Aggregation of lung cancer in families: results from a population-based case-control study in Germany

Association between a family history of cancer and multiple primary lung cancer risks: a population-based analysis from China

OBJECTIVES

The incidence of multiple primary lung cancer (MPLC) has increased in recent years. The risk factors of MPLC are not well studied, especially in the Asian population. This case-control study investigated the association between a family history of cancer and MPLC risk.

METHODS

We used data from people who surgically confirmed MPLC with at least 2 nodes of Fujian Medical University Union Hospital and matched 1:2 normal individuals as controls between 2016 and 2017. Information on age, sex, lifestyle, personal history, and family history of cancer was collected using a self-administered questionnaire, and odds ratios (OR) were estimated using unconditional logistic regression.

RESULTS

We included 2 104 patients. In total, 321 patients with histologically confirmed MPLC and 642 healthy controls were studied. The significantly higher ratio of current smokers was observed for the cases than the controls (54.1% vs. 30.0%). A family history of LC in first-degree relatives of the cases reported a significantly higher proportion than in the controls (15.3% vs. 8.6%). Family history of all cancers and LC significantly increased the risk of MPLC (OR = 1.64, P = 0.009 and OR = 2.59, P = 0.000, respectively). The multivariate analysis identified a significantly increased risk of MPLC (OR = 2.45, P = 0.000) associated with parents and siblings influenced by LC history. The younger age (aged < 55 years) of LC cases at diagnosis exhibited a significantly increased risk of MPLC (OR = 2.39, P = 0.000). A significant association with a family history of LC was found for male squamous carcinoma and male adenocarcinoma (OR = 1.59, p = 0.037 and OR = 1.64, p = 0.032, respectively). A positive association with LC history was only observed for female adenocarcinoma (OR = 2.23, p = 0.028). The risk of MPLC was not significantly associated with A family history of cancers in non-smokers (OR = 0.91, P = 0.236). Ever-smokers with a positive family history of cancer or LC had a significantly elevated risk of MPLC (OR = 4.01, P = 0.000 and OR = 6.49, P = 0.000, respectively). We also observed a very elevated risk for smokers with no family history (OR = 3.49, P = 0.000). Such a positive association was also observed in ever-smokers with no family history of LC (OR = 3.55, P = 0.000). Adenocarcinoma in females was prevalent and significantly associated with a family history of LC in risk of MPLC compared with other histologic subtypes.

CONCLUSIONS

Our findings suggest an association between a family history of LC and MPLC risk among an Asian population. Smoking status and family history of LC have a synergistic effect on MPLC. These findings indicate that MPLC exhibits familiar aggregation and that inherited genetic susceptibility may contribute to the development of MPLC.

Association between family history of lung cancer and lung cancer risk: a systematic review and meta-analysis

BACKGROUND

Familial risk of lung cancer has been widely studied but the effects of sociodemographic factors and geographical regions are largely unknown.

METHODS

PubMed and Embase were systematically searched until 1^st October 2019. A total of 84 articles were identified and (19 cohort and 66 case control studies) included in this systematic review and meta-analysis. Pooled summary estimates and 95% confidence intervals were estimated, and the analysis was stratified by sociodemographic factors and geographical regions.

RESULTS

Geographical regions, sex, age of proband, smoking status, type of first-degree relatives, number of affected relatives, and early onset of lung cancer in affected relatives were significant determinants of familial risk of lung cancer. Higher risk of familial lung cancer was found among Asians as compared to non-Asians, younger individuals (age≤50) as compared with older individuals (age>50), individuals with ≥2 affected relatives as compared with individuals with one affected relative, ever-smokers as compared with never-smokers, Asian females as compared with Western females, and never-smokers in Asia as compared with never-smokers in the West.

CONCLUSIONS

Familial risk of lung cancer is influenced by both genetic and environmental factors. Future studies should control for environmental factors such as air pollution and environmental tobacco smoke which are prevalent in Asia.

ACE inhibitor use and risk of cataract: a case-control analysis

BACKGROUND/AIM

Use of ACE inhibitors (ACEIs) has been associated with an increased risk of cataract in a previous observational study in humans. In contrast, ACEIs were associated with beneficial effects on cataract development in experimental studies. We assessed the risk of cataract in relation to exposure to ACEI and other antihypertensive drugs.

METHODS

This is a case-control study based on data from the UK-based Clinical Practice Research Datalink (CPRD). We included first-time cataract patients aged ≥40 years between 1995 and 2015 and an equal number of cataract-free controls. We matched the controls to cases on age, sex, general practice, date of first cataract (ie, index date) and years of history in the CPRD prior to the index date. We assessed the number of prescriptions for ACEI and other antihypertensive drugs in detail and explored the use of single ACEI substances. We performed conditional logistic regression and conducted various sensitivity analyses to test the robustness of our findings. We calculated the risk of cataract associated with previous exposure to ACEI, measured as OR with 95% CIs, and adjusted the multivariable model for body mass index, smoking, diabetes, hypertension, prescriptions of systemic corticosteroids and other antihypertensive drugs.

RESULTS

We identified 206 931 cataract cases and the same number of matched controls. Use of ACEI was not associated with a materially altered risk of cataract compared with non-use of ACEI, neither in the main analysis (OR 1.06, 95% CI 1.04 to 1.08) nor in any of the sensitivity or stratified analyses.

CONCLUSION

In our large observational study, use of ACEI was not associated with an altered risk of cataract.

Lung cancer health disparities

Compared with all other racial and ethnic groups in the United States, African Americans are disproportionally affected by lung cancer, both in terms of incidence and survival. It is likely that smoking, as the main etiological factor associated with lung cancer, contributes to these disparities, but the precise mechanism is still unclear. This paper seeks to explore the history of lung cancer disparities and review to the literature regarding the various factors that contribute to them.

Meta-Analysis and Systematic Review in Environmental Tobacco Smoke Risk of Female Lung Cancer by Research Type

More than 50% of women worldwide are exposed to Environmental Tobacco Smoke (ETS). The impact of ETS on lung cancer remains unclear. Cohort studies since the late 1990s have provided new evidence of female lung cancer risk due to ETS. The objective of this meta-analysis and systematic review was to analyze the association of ETS with female lung cancer risk from 1997 to 2017, organised based on research design. According to our applied inclusion and exclusion criteria, 41 published studies were included. The relative risk (RR) from the cohort studies or odds ratio (OR) from case-control studies were extracted to calculate the pooled risks based on the type of study. The summary risks of ETS were further explored with the modulators of ETS exposure sources and doses. The pooled risks of lung cancer in non-smoking women exposed to ETS were 1.35 (95% CI: 1.17⁻1.56), 1.17 (95% CI: 0.94⁻1.44), and 1.33 (95% CI: 1.17⁻1.51) for case-control studies, cohort studies, and both types of studies, respectively. The summary RR estimate of the cohort studies was not statistically significant, but the RR increased with increasing doses of ETS exposure (p trend < 0.05). Based on the results of this study, ETS might be an important risk factor of female lung cancer in non-smokers.

Characterization of germline mutations in familial lung cancer from the Chinese population

Compared with numerous studies of somatic mutations using sporadic lung cancer, the research into germline mutations using familial lung cancer (FLC) is limited. In the present study, we used FLC samples obtained from the Chinese population in highly air-polluted regions to screen for novel germline mutations in lung cancer. Through a whole genome sequencing (WGS) analysis of the nine subjects (four lung cancer patients and five normal family members of FLC), we obtained a whole genome dataset of DNA alterations in FLC samples. A total of 1218 genes were identified with mutations of multiple types. Subsequently, the top 12 highly mutated genes were selected for validation by polymerase chain reaction and DNA sequencing in an expanded sample set including FLC, sporadic lung cancer, and healthy population. Mutations of the five genes (ARHGEF5, ANKRD20A2, ZNF595, ZNF812, MYO18B) may be potential germline mutations of lung cancer. We also analyzed specific mutations within the 12 genes and found that some specific mutations within the MUC12, FOXD4L3 and FOXD4L5 genes showed higher frequencies in the samples of FLC and/or lung cancer tissue, compared with the healthy population. Moreover, some genes with copy number variation may be potentially associated with a predisposition to lung cancer. Furthermore, non-coding DNA alterations of the WGS data in FLC were systematically analyzed and arranged. Interestingly, we found that germline mutations also occurred in many genes of non-coding RNA. This study uncovered the mutation spectrum in FLC and provided important clues for the evaluation of the genetic susceptibility to lung cancer.

Screening for lung cancer

This review will comprise a general overview of the epidemiology of lung cancer, as well as lung cancer risk factors, screening modalities, current guideline recommendations for screening, and our approach to lung cancer screening.

Familial risk for lung cancer

Lung cancer, which has a low survival rate, is a leading cause of cancer-associated mortality worldwide. Smoking and air pollution are the major causes of lung cancer; however, numerous studies have demonstrated that genetic factors also contribute to the development of lung cancer. A family history of lung cancer increases the risk for the disease in both smokers and never-smokers. This review focuses on familial lung cancer, in particular on the familial aggregation of lung cancer. The development of familial lung cancer involves shared environmental and genetic factors among family members. Familial lung cancer represents a good model for investigating the association between environmental and genetic factors, as well as for identifying susceptibility genes for lung cancer. In addition, studies on familial lung cancer may help to elucidate the etiology and mechanism of lung cancer, and may identify novel biomarkers for early detection and diagnosis, targeted therapy and improved prevention strategies. This review presents the aetiology and molecular biology of lung cancer and then systematically introduces and discusses several aspects of familial lung cancer, including the characteristics of familial lung cancer, population-based studies on familial lung cancer and the genetics of familial lung cancer.

Post-Inhaled Corticosteroid Pulmonary Tuberculosis Increases Lung Cancer in Patients with Asthma

Purpose

To evaluate the association between post-inhaled corticosteroid (ICS) pulmonary tuberculosis (TB), pneumonia and lung cancer in patients with asthma.

Methods

The study samples were collected from the National Health Insurance Database. Asthmatic patients who were first-time users of ICS between 2003 and 2005 were identified as cases. For each case, 4 control individuals were randomly matched for sex, age and date of ICS use. Cases and matched controls were followed up until the end of 2010. Cox proportional hazard regression was used to determine the hazard ratio for pulmonary infections and lung cancer risk in the ICS users and non-users.

Results

A total of 10,904 first-time users of ICS were matched with 43,616 controls. The hazard ratios for lung cancer were: 2.52 (95% confidence interval [CI], 1.22–5.22; p = 0.012) for individuals with post-ICS TB, 1.28 (95%CI, 0.73–2.26; p = 0.389) for post-ICS pneumonia, 2.31(95%CI, 0.84–6.38; p = 0.105) for post-ICS pneumonia+TB, 1.08 (95%CI, 0.57–2.03; p = 0.815) for TB, 0.99 (95%CI, 0.63–1.55; p = 0.970) for pneumonia, and 0.32 (95%CI, 0.05–2.32; p = 0.261) for pneumonia+ TB, respectively.

Conclusions

Post-ICS TB increased lung cancer risk in patients with asthma. Because of the high mortality associated with lung cancer, screening tests are recommended for patients with post-ICS TB.

R331W Missense Mutation of Oncogene YAP1 Is a Germline Risk Allele for Lung Adenocarcinoma With Medical Actionability

PURPOSE

Adenocarcinoma is the most dominant type of lung cancer in never-smoker patients. The risk alleles from genome-wide association studies have small odds ratios and unclear biologic roles. Here we have taken an approach featuring suitable medical actionability to identify alleles with low population frequency but high disease-causing potential.

PATIENTS AND METHODS

Whole-genome sequencing was performed for a family with an unusually high density of lung adenocarcinoma with available DNA from the affected mother, four affected daughters, and one nonaffected son. Candidate risk alleles were confirmed by matrix-assisted laser desorption ionization time of flight mass spectroscopy. Validation was conducted in an external cohort of 1,135 participants without cancer and 1,312 patients with lung adenocarcinoma. Family follow-ups were performed by genotyping the relatives of the original proband and the relatives of the identified risk-allele carriers. Low-dose computed tomography scans of the chest were evaluated for lung abnormalities.

RESULTS

YAP1 R331W missense mutation from the original family was identified and validated in the external controls and the cohort with lung adenocarcinoma. The YAP1 mutant-allele carrier frequency was 1.1% in patients with lung adenocarcinoma compared with 0.18% in controls (P = .0095), yielding an odds ratio (adjusted for age, sex, and smoking status) of 5.9. Among the relatives, YAP1-mutant carriers have overwhelmingly higher frequencies of developing lung adenocarcinoma or ground-glass opacity lung lesions than those who do not carry the mutation (10:0 v 1:7; P < .001). YAP1 mutation was shown to increase the colony formation ability and invasion potential of lung cancer cells.

CONCLUSION

These results implicated YAP1 R331W as an allele predisposed for lung adenocarcinoma with high familial penetrance. Low-dose computed tomography scans may be recommended to this subpopulation, which is at high risk for lung cancer, for personalized prevention and health management.

Tag SNPs of CFI contributed to the susceptibility for non-small cell lung cancer in Chinese population

Complement factor I (CFI) plays an important role in the development of non-small cell lung cancer (NSCLC). This study aims to examine the association of CFI genetic variants with the risk of developing NSCLC in Chinese population. A hospital-based case-control study was conducted in 470 patients with NSCLC and 470 controls in Chinese population. Totally, 13 tag single nucleotide polymorphisms (tag SNPs) of CFI were selected by Haploview software using the HapMap database. Genotyping was performed using iPLEX Gold Genotyping Assay and Sequenom MassARRAY. The odds ratios (ORs) and 95% confidence interval (95% CI) were calculated by logistic regression model. Our results showed that individuals with rs6822976 GG genotype had a significant decreased risk of NSCLC (OR = 0.64; 95% CI = 0.42-0.98) when compared with rs6822976 AA genotype carriers. We also found that rs7671905 TT genotype exhibited a significant decreased risk of NSCLC compared with CC genotype with OR (95% CI) of 0.55 (0.33-0.91). There was no significant association between other selected SNPs and the risk of NSCLC. When stratified by smoking status, the decreased risk of NSCLC was observed to be associated with the genotype with at least one rs6822976 G allele among non-smokers (OR = 0.66; 95% CI = 0.47-0.93), but not among smokers (OR = 1.01; 95% CI = 0.67-1.53). For CFI rs7671905 polymorphism, the individuals with at least one T allele have a decreased risk of NSCLC with OR (95 % CI) of 0.71 (0.51-0.99), but not among smokers (OR = 0.93; 95% CI = 0.61-1.41). When stratified by age, we found that rs7671905 TT genotype has contributed to the decreased risk of NSCLC among older subjects with OR (95% CI) of 0.46 (0.23-0.95), but not among younger subjects with OR (95% CI) of 0.64 (0.31-1.34) (P(interaction) = 0.03). After stratifying by sex, our study showed that rs7671905 TT genotype was related to the risk of NSCLC among males (OR = 0.53; 95% CI = 0.29-0.98), but not among females (OR = 0.62; 95% CI = 0.25-1.57) (P(interaction) = 0.03). CFI genetic variants played an important role in the development of NSCLC in Chinese population.

A clinical model to estimate the pretest probability of lung cancer, based on 1198 pedigrees in China

INTRODUCTION

Computed tomography screening can detect lung cancer that is curable. However, some studies demonstrated that the risk for false-positives was about 50%. To make screening more efficient, we sought to create a forecasting model for individuals with different risks for lung cancer.

METHODS

We used multiple logistic regression analysis to identify independent predictors and to develop a prediction model. The pathological diagnoses in Guangdong Lung Cancer Institute were consecutively chosen as probands. All first-degree relatives of probands and their spouses were included as subjects. We divided the probands and their spouses into three subgroups according to the odds ratios (ORs), and the accuracy of lung cancer predictions for patients within the subgroups increased synchronously.

RESULTS

There were 633 proband pedigrees and 565 spouse pedigrees. Independent predictors of lung cancer included sex (OR, 1.6; 95% confidence interval [CI], 1.1-2.3), smoking history (light smoker: OR, 1.1; 95% CI, 0.7-1.8; heavy smoker: OR, 4.7; 95% CI, 3.1-7.1), lung disease history (OR, 5.3; 95% CI, 2.8-10.0), occupational exposure (OR, 1.6; 95% CI, 1.1-2.2), and number of affected individuals among first-degree relatives (n = 1: OR, 2.1; 95% CI, 1.3-3.4; n ≥ 2: OR, 4.7; 95% CI, 0.5-41.2). The accuracy of the pretest probability increased for those with higher ORs: low-OR subgroup, 68.3%; mid-OR subgroup, 84.0%; and high-OR subgroup, 91.9%.

CONCLUSIONS

Our prediction rule is recommended for estimating the pretest probability of lung cancer, thereby facilitating early screening.

Drug Resistance Mechanisms in Non-Small Cell Lung Carcinoma

Lung cancer is the most commonly diagnosed cancer in the world. “Driver” and “passenger” mutations identified in lung cancer indicate that genetics play a major role in the development of the disease, progression, metastasis and response to therapy. Survival rates for lung cancer treatment have remained stagnant at ~15% over the past 40 years in patients with disseminated disease despite advances in surgical techniques, radiotherapy and chemotherapy. Resistance to therapy; either intrinsic or acquired has been a major hindrance to treatment leading to great interest in studies seeking to understand and overcome resistance. Genetic information gained from molecular analyses has been critical in identifying druggable targets and tumor profiles that may be predictors of therapeutic response and mediators of resistance. Mutated or overexpressed epidermal growth factor receptor (EGFR) and translocations in the echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) genes (EML4-ALK) are examples of genetic aberrations resulting in targeted therapies for both localized and metastatic disease. Positive clinical responses have been noted in patients harboring these genetic mutations when treated with targeted therapies compared to patients lacking these mutations. Resistance is nonetheless a major factor contributing to the failure of targeted agents and standard cytotoxic agents. In this review, we examine molecular mechanisms that are potential drivers of resistance in non-small cell lung carcinoma, the most frequently diagnosed form of lung cancer. The mechanisms addressed include resistance to molecular targeted therapies as well as conventional chemotherapeutics through the activity of multidrug resistance proteins.

Clinicopathological characteristics and prognosis of non-small cell lung cancer patients associated with a family history of lung cancer

INTRODUCTION

Clinicopathological characteristics and prognosis of non-small cell lung cancer (NSCLC) patients with a family history of lung cancer (FHLC) have not been well established.

METHODS

Clinical records of patients with NSCLC treated at our institute from 1982 to 2010 were reviewed with special reference to family history of lung cancer and clinicopathological factors including patient's outcome. Univariate analyses of the factors between the groups of FHLC and non-FHLC were performed using unpaired two-tailed t tests or the chi-square test. The Cox proportional hazards model was used to evaluate the hazard ratio of death.

RESULTS

Of the 1013 NSCLC patients, 124 (12.2%) had a FHLC of whom 119 (96%) were the first-degree relatives. The frequency of early stages of lung cancer was high in both groups of FHLC and non-FHLC patients. Patients with FHLC had a significantly higher frequency of early pathological stages and a prepomderance of adenocarcinoma, and a hazard ratio of death of 0.870 (95% confidence interval: 0.599-1.263, p value: 0.465) compared with the non-FHLC patients.

CONCLUSIONS

NSCLC patients with FHLC could be characterized by early pathological stages and preponderance of adenocarcinoma, however they were not at a decreased hazard ratio of death. These findings emphasize the importance of early detection of lung cancer and employment of less invasive therapeutic interventions.

The impact of positive cancer family history on the clinical features and outcome of patients with non-small cell lung cancer

The purpose of this study is to investigate the impact of positive cancer/lung cancer family history (FH) on clinical features and outcome in non-small cell lung cancer (NSCLC) patients. We analyzed 4,491 NSCLC patients with NSCLC who presented from January 1999-December 2005. Chi-square test and Wilcoxon test were used for univariate comparisons, while Cox Proportional Hazards regression analysis was performed to evaluate the adjusted risk of death. Univariate probability of survival was calculated using Kaplan-Meier estimate and compared using the log-rank test. Of 4,491 patients, 579 patients (12.89%) had positive FH, including 233 patients (5.19%) with FH of lung cancer. Patients with positive lung cancer FH, compared to those with negative FH, were diagnosed at earlier age (57 vs. 60; P < 0.001), presented more cases of adenocarcinoma (58.80 vs. 50.69%; P = 0.016), and at more advanced stage (Stage IIIB/IV 45.74 vs. 36.79%; P < 0.001). These differences were also detected in patients with positive cancer FH. In addition, more females and non-smokers were among patients with positive cancer FH (30.05 vs. 26.15%; P = 0.045 and 39.90 vs. 33.82%; P = 0.008, respectively). Furthermore, patients with advanced cancer (stage IIIB/IV) who had positive FH had lower response rate to chemotherapy (CR&PR 24.68 vs. 34.42%; P = 0.024). Nevertheless, patients with positive lung cancer FH had better prognosis (P = 0.015), especially if diagnosed at an early stage (P = 0.035), and their adjusted relative risk of death was lower (RR 0.69; 95% CI: 0.51-0.93; P = 0.015). Definite epidemiologic and survival differences exist between NSCLC patients with positive or negative FH of cancer. Our results suggest that cancer FH is an important factor of clinical features, and could serve as a prognostic indicator for NSCLC.

[Forecasting model of risk of cancer in lung cancer pedigree in a case-control study]

背景与目的

对人群每年进行低剂量胸部CT筛查可提高早期肺癌诊断率，但其假阳性率较高，常导致不必要的手术。本研究拟建立肺癌家系风险度预测模型，从中细分高危人群，从而提高筛选效能。

方法

以经病理确诊的肺癌患者的家系作为研究人群，同时收集先证者的配偶家系作为对照家系，共收集先证者家系633例和对照家系565例。应用SPSS 17.0进行统计学分析。

结果

先证者家系一级亲属患肿瘤的风险性为对照组家系一级亲属的1.71倍（OR=1.71, P < 0.001）。家系中患癌个数分别为=1和≥2的两组与对照组比较有统计学差异（P=0.005, P=0.002）。建立回归模型后赋值得到与普通人群相比的肺癌风险度为0.38-63.08（倍）。风险度为普通人群10倍以上的群体，应用本模型的正确率为88.1%。

结论

如果一级亲属患癌个数越多，患肺癌的风险越高。根据本研究建立的风险度预测模型，风险度达普通人群10倍以上的主要为重度吸烟的吸烟人群，应加强筛查。特点为：有肺部既往疾病史的重度吸烟人群，加上男性、职业暴露和一级亲属肿瘤家族史三项中的任一项；有肺部既往疾病史或重度吸烟的人群中，有职业暴露的男性且一级亲属有不少于两位肿瘤患者。

An analysis of single nucleotide polymorphisms of 125 DNA repair genes in the Texas genome-wide association study of lung cancer with a replication for the XRCC4 SNPs

DNA repair genes are important for maintaining genomic stability and limiting carcinogenesis. We analyzed all single nucleotide polymorphisms (SNPs) of 125 DNA repair genes covered by the Illumina HumanHap300 (v1.1) BeadChips in a previously conducted genome-wide association study (GWAS) of 1154 lung cancer cases and 1137 controls and replicated the top-hits of XRCC4 SNPs in an independent set of 597 cases and 611 controls in Texas populations. We found that six of 20 XRCC4 SNPs were associated with a decreased risk of lung cancer with a P-value of 0.01 or lower in the discovery dataset, of which the most significant SNP was rs10040363 (P for allelic test=4.89 x 10⁻⁴). Moreover, the data in this region allowed us to impute a potentially functional SNP rs2075685 (imputed P for allelic test=1.3 x 10⁻³). A luciferase reporter assay demonstrated that the rs2075685G>T change in the XRCC4 promoter increased expression of the gene. In the replication study of rs10040363, rs1478486, rs9293329, and rs2075685, however, only rs10040363 achieved a borderline association with a decreased risk of lung cancer in a dominant model (adjusted OR=0.80, 95% CI=0.62-1.03 and P=0.079). In the final combined analysis of both the Texas GWAS discovery and replication datasets, the strength of the association was increased for rs10040363 (adjusted OR=0.77, 95% CI=0.66-0.89, P(dominant)=5 x 10⁻⁴ and P for trend=5 x 10⁻⁴) and rs1478486 (adjusted OR=0.82, 95% CI=0.71-0.94, P(dominant)=6 x 10⁻³ and P for trend=3.5 x 10⁻³). Finally, we conducted a meta-analysis of these XRCC4 SNPs with available data from published GWA studies of lung cancer with a total of 12,312 cases and 47,921 controls, in which none of these XRCC4 SNPs was associated with lung cancer risk. It appeared that rs2075685, although associated with increased expression of a reporter gene and lung cancer risk in the Texas populations, did not have an effect on lung cancer risk in other populations. This study underscores the importance of replication using published data in larger populations.

[Systematic review of the relationship between family history of lung cancer and lung cancer risk]

背景与目的

四十多年前Tokuhata和Lilienfeld首次从流行病学的角度证实肺癌的家族聚集现象。随后的多个研究也证实了家族聚集现象是肺癌危险性的一个家族性成分，但研究结果并不完全一致。本研究旨在进一步分析和评价一级亲属患肺癌者在肺癌发生中的作用。

方法

检索PubMed、CENTRAL、中国生物医学文献数据库系统（CBM）、中国期刊全文数据库（CNKI）、中文科技期刊全文数据库（VIP）等收集国内外公开发表的肺癌家族聚集性的病例对照研究。采用RevMan version 4.2统计软件对各研究结果进行分析，计算其合并优势比和95%可信区间。

结果

纳入合并分析的文献共有28篇，分析结果表明：肺癌先证家系一级亲属患肺癌的风险是对照家系一级亲属的1.88倍（P < 0.001)。分层分析，先证家系的父亲、母亲及兄弟姐妹患肺癌的风险分别是对照家系的1.62倍（P < 0.001）、1.96倍（P < 0.001）和1.92倍（P < 0.001）；吸烟和非吸烟先证者一级亲属患肺癌的风险分别是对照组中吸烟者和非吸烟者一级亲属患肺癌的1.73倍（P < 0.001）和1.42倍（P=0.02）；女性和男性肺癌先证者一级亲属患肺癌的风险性分别是对照组中女性和男性一级亲属患肺癌的1.89倍（P < 0.001）和1.99倍（P < 0.001）。

结论

先证家系一级亲属患肺癌的风险性增加，肺癌存在明显的家族聚集现象。

Family history and lung cancer risk: international multicentre case-control study in Eastern and Central Europe and meta-analyses

Lung cancer is the most common neoplastic disease in Eastern and Central Europe. The role of hereditary factors in lung carcinogenesis is not fully understood. Family history (FH) of lung cancer and other tobacco-related cancers might be a strong predictor of the lung cancer risk. We investigated family history of cancer among first-degree relatives of 2,861 patients with lung cancer and 3,118 controls from the Czech Republic, Hungary, Poland, Romania, Russia, Slovakia, and United Kingdom within the IARC Multicenter Case-Control Study. Odds ratios (ORs) and 95% CI were calculated using logistic regression, adjusting for age, gender, study center, education, tobacco smoking, and number of first-degree relatives. In addition, we conducted a meta-analysis of 41 studies on FH of cancer and lung cancer risk. Positive FH of lung cancer increased risk of lung cancer with OR of 1.63 (95%CI: 1.31-2.01), and having two or more affected relatives with lung cancer further increased the risk of lung cancer with OR 3.60 (95%CI: 1.56-8.31). Among subjects aged less than 50, the OR for FH of lung cancer was 2.08 (95%CI: 1.18-3.63). The associations were generally stronger for squamous cell carcinoma and large cell carcinoma subtypes. Heterogeneity in results was not found with respect to smoking status and gender. A significant association was not observed for FH of other smoking-related tumors. The results of meta-analysis were consistent with that of our study with regard to young onset, non-smokers and histology. FH of lung cancer is a predictor of an increased risk of lung cancer, especially in subjects aged less than 50.

FAMILIAL RISK FOR LUNG CANCER BY HISTOLOGY AND AGE OF ONSET: EVIDENCE FOR RECESSIVE INHERITANCE

The authors used the Swedish Family-Cancer Database to search for evidence for a genetic predisposition in lung cancer. Familial risks in offspring were increased for all lung cancer to 1.77 when a parent was affected with any lung cancers; the comparable risk among siblings was 2.15. At young age, risks between siblings were higher than those between offspring and parents for all histological types of lung cancer. The present data suggest that 1.7% of lung cancers up to age 68 years are heritable and probably due to a high-penetrant recessive gene or genes that predispose to tobacco carcinogens.

Family history of cancer and nonmalignant lung diseases as risk factors for lung cancer

Family history (FH) of lung cancer is an established risk factor for lung cancer, but the modifying effect of smoking in relatives has been rarely examined. Also, the role of FH of nonmalignant lung diseases on lung cancer risk is not well known. We examined the role of FH of cancer and nonmalignant lung diseases in lung cancer risk overall, and by personal smoking, FH of smoking and histology in 1,946 cases and 2,116 population-based controls within the Environment And Genetics in Lung cancer Etiology (EAGLE) study. Odds ratios (ORs) and 95% CI from logistic regression were calculated adjusting for age, gender, residence, education and cigarette smoking. FH of lung cancer in any family member was associated with increased lung cancer risk (OR = 1.57, 95% CI = 1.25-1.98). The odds associated with fathers', mothers' and siblings' history of lung cancer were 1.41, 2.14 and 1.53, respectively. The associations were generally stronger in never smokers, younger subjects and for the adenocarcinoma and squamous cell carcinoma subtypes. FH of chronic bronchitis and pneumonia was associated with increased (OR = 1.49, 95% CI = 1.23-1.80) and decreased (OR = 0.73, 95% CI = 0.61-0.87) lung cancer risk, respectively. FH of lung cancer and nonmalignant lung diseases affected lung cancer risk independently, and did not appear to be modified by FH of smoking.

Cancer diagnosis in first-degree relatives and non-small cell lung cancer risk: results from a multi-centre case-control study in Europe

Because aggregation of cancers at different sites can occur in families, cancer could be considered as a broad phenotype with shared genetic factors. Here, we report results from a multi-centre case-control study of non-small cell lung cancer (NSCLC), with particular emphasis on a history of cancer in first-degree relatives and the risk of lung cancer. From 2002 to 2006, 733 NSCLC patients treated surgically were recruited in 8 European countries and matched to 1312 controls, by centre, sex and age. We used multivariate conditional logistic regression models to test the association between a history of cancer in first-degree relatives and risk of NSCLC. A family history of lung cancer was associated with an odds ratio (OR) for early-onset (54 years or younger) NSCLC of 4.72 (95% confidence interval [CI]=1.02-21.90). A family history of gastric cancer was associated with an OR for NSCLC of 1.82 (95% CI=1.08-3.06) and for late-onset (55 years or older) NSCLC of 2.92 (95% CI=1.10-7.75). Our findings provide further evidence of a familial predisposition to lung cancer and support the hypothesis that family history is a significant risk factor for the disease. Because of the inherent potential for bias in familial case-control study design, cautious interpretation is warranted.

Relation of age-related cataract with obesity and obesity genes in an Asian population

Obesity shows an inconsistent association with cataract. Causality has not been established. Polymorphisms at the fat mass- and obesity-associated (FTO) locus are associated with obesity and offer an opportunity to examine the obesity-cataract association using a mendelian randomization approach. The authors conducted a population-based study among Singaporean Malay adults (2004-2006) in which nuclear, cortical, and posterior subcapsular (PSC) cataracts were assessed and defined by slit-lamp examination using Lens Opacity Classification System III. Obesity was defined as body mass index (weight (kg)/height (m)(2)) > or =30. The study included 3,000 subjects, of whom 1,339 (44.6%) had cataract (848 (28.3%) nuclear, 939 (31.3%) cortical, and 285 (9.5%) PSC). After multivariable adjustment for age, gender, diabetes, hypertension, smoking, and education, obesity was significantly associated with cortical (odds ratio (OR) = 1.31, 95% confidence interval (CI): 1.01, 1.71) and PSC (OR = 1.60, 95% CI: 1.10, 2.32) cataracts but not nuclear cataract. FTO single nucleotide polymorphisms known to be associated with obesity in this study population were not associated with cortical or PSC cataract but were associated with nuclear cataract (OR = 1.33, 95% CI: 1.11, 1.58), even in multivariate analyses controlling additionally for body mass index, diabetes, hypertension, and smoking (OR = 1.30, 95% CI: 1.08, 1.55). These results do not support a causal association between obesity and cortical or PSC cataract. The FTO gene may be involved in the pathogenesis of nuclear cataract.

Estimation of the effects of smoking and DNA repair capacity on coefficients of a carcinogenesis model for lung cancer

Numerous prospective and retrospective studies have clearly demonstrated a dose-related increased lung cancer risk associated with cigarette smoking, with evidence also for a genetic component to risk. In this study, using the two-stage clonal expansion stochastic model framework, for the first time we investigated the roles of both genetic susceptibility and smoking history in the initiation, clonal expansion, and malignant transformation processes in lung carcinogenesis, integrating information collected by a case-control study and a large-scale prospective cohort study. Our results show that individuals with suboptimal DNA repair capacity have enhanced transition rates of key events in carcinogenesis.

Previous pulmonary disease and family cancer history increase the risk of lung cancer among Hong Kong women

Chinese women in Hong Kong have among the highest incidence and mortality of lung cancer in the world, in spite of a low prevalence of smoking. We carried out this population-based case-control study to evaluate the associations of previous lung disease and family cancer history with the occurrence of lung cancer among them. We selected 212 cases that were newly diagnosed with primary lung cancer, and randomly sampled 292 controls from the community, frequency matched by age group. All the cases and controls were lifetime nonsmokers. We estimated the main effects of preexisting asthma, pulmonary tuberculosis, pneumonia, chronic bronchitis, and family lung/all cancer history, using unconditional logistic regression, accounting for various potential risk factors and confounders. All of the previous lung diseases, except chronic bronchitis, were related to an elevated risk for lung cancer, and the association with asthma was significant. Those who had more than one previous lung disease tended to be at higher risk than those with only one of them. Positive family history of any cancer was associated with over 2-fold risk than negative family history. The joint effect of positive history of previous pulmonary diseases and positive family cancer history appeared to be additive, indicating the two factors acted independently. The results support an etiological link of preexisting lung disease and family cancer history to the risk of lung cancer.

The changing epidemiology of lung cancer

The 20th century witnessed the scourge of lung cancer as the disease rapidly rose the ranks to become the commonest cause of cancer mortality in the world. Epidemiological evidence conclusively associated cigarette smoking with the causation of lung cancer in the 1950s. Since then and the few decades after, lung cancer of the squamous cell or small cell histological subtypes was mainly diagnosed among male smokers in developed countries. As we move into the 21st century, the incidence of lung cancer is unlikely to abate but the burden will shift from the developed to the less-developed countries. Other epi-demiological changes of lung cancer include the narrowing of the gap between men and women affected by the disease, predominance of the adenocarcinoma histological subtypes as well as more never-smokers afflicted with the disease. Unless we eliminate tobacco smoking completely, lung cancer will continue its wrath into the 21st century.

Association of positive family history with survival of patients with lung cancer

BACKGROUND

Risk factors for development of lung cancer include a family history of the disease. The effect of family history on lung cancer outcomes is unknown. A study was conducted to investigate this.

METHODS

The medical records of all patients with lung cancer seen in an academic medical oncology lung cancer clinic between 1999 and 2006 were reviewed for outcomes and family history of lung cancer. chi(2)-test and Wilcoxon test were used for univariate comparisons, while Cox Proportional Hazards regression analysis was used to evaluate the adjusted risk of death. Univariate probability of survival was computed using Kaplan-Meier estimate and compared using the log-rank test.

RESULTS

Of the 560 patients evaluated, 289 (51%) were male and 519 (93%) had a smoking history. Of the 148 patients (26%) with a family history of lung cancer, 115 had an affected first-degree relative. No association between family history and histology or stage at diagnosis was detected. Median survival in patients with a family history of lung cancer was 53 months compared to 58 months in patients without such a history (p=0.06). Patients with a positive family history had an adjusted relative risk of death of 1.65 (95% CI: 1.07-2.56; p=0.02) compared to those without a family history. This risk was especially increased in those with an affected first-degree relative (RR: 1.72; 95% CI: 1.08-2.75, p=0.02).

CONCLUSIONS

Lung cancer patients with a first-degree relative with lung cancer have a poorer outcome than those without such a history.

Family history of cancer and risk of lung cancer among nonsmoking Chinese women

The relationship between family cancer history in first-degree relatives and risk of lung cancer was evaluated among a population-based cohort of 71,392 female nonsmokers in Shanghai, China. A total of 179 newly diagnosed lung cancer patients were identified during 441,410 person-years of follow-up. Lung cancer risk was not elevated among those with a family history of lung cancer. However, risk of lung cancer was increased among subjects who had two or more first-degree relatives with any type of cancers {rate ratio [RR], 1.95 [95% confidence intervals (95% CI), 1.08-3.54] for two relatives with any cancers and RR, 3.17 [95% CI, 1.00-10.03] for three or more relatives with any cancer}. Having a family history of colorectal cancer (RR, 2.38; 95% CI, 1.21-4.70) and having siblings with stomach cancer (RR, 2.16; 95% CI, 1.01-4.65) and pancreatic cancer (RR, 4.19; 95% CI, 1.04-16.95) were also found to be associated with lung cancer risk. This cohort study indicated a moderate association of lung cancer risk with a family cancer history in general, but not with a family history of lung cancer specifically. The associations were stronger when a sibling, rather than a parent, was affected. The apparent link between lung cancer risk and a family history of colorectal, stomach, and pancreas cancers may be worth further investigation.

Do genetic factors protect for early onset lung cancer? A case control study before the age of 50 years

BACKGROUND

Early onset lung cancer shows some familial aggregation, pointing to a genetic predisposition. This study was set up to investigate the role of candidate genes in the susceptibility to lung cancer patients younger than 51 years at diagnosis.

METHODS

246 patients with a primary, histologically or cytologically confirmed neoplasm, recruited from 2000 to 2003 in major lung clinics across Germany, were matched to 223 unrelated healthy controls. 11 single nucleotide polymorphisms of genes with reported associations to lung cancer have been genotyped.

RESULTS

Genetic associations or gene-smoking interactions was found for GPX1(Pro200Leu) and EPHX1(His113Tyr). Carriers of the Leu-allele of GPX1(Pro200Leu) showed a significant risk reduction of OR = 0.6 (95% CI: 0.4-0.8, p = 0.002) in general and of OR = 0.3 (95% CI:0.1-0.8, p = 0.012) within heavy smokers. We could also find a risk decreasing genetic effect for His-carriers of EPHX1(His113Tyr) for moderate smokers (OR = 0.2, 95% CI:0.1-0.7, p = 0.012). Considered both variants together, a monotone decrease of the OR was found for smokers (OR of 0.20; 95% CI: 0.07-0.60) for each protective allele.

CONCLUSION

Smoking is the most important risk factor for young lung cancer patients. However, this study provides some support for the T-Allel of GPX1(Pro200Leu) and the C-Allele of EPHX1(His113Tyr) to play a protective role in early onset lung cancer susceptibility.

Aggregation of cancer among relatives of never-smoking lung cancer patients

The authors evaluated the familial aggregation of lung and other cancers in first-degree relatives of lung cancer patients self-reported to be lifetime never smokers. The data, derived from a large lung cancer case-control study, included 2,465 first-degree relatives of 316 never smoker lung cancer cases and 2,441 first-degree relatives of 318 never smoker controls, frequency matched to the cases on age, gender and ethnicity. The median age of the cases and the controls was 61 years, about 2/3 were women, and about 80% were Caucasian. Overall, there was a 25% excess risk [95% CI (1.05-1.50)] of any type of cancer among the first-degree relatives of cases, and case offspring exhibited a 2-fold excess cancer risk (1.03-4.10) compared with control offspring. There was also a 44% excess risk (1.05-1.97) of young onset cancers (before age 50) among relatives of cases. Smoking case relatives had an increased risk of any cancer [odds ratio (OR) = 1.36 (1.03-1.81)] and a 5.52-fold risk (1.19-25.51) of young onset lung cancer compared with smoking control relatives. Female case relatives had a 58% excess breast cancer risk (1.04-2.43), and case mothers a 2.57-fold breast cancer risk (1.16-4.24). A significant excess of testicular cancer was observed among case male relatives [OR = 12.32 (1.71-88.90)], although based on only 9 cases. The age at lung cancer diagnosis tended to be earlier in case relatives (61.4, SD = 12.9) compared with control relatives (66.2, SD = 11.4; p = 0.07). Our analysis provides further evidence for the importance of genetic factors for lung cancer in never smokers.

A risk model for prediction of lung cancer

BACKGROUND

Reliable risk prediction tools for estimating individual probability of lung cancer have important public health implications. We constructed and validated a comprehensive clinical tool for lung cancer risk prediction by smoking status.

METHODS

Epidemiologic data from 1851 lung cancer patients and 2001 matched control subjects were randomly divided into separate training (75% of the data) and validation (25% of the data) sets for never, former, and current smokers, and multivariable models were constructed from the training sets. The discriminatory ability of the models was assessed in the validation sets by examining the areas under the receiver operating characteristic curves and with concordance statistics. Absolute 1-year risks of lung cancer were computed using national incidence and mortality data. An ordinal risk index was constructed for each smoking status category by summing the odds ratios from the multivariable regression analyses for each risk factor.

RESULTS

All variables that had a statistically significant association with lung cancer (environmental tobacco smoke, family history of cancer, dust exposure, prior respiratory disease, and smoking history variables) have strong biologically plausible etiologic roles in the disease. The concordance statistics in the validation sets for the never, former, and current smoker models were 0.57, 0.63, and 0.58, respectively. The computed 1-year absolute risk of lung cancer for a hypothetical male current smoker with an estimated relative risk close to 9 was 8.68%. The ordinal risk index performed well in that true-positive rates in the designated high-risk categories were 69% and 70% for current and former smokers, respectively.

CONCLUSIONS

If confirmed in other studies, this risk assessment procedure could use easily obtained clinical information to identify individuals who may benefit from increased screening surveillance for lung cancer. Although the concordance statistics were modest, they are consistent with those from other risk prediction models.

Racial Differences in Cancer Risk Among Relatives of Patients With Early Onset Lung Cancer

BACKGROUND

Relatives of patients with early onset lung cancer are at increased risk for lung cancer, and this risk varies by race. This study evaluates whether first-degree relatives of patients with early onset lung cancer are at increased risk for cancer at sites other than lung.

METHODS

Family histories were ascertained from 673 lung cancer patients < 50 years of age identified from the Metropolitan Detroit Surveillance, Epidemiology and End Results program, and 773 age-, race-, and sex-matched control subjects were obtained via random-digit dialing. Data were collected for 3,556 case relatives (mothers, fathers, and siblings) and 3,943 control relatives, and unconditional logistic regression models using generalized estimating equations were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among case relatives, African Americans were 2.44-fold more likely to have head and neck cancers and 1.86-fold more likely to have any tobacco-related cancer compared to white case relatives (95% CI, 1.04 to 5.69% and 95% CI, 1.25 to 2.76, respectively). African-American case relatives were at increased risk for head and neck cancers (OR, 13.42; 95% CI, 1.65 to 109.01), all tobacco-related cancers (OR, 3.77; 95% CI, 2.16 to 6.55), tobacco-related cancers other than lung (OR, 4.10; 95% CI, 1.56 to 10.79), and cancer at any site (OR, 1.45, 95% CI, 1.04 to 2.02) compared to African-American control relatives.

CONCLUSIONS

These results can be used to counsel family members of patients with early onset lung cancer, and suggest target populations for preventive strategies, including smoking cessation and appropriate screening.

Factores etiológicos del cáncer de pulmón: fumador activo, fumador pasivo, carcinógenos medioambientales y factores genéticos

Every year, in Spain 18,000 new cases of lung cancer (LC) are diagnosed. Approximately, 80-90% LC in men and women are directly attributable to tobacco abuse. Cigarette smoke contains over 300 chemicals, 40 of which are known to be potent carcinogens. In the last decade, as in Spain, prevalence of smoking in women has generally increased in the European Union. LC risk can be substantially reduced after smoking cessation, yet never reaches baseline. On the other hand, environmental tobacco smoke exposure (passive smoking) in nonsmokers appears to have a significantly increased risk of LC. An updated of etiology factors of LC, risk related to duration as well as intensity of smoking, relationship between environmental tobacco smoke exposure and LC risk, genetic predisposition and a variety of occupational and environmental exposures implicated as potential risk factors for the development of LC will be reviewed here.

Lung cancer in systemic lupus erythematosus

BACKGROUND

Evidence points to a link between systemic lupus erythematosus (SLE) and an increased risk of lung cancer. Our objective was to provide a brief report of the lung cancer cases from an SLE cohort, with respect to demographics, histology, and exposures to smoking and immunosuppressive medications.

METHODS

Data were obtained from a multi-site international cohort study of over 9500 SLE patients from 23 centres. Cancer cases were ascertained through linkage with regional tumor registries.

RESULTS

We analyzed information on histology subtype for 30 lung cancer cases that had occurred across five countries. Most (75%) of these 30 cases were female, with a median age of 61 (range 27-91) years. In eight cases, the histological type was not specified. In the remainder, the most common histological type reported was adenocarcinoma (N=8; two of the adenocarcinomas were bronchoalveolar carcinoma) followed by small cell carcinoma (N=6), and squamous cell carcinoma (N=6) with one case each of large cell carcinoma and carcinoid tumor. Most (71%) of the lung cancer cases were smokers; only the minority (20%) had been previously exposed to immunosuppressive agents.

CONCLUSIONS

The histological distribution of the lung cancers from the SLE sample appeared similar to that of lung cancer patients in the general population, though the possibility of a higher proportion of more uncommon tumors (such as bronchoalveolar and carcinoid) cannot be excluded. A large proportion of the cancer cases were smokers, which is also not surprising. However, only a minority appeared to have been exposed to immunosuppressive agents. A large case-cohort study currently in progress should help shed light on the relative importance of these exposures in lung cancer risk for SLE patients.

Die Einbeziehung genetischer Faktoren in Studien der Epidemiologie

During the last two decades, genetic epidemiology has been established in parallel to the area of classical epidemiology. This paper presents some essentials of the epidemiology of genetic factors. It begins with a discussion of complex diseases that are characterized by an involvement of several genes. The problems that are attached to modeling gene-gene and gene-environment interactions and their integration into causal pathways are elucidated and the role of genetic factors in the etiology of complex diseases is investigated. Classical and new epidemiological study designs that allow an integration of genetic data are introduced. The introduction of this data is partly motivated by the danger of bias due to genetic heterogeneity (population stratification) in classical designs. The problem of replication of study results is discussed and the concept of Mendelian randomization is presented.

Association Between Lung Cancer Incidence and Family History of Lung Cancer

STUDY OBJECTIVES

To clarify the possibility of a hereditary predisposition to lung cancer, we investigated the association between a family history of lung cancer and subsequent risk of lung cancer in a large-scale, population-based cohort study.

DESIGN

We investigated 102,255 middle-aged and older Japanese subjects (48,834 men and 53,421 women) with 13-year follow-up. A total of 791 cases of lung cancer were newly diagnosed during the follow-up period.

RESULTS

A family history of lung cancer in a first-degree relative was associated with a significantly increased risk of lung cancer (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.31 to 2.88). The association was stronger in women than in men (HR, 2.65; 95% CI, 1.40 to 5.01 and HR, 1.69; 95% CI, 1.03 to 2.78, respectively), and in never-smokers than in current smokers (HR, 2.48; 95% CI, 1.27 to 4.84 and HR, 1.73; 95% CI, 0.99 to 3.00, respectively). In addition, family history was more strongly associated with the risk of squamous cell carcinoma than with other histologic types (HR, 2.79; 95% CI, 1.37 to 5.68), while no clear increase in risk was observed in adenocarcinoma and small cell carcinoma. A family history of overall cancer was not associated with an increased risk of lung cancer.

CONCLUSIONS

These results suggest that those with a family history of lung cancer are more likely to acquire lung cancer themselves.

Family history and risk of lung cancer: age-at-diagnosis in cases and first-degree relatives

To investigate the little known risk of lung cancer at an early age when a first-degree relative has had such a diagnosis, 579 incident cases and 1157 population controls were studied in Liverpool between 1998 and 2004 using standardised questionnaires covering demography and lifestyle. A history of lung cancer in first-degree relatives was associated with a significantly increased risk in the proband where in both individuals the cancers were diagnosed before the age of 60 years (odds ratio (OR)=4.89; 95% confidence interval (CI): 1.47–16.25). A significantly elevated risk of lung cancer was also observed in association with a relative affected before the age of 60 years, regardless of age-at-onset of the disease (OR=2.08; 95% CI: 1.20–3.59). This finding is strongly consistent with a genetic component in early-onset lung cancer risk.

Family history of gastric cancer: a correlation between epidemiologic findings and clinical data

BACKGROUND

The pathogenetic mechanisms behind gastric cancer are still unclear. Its familial aggregation, on the other hand, has been very well documented by many epidemiologists. Nonetheless, only a limited number of studies have analyzed possible correlations between demographic and clinical data.

METHODS

Between January 1988 and August 2004, 541 patients underwent gastric resection with a curative intent at our department; demographic information, laboratory data, imaging, operative notes, and pathology reports were available for all patients. During 2004 we conducted a series of structured interviews with the surviving patients or their closest relatives regarding oncological family history, limited to first-degree relatives.

RESULTS

Family history could be obtained in 383 patients (70.8%). Gastric cancer was by far the most frequently associated tumor: 21.9% of the overall number of tumors reported in the family histories were gastric cancers. Patients were also subdivided into those having at least one other family member with stomach cancer (71 patients; 18.5%) and those with no relatives affected by gastric cancer (312 patients; 81.5%). No statistically significant differences between the groups were observed regarding the primary tumor location, size, pTNM classification, and ABO or Rh blood types. However, the intestinal histotype was significantly (P = 0.015) more frequently represented in individuals with at least one family member affected by gastric cancer compared with those with no relatives with stomach cancer (71.8% vs 55.1%, respectively).

CONCLUSIONS

Stomach cancer has a relevant degree of familial aggregation and in our series of patients, this was even more pronounced for the intestinal histotype.

Analysis of co-aggregation of cancer based on registry data

OBJECTIVE

An exploratory analysis of co-aggregation of cancers using registry-based data.

METHODS

We utilized sibships from over 18,000 families who had been recruited to the NCI-sponsored multi-institutional Cancer Genetics Network. The analysis assesses co-aggregation at the individual and family level and adjusts for ascertainment.

RESULTS

We found statistically significant familial co-aggregation of lung cancer with pancreatic (adjusted p < 0.001), prostate (adjusted p < 0.003), and colorectal cancers (adjusted p = 0.004). In addition, we found significant familial co-aggregation of pancreatic and colorectal cancers (adjusted p = 0.018), and co-aggregation of hematopoietic and (non-ovarian) gynecologic cancers (adjusted p = 0.01).

CONCLUSION

This analysis identified familial aggregation of cancers for which a genetic component has yet to be established.

Never smokers and lung cancer risk: a case-control study of epidemiological factors

We performed an analysis of potential epidemiological risk factors for lung cancer using data from 280 cases and 242 hospital-based controls, all lifetime never smokers (those who had smoked <100 cigarettes in their lifetimes) and frequency matched on age, gender and ethnicity. The data on demographic characteristics, medical history of respiratory diseases (asthma, emphysema, pneumonia and hay fever), weight and height, family history, female characteristics and environmental tobacco smoke (ETS) and dust exposure were derived from personal interviews. We performed a logistic regression analysis of these variables adjusting for age, gender, ethnicity, income and years of education. Exposure to ETS (OR = 2.08, 95% CI [1.25-3.43]) and dusts (OR = 2.43, 95% CI [1.53-3.88]) were associated with significantly increased risk. In the analysis for joint effects, exposure to both ETS and dusts conferred a higher risk (OR = 3.25, 95% CI [1.58-6.70]) than exposure to either alone. Family history of any cancer with onset before age 50 in at least 1 first degree relative was a significant risk predictor (OR = 1.70, 95% CI [1.10-2.64]). Individuals with a self-reported physician-diagnosed history of hay fever, but not asthma, had a decreased lung cancer risk (OR = 0.57, 95% CI [0.35-0.92]). In the multivariate analysis, exposure to ETS and dusts, and family history of cancer with onset before age 50 were significant risk factors, while a history of hay fever (occurring without asthma) was significantly protective.

Diagnostic agreement in the histopathological evaluation of lung cancer tissue in a population-based case-control study

Only few studies have compared the agreement of histological lung carcinoma diagnosis of a population-based case series and an independent pathology review. We analyzed data of our population-based lung cancer case-control study to determine the agreement in the histopathological evaluation of lung cancer. Six-hundred and sixty-eight out of 1004 interviewed male and female lung cancer cases were histologically evaluated according to the 1981 WHO classification by regional pathologists and a central pathologist who was blinded to the evaluations of the regional pathologists. The observed agreement was 0.65 with kappa = 0.54 (95% CI: 0.49-0.58). It was highest for small-cell carcinoma (0.94; kappa = 0.82) and lower for squamous-cell carcinoma (0.81; kappa = 0.58) and adenocarcinoma (0.81; kappa = 0.55). Agreement was slightly higher among women than men. The observed agreement among non-smoking cases was 58% as compared to 67% heavy smoking cases. The moderate agreement for squamous-cell and adenocarcinoma complicates epidemiological studies that address these histological subtypes.

Unlimited Access to Care: Effect on Racial Disparity and Prognostic Factors in Lung Cancer

STUDY OBJECTIVE

Evaluate the prognostic factors influencing lung cancer survival under a universal health care system and determine if access to care eliminates clinical outcome disparity.

DESIGN

Retrospective case series review.

BACKGROUND

Lung cancer survival is worse in men and in African Americans, thought to be related to poor general health in men and limited access to heath care in African Americans. The Military Health Care System, with unlimited access to care, provides an excellent setting for evaluating gender and racial disparities in lung cancer survival.

METHODS

Lung cancers diagnosed at Walter Reed Army Medical Center, from 1990 to 2000, were evaluated by chart review for age, gender, race, smoking history, cancer history, histology, stage, and completeness of resection.

RESULTS

Seven hundred thirteen Caucasians and 173 African Americans, 2:1 male predominance, had a 22% 5-year survival. Cox model analysis showed that male gender [hazard ratio (HR, 1.31) 95% confidence interval (95% CI), 1.02-1.68], advanced-stage disease (stage III: HR, 2.58; 95% CI, 1.57-4.26/stage IV: HR, 4.20; 95% CI, 2.51-7.41), and incomplete resection (HR, 4.06; 95% CI, 2.75-5.99) were predictors of poor outcome; whereas bronchoalveolar carcinoma features (HR, 0.35; 95% CI, 0.23-0.52) and smoking cessation >7 years (HR, 0.70; 95% CI, 0.49-0.99) were predictors of favorable outcome. No ethnic differences in survival were observed.

CONCLUSIONS

No racial disparities in survival when access to medical care is universal. Male gender, incomplete resection, and advanced stage are significant predictors of poor outcome in lung cancer.

Systematic review of the relationship between family history and lung cancer risk

We performed a systematic review of 28 case–control, 17 cohort and seven twin studies of the relationship between family history and risk of lung cancer and a meta-analysis of risk estimates. Data from both case–control and cohort studies show a significantly increased lung cancer risk associated with having an affected relative. Risk appears to be greater in relatives of cases diagnosed at a young age and in those with multiple affected family members. Increased lung cancer risk was observed in association with an affected spouse and twin studies, while limited, favour shared environmental exposures. The limitations of the currently published epidemiological studies to infer genetic susceptibility are discussed.