second-degree, third-degree and fourth-degree relatives of smoking-related lung cancer cases.

CONCLUSIONS

Non-smoking-related lung cancer cases show significant excess relatedness for close and distant relationships, providing strong evidence for a genetical contribution as well as an environmental contribution. Significant excess relatedness for only close family relationships in all lung cancer cases and in only smoking-related lung cancer cases implies environmental contribution. Additionally, the highest RR for lung cancer was observed in the relatives of smoking-related lung cancer, suggesting predisposition gene carriers who smoke are at highest risk for lung cancer. Screening and gene identification should focus on high-risk pedigrees.

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.

The aggregation of early-onset melanoma in young Western Australian families

BACKGROUND

Few studies have examined the familial aggregation of melanoma or its co-aggregation with other cancers using whole-population based designs. This study aimed to investigate aggregation patterns in young Western Australian families, using population-based linked health data to identify individuals born in Western Australia between 1974 and 2007, their known relatives, and all incident cancer diagnoses within the resulting 1,506,961 individuals.

METHODS

Cox proportional hazards regression models were used to compare the risk of melanoma for first-degree relatives of melanoma cases to that for first-degree relatives of controls, with bootstrapping used to account for correlations within families. The risk of (i) developing melanoma based on the number of first-degree relatives with other cancers, and (ii) developing non-melanoma cancers based on the number of first-degree relatives diagnosed with melanoma was also investigated.

RESULTS

First-degree relatives of melanoma cases had a significantly greater incidence of melanoma than first-degree relatives of individuals not affected with melanoma (Hazard Ratio (HR)=3.58, 95% bootstrap confidence interval (CI): 2.43-5.43). Sensitivity analyses produced a higher hazard ratio estimate when restricted to melanoma cases diagnosed before 40 years of age (HR=3.77, bootstrap 95% CI: 2.49-6.39) and a lower estimate when only later-onset cases (>40 years) were considered (HR=2.45, bootstrap 95% CI: 1.23-4.82). No significant evidence was found for co-aggregation between melanoma and any other cancers.

CONCLUSIONS

Results indicated a strong familial basis of melanoma, with the higher than expected hazard ratio observed likely to reflect early-age at onset cases in this young cohort, supported by the results of the sensitivity analyses. Exploratory analyses suggested that the determinants of melanoma causing the observed aggregation within families may be independent of other malignancies, although these analyses were limited by the young age of the sample. Determining familial aggregation patterns will provide valuable knowledge regarding improved clinical risk prediction and the underlying biological mechanisms of melanoma and other cancers.

Prostate cancer risk prediction based on complete prostate cancer family history

BACKGROUND

Prostate cancer (PC) relative risks (RRs) are typically estimated based on status of close relatives or presence of any affected relatives. This study provides RR estimates using extensive and specific PC family history.

METHODS

A retrospective population-based study was undertaken to estimate RRs for PC based on complete family history of PC. A total of 635,443 males, all with ancestral genealogy data, were analyzed. RRs for PC were determined based upon PC rates estimated from males with no PC family history (without PC in first, second, or third degree relatives). RRs were determined for a variety of constellations, for example, number of first through third degree relatives; named (grandfather, father, uncle, cousins, brothers); maternal, paternal relationships, and age of onset.

RESULTS

In the 635,443 males analyzed, 18,105 had PC. First-degree RRs ranged from 2.46 (=1 first-degree relative affected, CI = 2.39-2.53) to 7.65 (=4 first-degree relatives affected, CI = 6.28-9.23). Second-degree RRs for probands with 0 affected first-degree relatives ranged from 1.51 (≥1 second-degree relative affected, CI = 1.47-1.56) to 3.09 (≥5 second-degree relatives affected, CI = 2.32-4.03). Third-degree RRs with 0 affected first- and 0 affected second-degree relatives ranged from 1.15 (≥1 affected third-degree relative, CI = 1.12-1.19) to 1.50 (≥5 affected third-degree relatives, CI = 1.35-1.66). RRs based on age at diagnosis were higher for earlier age at diagnoses; for example, RR = 5.54 for ≥1 first-degree relative diagnosed before age 50 years (CI = 1.12-1.19) and RR = 1.78 for >1 second-degree relative diagnosed before age 50 years, CI = 1.33, 2.33. RRs for equivalent maternal versus paternal family history were not significantly different.

CONCLUSIONS

A more complete PC family history using close and distant relatives and age at diagnosis results in a wider range of estimates of individual RR that are potentially more accurate than RRs estimated from summary family history. The presence of PC in second- and even third-degree relatives contributes significantly to risk. Maternal family history is just as significant as paternal family history. PC RRs based on a proband's complete constellation of affected relatives will allow patients and care providers to make more informed screening, monitoring, and treatment decisions.

Significant evidence of linkage for a gene predisposing to colorectal cancer and multiple primary cancers on 22q11

Objectives:

The genetic basis of colorectal cancer (CRC) is not completely specified. Part of the difficulty in mapping predisposition genes for CRC may be because of phenotypic heterogeneity. Using data from a population genealogy of Utah record linked to a statewide cancer registry, we identified a subset of CRC cases that exhibited familial clustering in excess of that expected for all CRC cases in general, which may represent a genetically homogeneous subset of CRC.

Methods:

Using a new familial aggregation method referred to as the subset genealogic index of familiality (subsetGIF), combined with detailed information from a statewide tumor registry, we identified a subset of CRC cases that exhibited excess familial clustering above that expected for CRC: CRC cases who had at least one other primary tumor at a different site. A genome-wide linkage analysis was performed on a set of high-risk CRC pedigrees that included multiple CRC cases with additional primaries to identify evidence for predisposition loci.

Results:

A total of 13 high-risk CRC pedigrees with multiple CRC cases with other primary cancers were identified. Linkage analysis identified one pedigree with a significant linkage signal at 22q11 (LOD (logarithm (base 10) of odds)=3.39).

Conclusions:

A predisposition gene or variant for CRC that also predisposes to other primary cancers likely resides on chromosome 22q11. The ability to use statewide population genealogy and tumor registry data was critical to identify an informative subset of CRC cases that is possibly more genetically homogeneous than CRC in general, and may have improved statistical power for predisposition locus identification in this study.

A population-based analysis of clustering identifies a strong genetic contribution to lethal prostate cancer

BACKGROUND

Prostate cancer is a common and often deadly cancer. Decades of study have yet to identify genes that explain much familial prostate cancer. Traditional linkage analysis of pedigrees has yielded results that are rarely validated. We hypothesize that there are rare segregating variants responsible for high-risk prostate cancer pedigrees, but recognize that within-pedigree heterogeneity is responsible for significant noise that overwhelms signal. Here we introduce a method to identify homogeneous subsets of prostate cancer, based on cancer characteristics, which show the best evidence for an inherited contribution.

METHODS

We have modified an existing method, the Genealogical Index of Familiality (GIF) used to show evidence for significant familial clustering. The modification allows a test for excess familial clustering of a subset of prostate cancer cases when compared to all prostate cancer cases.

RESULTS

Consideration of the familial clustering of eight clinical subsets of prostate cancer cases compared to the expected familial clustering of all prostate cancer cases identified three subsets of prostate cancer cases with evidence for familial clustering significantly in excess of expected. These subsets include prostate cancer cases diagnosed before age 50 years, prostate cancer cases with body mass index (BMI) greater than or equal to 30, and prostate cancer cases for whom prostate cancer contributed to death.

CONCLUSIONS

This analysis identified several subsets of prostate cancer cases that cluster significantly more than expected when compared to all prostate cancer familial clustering. A focus on high-risk prostate cancer cases or pedigrees with these characteristics will reduce noise and could allow identification of the rare predisposition genes or variants responsible.

Family history of cancer and the risk of cancer: a network of case-control studies

BACKGROUND

The risk of many cancers is higher in subjects with a family history (FH) of cancer at a concordant site. However, few studies investigated FH of cancer at discordant sites.

PATIENTS AND METHODS

This study is based on a network of Italian and Swiss case-control studies on 13 cancer sites conducted between 1991 and 2009, and including more than 12 000 cases and 11 000 controls. We collected information on history of any cancer in first degree relatives, and age at diagnosis. Odds ratios (ORs) for FH were calculated by multiple logistic regression models, adjusted for major confounding factors.

RESULTS

All sites showed an excess risk in relation to FH of cancer at the same site. Increased risks were also found for oral and pharyngeal cancer and FH of laryngeal cancer (OR = 3.3), esophageal cancer and FH of oral and pharyngeal cancer (OR = 4.1), breast cancer and FH of colorectal cancer (OR = 1.5) and of hemolymphopoietic cancers (OR = 1.7), ovarian cancer and FH of breast cancer (OR = 2.3), and prostate cancer and FH of bladder cancer (OR = 3.4). For most cancer sites, the association with FH was stronger when the proband was affected at age <60 years.

CONCLUSIONS

Our results point to several potential cancer syndromes that appear among close relatives and may indicate the presence of genetic factors influencing multiple cancer sites.

Family, frailty, and fatal futures? Own-health and family-health predictors of subjective life expectancy

Subjective life expectancy is a powerful predictor of a variety of health and economic behaviors. This research expands upon the life expectancy literature by examining the influence of familial health histories. Using a genetic/environmental model, we hypothesize that individuals' assessments of their life expectancies will be linked to the health of first-degree and second-degree relatives, with same-sex relatives' health exercising a stronger effect than that of opposite-sex relatives. Multivariate analyses based on data from a 2009 survey merged with familial health records (N = 1,019) confirm that the health experiences of same-sex, first-degree relatives are linked to respondents' subjective life expectancy. The relationship between the health experiences of second-degree relatives and subjective life expectancy is much less pronounced. These findings have the potential not only to inform our understanding of health behaviors but also to encourage communication between patients and health professionals aimed at promoting preventative behaviors.