The population impact of familial cancer, a major cause of cancer

Interaction between body mass index and family history of cancer on the risk of female breast cancer

Both body mass index (BMI) and family history of cancer are established risk factors for female breast cancer. However, few studies explored the potential interaction between both factors. We assessed the association of BMI and its interaction with family cancer history on the risk of female breast cancer in Shanghai, China. Based on a population-based prospective cohort study started from 2008 to 2012 with 15,055 Chinese female participants in Minhang district, Shanghai. Cox regression models were used to estimate the association of BMI and its interaction with a family history of cancer on breast cancer risk. The additive interaction was evaluated by the relative excess risk due to interaction (RERI) and the attributable proportion due to interaction (AP), and the multiplicative interaction was assessed by the product term (BMI* family history of cancer) in the Cox regression model. Compared with BMI of < 24 kg/m2 and no family history of cancer, women with BMI of ≥ 24 kg/m2 and a family history of cancer had a higher risk for breast cancer with HR 2.06 (95% CI 1.39, 3.06). There was an additive interaction between BMI and family history of cancer on breast cancer incidence, with the RERI being 0.29 (95% CI 0.08, 0.51) and the AP being 0.37 (95% CI 0.08, 0.66). The coexistence of obesity and cancer family history may exacerbate breast cancer incidence risk, highlighting the importance of weight management in women with a family history of cancer.

Risk of second primary malignancies in survivors of pancreatic neuroendocrine neoplasms from 2000 to 2018

BACKGROUND AND AIM

As a result of improved survival, cancer survivors continue to remain at risk of developing second primary malignancies (SPMs). However, the association between first primary pancreatic neuroendocrine neoplasms (PanNENs) and SPMs has not been thoroughly investigated.

METHODS

Using the Surveillance, Epidemiology, and End Results-18 database, patients histologically diagnosed with PanNENs as their first malignancy between 2000 and 2018 were identified. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) and excess absolute risks per 10 000 person-years of SPMs were calculated to estimate the risk of being diagnosed with subsequent cancers compared with the general population.

RESULTS

A total of 489 (5.7%) PanNENs survivors developed an SPM during the follow up, with a median latency between first and second cancer diagnoses of 32.0 months. The overall SIR of SPMs was 1.30 (95% CI: 1.19, 1.42) and the excess absolute risk was 35.67 cases per 10 000 person-years in comparison with the general population. Age 25-64 years at PanNENs diagnosis was associated with statistically higher risks for SPMs of all cancers combined. Latency stratification was significant for elevated SPMs risk between 2-23 and 84+ months after diagnosis. White patients were found to have a significantly increased incidence of SPMs (SIR: 1.23, 95% CI: 1.11, 1.35), mainly owing to the higher risk of stomach, small intestine, pancreas, kidney and renal pelvis, and thyroid cancers.

CONCLUSION

Pancreatic neuroendocrine neoplasms survivors experience a significant increase in the burden of SPMs compared with the reference population. The heightened relative risk calls for careful long-term scrutiny as part of survivorship care plans.

Genetic Analysis of Multiple Primary Malignant Tumors in Women with Breast and Ovarian Cancer

Familial cancer syndromes, which are commonly caused by germline mutations in oncogenes and tumor suppressor genes, are generally considered to be the cause of primary multiple malignant neoplasias (PMMNs). Using targeted genomic sequencing, we screened for eight germline mutations: BRCA1 185delAG, BRCA1 T300G, BRCA1 2080delA, BRCA1 4153delA, BRCA1 5382insC, BRCA2 6174delT, CHEK2 1100delC, and BLM C1642T, which provoke the majority of cases of hereditary breast and ovary cancer syndrome (HBOC), in genomic (blood) DNA from 60 women with PMMNs, including breast (BC) and/or ovarian cancer(s) (OC). Pathogenic allelic forms were discovered in nine samples: in seven instances, it was BRCA1 5382insC, and in the following two, BRCA1 4153delA and BRCA1 T300G. The age of onset in these patients (46.8 years) was younger than in the general Russian population (61.0) for BC but was not for OC: 58.3 and 59.4, correspondingly. There were invasive breast carcinomas of no special type and invasive serous ovarian carcinomas in all cases. Two or more tumors of HBOC-spectrum were only in five out of nine families of mutation carriers. Nevertheless, every mutation carrier has relatives who have developed malignant tumors.

Are population level familial risks and germline genetics meeting each other?

Large amounts of germline sequencing data have recently become available and we sought to compare these results with population-based family history data. Family studies are able to describe aggregation of any defined cancers in families. The Swedish Family-Cancer Database is the largest of its kind in the world, covering the Swedish families through nearly a century with all cancers in family members since the start of national cancer registration in 1958. The database allows estimation of familial risks, ages of cancer onset and the proportion of familial cancer in different family constellations. Here, we review the proportion of familial cancer for all common cancers and specify them based on the number of affected individuals. With the exception of a few cancers, age of onset of familial cancer is not different from all cancers combined. The highest proportions of familial cancer were found for prostate (26.4%), breast (17.5%) and colorectal (15.7%) cancers, but the proportions of high-risk families with multiple affected individuals were only 2.8%, 1% and 0.9%, respectively. A large sequencing study on female breast cancer found that BRCA1 and BRCA2 mutations could account for 2% of the cases (subtracting the proportions in healthy individuals) and that all germline mutations accounted for 5.6% of the cases. Early age of onset was a distinct feature of only BRCA mutations. In heritable colorectal cancer, Lynch syndrome genes dominate. Large studies on penetrance in Lynch syndrome have shown an approximately linear increase in risk from 40-50 years up to age 80 years. Interesting novel data revealed a strong modification of familial risk by unknown factors. High-risk germline genetics of prostate cancer is characterized by BRCA and other DNA repair genes. HOXB13 encodes a transcription factor which contributes to germline risk of prostate cancer. A strong interaction was shown with a polymorphism in the CIP2A gene. The emerging germline landscape of common cancers can be reasonably accommodated by family data on these cancers as to high-risk proportions and age of onset.

Dairy consumption and incident risk of thyroid cancer in Japan: a pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study

PURPOSE

The impact of dairy consumption on thyroid cancer is unclear. The purpose of this study was to elucidate the association between dairy consumption and the risk of thyroid cancer in Japanese people.

METHODS

The association between dairy consumption and the risk of thyroid cancer in Japanese people was examined by conducting a pooled analysis of two prospective studies of residents in Miyagi Prefecture, Japan. Data from 64,340 men and women aged 40-79 years registered in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994 were analyzed. Dairy consumption was assessed at baseline using a self-administered food frequency questionnaire and was divided into quartiles based on the weight (in grams) of total dairy consumption per day.

RESULTS

During 1,075,018 person-years of follow-up, there were 190 incident cases of thyroid cancer (29 men and 161 women). The hazard ratios (HRs) and 95% confidence intervals (CIs) for thyroid cancer incidence in the highest quartile of dairy consumption compared with the lowest quartile were 0.83 (95% CIs 0.28-2.43, P-trend = 0.823) for men and 0.67 (95% CIs 0.42-1.06, P-trend = 0.056) for women. After stratification for BMI, a decreased risk was observed in women with BMI ≥ 25 kg/m² (HRs: 0.37, 95% CIs 0.18-0.79, P-trend = 0.010).

CONCLUSION

Dairy consumption is inversely associated with the risk of thyroid cancer in women with BMI ≥ 25 kg/m².

Survival in Lung Cancer in the Nordic Countries Through A Half Century

Objective

Lung cancer is often diagnosed at an advanced stage and survival has been poor, although long-term studies have been rare. We analyzed data on survival in lung cancer from Denmark, Finland, Norway, and Sweden over a 50-year period (1971-2020).

Methods

Relative 1- and 5-year survival data were obtained from the NORDCAN database for 1971-2020. We used generalized additive models to estimate survival trends over time and uncertainty of these estimates. We additionally calculated conditional survival from the 1st to 5th year (5/1-year), estimated annual changes in survival rates, and determined significant breaking points.

Results

In 2016-2020, 5-year survival rate for lung cancer was best for Norwegian men (26.6%) and women (33.2%). The sex difference was significant and it was found for each country. Survival improved modestly until the year 2000, after which time survival curves increased steeply and kept the linear shape to the end of follow-up, indicating consistent improvement in survival. Survival curves for 1- and 5/1-year survival were almost superimposable, indicating that deaths in the first year were approximately as many as in the subsequent 4 years, thus marking sustained long-term survival.

Conclusion

We could document a positive development in lung cancer survival with steep upward trends after the year 2000. Intensions for curative treatment have been increasing and the outcomes have been improving with the help of novel imaging methods. Pathways for facile patient access to treatment have been instituted. Close to 90% of the patients are ever smokers. National anti-smoking acts and alerting people who smoke about early symptoms may be beneficial, as metastatic lung cancer remains difficult to cure.

Incidence trends in lung and bladder cancers in the Nordic Countries before and after the smoking epidemic

Cigarette smoking epidemic, which started before the World War II, completely changed the cancer landscape. Reliable incidence data spanning the stepwise spreading epidemic are rare, but the Nordic cancer registries are unique sources in being able to catch the pre-epidemic situation in the female population where smoking became more prevalent after the War. For Swedish men, smoking prevalence has decease early and cancer rates may herald postsmoking rates. We used data from the NORDCAN database, constructed by the cancer registries of Denmark, Finland, Norway and Sweden, for the analysis of incidence changes in lung and bladder cancers from year 1943 (Denmark), from 1953 (Finland and Norway) and from 1960 (Sweden) until year 2016. The analyses revealed four novel observation relevant to the smoking epidemic. (1) The incidence of lung cancer in Norwegian women in the 1950s, when the smoking prevalence was very low, was 1.8/100 000 (world standard rate), which is at the level of lowest global female rates known to-date; (2) the earliest lung-to-bladder incidence ratio among Norwegian women was 0.64, probably benchmarking the incidence rates prior to the smoking epidemic; (3) bladder cancer incidence for Finnish women diagnosed in the 1950s was 1.2/100 000 which is at the level of the lowest rates currently known and (4) Swedish men with the lowest smoking prevalence in Europe, showed an epochal crossing of lung and bladder cancer incidence rates before year 2015. The data suggest that the approaching of the incidence rates for lung and bladder cancer can be expected in the course of the abating smoking epidemic.

Familial Risks for Liver, Gallbladder and Bile Duct Cancers and for Their Risk Factors in Sweden, a Low-Incidence Country

We used the Swedish Cancer Registry data to address familial risks for concordant (same) and discordant (different) hepatobiliary cancers, including their associations with any other cancers and with known risk factors. Risks were also assessed between spouses. The analysis covered Swedish families and their cancers between years 1958 and 2018. Adjusted familial risks were expressed as standardized incidence ratios (SIRs). Familial SIRs for concordant hepatocellular carcinoma (HCC) were 2.60, and for gallbladder cancer they were at the same level (2.76). Familial risk was also found for intrahepatic bile duct cancer and for female extrahepatic bile duct cancer. HCC was associated with lung and cervical cancers; extrahepatic bile duct and ampullary cancers were associated with colon and pancreatic cancers, suggesting Lynch syndrome. Among spouses, hepatobiliary cancer was associated with HCC, stomach, pancreatic, cervical and upper aerodigestive tract cancers. Among risk factors, family members diagnosed with alcohol-related disease showed association with HCC. The observed familial risks for hepatobiliary cancers were relatively high, and considering the poor prognosis of these cancers, prevention is of the utmost importance and should focus on moderation of alcohol consumption, vaccination/treatment of hepatitis viral infections and avoidance of overweight and other risk factors of type 2 diabetes.

Germline Variants of CYBA and TRPM4 Predispose to Familial Colorectal Cancer

Simple Summary

Whole-genome sequencing and bioinformatics analysis on unique colorectal cancer families revealed two attractive candidate predisposition genes, CYBA and TRPM4, each with a loss-of-function variant. Supported by our functional studies, we suggest that the two gene defects mechanistically involve intestinal barrier integrity through reactive oxygen species and mucus biology, which converges in chronic bowel inflammation, a known risk factor for colorectal cancer.

Abstract

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

Family history of breast cancer as a second primary malignancy in relatives: a nationwide cohort study

Background

With the increasing number of breast cancer (BC) diagnosed as a second primary malignancy after a first primary non-breast cancer (BCa-2), it is unclear about the familial risk of BC among women with a first-degree relative (FDR, parents or siblings) affected by a BCa-2.

Methods

In this Swedish nationwide cohort study, 5315 women with a FDR affected by BCa-2 and 115,048 women with a FDR affected by BC as the first primary cancer (BCa-1) were followed for the first primary invasive BC diagnosis. Relative risk (RR) of BC was estimated through Poisson regression by using 2,743,777 women without a family history of cancer as reference. The risk was stratified by the diagnostic age of BC in FDR, proband type, the time interval between the first primary cancer and BCa-2 in FDR as well as the site of first primary cancer diagnosed in FDR before BCa-2. We also calculated the cumulative incidence of BC from birth to a specific age for the three groups.

Results

The cumulative incidence from birth to age 70 was 10% among women with a family history of BCa-2. The RR of BC with a family history of BCa-2 (RR, 1.68, 95%CI, 1.49 to 1.88) was comparable to that with BCa-1 (1.68, 1.63 to 1.73). The risk was largely consistent irrespective of proband type. The age of onset of BCa-2 in FDR (RR _early-onset, 1.72 vs. RR _late-onset 1.67) had less influence on the risk compared to BCa-1 in FDR (1.89 vs. 1.63). In the analysis stratified by the time between the first primary cancer and BCa-2 in relatives, the risks were largely similar. For the site of first primary cancer diagnosed in FDR before BCa-2, the increased BC risk was found in women whose FDRs were diagnosed with first primary gastric, colorectal, endometrial, ovarian, nervous system and endocrine gland cancers, and non-Hodgkin lymphoma.

Conclusions

Women with a family history of BCa-2 have a similar overall BC risk as those with a family history of BCa-1. The risk varied according to the site of first primary cancer diagnosed in FDR before BCa-2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08925-y.

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.

Incidence trends in bladder and lung cancers between Denmark, Finland and Sweden may implicate oral tobacco (snuff/snus) as a possible risk factor

Background

The dominant risk factor for urinary bladder cancer has been cigarette smoking, but, as smoking prevalence is decreasing in many populations, other risk factors may become uncovered. Such new risk factors could be responsible for halting the declining incidence of bladder cancer. We hypothesize that snuff use by Swedish men may increase the rate for bladder cancer, as snuff contains carcinogenic nitrosamines.

Methods

We carried out an ecological study by comparing incidence trends in lung and bladder cancers between Danish, Finnish and Swedish men in order to test if the Swedish bladder cancer rate deviates from the Danish and Finnish ones. We used the NORDCAN database for cancer data from 1960 through 2016 to test the hypothesis.

Results

In the three countries, the incidence of lung cancer started to decrease after a peak incidence, and this was later followed by declining incidence in bladder cancer in Denmark from 1990 to 2016 by 14.3%, in Finland by 8.3% but not in Sweden (the decline of 1.4% was not significant). The difference in trends can be partly explained by the increasing incidence in Swedish men aged 70 or more years. Sweden differs from the two other countries by low male smoking prevalence but increasing use of snuff recorded by various surveys.

Conclusion

The stable bladder cancer trend for Swedish men was opposite to the declining trends in Denmark, Finland and globally. We suggest that this unusual finding may be related to the increasing use of snuff by Swedish men. Average users of snuff are exposed to at least 3 times higher levels of carcinogenic tobacco-specific nitrosamines than a smoker of one daily pack of cigarettes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08371-w.

Expression of miR-451a in Prostate Cancer and Its Effect on Prognosis

Background:

To investigate the expression of miR-451a in prostate cancer tissues and its effect on prognosis.

Methods:

Each of 78 specimens of prostate cancer tissues and corresponding adjacent normal tissues were collected from patients in Changshu Hospital Affiliated to Soochow University, Changshu, China from Apr 2014 to Jun 2015. Real-time quantitative RT-PCR (qRT-PCR) was used to detect the expression of miR-451a in tissues. The relationship between the expression of miR-451a and clinical pathological parameters was analyzed. The median expression of miR-451a in the experimental group was used to distinguish the high and low expressions of miR-451a in the experimental group. Kaplan-Meier was used to analyze the survival of miR-451a high and low expression groups.

Results:

The expressions of miR-451a in the patient’s tissues and serum were decreased, and the correlation analysis found that they were positively correlated. ROC curve analysis showed that miR-451a had a high clinical value in the diagnosis of prostate cancer and the area under the curve was 0.921. The incidence of stage III+IV lymph node metastasis, Gleason score of >7 points and a serum Prostate-specific antigen (PSA) level of >20 ng/ml in patients of the low expression group increased significantly. The 5-yr survival rate of patients with low expression was significantly lower than that of those with high expression (P=0.005). MiR-451a was an independent factor affecting the prognosis of patients.

Conclusion:

miR-451a is lowly expressed in prostate cancer, and patients with low expression have a poor prognosis.

A Novel Low-Risk Germline Variant in the SH2 Domain of the SRC Gene Affects Multiple Pathways in Familial Colorectal Cancer

Colorectal cancer (CRC) shows one of the largest proportions of familial cases among different malignancies, but only 5-10% of all CRC cases are linked to mutations in established predisposition genes. Thus, familial CRC constitutes a promising target for the identification of novel, high- to moderate-penetrance germline variants underlying cancer susceptibility by next generation sequencing. In this study, we performed whole genome sequencing on three members of a family with CRC aggregation. Subsequent integrative in silico analysis using our in-house developed variant prioritization pipeline resulted in the identification of a novel germline missense variant in the SRC gene (V177M), a proto-oncogene highly upregulated in CRC. Functional validation experiments in HT-29 cells showed that introduction of SRC^V177M resulted in increased cell proliferation and enhanced protein expression of phospho-SRC (Y419), a potential marker for SRC activity. Upregulation of paxillin, β-Catenin, and STAT3 mRNA levels, increased levels of phospho-ERK, CREB, and CCND1 proteins and downregulation of the tumor suppressor p53 further proposed the activation of several pathways due to the SRC^V177M variant. The findings of our pedigree-based study contribute to the exploration of the genetic background of familial CRC and bring insights into the molecular basis of upregulated SRC activity and downstream pathways in colorectal carcinogenesis.

The association between family history of prostate cancer and development of prostate cancer among Korean population: A prospective cohort study using KoGES data

This study aimed to assess the impact of family history (FH) on prostate cancer (PCa) development among a general Korean population. We conducted a prospective cohort study based on the registry records of 211,789 participants in the database of the Korean Genome and Epidemiology Study from 2001 to 2013. A total of 69,693 men with appropriate records were evaluated by being categorizing into 2 groups; a PCa group (100) and control group (69,593). FH of PCa was also categorized as FH of total, father, or brother. Odds ratios (ORs) of PCa development were calculated by using stratified logistic regression models. The adjusted OR of PCa history of father was 27.7 (95% confidence interval [CI] = 9.7-79.2, P < .001) in PCa patients compared to control, and that of PCa history of brother was 15.8 (95% CI = 3.6-69.6, P < .001). Among the adjusted variables, age (OR, 1.17; 95% CI, 1.14-1.21; P < .001), and hyperlipidemia (OR, 2.25; CI, 1.32-3.84; P = .003) were also identified as significant predictors of PCa development. There was no difference in the impact of FH on PCa development between different age groups at PCa diagnosis (<60 vs ≥60 years). To our knowledge, this study represents the first prospective cohort study based on the registry data of a Korean population showing the significance of FH on PCa development. Additionally, the effect of FH on the early onset of PCa has not been confirmed in our analysis.

Genetic epidemiology of colorectal cancer and associated cancers

We review here data on familial risk in colorectal cancer (CRC) generated from the Swedish Family-Cancer Database, the largest resource of its kind in the world. Although the concordant familial risk for CRC (i.e. CRC risk in families of CRC patients) has been reasonably well established, the studies on discordant familial risks (i.e. CRC risk in families with any other cancers) are rare. Because different cancers could be caused by shared genetic susceptibility or shared environment, data of associations of discordant cancers may provide useful information for identifying common risk factors. In analyses between any of 33 discordant cancers relative risks (RRs) for discordant cancers were estimated in families with increasing numbers of probands with CRC; in the reverse analyses, RRs for CRC were estimated in families with increasing numbers of probands with discordant cancers. In separate analyses, hereditary non-polyposis colorectal cancer (HNPCC) families were excluded from the study, based on HNPCC related double primary cancers, to assess the residual familial RRs. We further reviewed familial risks of colon and rectal cancers separately in search for distinct discordant associations. The reviewed data suggested that colon cancer was associated with a higher familial risk for CRC compared to rectal cancer. The previous data had reported associations of CRC with melanoma, thyroid and eye cancers. Nervous system cancer was only associated with colon cancer, and lung cancer only associated with rectal cancer. The reviewed data on discordant association may provide guidance to gene identification and may help genetic counseling.

The Asthma Family Tree: Evaluating Associations Between Childhood, Parental, and Grandparental Asthma in Seven Chinese Cities

Objective: To evaluate the associations between childhood, parental, and grandparental asthma. Methods: We studied 59,484 children randomly selected from 94 kindergartens, elementary, and middle schools in seven Chinese cities from 2012 to 2013, using a cross-sectional survey-based study design. Information on their and their family members' (parents, paternal grandparents, and maternal grandparents) asthma status were reported by children's parents or guardians. Mixed effects logistic regressions were used to assess hereditary patterns of asthma and mediation analysis was performed to estimate the potential mediation effect of parents on the association between grandparental asthma and childhood asthma. Results: The magnitude of ORs for childhood asthma increased as the number of family members affected by asthma increased. Among children who had one family member with asthma, childhood asthma was associated with asthma in maternal grandmothers (OR: 2.08, 95% CI: 1.67-2.59), maternal grandfathers (OR: 2.08, 95% CI: 1.71-2.53), paternal grandmothers (OR: 2.40, 95% CI: 1.93-2.99), and paternal grandfathers (OR: 2.59, 95% CI: 2.14-3.13). Among children who had two family members with asthma, the highest asthma risk was found when both parents had asthma (OR: 15.92, 95% CI: 4.66-54.45). Parents had a small proportion of mediation effect (9-12%) on the association between grandparental asthma and childhood asthma. Conclusions: Grandparents with asthma were associated with childhood asthma and parents with asthma partially mediated the association.

Familial aggregation of subcutaneous panniculitis-like T cell lymphoma: A case report of monozygotic twin brothers

RATIONALE

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare subtype of cutaneous lymphoma, which was first defined as a clinical entity in 1991 as a cytotoxic T-cell lymphoma preferentially infiltrating subcutaneous tissue. Herein, we report 2 patients of SPTCL who are a pair of twin brothers.

PATIENT CONCERNS

The disease afflicted the monozygotic twin brothers at different time with an interval period of 5 years. The older twin brother had disease onset at 27 years of age. In June 2012, he developed prolonged fever accompanied by subcutaneous nodules in the left upper arm and left chest due to unknown origin. The younger twin brother had disease onset at 32 years of age. In June 2017, the younger brother presented with repeated high fever for more than 10 days, accompanied by head distension.

DIAGNOSIS

On August 7, 2012, skin biopsy was performed on the lesion of left upper arm of the older twin brother, and then, a diagnosis of subcutaneous panniculitis-like T cell lymphoma (SPTCL) was made. On June 19, 2017, the younger twin brother underwent whole-body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography for diagnosis. Soon afterwards, abdominal subcutaneous nodule resection and biopsy was performed on June 28, 2018, and the specimen was diagnosed as SPTCL.

INTERVENTIONS

For the older brother, a total of 14 systemic chemotherapy sessions were performed from August 16, 2012, to September 21, 2014. For the younger brother, a total of 9 systemic chemotherapy sessions were performed from July 14, 2017, to March 8, 2018, then he was switched to oral chemotherapy with chidamide twice a week for 6 months.

OUTCOMES

The older twin brother died in March 2015, the younger brother has recovered well and is no longer receiving any treatment LESSONS:: To the best of our knowledge, twin brothers both having this disease has never been previously reported. Moreover, some of the involved areas are also extremely rare detected by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography at initial stage. It is beneficial to people to gain some new understanding for SPTCL by this special case and some extremely unusual involved sites in the younger twin brother.

The missing heritability of familial colorectal cancer

Pinpointing heritability factors is fundamental for the prevention and early detection of cancer. Up to one-quarter of colorectal cancers (CRCs) occur in the context of familial aggregation of this disease, suggesting a strong genetic component. Currently, only less than half of the heritability of CRC can be attributed to hereditary syndromes or common risk loci. Part of the missing heritability of this disease may be explained by the inheritance of elusive high-risk variants, polygenic inheritance, somatic mosaicism, as well as shared environmental factors, among others. A great deal of the missing heritability in CRC is expected to be addressed in the coming years with the increased application of cutting-edge next-generation sequencing technologies, routine multigene panel testing and tumour-focussed germline predisposition screening approaches. On the other hand, it will be important to define the contribution of environmental factors to familial aggregation of CRC incidence. This review provides an overview of the known genetic causes of familial CRC and aims at providing clues that explain the missing heritability of this disease.

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

BACKGROUND

Patients with squamous cell skin cancer (SCC) have an excellent prognosis but second primary cancers (SPCs) weaken survival prospects. Family history is a known risk factor for cancer but whether it is a risk factor for SPC in patients with SCC is not known.

OBJECTIVES

To quantify the risk of family history on SPCs in patients with SCC and estimate survival probabilities of patients with SPCs depending on family history.

METHODS

With 13 945 histologically verified SCCs, relative risks (RRs) were estimated for family history using a generalized regression model. For survival analysis, hazard ratios (HRs) were assessed using a multivariable Cox proportional-hazards model.

RESULTS

Family history of invasive SCC increased risk of second invasive SCC [RR = 42·92, 95% confidence interval (CI) 33·69-50·32] compared with risk without family history (RR 19·12, 95% CI 17·88-21·08). Family history of any nonskin cancer in invasive SCC increased risk of the same cancers to be diagnosed as SPC (RRF_H = 1·48, 95% CI 1·35-1·61 vs. RR_{no FH} = 1·40, 95% CI 1·32-1·48); significant increases were observed for seven different nonskin cancers. Most results were replicated for in situ SCC. SPC was deleterious for survival irrespective of family history; HR for patients with SPC was 4·28 (95% CI 3·83-4·72) vs. those without SPC (1·04).

CONCLUSIONS

Family history of nonskin cancer was associated with approximately a doubling of risk for SPCs in patients with SCC. SPC increases the death rate in patients with SCC 3-4 times, irrespective of family history. Taking family history into account at SCC diagnosis may help prevention or early detection of SPCs. What's already known about this topic? Second primary cancers (SPCs) are frequently diagnosed in patients with invasive and in situ squamous cell carcinoma (SCC); some epidemiological studies suggest a link to immune dysfunction. Family history of cancer is a risk factor for practically all first primary cancers but whether it also influences risk of SPCs in patients with SCC is not known. The possible influence of family history on survival in patients with SCC remains to be established. Linked Comment: Youlden and Baade. Br J Dermatol 2020; 183:414-415.

Sex difference in incidence of gastric cancer: an international comparative study based on the Global Burden of Disease Study 2017

OBJECTIVES

To investigate sex difference in global gastric cancer incidence by year, age and socioeconomical status.

DESIGN

An international comparative study.

SETTING

We obtained the global and national sex-specific incidence of gastric caner by year and age from the Global Burden of Disease Study 2017. The human development index (HDI) in 2017 as an indicator of national socioeconomical status was extracted from the Human Development Report.

MAIN OUTCOME MEASURES

Sex-specific incidence of gastric cancer was compared by year and age at the global level. Linear regression analyses were performed to explore socioeconomic-associated sex difference in gastric cancer incidence.

RESULTS

Despite declining incidence of global gastric cancer in both sexes between 1990 and 2017, relative sex difference showed an increasing trend, with male to female ratios of age-standardised incidence rates (ASRs) rising from 1.86 to 2.20. Sex difference was almost negligible under 45 years of age and relative difference maximised in the age range of 65-69 years with male to female ratios of ASRs being 2.74. Both absolute sex difference (standardised β=0.256, p<0.001) and relative difference (standardised β=0.387, p<0.001) in ASRs were positively associated with HDI.

CONCLUSIONS

This study revealed that decreasing incidence of global gastric cancer was accompanied by widening sex difference in the past few decades. Men always had higher incidence than women. Greater sex difference was found in older age and in more developed countries. These findings highlight the importance of making sex-sensitive health policy to cope with the global gastric cancer burden.

Effects of Family History on Relative and Absolute Risks for Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Guidelines recommend that individuals with familial colorectal cancer undergo colonoscopy surveillance instead of average-risk screening. However, these recommendations vary widely. To substantiate appropriate surveillance strategies, precise and valid evidence-based risk estimates are needed for individuals with a family history of colorectal cancer (CRC).

METHODS

We systematically searched MEDLINE, EMBASE, and Cochrane from inception to July 2018 for case-control and cohort studies investigating the effect of family history on CRC risk. We calculated summary estimates of pooled relative risks (RRs) using a random-effects model. Life tables were created to convert RR estimates into absolute risk estimates.

RESULTS

We screened 4417 articles and identified 42 eligible case-control and 20 cohort studies. In case-control studies, the RR for CRC in patients with 1 first-degree relative (FDR with CRC) was 1.92 (95% CI, 1.53-2.41) and 1.37 (95% CI, 0.76-2.46) for cohort studies. For individuals with 2 or more FDRs with CRC, the RR was 2.81 in case-control studies (95% CI, 1.73-4.55) and 2.40 in cohort studies (95% CI, 1.76-3.28). For individuals having a FDR diagnosed with CRC at an age younger than 50 years, the RR for CRC in their FDRs was 3.57 in case-control studies (95% CI, 1.07-11.85) and 3.26 in cohort studies (95% CI, 2.82-3.77). The cumulative absolute risks for CRC at 85 years in Western Europe were 4.8% for persons with 1 FDR with CRC (95% CI, 2.7%-8.3%), 8.2% for individuals with 2 or more FDRs (95% CI, 6.1%-10.9%), and 11% for persons with a FDR diagnosed with CRC at an age younger than 50 years (95% CI, 9.5%-12.4%).

CONCLUSIONS

In this systematic review and meta-analysis, we found that the RR of CRC among FDRs is lower than previously expected, especially based on cohort studies. Risk estimates are affected by the number of relatives with CRC and their age at diagnosis. Intensified colonoscopy surveillance strategies could be considered for high-risk groups. PROSPERO trial identification no: CRD42018103058.

Single nucleotide polymorphisms within MUC4 are associated with colorectal cancer survival

Mucins and their glycosylation have been suggested to play an important role in colorectal carcinogenesis. We examined potentially functional genetic variants in the mucin genes or genes involved in their glycosylation with respect to colorectal cancer (CRC) risk and clinical outcome. We genotyped 23 single nucleotide polymorphisms (SNPs) covering 123 SNPs through pairwise linkage disequilibrium (r2>0.80) in the MUC1, MUC2, MUC4, MUC5AC, MUC6, and B3GNT6 genes in a hospital-based case-control study of 1532 CRC cases and 1108 healthy controls from the Czech Republic. We also analyzed these SNPs in relation to overall survival and event-free survival in a subgroup of 672 patients. Among patients without distant metastasis at the time of diagnosis, two MUC4 SNPs, rs3107764 and rs842225, showed association with overall survival (HR 1.40, 95%CI 1.08-1.82, additive model, log-rank p = 0.004 and HR 0.64, 95%CI 0.42-0.99, recessive model, log-rank p = 0.01, respectively) and event-free survival (HR 1.31, 95%CI 1.03-1.68, log-rank p = 0.004 and HR 0.64, 95%CI 0.42-0.96, log-rank p = 0.006, respectively) after adjustment for age, sex and TNM stage. Our data suggest that genetic variation especially in the transmembrane mucin gene MUC4 may play a role in the survival of CRC and further studies are warranted.

Update on genetic predisposition to colorectal cancer and polyposis

The present article summarizes recent developments in the characterization of genetic predisposition to colorectal cancer (CRC). The main themes covered include new hereditary CRC and polyposis syndromes, non-CRC hereditary cancer genes found mutated in CRC patients, strategies used to identify novel causal genes, and review of candidate genes that have been proposed to predispose to CRC and/or colonic polyposis. We provide an overview of newly described genes and syndromes associated with predisposition to CRC and polyposis, including: polymerase proofreading-associated polyposis, NTHL1-associated polyposis, mismatch repair gene biallelic inactivation-related adenomatous polyposis (including MSH3- and MLH3-associated polyposes), GREM1-associated mixed polyposis, RNF43-associated serrated polyposis, and RPS20 mutations as a rare cause of hereditary nonpolyposis CRC. The implementation of next generation sequencing approaches for genetic testing has exposed the presence of pathogenic germline variants in genes associated with hereditary cancer syndromes not traditionally linked to CRC, which may have an impact on genetic testing, counseling and surveillance. The identification of new hereditary CRC and polyposis genes has not deemed an easy endeavor, even though known CRC-related genes explain a small proportion of the estimated familial risk. Whole-genome sequencing may offer a technology for increasing this proportion, particularly if applied on pedigree data allowing linkage type of analysis. The final section critically surveys the large number of candidate genes that have been recently proposed for CRC predisposition.

Familial colorectal cancer risk in half siblings and siblings: nationwide cohort study

OBJECTIVE

To explore the risk of colorectal cancer in family members of patients with colorectal cancer, with an emphasis on subtypes of second degree relatives, especially half siblings, which were lacking in the literature.

DESIGN

Ambidirectional cohort study.

SETTING

Nationwide Swedish Family Cancer Data (record linkage).

PARTICIPANTS

All people residing in Sweden and born after 1931, with their biological parents, totalling >16 million individuals (follow-up: 1958-2015); of those with clear genealogy, 173 796 developed colorectal cancer.

MAIN OUTCOME MEASURES

Lifetime (0-79 years) cumulative risk and standardised incidence ratio of colorectal cancer among first degree relatives and second degree relatives.

RESULTS

The overall lifetime cumulative risk of colorectal cancer in siblings of patients was 7%, which represents a 1.7-fold (95% confidence interval 1.6 to 1.7; n=2089) increase over the risk in those without any family history of colorectal cancer. A similarly increased lifetime cumulative risk (6%) was found among half siblings (standardised incidence ratio 1.5, 95% confidence interval 1.3 to 1.8; n=140). The risk in people with colorectal cancer in both a parent and a half sibling (standardised incidence ratio 3.6, 2.4 to 5.0; n=32) was close to the risk in those with both an affected parent and an affected sibling (2.7, 2.4 to 3.0; n=396). Family history of colorectal cancer in only one second degree relative other than a half sibling (without any affected first degree relatives), such as a grandparent, uncle, or aunt, showed minor association with the risk of colorectal cancer.

CONCLUSION

Family history of colorectal cancer in half siblings is similarly associated with colorectal cancer risk to that in siblings. The increase in risk of colorectal cancer among people with one affected second degree relative was negligible, except for half siblings, but the risk was substantially increased for a combination of family history in one affected second degree relative and an affected first degree relative (or even another second degree relative). These evidence based findings provide novel information to help to identify people at high risk with a family history of colorectal cancer that can potentially be used for risk adapted screening.

Importance of tumor location and histology in familial risk of upper gastrointestinal cancers: a nationwide cohort study

Background

Familial clustering of upper gastrointestinal (UGI) cancers and the significance of family history has been addressed previously. We aimed to elucidate the familial risk based on the specified tumor location and histology.

Method

In the Swedish Family-Cancer Database, we determined the familial risk of UGI cancer patients diagnosed (1958-2015) with esophageal and gastric cancer by tumor location using standardized incidence ratios (SIRs).

Results

Risk of esophageal cancer in first-degree relatives (FDRs) of patients with esophageal cancer increased 2.4-fold (SIR 95% CI 2.0-2.8), whereas risk of esophageal cancer in cases with family history of cancer in the middle third of the esophagus increased 3.4-fold (SIR 95% CI 2.1-5.1). Risk of gastric cancer in FDRs increased 1.6-fold (SIR 95% CI 1.5-1.7), occurrence of concordant subsite gastric cancer in the antrum, body, and cardia was 5.5-fold (SIR 95% CI 2.4-11), 4.6-fold (SIR 95% CI 2.6-7.4), and 1.7-fold (SIR 95% CI 1.1-2.5), respectively. Familial risk of concordant histological subtype in esophageal cancer was 4.1-fold for squamous cell carcinoma (SIR 95% CI 3.2-5.2) and 3.6-fold for adenocarcinoma (SIR 95% CI 2.5-5.1). The risk of concordant gastric adenocarcinoma was 1.6-fold for one affected FDR (SIR 95% CI 1.5-1.7), 6.1-fold for two FDRs (SIR 95% CI 4.4-8.4), and 8.6-fold among twins (SIR 95% CI 2.3-22).

Conclusion

Family history of cancer in the lower third of the esophagus and stomach cancer in specific locations such as the antrum, body, and cardia can be considered as important predictive evidence for cancer in the same location in relatives. Our findings might guide endoscopy-based surveillance by introducing subgroups of populations with a higher risk for UGI cancer with particular attention to concordance of location of lesions, which could be a reasonable strategy for early detection, and thus help save more lives.

What characterizes cancer family history collection tools? A critical literature review

Background

Many tools have been developed for the standardized collection of cancer family history (fh). However, it remains unclear which tools have the potential to help health professionals overcome traditional barriers to collecting such histories. In this review, we describe the characteristics, validation process, and performance of existing tools and appraise the extent to which those tools can support health professionals in identifying and managing at-risk individuals.

Methods

Studies were identified through searches of the medline, embase, and Cochrane central databases from October 2015 to September 2016. Articles were included if they described a cancer fh collection tool, its use, and its validation process.

Results

Based on seventy-nine articles published between February 1978 and September 2016, 62 tools were identified. Most of the tools were paper-based and designed to be self-administered by lay individuals. One quarter of the tools could automatically produce pedigrees, provide cancer-risk assessment, and deliver evidence-based recommendations. One third of the tools were validated against a standard reference for collected fh quality and cancer-risk assessment. Only 3 tools were integrated into an electronic health records system.

Conclusions

In the present review, we found no tool with characteristics that might make it an efficient clinical support for health care providers in cancer-risk identification and management. Adequately validated tools that are connected to electronic health records are needed to encourage the systematic identification of individuals at increased risk of cancer.

Familial risks in and between stone diseases: sialolithiasis, urolithiasis and cholelithiasis in the population of Sweden

BACKGROUND

According to the literature the three stone diseases, sialolithiasis (SL), urolithiasis (UL) and cholelithiasis (CL) share comorbidities. We assess familial and spouse risks between these stone disease and compare them to familial risks for concordant (same) stone disease.

METHODS

Study population including familiar relationships was obtained from the Swedish Multigeneration Register and stone disease patients were identified from nation-wide medical records. Standardized incidence ratios (SIRs) were calculated for 0-83 year old offspring when their first-degree relatives were diagnosed with stone disease and the rates were compared to individuals without a family history of stone disease. Numbers of offspring with SL were 7906, for UL they were 170,757 and for CL they were 204,369.

RESULTS

SIRs for concordant familial risks were 2.06 for SL, 1.94 for UL and 1.82 for CL. SIRs for SL and UL were slightly higher for women than for men. Familial risks between stone diseases were modest. The highest risk of 1.17 was for UL when family members were diagnosed with CL, or vice versa. The SIR for UL was 1.15 when family members were diagnosed with SL. Familial risks among spouses were increased only for UL-CL pairs (1.10).

CONCLUSIONS

Familial risks for concordant SL were 2.06 and marginally lower for the other diseases. Familial risks between stone diseases were low but higher than risks between spouses. The data show that familial clustering is unique to each individual stone disease which would imply distinct disease mechanisms. The results cast doubt on the reported comorbidities between these diseases.

The surprising implications of familial association in disease risk

BACKGROUND

A wide range of diseases show some degree of clustering in families; family history is therefore an important aspect for clinicians when making risk predictions. Familial aggregation is often quantified in terms of a familial relative risk (FRR), and although at first glance this measure may seem simple and intuitive as an average risk prediction, its implications are not straightforward.

METHODS

We use two statistical models for the distribution of disease risk in a population: a dichotomous risk model that gives an intuitive understanding of the implication of a given FRR, and a continuous risk model that facilitates a more detailed computation of the inequalities in disease risk. Published estimates of FRRs are used to produce Lorenz curves and Gini indices that quantifies the inequalities in risk for a range of diseases.

RESULTS

We demonstrate that even a moderate familial association in disease risk implies a very large difference in risk between individuals in the population. We give examples of diseases for which this is likely to be true, and we further demonstrate the relationship between the point estimates of FRRs and the distribution of risk in the population.

CONCLUSIONS

The variation in risk for several severe diseases may be larger than the variation in income in many countries. The implications of familial risk estimates should be recognized by epidemiologists and clinicians.

Familial risks in urolithiasis in the population of Sweden

OBJECTIVE

To assess detailed familial risks for medically diagnosed urolithiasis (UL, urinary tract stone disease) based on nationwide hospital and population records.

PATIENTS/SUBJECTS AND METHODS

Subjects were identified from the Swedish Multigeneration Register in which there were 211 718 patients with UL. Standardised incidence ratios (SIRs) were calculated by comparison to individuals without a family history of UL.

RESULTS

The highest familial SIRs were invariably found for the same (concordant) type of UL: 2.18 for kidney, 2.20 for ureter, and 1.93 for bladder. SIRs increased from 1.84, when one parent was affected, to 3.54 when both parents were affected, which was a multiplicative interaction. The SIR was 1.79 when one sibling was affected but it increased to 24.91 when two siblings were affected. Such excessive risks (5.2% of familial cases) are probably explained by high-penetrant genes. A low SIR of 1.29 between spouses suggested a minor contribution by shared environmental factors on the familial risk.

CONCLUSIONS

The results point to underlying genetic causes for the observed familial clustering and establish the genetic landscape of UL. Family histories should be taken in UL diagnostics and prevention could follow guidelines recommended for recurrent UL.

Familial risks for gallstones in the population of Sweden

Objectives

Gallstone disease (cholelithiasis) has a familial component, but detailed data on the modification of familial risk are lacking. Using nationwide hospital and population records, we aimed to determine detailed familial risks for medically diagnosed gallstone disease.

Design

Subjects were obtained from the Multigeneration Register, which contains family data on the Swedish population, and patients with gallstone disease were identified from the Hospital Discharge Register (1964-2015) and the Outpatient Register (2001-2015). Standardised incidence ratios (SIRs) were calculated as the ratio of observed to expected number of cases.

Results

Gallstone disease was diagnosed in 660 732 patients, with an overall incidence of 131 per 100 000 person-years. Familial cases accounted for 36.0% of all patients with gallstone disease. Of these, 50.9% had a parental family history (SIR 1.62), 35.1% had a sibling history (SIR 1.75) and 14.0% had a parental+sibling history (SIR 2.58). Among a total of 54 630 affected siblings, 84.4% were sibling pairs (SIR 1.55). However, the remaining 15.6% of the affected siblings constituted the high-risk group of multiple affected siblings and an SIR >10; these persons accounted for 7.7% of all familial cases. The spousal risk was only slightly increased to 1.18.

Conclusions

Overall, the results point to the underlying genetic causes for the observed familial clustering, which may involve polygenic gene-environmental interactions for most familial cases but high-risk genes in close to 10% of cases. Family histories should be taken into account in the medical setting and used for counselling of at-risk individuals.

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.

Familial Associations of Colorectal Cancer with Other Cancers

Colorectal cancer (CRC) has a strong familial component which extends to discordant cancers (ie non-CRC tumors). This is best seen in cancer syndromes such as hereditary non-polyposis colorectal cancer (HNPCC) which predisposes to several tumor types. Population-based family studies have also found discordant associations for CRC but they have included cancers which manifest in HNPCC, and there is no convincing evidence of discordant associations beyond the known syndromes. We address familial associations of non-CRC tumors with CRC using the resources of the Swedish Family-Cancer Database and applying a powerful approach of assessing familial relative risks in families of increasing numbers of patients with discordant cancers. Among 1.8 million cancer patients and over 200,000 CRC cases consistent familial associations of CRC was observed for several HNPCC related cancers. However, for small intestinal, pancreatic and nervous system cancers RRs remained essentially unchanged when potential HNPCC families were excluded, suggesting involvement of genes not related to HNPCC. Two independent associations of CRC were found for melanoma, thyroid and eye cancers and these appeared not to be related to known syndromes. A number of other cancers associated with CRC in single analyses and independent studies are required to assess the relevance of such findings.

Other cancers in lung cancer families are overwhelmingly smoking-related cancers

Familial risks of lung cancer are well-established, but whether lung cancer clusters with other discordant cancers is less certain, particularly beyond smoking-related sites, which may provide evidence on genetic contributions to lung cancer aetiology.

We used a novel approach to search for familial associations in the Swedish Family-Cancer Database. This involved assessment of familial relative risk for cancer X in families with increasing numbers of lung cancer patients and, conversely, relative risks for lung cancer in families with increasing numbers of patients with cancers X. However, we lacked information on smoking.

The total number of lung cancers in the database was 125 563. We applied stringent statistical criteria and found that seven discordant cancers were associated with lung cancer among family members, and six of these were known to be connected with smoking: oesophageal, upper aerodigestive tract, liver, cervical, kidney and urinary bladder cancers. A further novel finding was that cancer of unknown primary also associated with lung cancer. We also factored in histological evidence and found that anal and connective tissue cancers could be associated with lung cancer for reasons other than smoking. For endometrial and prostate cancers, suggestive negative associations with lung cancer were found.

Although we lacked information on smoking it is prudent to conclude that practically all observed discordant associations of lung cancer were with cancers for which smoking is a risk factor.

Among family members of lung cancer patients, 7 other cancers were found, all of which were smoking relatedhttp://ow.ly/ZLnt30csVfZ

Site-specific familial risk and survival of familial and sporadic head and neck cancer

The vast majority of head and neck cancers (HNCs) are sporadic squamous cell carcinomas, smoking and heavy drinking being the main risk factors. However, little is known about the possible role of family history and the importance of inherited factors versus shared environment. We used Swedish population-based registries to study the family history of HNC. In order to estimate the risk for family members to get the same cancer, and the risk for cancer-specific death in patients with a family history of HNC compared with patients without a family history, multivariate Cox proportional hazards analyses were performed. A 1.43-fold increased risk for developing HNC in the first-degree relatives (FDRs) of HNC patients [hazard ratio (HR), 1.43; 95% CI, 1.28-1.61] was found, when compared with relatives of healthy controls. In spouses of patients with HNC, the risk for developing any HNC was moderately increased (HR, 1.25; 95% CI, 1.01-1.53), compared with spouses of healthy controls. In addition, a 1.34-fold increased risk for death of HNC was found in HNC patients with a family history of HNC (HR, 1.34; 95% CI, (1.03-1.73) compared with HNC patients without a family history. We found an increased risk for HNC in relatives and spouses of HNC patients, when compared with family members of healthy controls. This suggests that in addition to inherited factors, shared environmental factors have a significant role in the development of the cancer. Family history of HNC was associated with worse survival in a newly diagnosed HNC patient.

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.

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.

Increased risk of hip fracture among spouses-evidence of a homogamy effect

Spouses tend to share habits and therefore have an increased risk of same diseases. We followed all married couples in Sweden, born 1902 to 1942, in hospital records from 1987 to 2002, and found that individuals whose spouse had a hip fracture had an increased risk of hip fracture.

INTRODUCTION

The purpose of this study was to determine whether spouses of hip fracture patients have an elevated risk of hip fracture.

METHODS

We performed a retrospective cohort study of all couples married for at least 5 years in Sweden and born between 1902 and 1942 (n = 904,451) and all patients registered with a hip fracture (n = 218,285) in the National Inpatients Register in Sweden from 1987 to 2002.

RESULTS

During the period 1987 to 2002 hip fractures occurred among spouses in 4212 married couples. The hazard ratio (HR) for hip fracture in a married woman following hip fracture in the husband was 1.11 (95 % confidence interval 1.07 to 1.16) compared to a woman whose husband did not have hip fracture. The corresponding HR for a married man was 1.20 (1.15 to 1.26) compared to a man whose wife did not have hip fracture. The risk was significantly elevated over the age range 60 to 90 years. The increased risk for hip fracture among spouses remained after adjustments for income, education, geographical latitude and urbanisation. In a common model with spouses and their siblings, the HR for spousal effect were 1.63 (1.01 to 2.64) and for sibling effect 2.18 (1.55 to 3.06) compared to married with spouse and sibling respectively without hip fracture.

CONCLUSION

The novel finding of an increased risk for hip fracture among spouses provides evidence indicating that there is a homogamy effect due to common social and lifestyle factors but could also be due to assortative mating.

Location of metastases in cancer of unknown primary are not random and signal familial clustering

Cancer of unknown primary (CUP) is a fatal disease diagnosed through metastases. It shows intriguing familial clustering with certain defined primary cancers. Here we examine whether metastatic location in CUP patients is related to primary non-CUP cancers in relatives based on the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for CUP patients defined by metastatic location depending on cancer in their first degree relatives. SIRs for CUP were high in association with liver (3.94), ovarian (3.41), lung (2.43) and colorectal cancers (1.83) in relatives. The SIR was 1.63 for CUP with metastases in the abdomen when a relative was diagnosed with ovarian cancer. CUP with liver metastases associated with liver (1.44) cancer in relatives. CUP with head and neck region metastases associated with relatives’ esophageal (2.87) cancer. CUP metastases in the thorax associated with a relative’s cancers in the upper aerodigestive tract (2.14) and lung (1.74). The findings, matching metastatic location in CUP and primary cancer in relatives, could be reconciled if these cases of CUP constitute a phenotypically modified primary lacking tissue identification, resulting from epitope immunoediting. Alternatively, CUP metastases arise in a genetically favored tissue environment (soil) promoting growth of both primary cancers and metastases (seeds).

Occupational exposure to pesticides and prostate cancer: a systematic review and meta-analysis

Epidemiological studies on exposure to pesticides and risk of prostate cancer (PC) provide inconsistent results. We aimed to explore various potential sources of heterogeneity not previously assessed and to derive updated risk estimates from homogenous studies. We searched PubMed, Web of Science and Scopus databases for case-control and cohort studies published from 1985 to April 2014. We assessed the quality of the articles using the Newcastle-Ottawa Scale. Pooled estimates were calculated using random-effects models. Heterogeneity was explored using subset analyses and metaregression. Fifty-two studies were included in the review and 25 in the meta-analysis. No association was found between low exposure to pesticides and PC, but association was significant for high exposure, pooled OR 1.33 (1.02 to 1.63), I(2)=44.8%, p=0.024. Heterogeneity was explained by a number of variables including method used to assess exposure. Pooled OR was weak and non-significant for studies measuring serum pesticide level, 1.12 (0.74 to 1.50), I(2)=0.00%, p=0.966. For studies applying self-reporting of exposure, pooled estimate was 1.34 (0.91 to 1.77), I(2)=0.00%, p=0.493, while a high significant association was detected for grouped exposure assessment, 2.24 (1.36 to 3.11), I(2)=0.00%, p=0.955. In spite of a weak significant association detected when pooling ORs for high occupational exposure to pesticides, the magnitude of the association was related to the method of exposure assessment used by the original studies. A family history-pesticide exposure interaction was also observed for a number of pesticides.

A positive family history as a risk factor for prostate cancer in a population-based study with organised prostate-specific antigen screening: results of the Swiss European Randomised Study of Screening for Prostate Cancer (ERSPC, Aarau)

OBJECTIVE

To assess the value of a positive family history (FH) as a risk factor for prostate cancer incidence and grade among men undergoing organised prostate-specific antigen (PSA) screening in a population-based study.

SUBJECTS AND METHODS

The study cohort comprised all attendees of the Swiss arm of the European Randomised Study of Screening for Prostate Cancer (ERSPC) with systematic PSA level tests every 4 years. Men reporting first-degree relative(s) diagnosed with prostate cancer were considered to have a positive FH. Biopsy was exclusively PSA triggered at a PSA level threshold of 3 ng/mL. The primary endpoint was prostate cancer diagnosis. Kaplan-Meier and Cox regression analyses were used.

RESULTS

Of 4 932 attendees with a median (interquartile range, IQR) age of 60.9 (57.6-65.1) years, 334 (6.8%) reported a positive FH. The median (IQR) follow-up duration was 11.6 (10.3-13.3) years. Cumulative prostate cancer incidence was 60/334 (18%, positive FH) and 550/4 598 (12%, negative FH) [odds ratio 1.6, 95% confidence interval (CI) 1.2-2.2, P = 0.001). In both groups, most prostate cancer diagnosed was low grade. There were no significant differences in PSA level at diagnosis, biopsy Gleason score or Gleason score on pathological specimen among men who underwent radical prostatectomy between both groups. On multivariable analysis, age (hazard ratio [HR] 1.04, 95% CI 1.02-1.06), baseline PSA level (HR 1.13, 95% CI 1.12-1.14), and FH (HR 1.6, 95% CI 1.24-2.14) were independent predictors for overall prostate cancer incidence (all P < 0.001). Only baseline PSA level (HR 1.14, 95% CI 1.12-1.16, P < 0.001) was an independent predictor of Gleason score ≥7 prostate cancer on prostate biopsy. The proportion of interval prostate cancer diagnosed in-between the screening rounds was not significantly different.

CONCLUSION

Irrespective of the FH status, the current PSA-based screening setting detects the majority of aggressive prostate cancers and missed only a minority of interval cancers with a 4-year screening algorithm. Our results suggest that men with a positive FH are at increased risk of low-grade but not aggressive prostate cancer.

Population Landscape of Familial Cancer

Public perception and anxiety of familial cancer have increased demands for clinical counseling, which may be well equipped for gene testing but less prepared for counseling of the large domain of familial cancer with unknown genetic background. The aim of the present study was to highlight the full scope of familial cancer and the variable levels of risk that need to be considered. Data on the 25 most common cancers were obtained from the Swedish Family Cancer Database and a Poisson regression model was applied to estimate relative risks (RR) distinguishing between family histories of single or multiple affected first-degree relatives and their diagnostic ages. For all cancers, individual risks were significantly increased if a parent or a sibling had a concordant cancer. While the RRs were around 2.00 for most cancers, risks were up to 10-fold increased for some cancers. Familial risks were even higher when multiple relatives were affected. Although familial risks were highest at ages below 60 years, most familial cases were diagnosed at older ages. The results emphasized the value of a detailed family history as a readily available tool for individualized counseling and its preventive potential for a large domain of non-syndromatic familial cancers.

Prostate cancer, prostate cancer death, and death from other causes, among men with metabolic aberrations

Supplemental Digital Content is available in the text.

Background:

Few previous studies of metabolic aberrations and prostate cancer risk have taken into account the fact that men with metabolic aberrations have an increased risk of death from causes other than prostate cancer. The aim of this study was to calculate, in a real-life scenario, the risk of prostate cancer diagnosis, prostate cancer death, and death from other causes.

Methods:

In the Metabolic Syndrome and Cancer Project, prospective data on body mass index, blood pressure, glucose, cholesterol, and triglycerides were collected from 285,040 men. Risks of prostate cancer diagnosis, prostate cancer death, and death from other causes were calculated by use of competing risk analysis for men with normal (bottom 84%) and high (top 16%) levels of each factor, and a composite score.

Results:

During a mean follow-up period of 12 years, 5,893 men were diagnosed with prostate cancer, 1,013 died of prostate cancer, and 26,328 died of other causes. After 1996, when prostate-specific antigen testing was introduced, men up to age 80 years with normal metabolic levels had 13% risk of prostate cancer, 2% risk of prostate cancer death, and 30% risk of death from other causes, whereas men with metabolic aberrations had corresponding risks of 11%, 2%, and 44%.

Conclusions:

In contrast to recent studies using conventional survival analysis, in a real-world scenario taking risk of competing events into account, men with metabolic aberrations had lower risk of prostate cancer diagnosis, similar risk of prostate cancer death, and substantially higher risk of death from other causes compared with men who had normal metabolic levels.

Risk factors for pancreatic cancer: a summary review of meta-analytical studies

BACKGROUND

The aetiology of pancreatic cancer (PC) has been extensively studied and is the subject of numerous meta-analyses and pooled analyses. We have summarized results from these pooled and meta-analytical studies to estimate the fraction of PCs attributable to each of the identified risk factors.

METHODS

Using a comprehensive strategy, we retrieved 117 meta-analytical or pooled reports dealing with the association between specific risk factors and PC risk. We combined estimates of relative risk and estimates of exposure to calculate the fraction of PCs caused or prevented by a particular exposure.

RESULTS

Tobacco smoking ('strong' evidence) and Helicobacter pylori infection ('moderate' evidence) are the major risk factors associated with PC, with respective estimated population attributable fractions of 11-32% and 4-25%. The major protective factors are history of allergy ('strong' evidence) and increasing fruit or folate intake ('moderate' evidence), with respective population preventable fractions of 3-7% and 0-12%.

CONCLUSIONS

We summarized results of 117 meta-analytical or pooled data reports dealing with 37 aetiological exposures, to obtain robust information about the suspected causes of PC. By combining these estimates with their prevalences in the population, we calculated population attributable or population preventable fractions. About two-thirds of the major risk factors associated with PC are potentially modifiable, affording a unique opportunity for preventing one of our deadliest cancers.