How common is familial cancer?

The 5-WS of targeting DNA-damage repair (DDR) pathways in prostate cancer

DNA-damage repair (DDR) pathways alterations, a growing area of interest in oncology, are detected in about 20% of patient with prostate cancer and are associated with improved sensitivity to poly(ADP ribose) polymerases (PARP) inhibitors. In May 2020, the Food and Drug Administration (FDA) approved two PARP inhibitors (olaparib and rucaparib) for prostate cancer treatment. Moreover, germline aberrations in DDR pathways genes have also been related to familial or hereditary prostate cancer, requiring tailored health-care programs. These emerging scenarios are rapidly changing diagnostic, prognostic and therapeutic approaches in prostate cancer management. The aim of this review is to highlight the five W-points of DDR pathways in prostate cancer: why targeting DDR pathways in prostate cancer; what we should test for genomic profiling in prostate cancer; "where" testing genetic assessment in prostate cancer (germline or somatic, solid or liquid biopsy); when genetic testing is appropriate in prostate cancer; who could get benefit from PARP inhibitors; how improve patients outcome with combinations strategies.

Prevalence of family history of cancer in the NC-CCAPH consortium of Japan

The objective of this study was to identify the prevalence of family history of cancer using cohorts participating in the Japanese National Center Cohort Collaborative for Advancing Population Health (NC-CCAPH). We pooled data from seven eligible cohorts of the Collaborative with available data on family history of cancer. Prevalence of family history of cancer and corresponding 95% confidence intervals are presented for all cancers and selected site-specific cancers for the total population and stratified by sex, age, and birth cohort. Prevalence of family history of cancer increased with age ranging from 10.51% in the 15 to 39 year age category to 47.11% in 70-year-olds. Overall prevalence increased in birth cohorts from ≤ 1929 until 1960 and decreased for the next two decades. Gastric cancer (11.97%) was the most common site recorded for family members, followed by colorectal and lung (5.75%), prostate (4.37%), breast (3.43%) and liver (3.05%) cancer. Women consistently had a higher prevalence of family history of cancer (34.32%) versus men (28.75%). Almost one in three participants had a family history of cancer in this Japanese consortium study highlighting the importance of early and targeted cancer screening services.

Whole exome sequencing identifies novel germline variants of SLC15A4 gene as potentially cancer predisposing in familial colorectal cancer

About 15% of colorectal cancer (CRC) patients have first-degree relatives affected by the same malignancy. However, for most families the cause of familial aggregation of CRC is unknown. To identify novel high-to-moderate-penetrance germline variants underlying CRC susceptibility, we performed whole exome sequencing (WES) on four CRC cases and two unaffected members of a Polish family without any mutation in known CRC predisposition genes. After WES, we used our in-house developed Familial Cancer Variant Prioritization Pipeline and identified two novel variants in the solute carrier family 15 member 4 (SLC15A4) gene. The heterozygous missense variant, p. Y444C, was predicted to affect the phylogenetically conserved PTR2/POT domain and to have a deleterious effect on the function of the encoded peptide/histidine transporter. The other variant was located in the upstream region of the same gene (GRCh37.p13, 12_129308531_C_T; 43 bp upstream of transcription start site, ENST00000266771.5) and it was annotated to affect the promoter region of SLC15A4 as well as binding sites of 17 different transcription factors. Our findings of two distinct variants in the same gene may indicate a synergistic up-regulation of SLC15A4 as the underlying genetic cause and implicate this gene for the first time in genetic inheritance of familial CRC.

Comprehensive cancer-oriented biobanking resource of human samples for studies of post-zygotic genetic variation involved in cancer predisposition

The progress in translational cancer research relies on access to well-characterized samples from a representative number of patients and controls. The rationale behind our biobanking are explorations of post-zygotic pathogenic gene variants, especially in non-tumoral tissue, which might predispose to cancers. The targeted diagnoses are carcinomas of the breast (via mastectomy or breast conserving surgery), colon and rectum, prostate, and urinary bladder (via cystectomy or transurethral resection), exocrine pancreatic carcinoma as well as metastases of colorectal cancer to the liver. The choice was based on the high incidence of these cancers and/or frequent fatal outcome. We also collect age-matched normal controls. Our still ongoing collection originates from five clinical centers and after nearly 2-year cooperation reached 1711 patients and controls, yielding a total of 23226 independent samples, with an average of 74 donors and 1010 samples collected per month. The predominant diagnosis is breast carcinoma, with 933 donors, followed by colorectal carcinoma (383 donors), prostate carcinoma (221 donors), bladder carcinoma (81 donors), exocrine pancreatic carcinoma (15 donors) and metachronous colorectal cancer metastases to liver (14 donors). Forty percent of the total sample count originates from macroscopically healthy cancer-neighboring tissue, while contribution from tumors is 12%, which adds to the uniqueness of our collection for cancer predisposition studies. Moreover, we developed two program packages, enabling registration of patients, clinical data and samples at the participating hospitals as well as the central system of sample/data management at coordinating center. The approach used by us may serve as a model for dispersed biobanking from multiple satellite hospitals. Our biobanking resource ought to stimulate research into genetic mechanisms underlying the development of common cancers. It will allow all available "-omics" approaches on DNA-, RNA-, protein- and tissue levels to be applied. The collected samples can be made available to other research groups.

Metabolomics and the Multi-Omics View of Cancer

Cancer is widely regarded to be a genetic disease. Indeed, over the past five decades, the genomic perspective on cancer has come to almost completely dominate the field. However, this genome-only view is incomplete and tends to portray cancer as a disease that is highly heritable, driven by hundreds of complex genetic interactions and, consequently, difficult to prevent or treat. New evidence suggests that cancer is not as heritable or purely genetic as once thought and that it really is a multi-omics disease. As highlighted in this review, the genome, the exposome, and the metabolome all play roles in cancer’s development and manifestation. The data presented here show that >90% of cancers are initiated by environmental exposures (the exposome) which lead to cancer-inducing genetic changes. The resulting genetic changes are, then, propagated through the altered DNA of the proliferating cancer cells (the genome). Finally, the dividing cancer cells are nourished and sustained by genetically reprogrammed, cancer-specific metabolism (the metabolome). As shown in this review, all three “omes” play roles in initiating cancer. Likewise, all three “omes” interact closely, often providing feedback to each other to sustain or enhance tumor development. Thanks to metabolomics, these multi-omics feedback loops are now much more evident and their roles in explaining the hallmarks of cancer are much better understood. Importantly, this more holistic, multi-omics view portrays cancer as a disease that is much more preventable, easier to understand, and potentially, far more treatable.

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.

Risk of prostate cancer in relatives of prostate cancer patients in Sweden: A nationwide cohort study

BACKGROUND

Evidence-based guidance for starting ages of screening for first-degree relatives (FDRs) of patients with prostate cancer (PCa) to prevent stage III/IV or fatal PCa is lacking in current PCa screening guidelines. We aimed to provide evidence for risk-adapted starting age of screening for relatives of patients with PCa.

METHODS AND FINDINGS

In this register-based nationwide cohort study, all men (aged 0 to 96 years at baseline) residing in Sweden who were born after 1931 along with their fathers were included. During the follow-up (1958 to 2015) of 6,343,727 men, 88,999 were diagnosed with stage III/IV PCa or died of PCa. The outcomes were defined as the diagnosis of stage III/IV PCa or death due to PCa, stratified by age at diagnosis. Using 10-year cumulative risk curves, we calculated risk-adapted starting ages of screening for men with different constellations of family history of PCa. The 10-year cumulative risk of stage III/IV or fatal PCa in men at age 50 in the general population (a common recommended starting age of screening) was 0.2%. Men with ≥2 FDRs diagnosed with PCa reached this screening level at age 41 (95% confidence interval (CI): 39 to 44), i.e., 9 years earlier, when the youngest one was diagnosed before age 60; at age 43 (41 to 47), i.e., 7 years earlier, when ≥2 FDRs were diagnosed after age 59, which was similar to that of men with 1 FDR diagnosed before age 60 (41 to 45); and at age 45 (44 to 46), when 1 FDR was diagnosed at age 60 to 69 and 47 (46 to 47), when 1 FDR was diagnosed after age 69. We also calculated risk-adapted starting ages for other benchmark screening ages, such as 45, 55, and 60 years, and compared our findings with those in the guidelines. Study limitations include the lack of genetic data, information on lifestyle, and external validation.

CONCLUSIONS

Our study provides practical information for risk-tailored starting ages of PCa screening based on nationwide cancer data with valid genealogical information. Our clinically relevant findings could be used for evidence-based personalized PCa screening guidance and supplement current PCa screening guidelines for relatives of patients with PCa.

[Familial prostate cancer and genetic predisposition]

BACKGROUND

Twenty percent of all prostate cancer patients have a positive family history (at least 1 first-degree relative with prostate cancer) and a part of these patients have a genetic predisposition.

OBJECTIVES

A literature search and analysis of studies investigating incidence, diagnosis, and clinical course of familial compared to sporadic prostate cancer as well as genetic predisposition was performed using PubMed and Embase.

RESULTS

Risk of prostate cancer depends on number, degree of relationship, and age of onset of affected men in the family. The incidence of familial prostate cancer is higher and the age of diagnosis lower compared to sporadic cases. The clinical course of the disease is comparable, but in individuals with a germline mutation, more intensive therapy is needed due to a more aggressive disease.

CONCLUSIONS

Crucial for risk assessment is a detailed family history, including creation of a pedigree with cancer family history if necessary. In high-risk families, genetic counselling and annual prostate-specific antigen (PSA) screening beginning at the age of 40 should be performed. Verification of a germline mutation requires more intensive therapy due to more aggressive disease.

Risk of invasive breast cancer in relatives of patients with breast carcinoma in situ: a prospective cohort study

BACKGROUND

Wide implementation of mammography screening has resulted in increased numbers of women diagnosed with breast carcinoma in situ. We aimed to determine the risk of invasive breast cancer in relatives of patients with breast carcinoma in situ in comparison to the risk in relatives of patients with invasive breast cancer.

METHODS

We analyzed the occurrence of cancer in a nationwide cohort including all 5,099,172 Swedish women born after 1931 with at least one known first-degree relative. This was a record linkage study of Swedish family cancer datasets, including cancer registry data collected from January 1, 1958, to December 31, 2015. We calculated standardized incidence ratios (SIRs) and 10-year cumulative risk of breast cancer diagnosis for women with a family history of in situ and invasive breast cancer.

RESULTS

Having one first-degree relative with breast carcinoma in situ was associated with 50% increased risk of invasive breast cancer (SIR = 1.5, 95% CI 1.4-1.7) when compared to those who had no family history of invasive breast cancer or breast carcinoma in situ in either first- or second-degree relatives. Similarly, having one first-degree relative with invasive breast cancer was associated with 70% (1.7, 1.7-1.8) increased risk. The 10-year cumulative risk for women at age 50 with a relative with breast carcinoma in situ was 3.5% (2.9-3.9%) and was not significantly different from 3.7% (3.6-3.8%) risk for 50-year-old women with a relative with invasive breast cancer (95% confidence intervals overlapped).

CONCLUSIONS

The risk of invasive breast cancer for women with a family history of breast carcinoma in situ was comparable to that for women with a family history of invasive breast cancer. Therefore, family history of breast carcinoma in situ should not be overlooked in recommendations for breast cancer prevention for women with a family history of breast cancer.

Gender differences in self-reported family history of cancer: A review and secondary data analysis

Background

Assessment of family history of cancer (FHC) mostly relies on self‐report. Our goal was to find out whether there is a systematic gender difference in self‐reported FHC.

Methods

We identified nine population‐based studies which provided statistics of FHC in men and women (N₁ = 404 541). Furthermore, we analyzed data (N₂ = 167 154) from several iterations of the US‐based Health Information National Trends Survey (HINTS) and the National Health Interview Survey (NHIS). We calculated the proportion of positive FHC, odds ratios (OR M/F), 95% confidence intervals, and aggregated statistics. We additionally analyzed in‐depth questions about FHC from HINTS 5 Cycle 2.

Results

In the reviewed studies the odds of men reporting a FHC were lower compared with the odds of women with an average OR of 0.84 [0.71; 1.00] across all studies and an OR of 0.75 [0.70; 0.80] for the six studies from the US and Europe. The gender gap was replicated in our own analyses of HINTS and NHIS with an average OR of 0.75 [0.71; 0.79]. In HINTS 5 Cycle 2 men described themselves as less familiar with their FHC and less confident answering questions regarding FHC. They were also less likely to discuss FHC with family members.

Conclusions

Men— at least in the US and Europe—were consistently less likely to report FHC compared with women. Future research should investigate how the assessment of FHC can be improved to reduce these differences. Health care professionals should also consider the potential for biased reporting by gender when assessing FHC.

Risk of invasive prostate cancer and prostate cancer death in relatives of patients with prostatic borderline or in situ neoplasia: A nationwide cohort study

BACKGROUND

The question of whether having a family history of prostatic borderline or in situ neoplasia (PBISN) is associated with an increased risk of invasive prostate cancer (PCa) or death from PCa remains unanswered. The objective of the current study was to provide an evidence-based risk estimation for the relatives of patients with PBISN.

METHODS

Nationwide Swedish family cancer data sets were used for the current study, including data regarding all residents of Sweden who were born after 1931 and their parents. Standardized incidence ratios (SIRs), standardized mortality ratios (SMRs), and lifetime cumulative risks of PCa were calculated for men with different constellations of family history. Family history was defined as a dynamic (time-dependent) variable considering changes during follow-up (1958-2015).

RESULTS

Of the 6,343,727 men in the current study, a total of 238,961 developed invasive PCa and 5756 were diagnosed with PBISN during the follow-up. Men with 1 first-degree relative who was diagnosed with PBISN had a 70% increased risk of invasive PCa (SIR, 1.7; 95% confidence interval, 1.5-1.9) and PCa death (SMR, 1.7; 95% confidence interval, 1.3-2.2) compared with men with no family history of PBISN or invasive PCa. These were rather close to estimates in men with 1 first-degree relative diagnosed with invasive PCa (SIR, 2.1 and SMR, 1.8). A higher risk of PCa in family members was found among patients with a family history of PBISN and/or PCa diagnosed before age 60 years. The results in terms of cumulative risk resembled this trend.

CONCLUSIONS

A family history of PBISN appears to be as important as a family history of invasive PCa with regard to an increased risk of invasive PCa or PCa mortality. Such a history should not be overlooked in PCa screening recommendations or in future research regarding familial PCa.

Calculating the Starting Age for Screening in Relatives of Patients With Colorectal Cancer Based on Data From Large Nationwide Data Sets

BACKGROUND & AIMS

Although colorectal cancer (CRC) screening guidelines acknowledge the need for earlier screening for high-risk individuals, such as those with family history of CRC, there is limited information on how many years earlier these high-risk individuals should be screened; current practice is based on weak evidence. We aimed to provide risk-adapted recommendations on the starting age of CRC screening for individuals with different family histories.

METHODS

We collected data from nationwide family-cancer data sets in Sweden and calculated risk-adapted starting ages of screening for individuals with different family histories of CRC. Family history was defined as a dynamic (time-dependent) variable, allowing for changes during the follow-up period of 1958 through 2015.

RESULTS

During a follow-up of 12,829,251 individuals with genealogy information, 173,796 developed CRC. The 10-year cumulative risk for the average-risk population at age 50 years (the guideline-recommended age for screening) was 0.44%. Individuals with different family histories of CRC attained this equivalent 0.44% risk 3-29 years earlier than their peers in the general population without such a family history. For example, individuals with 1 affected first-degree relative diagnosed before age 45 years reached the corresponding risk level 16 years earlier.

CONCLUSIONS

We determined risk-adapted starting ages of CRC screening for close or distant relatives of patients with CRC, using high quality nationwide data sets. These findings might be used in counselling individuals about the appropriate age to start CRC screening, to optimize screening practice, and to supplement guidelines for CRC screening.

Effectiveness of interventions to identify and manage patients with familial cancer risk in primary care: a systematic review

This systematic review evaluated the effectiveness of strategies to identify and manage patients with familial risk of breast, ovarian, colorectal and prostate cancer in primary care to improve clinical outcomes. MEDLINE, EMBASE, CINAHL and Cochrane library were searched from January 1980 to October 2017. We included randomised controlled trials (RCT) and non-randomised studies of interventions (NRSI). Primary outcomes were cancer incidence, cancer-related clinical outcomes or the identification of cancer predisposition; secondary outcomes were the appropriateness of referral, uptake of preventive strategies and cognitive and psychological effect. From 11,842 abstracts, 111 full texts were reviewed and three eligible studies (nine articles) identified. Two were cluster RCTs and one NRSI; all used risk assessment software. No studies identified our primary outcomes, with no consistent outcome across the three studies. In one RCT, intervention improved the proportion of genetic referrals meeting referral guidelines for breast cancer (OR 4.5, 95% CI 1.6 to 13.1). In the other RCT, there was no difference in screening adherence between the intervention and control group. However, there was borderline increased risk perception (OR 1.89, 95% CI 0.99 to 3.59) in the subgroup that under-estimated their colon cancer risk. In the NRSI, there was no change in psychological distress in patients at increased familial breast cancer risk, but population risk patients had reduced anxiety after intervention (state anxiety mean change - 3, 95% CI - 5 to - 2). Future studies should have better-defined comparator groups and longer follow-up and assess outcomes using validated tools.

Impact of a Changing Population Structure and Clustering of Cancer in Prostate Cancer Patients Depending on a First-Degree Family History

INTRODUCTION

In the last century, there have been major changes within the population structure in Germany. The aim of this study was to determine the impact of a changing population structure on identification of familial prostate cancer (PCa), and to investigate how many and which types of other cancers have occurred in patients and their first-degree relatives.

MATERIALS AND METHODS

A total of 19,540 patients were evaluated in a prospectively collected PCa family database and divided into four birth cohorts: 1925-1934 (cohort A), 1935-1944 (cohort B), 1945-1954 (cohort C), and 1955-1964 (cohort D). Other primary cancers and cancers of first-degree relatives were evaluated.

RESULTS

The percentage of PCa patients with ≥2 sons declined (A: 28.9% to D: 21.6%). The percentage of patients whose fathers lived for ≥65 years increased (B: 64.2% to D: 73.0%). Malignancies of the skin, the urinary tract, and the lymphoid/hematopoietic tissue were more common in patients with a positive first-degree PCa family history and their first-degree relatives. Additionally, first-degree relatives reported more often neoplasms of respiratory/intrathoracic organs and the female breast.

CONCLUSIONS

A small family size, an early deceased father, and a high number of sporadic cases complicate the identification of familial PCa patients. Thus, a detailed family history should also include unaffected first-degree relatives to avoid any misclassification. Findings of other primary cancers in patients and their relatives warrant further investigation.

Lifestyle and cancer incidence and mortality risk depending on family history of cancer in two prospective cohorts

The extent to which a favorable lifestyle may lower cancer risk in subjects with a family history of cancer is unknown. We conducted a prospective study in two Swedish cohorts, the Malmö Diet and Cancer Study (MDCS; n = 25,604) and the Malmö Preventive Project (MPP; n = 16,216). The association between a favorable lifestyle (based on nonsmoking, normal weight, absence of excessive drinking, regular physical activity and healthy diet) and cancer incidence and mortality risk was assessed using Cox regression stratified by family history of cancer (all types). A favorable lifestyle was associated with a 22% (95% confidence interval [CI]: 18-26%) and 40% (95% CI: 36-44%) lower risk of cancer incidence and mortality, respectively, compared to an unfavorable lifestyle. No significant effect modification by family history was observed but there was a null association between lifestyle and cancer incidence among subjects with two or more affected first-degree relatives. The observed relative risk estimates comparing an unfavorable with a favorable lifestyle corresponded to standardized 10-year cancer incidence rates of 11.2 vs. 9.5% in the MDCS, and 4.4 vs. 3.2% in the MPP, and a reduction in 20-year cancer mortality rate from 11.7% to 7.4% in the MDCS and 6.7% to 3.9% in the MPP. Improved adherence to cancer prevention recommendations may reduce cancer incidence and mortality risk in the general population, however, further studies are needed to assess the impact of lifestyle on cancer incidence among subjects with strong familial or polygenic risk for specific cancers.

Development, Evaluation, and Implementation of a Pan-African Cancer Research Network: Men of African Descent and Carcinoma of the Prostate

PURPOSE

Cancer of the prostate (CaP) is the leading cancer among men in sub-Saharan Africa (SSA). A substantial proportion of these men with CaP are diagnosed at late (usually incurable) stages, yet little is known about the etiology of CaP in SSA.

METHODS

We established the Men of African Descent and Carcinoma of the Prostate Network, which includes seven SSA centers partnering with five US centers to study the genetics and epidemiology of CaP in SSA. We developed common data elements and instruments, regulatory infrastructure, and biosample collection, processing, and shipping protocols. We tested this infrastructure by collecting epidemiologic, medical record, and genomic data from a total of 311 patients with CaP and 218 matched controls recruited at the seven SSA centers. We extracted genomic DNA from whole blood, buffy coat, or buccal swabs from 265 participants and shipped it to the Center for Inherited Disease Research (Baltimore, MD) and the Centre for Proteomics and Genomics Research (Cape Town, South Africa), where genotypes were generated using the UK Biobank Axiom Array.

RESULTS

We used common instruments for data collection and entered data into the shared database. Double-entered data from pilot participants showed a 95% to 98% concordance rate, suggesting that data can be collected, entered, and stored with a high degree of accuracy. Genotypes were obtained from 95% of tested DNA samples (100% from blood-derived DNA samples) with high concordance across laboratories.

CONCLUSION

We provide approaches that can produce high-quality epidemiologic and genomic data in multicenter studies of cancer in SSA.

Genetic Hitchhiking and Population Bottlenecks Contribute to Prostate Cancer Disparities in Men of African Descent

Prostate cancer incidence and mortality rates in African and African American men are greatly elevated compared with other ethnicities. This disparity is likely explained by a combination of social, environmental, and genetic factors. A large number of susceptibility loci have been reported by genome-wide association studies (GWAS), but the contribution of these loci to prostate cancer disparities is unclear. Here, we investigated the population structure of 68 previously reported GWAS loci and calculated genetic disparity contribution statistics to identify SNPs that contribute the most to differences in prostate cancer risk across populations. By integrating GWAS results with allele frequency data, we generated genetic risk scores for 45 African and 19 non-African populations. Tests of natural selection were used to assess why some SNPs have large allele frequency differences across populations. We report that genetic predictions of prostate cancer risks are highest for West African men and lowest for East Asian men. These differences may be explained by the out-of-Africa bottleneck and natural selection. A small number of loci appear to drive elevated prostate cancer risks in men of African descent, including rs9623117, rs6983267, rs10896449, rs10993994, and rs817826. Although most prostate cancer-associated loci are evolving neutrally, there are multiple instances where alleles have hitchhiked to high frequencies with linked adaptive alleles. For example, a protective allele at 2q37 appears to have risen to high frequency in Europe due to selection acting on pigmentation. Our results suggest that evolutionary history contributes to the high rates of prostate cancer in African and African American men.Significance: A small number of genetic variants cause an elevated risk of prostate cancer in men of West African descent. Cancer Res; 78(9); 2432-43. ©2018 AACR.

Time-dependent risks of cancer clustering among couples: a nationwide population-based cohort study in Taiwan

OBJECTIVES

Spousal clustering of cancer warrants attention. Whether the common environment or high-age vulnerability determines cancer clustering is unclear. The risk of clustering in couples versus non-couples is undetermined. The time to cancer clustering after the first cancer diagnosis is yet to be reported. This study investigated cancer clustering over time among couples by using nationwide data.

METHODS

A cohort of 5643 married couples in the 2002-2013 Taiwan National Health Insurance Research Database was identified and randomly matched with 5643 non-couple pairs through dual propensity score matching. Factors associated with clustering (both spouses with tumours) were analysed by using the Cox proportional hazard model.

RESULTS

Propensity-matched analysis revealed that the risk of clustering of all tumours among couples (13.70%) was significantly higher than that among non-couples (11.84%) (OR=1.182, 95% CI 1.058 to 1.321, P=0.0031). The median time to clustering of all tumours and of malignant tumours was 2.92 and 2.32 years, respectively. Risk characteristics associated with clustering included high age and comorbidity.

CONCLUSIONS

Shared environmental factors among spouses might be linked to a high incidence of cancer clustering. Cancer incidence in one spouse may signal cancer vulnerability in the other spouse. Promoting family-oriented cancer care in vulnerable families and preventing shared lifestyle risk factors for cancer are suggested.

A Bayesian scoring rule on clustered event data for familial risk assessment - An example from colorectal cancer screening

Colorectal cancer screening is well established. The identification of high risk populations is the key to implement effective risk-adjusted screening. Good statistical approaches for risk prediction do not exist. The family's colorectal cancer history is used for identification of high risk families and usually assessed by a questionnaire. This paper introduces a prediction algorithm to designate a family for colorectal cancer risk and discusses its statistical properties. The new algorithm uses Bayesian reasoning and a detailed family history illustrated by a pedigree and a Lexis diagram. The algorithm is able to integrate different hereditary mechanisms that define complex latent class or random factor structures. They are generic and do not reflect specific genetic models. This is comparable to strategies in complex segregation analysis. Furthermore, the algorithm can integrate different statistical penetrance models for right censored event data. Computational challenges related to the handling of the likelihood are discussed. Simulation studies assess the predictive quality of the new algorithm in terms of ROC curves and corresponding AUCs. The algorithm is applied to data of a recent study on familial colorectal cancer risk. Its predictive performance is compared to that of a questionnaire currently used in screening for familial colorectal cancer. The results of the proposed algorithm are robust against different inheritance models. Using the simplest hereditary mechanism, the simulation study provides evidence that the algorithm improves detection of families with high cancer risk in comparison to the currently used questionnaire. The applicability of the algorithm goes beyond the field of colorectal cancer.

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.

Prostate Cancer Genetics: Variation by Race, Ethnicity, and Geography

Prostate cancer rates vary substantially by race, ethnicity, and geography. These disparities can be explained by variation in access to screening and treatment, variation in exposure to prostate cancer risk factors, and variation in the underlying biology of prostate carcinogenesis (including genomic propensity of some groups to develop biologically aggressive disease). It is clear that access to screening and access to treatment are critical influencing factors of prostate cancer rates; yet, even among geographically diverse populations with similar access to care (eg, low- and medium-income countries), African descent men have higher prostate cancer rates and poorer prognosis. To date, the proportion of prostate cancer that can be explained by environmental exposures is small, and the effect of these factors across different racial, ethnic, or geographical populations is poorly understood. In contrast, prostate cancer has one of the highest heritabilities of all major cancers. Numerous genetic susceptibility markers have been identified from family-based studies, candidate gene association studies, and genome-wide association studies. Some prostate cancer loci, including the risk loci found at chromosome 8q24, have consistent effects in all groups studied to date. However, replication of many susceptibility loci across race, ethnicity, and geography remains limited, and additional studies in certain populations (particularly in men of African descent) are needed to better understand the underlying genetic basis of prostate cancer.

Clinicopathologic features of gastric cancer with synchronous and metachronous colorectal cancer in Korea: are microsatellite instability and p53 overexpression useful markers for predicting colorectal cancer in gastric cancer patients?

BACKGROUND

A large-scale study was performed to identify the risk factors for developing synchronous and metachronous colorectal cancer (CRC) in gastric cancer (GC) patients, including microsatellite instability (MSI) and p53 overexpression.

METHODS

A total of 1041 GC patients who underwent endoscopic resection or surgery and underwent colonoscopy simultaneously or during surveillance for GC were consecutively enrolled. Clinicopathologic characteristics, MSI, and p53 overexpression were compared between the GC patients with and those without synchronous and metachronous CRC.

RESULTS

Of the 1041 patients, CRCs were detected in 67 (6.4 %) patients with GC. Forty-six (4.4 %) had synchronous CRC and 21 (2.0 %) had metachronous CRC. Univariate analysis indicated that age ≥63 years (P < 0.001), male sex (P = 0.005), and p53 overexpression (P = 0.040) were significantly associated with a higher incidence of CRC. However, body mass index, smoking, tumor location, tumor multiplicity, tumor histology, TNM stage, and MSI were not significantly associated with the incidence of CRC. Age ≥63 years (OR: 5.881; 95 % CI: 3.083-11.221; P < 0.001) and male sex (OR: 2.933; 95 % CI: 1.307-6.584; P = 0.009) were risk factors for CRC in GC patients according to multivariate analysis.

CONCLUSIONS

GC patients who are male and/or ≥63 years old are recommended to receive colonoscopy to detect CRC. MSI and p53 overexpression were not useful molecular markers for predicting CRC in GC.

Validity of self-reported family history of cancer: A systematic literature review on selected cancers

Evidence regarding validity of self-reported family history of cancer (FHC) has been reviewed only for breast, colorectal, prostate, ovarian, endometrial and uterine cancer. We aimed to systematically review studies assessing validity of self-reported family history for the remaining cancer sites. We searched the Medline database for relevant studies published by January 2016. We extracted information on the study design and the positive predictive value (PPV) of self-reported FHC, defined as the proportion of reported cancer diagnoses among relatives that was confirmed by a reference standard (as a measure of over-reporting). We also extracted information on sensitivity of self-reported FHC (as a measure of underreporting). Overall, 21 studies were included that provided information on the PPV of self-reported FHC for relevant cancers and four studies also provided information on sensitivity. The PPV was highest (mostly >70%) for pancreatic, lung, thyroid and urinary system cancers and for leukemia and lymphoma, while it was lowest for stomach and liver cancer. Sensitivity was highest (>70%) for pancreatic cancer, lung cancer, brain cancer, melanoma, leukemia and lymphoma. For several cancers, sample sizes were low and the number of studies limited, particularly regarding sensitivity of self-reported FHC. In conclusion, for some cancers (e.g., pancreatic cancer, lung cancer, leukemia, lymphoma) self-reported FHC can be considered sufficiently valid to be useful, for example, in preventive counseling. For several cancers, it is not sufficiently studied or the pattern is inconsistent. This needs to be taken into account when using self-reported information about FHC in clinical practice or epidemiological research.

Cancer Genomics: Diversity and Disparity Across Ethnicity and Geography

Ethnic and geographic differences in cancer incidence, prognosis, and treatment outcomes can be attributed to diversity in the inherited (germline) and somatic genome. Although international large-scale sequencing efforts are beginning to unravel the genomic underpinnings of cancer traits, much remains to be known about the underlying mechanisms and determinants of genomic diversity. Carcinogenesis is a dynamic, complex phenomenon representing the interplay between genetic and environmental factors that results in divergent phenotypes across ethnicities and geography. For example, compared with whites, there is a higher incidence of prostate cancer among Africans and African Americans, and the disease is generally more aggressive and fatal. Genome-wide association studies have identified germline susceptibility loci that may account for differences between the African and non-African patients, but the lack of availability of appropriate cohorts for replication studies and the incomplete understanding of genomic architecture across populations pose major limitations. We further discuss the transformative potential of routine diagnostic evaluation for actionable somatic alterations, using lung cancer as an example, highlighting implications of population disparities, current hurdles in implementation, and the far-reaching potential of clinical genomics in enhancing cancer prevention, diagnosis, and treatment. As we enter the era of precision cancer medicine, a concerted multinational effort is key to addressing population and genomic diversity as well as overcoming barriers and geographical disparities in research and health care delivery.

[Familial prostate cancer research: meaningfulness of hereditary criteria in view of demographic change]

BACKGROUND

In view of demographic changes and previous research results, it is debatable whether hereditary criteria should be further applied when it comes to determining the status of prostate carcinoma (PC) patients.

MATERIALS AND METHODS

A total of 30,455 patients in the national research program "Familial Prostate Carcinoma" were divided into four groups based on birth year: I: 1920-1929 (n = 3.968), II: 1930-1939 (n = 14.110), III: 1940-1949 (n = 10.137), IV: 1950-1959 (n = 2.169). In all, 9.316 PC patients with a positive family history were analyzed with respect to their relatives (first degree).

RESULTS

The average number of siblings (group I: 3.3; IV: 2.2), brothers (I: 2.1; IV: 1.3), children (I: 2.2; IV: 1.7), and sons (I: 1.1; IV: 0.9) have decreased. The number of patients without a brother/son (I: 9.6/32.8%; IV: 27.6/37.5%) has increased. In the same period of time, the number of patients with two brothers/sons (I: 34.5/6.3%; IV: 14.8/2.2 %) has decreased. The number of fathers > 65 years has risen from 66.8% (I) to 71.1% (IV).

CONCLUSION

Hereditary criteria are less and less suited in order to determine the status of PC patients. However, positive family history remains one of the most crucial risk factors of prostate carcinoma and, therefore, detailed data ascertainment should be urged.

Multiple primary (even in situ) melanomas in a patient pose significant risk to family members

BACKGROUND

We aimed at assessing familial risk of melanoma by considering a detailed family history of multiple primary (invasive/in situ) melanomas (MPM), stratified by histology and location.

METHODS

Among 65,429 melanoma patients diagnosed in 1958-2010 in the Swedish Family-Cancer Database, there were 4248 patients with familial melanoma. A detailed family history of MPM was investigated by number of melanomas in one first-degree relative (FDR) and in ⩾2 FDRs. Familial melanoma risk was assessed by standardised incidence ratios (SIRs) comparing those with family history of melanoma to those without. Combining invasive/in situ melanoma was due to essentially identical familial risks.

RESULTS

For one affected FDR, familial risk increased from SIR=2.2 (95% confidence interval (CI)=2.2-2.3) for single melanoma to 16.3 (9.5-26.1) for ⩾5 melanomas, while for ⩾2 affected FDRs, the risk increased from 5.5 (4.8-6.2) for single melanoma to 23.9 (13.6-38.8) for ⩾2 melanomas. Significantly higher familial risks for superficial spreading melanoma (SSM) [2.5 (2.3-2.6)] than lentigo maligna melanoma (LMM) [1.8 (1.6-2.1)], and for multiple parts [5.3 (3.1-8.4)] and trunk [2.6 (2.5-2.8)] than head/neck [2.0 (1.8-2.2)] were observed. Only at head/neck, significantly higher risk for SSM [2.4 (1.9-3.0)] than LMM [1.6 (1.4-1.8)] was noted.

CONCLUSION

We found, for the first time, that familial risks were similar for two/three melanomas in one FDR or for a single melanoma in ⩾2 FDRs and, higher familial risks for SSM than LMM occurred only at head/neck. This study provides new evidence for genetic counselling in melanoma, suggesting the need for considering not only the number of affected family members but also the diagnosis of MPM (even in situ) in relatives.

Familial malignant mesothelioma: a population-based study in central Italy (1980-2012)

Malignant mesothelioma is a sporadic cancer linked to asbestos exposure. Its occurrence among blood relatives (familial mesothelioma) may point to genetic susceptibility or shared exposures. The burden of the familial disease is unknown. The aims of the study were to assess at population level the proportion of familial mesotheliomas among all mesotheliomas and to investigate the family history of cancer among relatives of mesothelioma cases. We actively searched familial clusters based on a mesothelioma registry from central Italy (5.5 million people, 10% of the Italian population) of the National Mesothelioma Register network (ReNaM) as well as a pathology-based archive. Among 997 incident mesotheliomas recorded in a 32-year-period (1980-2012), we detected 13 clusters and 34 familial cases, accounting for 3.4% of all mesotheliomas. The most common clusters where those with affected siblings and unaffected parents. Asbestos exposure was occupational (n=7 clusters), household (n=2), environmental (n=1), or not attributable for insufficient information (n=3). There were 25 additional cancers in nine families. Some were cancer sites for which there is sufficient evidence (lung and larynx) or limited evidence (stomach and colon) of causal association with asbestos. The results suggest potential genetic recessive effects in mesothelioma that interact with asbestos exposure, but it is not possible to estimate the specific proportion attributable to each of these components.

Genomics in primary care practice

This article discusses the clinical utility of genomic information for personalized preventive care of a healthy adult. Family health history is currently the most applicable genomic predictor for common, multifactorial diseases, and can also show patterns that suggest an inherited high susceptibility to a particular form of cancer or other disease. Both bloodline ancestry and shared environmental factors are important predictors for many disease states. DNA and family history analyses give information that is probabilistic, not deterministic. Therefore, family history can highlight behavioral, social, or cultural risk factors that can be modified to prevent diseases.

Familial predisposition for salivary gland cancer in Finland

BACKGROUND

Salivary gland cancer (SGC) accounts for 3–5% of head and neck malignancies, and register-based studies estimate the familial proportion to be 0.15%.

OBJECTIVE

We studied familial predisposition for SGC in the genetically distinct Finnish population.

PATIENTS AND METHODS

We sent a patient questionnaire to 161 Finnish SGC patients, 86 of whom responded.

RESULTS

A total of 76% of the patients reported having one or more relatives with cancer, 30% two or more, and 9% three or more but only one patient reported having a relative with SGC. Tracing the birthplaces of the SGC patients’ grandparents showed no regional clustering suggestive of a founder effect.

CONCLUSIONS

Lack of familial SGC patients and the absence of a founder effect strongly suggest that familial predisposition for SGC is insignificant in the Finnish population. Various histological subtypes and the rarity of these neoplasms make it impossible to draw conclusions about site-specific association between SGC and other malignancies.

US Primary Care Physicians' Prostate Cancer Screening Practices: A Vignette-Based Analysis of Screening Men at High Risk

BACKGROUND

Limited information exists on primary care physicians' (PCPs) use of the prostate-specific antigen (PSA) test by patient risk category. We describe PCP responses to hypothetical patient scenario (PS) involving PSA testing among high-risk asymptomatic men.

METHODS

Data were from the 2007 to 2008 National Survey of Primary Care Physicians' Practices Regarding Prostate Cancer Screening. PS#1: healthy 55-year-old white male with no family history of prostate cancer; PS#2: healthy 45-year-old African American male with no family history of prostate cancer; and PS#3: healthy 50-year-old male with a family history of prostate cancer. Data were analyzed in SAS/SUDAAN.

RESULTS

Most PCPs indicated that they generally discuss the possible benefits/risks of PSA testing with the patient and then recommend the test (PS#1-PS#3 range, 53.4%-68.7%; P < .001); only about 1% reported discussing and then recommending against the test. For PS#3, compared to PS#1 and #2, PCPs were more likely to discuss and recommend the test or attempt to persuade the patient who initially declines the test. For PS#3, all clinicians generally would order/discuss the PSA test and not rely on the patient to ask.

CONCLUSION

Clinicians treat family history as an important reason to recommend, persuade, and initiate PSA testing.

Associations among family history of cancer, cancer screening and lifestyle behaviors: a population-based study

PURPOSE

Some cancers are largely preventable through modification of certain behavioral risk factors and preventive screening, even among those with a family history of cancer. This study examined the associations between (1) family cancer history and cancer screening, (2) family history and cancer preventive lifestyle behaviors, and (3) cancer screening and lifestyle behaviors.

METHODS

Data were from the 2009 California Health Interview Survey (n = 12,603). Outcomes included screening for breast cancer (BC) and colorectal cancer (CRC) and six cancer preventive lifestyle behaviors, based on World Cancer Research Fund recommendations. Multivariate logistic regression analyses, stratified by gender and race-ethnicity, examined associations. Predicted probabilities of cancer screening by family cancer history, race-ethnicity, and sex were computed.

RESULTS

Family history of site-specific cancer-CRC for men and women, and BC for women-was associated with higher probability of cancer screening for most groups, especially for CRC, but was largely unrelated to other lifestyle behaviors. In the few cases in which family history was significantly associated with lifestyle-for example, physical activity among White and Latino males, smoking among White and Asian females-individuals with a family history had lower odds of adherence to recommendations than those with no family history. Greater overall adherence to lifestyle recommendations was associated with higher odds of up-to-date CRC screening among White and Asian males, and lower odds among Asian females (no significant association with BC screening); this relationship did not vary by family cancer history.

CONCLUSION

The fact that family history of cancer is not associated with better lifestyle behaviors may reflect shared behavioral risks within families, or the lack of knowledge about how certain lifestyle behaviors impact personal cancer risk. Findings can inform interventions aimed at lifestyle behavioral modification for individuals at increased cancer risk due to family history.

The genetics of cancer risk

One hundred years ago, decades before the discovery of the structure of DNA, debate raged regarding how human traits were passed from one generation to the next. Phenotypes, including risk of disease, had long been recognized as having a familial component. Yet it was difficult to reconcile genetic segregation as described by Mendel with observations exhaustively documented by Karl Pearson and others regarding the normal distribution of human characteristics. In 1918, R. A. Fisher published his landmark article, "The Correlation Between Relatives on the Supposition of Mendelian Inheritance," bridging this divide and demonstrating that multiple alleles, all individually obeying Mendel's laws, account for the phenotypic variation observed in nature.Since that time, geneticists have sought to identify the link between genotype and phenotype. Trait-associated alleles vary in their frequency and degree of penetrance. Some minor alleles may approach a frequency of 50% in the human population, whereas others are present within only a few individuals. The spectrum for penetrance is similarly wide. These characteristics jointly determine the segregation pattern of a given trait, which, in turn, determine the method used to map the trait. Until recently, identification of rare, highly penetrant alleles was most practical. Revolutionary studies in genomics reported over the past decade have made interrogation of most of the spectrum of genetic variation feasible.The following article reviews recent discoveries in the genetic basis of inherited cancer risk and how these discoveries inform cancer biology and patient management. Although this article focuses on prostate cancer, the principles are generic for any cancer and, indeed, for any trait.

[Ten years national research project "familial prostate cancer": problems in identifying risk families]

BACKGROUND

The German national research project"familial prostate cancer" has been recruiting prostate cancer patients nationwide since 1999. In 2009, a comprehensive data analysis of the 25,065 families recruited was performed. Of these, 77.4% were identified as sporadic, 20.0% as familial and 2.6% as hereditary cases of prostate cancer. However, obtaining comprehensive, validated information about all relatives often fails.

RESULTS

The high average age of the patients, the lower life expectancy in further generations and the low number of first-degree male relatives hampers the classification of sporadic, familial and hereditary cases. Consequently we describe here that in our database the identification of 100 hereditary cases requires a recruitment of more than 5,000 patients with their families. For 100 sporadic patients with 2 first-degree male relatives without a case history 1,250 patients are needed.

An epidemiological reappraisal of the familial aggregation of prostate cancer: a meta-analysis

Studies on familial aggregation of cancer may suggest an overall contribution of inherited genes or a shared environment in the development of malignant disease. We performed a meta-analysis on familial clustering of prostate cancer. Out of 74 studies reporting data on familial aggregation of prostate cancer in unselected populations retrieved by a Pubmed search and browsing references, 33 independent studies meeting the inclusion criteria were used in the analysis performed with the random effects model. The pooled rate ratio (RR) for first-degree family history, i.e. affected father or brother, is 2.48 (95% confidence interval: 2.25-2.74). The incidence rate for men who have a brother who got prostate cancer increases 3.14 times (CI:2.37-4.15), and for those with affected father 2.35 times (CI:2.02-2.72). The pooled estimate of RR for two or more affected first-degree family members relative to no history in father and in brother is 4.39 (CI:2.61-7.39). First-degree family history appears to increase the incidence rate of prostate cancer more in men under 65 (RR:2.87, CI:2.21-3.74), than in men aged 65 and older (RR:1.92, CI:1.49-2.47), p for interaction = 0.002. The attributable fraction among those having an affected first-degree relative equals to 59.7% (CI:55.6-63.5%) for men at all ages, 65.2% (CI:57.7-71.4%) for men younger than 65 and 47.9% (CI:37.1-56.8%) for men aged 65 or older. For those with a family history in 2 or more first-degree family members 77.2% (CI:65.4-85.0%) of prostate cancer incidence can be attributed to the familial clustering. Our combined estimates show strong familial clustering and a significant effect-modification by age meaning that familial aggregation was associated with earlier disease onset (before age 65).

Population-based proband-oriented pedigree information system: application to hypertension with population-based screening data (KCIS No. 25)

OBJECTIVE

To develop a population-based proband-oriented pedigree information system that can be easily applied to various diseases in genetic epidemiological studies, making allowance for the capture of theoretical family relationships. DESIGNS AND MEASUREMENTS: A population-based proband-oriented pedigree information system with ties of consanguinity based on both population-based household registry data and Keelung Community Integrated Screening data was proposed to build a comprehensive extended family pedigree structure to accommodate a series of genetic studies on different diseases. We also developed an algorithm to efficiently assess how well theoretical family relationships affecting the occurrence of diseases across three generations with respect to the relative relationship score, a quantitative indicator of genetic influence, were captured.

RESULTS

We applied this population-based proband-oriented pedigree information system to estimate the rate of hypertension with various relative relationships given the selection of probands. The degree of capturing complete familial relationships was assessed for three generations. The risk for early onset of hypertension was proportional to the proband-oriented relative relationship score with 2% increased risk and 1% correction for incomplete capture.

CONCLUSIONS

The population-based proband-oriented pedigree information system is powerful and can support various genetic descriptive and analytic epidemiological studies.

Genetics of prostate cancer risk

For decades, physicians and researchers have recognized that family history is a significant risk factor for prostate cancer. The identification of the genes responsible for inherited risk, however, proved difficult. With the sequencing of the human genome and the completion of the initial phases of the International HapMap Project, the tools are available to scan the entire genome and find genetic markers for disease. Since 2006, more than 30 inherited variants strongly associated with prostate cancer have been reported. As the inherited component of the disease is revealed, efforts are ongoing to translate genetic findings into the clinic.

The evolving role of familial history for prostate cancer

BACKGROUND

family history of prostate cancer is a risk factor for prostate cancer occurrence. Differently from other neoplasms no major predisposing gene has been identified.

MATERIAL AND METHODS

this review article presents the controversial results of studies about the prognostic and predictive role of family history in prostate cancer, reports the discovered predisposing genes, and biologic and pathologic findings.

RESULTS

mortality from PC remains a significant health care problem, but no trial investigated if it changed in presence of positive family history. The largest family study yet published concluded that men with family history are diagnosed and die at earlier ages than men without it. However, it failed to stress the prognostic value of family history. Genome-wide association studies of prostate cancer have identified a number of genetic variants at different loci in different populations. Prostate neoplasms of patients with positive family history exhibit a different pattern of expression of genes related with estrogen and androgen metabolism within the tumor. High-penetrance and low-penetrance genes in diagnosis and prognosis of prostate cancer, difficulties to define a classification and to quantify relative risks of single genes, documented gene-environment interactions are discussed.

CONCLUSION

family history stands for both shared genetic and environmental factors and their interaction. The availability of prostate-specific antigen test could explain partly the high familial risk, among brothers or shortly after the diagnosis of prostate cancer. Polymorphisms in genes associated with prostate cancer probably represent the most part of familial prostate cancer burden. An increasing knowledge of disregulated cellular pathways of lethal prostate cancer could define which of all genetic alterations have a role in defining new preventive and therapeutic strategies.

Familial risks in cancer of unknown primary: tracking the primary sites

PURPOSE

Cancer of unknown primary (CUP) is diagnosed at the metastatic stage, and despite extensive diagnostic work-up, the primary tumor often remains unidentified. No data are available on familial clustering of CUP. We hypothesize that familial clustering of CUP with other cancers may be informative of the primary sites.

PATIENTS AND METHODS

A total of 35,168 patients with CUP were identified in the Swedish Family-Cancer Database, and risks between family members were calculated for concordant (CUP-CUP) and discordant (CUP-any other cancer) cancers using standardized incidence ratio (SIR).

RESULTS

Familial cases of CUP accounted for 2.8% of all CUP cases in the offspring generation. Familial SIR for CUP was 1.69 when a sibling was diagnosed with CUP. As to discordant associations between siblings, CUP was associated with lung (SIR, 1.87), kidney (SIR, 1.82), liver (SIR, 1.67), ovarian (SIR, 1.45), colorectal (SIR, 1.26), and breast (SIR, 1.15) cancers and melanoma (SIR, 1.26). Upper aerodigestive tract, bladder, pancreatic, and prostate cancers were additionally associated with CUP. Notably, CUP was associated with families of kidney, lung, and colorectal cancers.

CONCLUSION

The present data show that CUP is not a disease of random metastatic cancers but, instead, a disease of a defined set of cancers. The association of CUP with families of kidney, lung, and colorectal cancers suggests a marked genetic basis and shared metastatic mechanisms by many cancer types. Familial sites shared by CUP generally match those arising in tissue-of-origin determinations and, hence, suggest sites of origin for CUP. Mechanistic exploration of CUP may provide insight into defense against primary tumors and the metastatic process.

Nervous system tumors in adult immigrants to Sweden by subsite and histology

BACKGROUND

The coding of histology of nervous system (NS) tumors with various degrees of malignancies differs between cancer registries, whereby the comparison of incidence rates from one registry to another seems difficult. No study has systematically defined whether the change in the risk of NS tumors upon immigration in adulthood varies by subsite or histology. Therefore, we aimed to address this issue amongst the first-generation immigrants to Sweden based on a large uniform cancer registry data (1958-2006).

METHODS

The nationwide Swedish Family-Cancer Database (2008 version; >11.8 million individuals; 1.8 million immigrants; histology code in force since 1958) was used to calculate standardized incidence ratios (SIRs). We analyzed 28,981 adult cases of NS tumors amongst Swedes and 2519 amongst immigrants (age ≥ 30).

RESULTS

Significantly decreased risks for brain glioma were amongst German (SIR = 0.64), Eastern European (0.62), some Asian (0.71), Chilean (0.34), and African immigrants (0.52). We found an increased risk for brain meningioma amongst Finns (1.15) and former Yugoslavians (1.33), whilst only Norwegians (0.71) and Latin Americans (0.21) had a decreased risk. The risk for spinal ependymoma and astrocytoma was increased in Germans (3.66) and former Yugoslavians (8.89). We found no significant difference for peripheral nerve tumors between immigrants and the native Swedes.

CONCLUSION

Significant differences between risk of NS tumors amongst immigrants and the native Swedes may suggest different risk factor profiles for glioma compared to meningioma indicating a higher etiological role of genetic background or childhood environmental risk factors rather than exposures after immigration.