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

Association between family history with lung cancer incidence and mortality risk in the Asia Cohort Consortium

Family history of lung cancer (FHLC) has been widely studied but most prospective cohort studies have primarily been conducted in non-Asian countries. We assessed the association between FHLC with risk of lung cancer (LC) incidence and mortality in a population of East Asian individuals. A total of 478,354 participants from 11 population-based cohorts in the Asia Cohort Consortium were included. A Cox proportional hazards regression model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 7,785 LC incident cases were identified. FHLC (any LC subtype) was associated with an increased risk of LC incidence (HR = 1.45, 95% CI = 1.30-1.63). The positive association was observed in men and women (HR = 1.44, 95% CI = 1.26-1.66 in men; HR = 1.47, 95% CI = 1.22-1.79 in women), and in both never-smokers and ever-smokers (HR = 1.43, 95% CI = 1.18-1.73 in never-smokers; HR = 1.46, 95% CI =1.27-1.67 in ever-smokers). FHLC was associated with an increased risk of lung adenocarcinoma (HR = 1.63, 95% CI: 1.36-1. 94), squamous cell carcinoma (HR = 1.88, 95% CI: 1.46-2.44), and other non-small cell LC (HR = 1.94, 95% CI: 1.02-3.68). However, we found no evidence of significant effect modification by sex, smoking status, and ethnic groups. In conclusion, FHLC was associated with increased risk of LC incidence and mortality, and the associations remained consistent regardless of sex, smoking status and ethnic groups among the East Asian population.

Decreasing incidence and mortality of lung cancer in Hungary between 2011 and 2021 revealed by robust estimates reconciling multiple data sources

Objective

Hungary has repeatedly been shown to have the highest cancer-related mortality and incidence in Europe. Despite lung cancer being the most abundant malignant diagnosis in Hungary, numerous concerns have been raised recently regarding the bias inherent to reported incidence estimates. Re-analysis of reimbursement claims has been suggested previously by our group as an alternative approach, offering revised figures of lung cancer incidence between 2011 and 2016. Leveraging on this methodology, we aimed at updating Hungarian lung cancer incidence estimates with an additional 5 years (2017-2021), including years affected by the COVID-19 pandemic. Additionally, we also attempted to improve the robustness of estimates by taking additional characteristics of the patient pathway into account.

Methods

Lung cancer patients between 2011 and 2021 were identified based on reimbursement-associated ICD-10 codes, histology codes and time patterns. Multiple query architectures were tested for sensitivity and compared to official estimates of the Hungarian National Cancer Registry (HNCR). Epidemiological trends were estimated by Poisson-regression, corrected for age and sex.

Results

A total of 89,948 lung cancer patients diagnosed in Hungary between 2011 and 2021 have been identified by our study. In 2019 alone, 7,887 patients were diagnosed according to our optimized query. ESP2013 standardized rate was estimated between 92.5/100,000 (2011) and 78.4/100,000 (2019). In 2019, standardized incidence was 106.8/100,000 for men and 59.7/100,000 for women. Up until the COVID-19 pandemic, lung cancer incidence was decreasing by 3.18% (2.1%-4.3%) yearly in men, while there was no significant decrease in women. Young age groups (40-49 and 50-59) featured the largest improvement, but women aged 60-79 are at an increasing risk for developing lung cancer. The COVID-19 pandemic resulted in a statistically significant decrease in lung cancer incidence, especially in the 50-59 age group (both sexes).

Conclusion

Our results show that using an optimized approach, re-analysis of reimbursement claims yields robust estimates of lung cancer incidence. According to this approach, the incidence rate of male lung cancer is declining in Hungary, in concordance with the trend observed for lung cancer mortality. Among women aged 60-79, the incidence of lung cancer has risen, requiring more attention in the near future.

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.

Lung Cancer Screening in Asia: An Expert Consensus Report

INTRODUCTION

The incidence and mortality of lung cancer are highest in Asia compared with Europe and USA, with the incidence and mortality rates being 34.4 and 28.1 per 100,000 respectively in East Asia. Diagnosing lung cancer at early stages makes the disease amenable to curative treatment and reduces mortality. In some areas in Asia, limited availability of robust diagnostic tools and treatment modalities, along with variations in specific health care investment and policies, make it necessary to have a more specific approach for screening, early detection, diagnosis, and treatment of patients with lung cancer in Asia compared with the West.

METHOD

A group of 19 advisors across different specialties from 11 Asian countries, met on a virtual Steering Committee meeting, to discuss and recommend the most affordable and accessible lung cancer screening modalities and their implementation, for the Asian population.

RESULTS

Significant risk factors identified for lung cancer in smokers in Asia include age 50 to 75 years and smoking history of more than or equal to 20 pack-years. Family history is the most common risk factor for nonsmokers. Low-dose computed tomography screening is recommended once a year for patients with screening-detected abnormality and persistent exposure to risk factors. However, for high-risk heavy smokers and nonsmokers with risk factors, reassessment scans are recommended at an initial interval of 6 to 12 months with subsequent lengthening of reassessment intervals, and it should be stopped in patients more than 80 years of age or are unable or unwilling to undergo curative treatment.

CONCLUSIONS

Asian countries face several challenges in implementing low-dose computed tomography screening, such as economic limitations, lack of efforts for early detection, and lack of specific government programs. Various strategies are suggested to overcome these challenges in Asia.

Let-7a Downregulation Accompanied by KRAS Mutation Is Predictive of Lung Cancer Onset in Cigarette Smoke-Exposed Mice

BACKGROUND

Let-7 is a tumor suppressor microRNA targeting the KRAS lung oncogene. Let-7a downregulation is reversible during the early stages of lung carcinogenesis but is irreversible in cancer cells. The aim of this study is to shed light on the relationship between oncogene (KRAS) mutation and let-7a downregulation in cigarette smoke (CS)-induced lung carcinogenesis.

METHODS

A total of 184 strain H Swiss albino mice were either unexposed (control) or exposed to CS for 2 weeks (short CS) or 8 months (long CS). After 8 months, the lungs were individually collected. The following end points have been evaluated: (a) DNA methylation of the let-7a gene promoter by bisulphite-PCR and pyrosequencing; (b) let-7a expression by qPCR; (c) KRAS mutation by DNA pyrosequencing; (d) cancer incidence by histopathological examination.

RESULTS

let-7a expression decreased by 8.3% in the mice exposed to CS for two weeks (CS short) and by 33.4% (p ≤ 0.01) in the mice exposed to CS for 8 months (CS long). No significant difference was detected in the rate of let-7a-promoter methylation between the Sham-exposed mice (55.1%) and the CS short-(53%) or CS long (51%)-exposed mice. The percentage of G/T transversions in KRAS codons 12 and 13 increased from 2.3% (Sham) to 6.4% in CS short- and to 11.5% in CS long-exposed mice. Cancer incidence increased significantly in the CS long-exposed mice (11%) as compared to both the Sham (4%) and the CS short-exposed (2%) mice. In the CS long-exposed mice, the correlation between let-7a expression and the number of KRAS mutations was positive (R = +0.5506) in the cancer-free mice and negative (R = -0.5568) in the cancer-bearing mice.

CONCLUSIONS

The effects of CS-induced mutations in KRAS are neutralized by the high expression of let-7a in cancer-free mice (positive correlation) but not in cancer-bearing mice where an irreversible let-7a downregulation occurs (negative correlation). This result provides evidence that both genetic (high load of KRAS mutation) and epigenetic alterations (let-7a irreversible downregulation) are required to produce lung cancer in CS-exposed organisms.

Case Report: Lung adenocarcinoma associated with germline ERCC2 frameshift mutation

Family history is an established risk factor for lung cancer. Previous studies have found that germline genetic alterations, such as those in EGFR, BRCA1, BRCA2, CHEK2, CDKN2A, HER2, MET, NBN, PARK2, RET, TERT, TP53, and YAP1, are associated with an increased risk of developing lung cancer. The study reports the first of a lung adenocarcinoma proband with germline ERCC2 frameshift mutation c.1849dup (p. A617Gfs*32). Her family cancer history review demonstrated that her two healthy sisters, a brother with lung cancer, and three healthy cousins were positive for ERCC2 frameshift mutation, which might contribute to increased cancer risk. Our study highlights the necessity of performing comprehensive genomic profiling in discovering rare genetic alterations, early cancer screening, and monitoring for patients with family cancer history.

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

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

A Primary Lung and Breast Cancer Patient with Germline EGFR R776H Mutation: A Case Report and Literature Review

For advanced non-small cell lung cancer (NSCLC) patients with common epidermal growth factor receptor (EGFR) mutations (exon 19 deletions or the exon 21 L858R mutation), tyrosine kinase inhibitors (TKIs) are the standard therapies. However, EGFR germline mutations are extremely rare in lung cancer, and the effective therapy is unclear. This study reports a patient with primary breast and lung cancer carried rare germline EGFR R776H and somatic L861Q mutation, who benefit from EGFR TKIs. Her family cancer history review demonstrated that her three out of four sisters with lung cancer were positive for EGFR R776H. Interestingly, only her healthy sister had type O blood, different from other sisters with type B blood. Our study provides a meaningful insight into the potential treatment option for patients with germline EGFR R776H and somatic L861Q mutation and highlights the importance of next-generation sequencing (NGS) in discovering rare genetic alterations to guide the prevention of genetic disease.

Lung Cancer Risk Prediction Nomogram in Nonsmoking Chinese Women: Retrospective Cross-sectional Cohort Study

BACKGROUND

It is believed that smoking is not the cause of approximately 53% of lung cancers diagnosed in women globally.

OBJECTIVE

The study aimed to develop and validate a simple and noninvasive model that could assess and stratify lung cancer risk in nonsmoking Chinese women.

METHODS

Based on the population-based Cancer Screening Program in Urban China, this retrospective, cross-sectional cohort study was carried out with a vast population base and an immense number of participants. The training set and the validation set were both constructed using a random distribution of the data. Following the identification of associated risk factors by multivariable Cox regression analysis, a predictive nomogram was developed. Discrimination (area under the curve) and calibration were further performed to assess the validation of risk prediction nomogram in the training set, which was then validated in the validation set.

RESULTS

In sum, 151,834 individuals signed up to take part in the survey. Both the training set (n=75,917) and the validation set (n=75,917) were comprised of randomly selected participants. Potential predictors for lung cancer included age, history of chronic respiratory disease, first-degree family history of lung cancer, menopause, and history of benign breast disease. We displayed 1-year, 3-year, and 5-year lung cancer risk-predicting nomograms using these 5 factors. In the training set, the 1-year, 3-year, and 5-year lung cancer risk areas under the curve were 0.762, 0.718, and 0.703, respectively. In the validation set, the model showed a moderate predictive discrimination.

CONCLUSIONS

We designed and validated a simple and noninvasive lung cancer risk model for nonsmoking women. This model can be applied to identify and triage people at high risk for developing lung cancers among nonsmoking women.

Special issue "The advance of solid tumor research in China": Participants with a family history of cancer have a higher participation rate in low-dose computed tomography for lung cancer screening

We aimed to determine participation in low-dose computed tomography (LDCT) of individuals with a family history of common cancers in a population-based screening program to provide timely evidence in high-risk populations in China. The analysis was conducted using data from the Cancer Screening Program in Urban China (CanSPUC), which recruited 282 377 participants aged 40 to 74 years from eight cities in the Henan province. Using the CanSPUC risk score system, 55 428 participants were evaluated to have high risk for lung cancer and were recommended for LDCT. We calculated the overall and group-specific participation rates using family history of common cancers and compared differences in participation rates between different groups. Odds ratios (ORs) and 95% confidence intervals were derived by multivariable logistic regression. Of the 55 428 participants, 22 260 underwent LDCT (participation rate, 40.16%). Family history of lung, esophageal, stomach, liver and colorectal cancer was associated with increased participation in LDCT screening. The odds of participants with a family history of one, two, three and four or more cancer cases undergoing LDCT screening were 1.9, 2.7, 2.8 and 3.5 times, respectively, than those without a family history of cancer. Compared to those without a history of cancer, participation in LDCT gradually increased as the number of cancer cases in the family increased (P < .001). Our findings suggest that there is room for improvement in lung cancer screening given the relatively low participation rate. Lung cancer screening in populations with a family history of cancer may improve efficiency and cost-effectiveness; however, this requires further verification.

Are calcium channel blockers related to lung cancer?

Background:

Calcium channel blocker (CCB) is a common antihypertensive agent for the treatment of hypertension. There are inconsistent data of an association of CCB and lung cancer in the literature. This study aimed to evaluate this association by a case-control design.

Methods:

The inclusion criteria were adult patients 18 years or over, diagnosed with hypertension, lung cancer or pulmonary tuberculosis, and presenting with one of the suggestive symptoms of lung cancer. Those who were pregnant or had a diagnosis of lung cancer or pulmonary tuberculosis prior to the diagnosis of hypertension were excluded. Diagnosis of lung cancer was made pathologically, while tuberculosis was made by positive acid-fast bacilli on sputum examination, sputum culture positive for Mycobacterium tuberculosis, or polymerase chain reaction positive for M. tuberculosis with a chest x-ray compatible with tuberculosis. Cases were those diagnosed with lung cancer, while controls were those diagnosed with tuberculosis. Factors associated with lung cancer were calculated by logistic regression analysis.

Results:

There were 178 patients who met the study criteria. Of those, 69 patients (38.8%) were in the case group. The lung cancer group had EGFR gene mutation in 21 patients (52.5%) and adenocarcinoma was the most common cell type of lung cancer (55 patients; 79.7%). There were two factors independently associated with lung cancer including dyslipidemia and family history of lung cancer.

Conclusions:

CCB was not associated with lung cancer in patients with hypertension but dyslipidemia and family history of lung cancer were independently associated with lung cancer in this setting.

Etiology of lung cancer: Evidence from epidemiologic studies

Lung cancer is one of the leading causes of cancer incidence and mortality worldwide. While smoking, radon, air pollution, as well as occupational exposure to asbestos, diesel fumes, arsenic, beryllium, cadmium, chromium, nickel, and silica are well-established risk factors, many lung cancer cases cannot be explained by these known risk factors. Over the last two decades the incidence of adenocarcinoma has risen, and it now surpasses squamous cell carcinoma as the most common histologic subtype. This increase warrants new efforts to identify additional risk factors for specific lung cancer subtypes as well as a comprehensive review of current evidence from epidemiologic studies to inform future studies. Given the myriad exposures individuals experience in real-world settings, it is essential to investigate mixture effects from complex exposures and gene-environment interactions in relation to lung cancer and its subtypes.

Recent advances in small cell lung cancer: the future is now?

Small cell lung cancer is a relevant clinical issue as it is a highly malignant cancer, often diagnosed in advanced stage. Similarly to non-small cell lung cancer, tobacco smoking is currently the main risk factor. Its incidence, at least in males, has declined over the past decades, due to the worldwide decreased percentage of active smokers. The typical small cells of this tumor type are characterized by a high Proliferation Index, chromosomal deletions such as 3p(14-23) involving the tumor-suppressor gene FHIT, alterations of the MYC or Notch family proteins and the frequent expression of neuroendocrine markers. The combination of thoracic radiotherapy and chemotherapy is the standard treatment for limited stage disease, while platinum-based chemotherapy is the most effective choice for extensive stage disease. Unfortunately, whatever chemotherapy is used, the results are disappointing. No regimen has proved to be effective in the long run, indeed small cell lung cancer rapidly progresses after a frequent initial strong response, and the mortality rate remains still high. The advent of immunotherapy is actually changing the landscape in oncology. As well as in other cancers, recent trials have demonstrated the efficacy of the combination of immune checkpoint inhibitors and chemotherapy, opening new perspectives for the future of our patients.

Risk factors for the development of lung cancer among never smokers: A systematic review

This review aimed to summarize the up-to-date evidence on non-genetic factors for the development of never smoking lung cancer (NSLC) and to explore reasons behind the conflicting results. Relevant literature was searched in three electronic databases (PubMed, Embase and Web of Science) from 1 January 2000-31 July 2022. Cohort studies that investigated non-genetic risk factors for primary lung cancer in never smokers were included. The effect of non-genetic factors about NSLC were summarized with pooled relative risk (RR) and 95 % confidence intervals (CIs) through meta-analysis or narrative description when unexplained statistical heterogeneity was observed. The Newcastle-Ottawa Scale was used to appraise the methodological quality of included studies. Sixty cohort studies were included, covering population from Asia, Europe and America. Most included studies (42, 70.0 %) were of high methodological quality. Over 50 years old (RR = 5.26), environmental tobacco smoke (Pooled RR = 1.30), Chronic obstructive pulmonary disease (COPD) (RR = 2.67), family history of lung cancer (Pooled RR = 1.83) and higher level of neutrophil-lymphocyte ratio (RR = 1.73) increased the risk of NSLC. Dairy foods consumption (RR = 0.79), isoflavone intake (Pooled RR = 0.65), and riboflavin intake (RR = 0.62) decreased the risk among female population. Inconsistency or unclear definition for never smokers and risk factors could be observed in included studies. Most life behavior factors associated with NSLC can be modified through lifestyle changes. Future cohort studies are suggested to adopt a clearer definition on never smokers and exposure, conducting subgroup analysis when evidence indicating there is heterogeneity between genders, and explore dose-response relationship between the identified factors and NSLC.

Risk Factors for Lung Cancer in the Province of Lecce: Results from the PROTOS Case–Control Study in Salento (Southern Italy)

In the province of Lecce (southern Italy), a higher incidence of lung cancer (LC) among men compared to regional and national data was reported. In a sub-area in the center of the province (cluster area), the incidence and mortality for LC was even higher. PROTOS is a case–control study aimed at investigating possible risk factors for LC in the province area. A total of 442 patients with LC and 1326 controls matched by sex and age living in the province of Lecce for at least 10 years were enrolled and georeferenced; they filled in a questionnaire with their personal information and exposures. For each risk factor, an Odds Ratio adjusted for all the other variables was calculated. The risk of LC increased with excessive use of alcohol in women, for those subjects with a family cancer history, for each increase in pack/year of cigarettes, for men more exposed considering the industrial district in the cluster area, and for those using pesticides in agriculture without wearing personal protective equipment. The higher incidence of adenocarcinoma in both sexes suggests that, in addition to cigarette smoking, concurrent exposures to other environmental, occupational, and life-style factors may play a role in increased cancer risk and should be more deeply explored.

Euphorbiasteroid Abrogates EGFR and Wnt/β-Catenin Signaling in Non-Small-Cell Lung Cancer Cells to Impart Anticancer Activity

EGFR and Wnt/β-catenin signaling pathways play a prominent role in tumor progression in various human cancers including non-small-cell lung carcinoma (NSCLC). Transactivation and crosstalk between the EGFR and Wnt/β-catenin pathways may contribute to the aggressiveness of cancers. Targeting these oncogenic pathways with small molecules is an attractive approach to counteract various types of cancers. In this study, we demonstrate the effect of euphorbiasteroid (EPBS) on the EGFR and Wnt/β-catenin pathways in NSCLC cells. EPBS induced preferential cytotoxicity toward A549 (wildtype EGFR-expressing) cells over PC-9 (mutant EGFR-expressing) cells. EPBS suppressed the expression of EGFR, Wnt3a, β-catenin, and FZD-1, and the reduction in β-catenin levels was found to be mediated through the activation of GSK-3β. EPBS reduced the phosphorylation of GSK-3β^S9 with a parallel increase in β-TrCP and phosphorylation of GSK-3β^Y216. Lithium chloride treatment increased the phosphorylation of GSK-3β^S9 and nuclear localization of β-catenin, whereas EPBS reverted these effects. Forced expression or depletion of EGFR in NSCLC cells increased or decreased the levels of Wnt3a, β-catenin, and FZD-1, respectively. Overall, EPBS abrogates EGFR and Wnt/β-catenin pathways to impart its anticancer activity in NSCLC cells.

Construction and Validation of a Lung Cancer Risk Prediction Model for Non-Smokers in China

Background

About 15% of lung cancers in men and 53% in women are not attributable to smoking worldwide. The aim was to develop and validate a simple and non-invasive model which could assess and stratify lung cancer risk in non-smokers in China.

Methods

A large-sample size, population-based study was conducted under the framework of the Cancer Screening Program in Urban China (CanSPUC). Data on the lung cancer screening in Henan province, China, from October 2013 to October 2019 were used and randomly divided into the training and validation sets. Related risk factors were identified through multivariable Cox regression analysis, followed by establishment of risk prediction nomogram. Discrimination [area under the curve (AUC)] and calibration were further performed to assess the validation of risk prediction nomogram in the training set, and then validated by the validation set.

Results

A total of 214,764 eligible subjects were included, with a mean age of 55.19 years. Subjects were randomly divided into the training (107,382) and validation (107,382) sets. Elder age, being male, a low education level, family history of lung cancer, history of tuberculosis, and without a history of hyperlipidemia were the independent risk factors for lung cancer. Using these six variables, we plotted 1-year, 3-year, and 5-year lung cancer risk prediction nomogram. The AUC was 0.753, 0.752, and 0.755 for the 1-, 3- and 5-year lung cancer risk in the training set, respectively. In the validation set, the model showed a moderate predictive discrimination, with the AUC was 0.668, 0.678, and 0.685 for the 1-, 3- and 5-year lung cancer risk.

Conclusions

We developed and validated a simple and non-invasive lung cancer risk model in non-smokers. This model can be applied to identify and triage patients at high risk for developing lung cancers in non-smokers.

Association between family history and lung cancer risk among Chinese women in Singapore

Risk factors of lung cancer unrelated to smoking are not well-studied, especially among women. Family history has been shown to play a role in predisposing individuals to lung cancer, but this relationship has not been investigated in the Southeast Asian population. A total of 1159 women were recruited in a case-control study conducted in public hospitals in Singapore from 2005 to 2008. After excluding participants with incomplete family history information, 374 cases and 785 controls remained in the final analysis. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated using logistic regression, adjusting for potential confounders. Overall, family history of lung cancer was associated with a higher risk for lung cancer (aOR 2.08, 95% CI 1.25-3.47). When stratified by smoking status, a significant association was observed among never-smokers (aOR 2.78, 95% CI 1.57-4.90). Further stratification by fruit consumption identified a significant association between family history of lung cancer and higher risk of lung cancer among never-smokers who had low fruit consumption (aOR 3.09, 95% CI 1.37-7.01). Our findings suggest that family history of lung cancer is a significant risk factor for lung cancer in Singaporean Chinese women, especially among never-smokers.

Lung cancer risk in never-smokers: An overview of environmental and genetic factors

Lung cancer is the leading cause of cancer-related mortality globally, accounting for 1.8 million deaths in 2020. While the vast majority are caused by tobacco smoking, 15%-25% of all lung cancer cases occur in lifelong never-smokers. The International Agency for Research on Cancer (IARC) has classified multiple agents with sufficient evidence for lung carcinogenesis in humans, which include tobacco smoking, as well as several environmental exposures such as radon, second-hand tobacco smoke, outdoor air pollution, household combustion of coal and several occupational hazards. However, the IARC evaluation had not been stratified based on smoking status, and notably lung cancer in never-smokers (LCINS) has different epidemiological, clinicopathologic and molecular characteristics from lung cancer in ever-smokers. Among several risk factors proposed for the development of LCINS, environmental factors have the most available evidence for their association with LCINS and their roles cannot be overemphasized. Additionally, while initial genetic studies largely focused on lung cancer as a whole, recent studies have also identified genetic risk factors for LCINS. This article presents an overview of several environmental factors associated with LCINS, and some of the emerging evidence for genetic factors associated with LCINS. An increased understanding of the risk factors associated with LCINS not only helps to evaluate a never-smoker's personal risk for lung cancer, but also has important public health implications for the prevention and early detection of the disease. Conclusive evidence on causal associations could inform longer-term policy reform in a range of areas including occupational health and safety, urban design, energy use and particle emissions, and the importance of considering the impacts of second-hand smoke in tobacco control policy.

Combined effects of lung disease history, environmental exposures, and family history of lung cancer to susceptibility of lung cancer in Chinese non-smokers

Background

Although cigarette smoking is a major risk factor for lung cancer, the incidence rate of lung cancer among non-smokers is notable. The etiology and potential mechanism of non-smoker lung cancer are worthy of further research. This study was designed to explore the collective effects of environmental factors and the relationship between environmental exposure index (EEI) and lung cancer among non-smokers by evaluating the joint effects among lung disease history, environmental factors, and family history of lung cancer without smoking confounders.

Methods

A total of 767 never-smoked lung cancer cases and 767 sex- and age-matched controls were selected from the department of Thoracic Surgery and Respiratory Medicine of three hospitals in Fujian, China. We used two methods to develop the EEI according to 12 statistically significant environmental risk factors. Restricted cubic spline (RCS) was applied to analyze the non-linear relationship between EEI and lung cancer in non-smokers. Combined effects, additive interaction, and multiplicative interaction were assessed among lung disease history, EEI, and family history of lung cancer to estimate susceptibility to develop lung cancer.

Results

Lung disease history, especially asthma, was significantly associated with an increased risk of lung cancer with an odds ratio (OR) for asthma history of 14.720 (95% CI: 1.877–115.449). Family history of lung cancer was related to susceptibility of lung cancer (OR = 3.347, 95% CI: 1.930–5.806). According to type of relatives and cancer, a parental or children’s history and a sibling’s history of lung cancer were significantly associated with an increased risk of lung cancer. The positive association between EEI and lung cancer was apparently stronger in those with lung disease history or family lung cancer history. Furthermore, there was a addictive interaction between EEI and lung disease history, and a possibly addictive interaction between EEI and family lung cancer history on development of lung cancer.

Conclusions

There were combined effects among lung disease history, environmental exposures, and family history of lung cancer toward susceptibility to lung cancer in Chinese non-smokers. Non-smokers who had a family history of lung cancer were at higher risk of lung cancer than non-smokers who had lung disease history. Non-smokers with family cancer history may obtain benefits from removal of environmental exposures and active treatment of lung disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01802-z.

Association between long-term exposure to high levels of ambient air pollution and incidence of lung cancer in a population-based cohort

Although outdoor air pollution including particulate matter (PM) was classified as carcinogenic to humans based on accumulating epidemiological evidence, these findings were suggested mostly from low-dose environments in North America and Europe. We aimed to examine the association of long-term exposure to PM ≤ 10 and 2.5 μm in diameter (PM₁₀ and PM_2.5) and nitrogen dioxide (NO₂) with lung cancer incidence using a population-based cohort in the Seoul Metropolitan Area (SMA), South Korea. Our study included 83,478 people residing in the SMA and followed up for 2007-2015 from the National Health Insurance Service-National Sample Cohort. This cohort was constructed based on the National Health Insurance database that contains sociodemographic and medical information under universal health coverage. Individual long-term concentrations of PM₁₀, PM_2.5, and NO₂ were estimated at people's district-level and annually-updated residential addresses for the previous 5 years by using previously-validated prediction models. We applied a time-dependent Cox proportional hazards model and estimated hazard ratios (HRs) per 10 μg/m³ and 10 ppb increases in PM and NO₂, respectively, after adjusting for individual characteristics. During 9 years of follow-up, 489 lung cancer new cases occurred (714,012 person-year). The adjusted HRs for PM₁₀ were greater than 1 but statistically non-significant (HR = 1.15; 95% CI = 0.88-1.52). We also did not find associations for PM_2.5 and NO₂. Despite null associations for the total population, our subgroup analysis suggested associations with PM in family members with cancer (PM₁₀: HR = 2.59, 95% CI = 1.26-5.32; PM_2.5: 5.55, 1.09-27.91) and in those who have smoked more than 1 pack per day (1.77, 0.96-3.25; 3.81, 1.00-14.44) or for less than 20 years (2.81; 1.13-7.07; 2.02, 0.21-19.23). Our study based on a highly urbanized population exposed to relatively high air pollution provides no evidence of the association between PM and lung cancer incidence in the total population but indicates the potential susceptibility in heavy smokers for relatively short periods and family members of cancer patients. Future studies should re-examine the association using improved exposure assessment and extended population.

Epidemiology of lung cancer

Lung cancer is the leading cause of global cancer incidence and mortality, accounting for an estimated 2 million diagnoses and 1.8 million deaths. Neoplasms of the lungs are the second most common cancer diagnosis in men and women (after prostate and breast cancer, respectively). With increasing access to tobacco and industrialization in developing nations, lung cancer incidence is rising globally. The average age of diagnosis is 70 years old. Men are twice as likely to be diagnosed with lung cancer, which largely reflects differences in tobacco consumption, although women may be more susceptible due to higher proportions of epidermal growth factor receptor mutations and the effects of oestrogen. African American men in the US are at the highest risk of lung cancer. Family history increases risk by 1.7-fold, with a greater risk among first-degree relatives. Tobacco smoking is the greatest preventable cause of death worldwide, accounting for up to 90% of lung cancer cases, and continued consumption is projected to increase global cancer incidence, particularly in developing nations such as China, Russia, and India. Second-hand smoke among children and spouses has likewise been implicated. Radon from natural underground uranium decay is the second leading cause of lung cancer in the developed world. Occupational hazards such as asbestos and environmental exposures such as air pollution, arsenic, and HIV and Tb infection have all been implicated in lung carcinogenesis, while cannabis smoking, electronic cigarettes, heated tobacco products, and COVID-19 have been hypothesized to increase risk.

Evaluation of a Low-Dose Computed Tomography Lung Cancer Screening Program in Henan, China

IMPORTANCE

Lung cancer screening has been widely implemented in Europe and the US. However, there is little evidence on participation and diagnostic yields in population-based lung cancer screening in China.

OBJECTIVE

To assess the participation rate and detection rate of lung cancer in a population-based screening program and the factors associated with participation.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used data from the Cancer Screening Program in Urban China from October 2013 to October 2019, with follow-up until March 10, 2020. The program is conducted at centers in 8 cities in Henan Province, China. Eligible participants were aged 40 to 74 and were evaluated for a high risk for lung cancer using an established risk score system.

MAIN OUTCOMES AND MEASURES

Overall and group-specific participation rates by common factors, such as age, sex, and educational level, were calculated. Differences in participation rates between those groups were compared. The diagnostic yield of both screening and nonscreening groups was calculated.

RESULTS

The study recruited 282 377 eligible participants and included 55 428 with high risk for lung cancer; the mean (SD) age was 55.3 (8.1) years, and 34 966 participants (63.1%) were men. A total of 22 260 participants underwent LDCT (participation rate, 40.16%; 95% CI, 39.82%-40.50%). The multivariable logistic regression model showed that female sex (odds ratio [OR], 1.64; 95% CI, 1.52-1.78), former smoking (OR, 1.26; 95% CI, 1.13-1.41), lack of physical activity (OR, 1.19; 95% CI, 1.14-1.24), family history of lung cancer (OR, 1.73; 95% CI, 1.66-1.79), and 7 other factors were associated with increased participation of LDCT screening. Overall, at 6-year follow-up, 78 participants in the screening group (0.35%; 95% CI, 0.29%-0.42%) and 125 in the nonscreening group (0.38%; 95% CI, 0.33%-0.44%) had lung cancer detected, which resulted in an odds ratio of 0.93 (95% CI, 0.70-1.23; P = .61).

CONCLUSIONS AND RELEVANCE

The low participations rate in the program studied suggests that an improved strategy is needed. These findings may provide useful information for designing effective population-based lung cancer screening strategies in the future.

The contribution of hereditary cancer-related germline mutations to lung cancer susceptibility

Background

Germline variations may contribute to lung cancer susceptibility besides environmental factors. The influence of germline mutations on lung cancer susceptibility and their correlation with somatic mutations has not been systematically investigated.

Methods

In this study, germline mutations from 1,026 non-small cell lung cancer (NSCLC) patients were analyzed with a 58-gene next-generation sequencing (NGS) panel containing known hereditary cancer-related genes, and were categorized based on American College of Medical Genetics and Genomics (ACMG) guidelines in pathogenicity, and the corresponding somatic mutations were analyzed using a 605-gene NGS panel containing known cancer-related genes.

Results

Plausible genetic susceptibility was found in 4.7% of lung cancer patients, in which 14 patients with pathogenic mutations (P group) and 34 patients with likely-pathogenic mutations (LP group) were identified. The ratio of the first degree relatives with lung cancer history of the P groups was significantly higher than the Non-P group (P=0.009). The ratio of lung cancer patients with history of other cancers was higher in P (P=0.0007) or LP (P=0.017) group than the Non-P group. Pathogenic mutations fell most commonly in BRCA2, followed by CHEK2 and ATM. Likely-pathogenic mutations fell most commonly in NTRK1 and EXT2, followed by BRIP1 and PALB2. These genes are involved in DNA repair, cell cycle regulation and tumor suppression. By comparing the germline mutation frequency from this study with that from the whole population or East Asian population (gnomAD database), we found that the overall odds ratio (OR) for P or LP group was 17.93 and 15.86, respectively, when compared with the whole population, and was 2.88 and 3.80, respectively, when compared with the East Asian population, suggesting the germline mutations of the P and LP groups were risk factors for lung cancer. Somatic mutation analysis revealed no significant difference in tumor mutation burden (TMB) among the groups, although a trend of lower TMB in the pathogenic group was found. The SNV/INDEL mutation frequency of TP53 in the P group was significantly lower than the other two groups, and the copy number variation (CNV) mutation frequency of PIK3CA and MET was significantly higher than the Non-P group. Pathway enrichment analysis found no significant difference in aberrant pathways among the three groups.

Conclusions

A proportion of 4.7% of patients carrying germline variants may be potentially linked to increased susceptibility to lung cancer. Patients with pathogenic germline mutations exhibited stronger family history and higher lung cancer risk.

Lung cancer incidence and mortality in Split-Dalmatia County, 2003-2012

OBJECTIVE

The aim of the study was to analyze indicators on lung cancer (C33-C34, ICD-10) in Split-Dalmatia County in the period 2003-2012.

METHODS

Data on lung cancer occurrence for the period 2003-2012 were obtained from the Croatian National Cancer Registry, while mortality data were obtained from electronic database of the Teaching Public Health Institute of Split-Dalmatia County. Croatian census 2011 and population estimates of the Central Bureau of Statistics of the Republic of Croatia were used to calculate the indicators. Results are presented as absolute numbers, shares (%), specific rates per 100,000 population, age-standardized rate (standard European population).

RESULTS

There were 2,804 registered patients with lung cancer in the period 2003-2012 in Split-Dalmatia County - 2,179 men (77.71%) and 625 women (22.29%); 2,737 people died from lung cancer in the same period - 2,117 men (77.35%) and 620 women (22.65%). Specific rates of incidence and mortality rates were four times higher among men than among women. From 2003 to 2012, the rate of incidence among men showed a significant decrease, while among women there were no significant changes of incidence and mortality.

CONCLUSIONS

According to the indicators of incidence and mortality of lung cancer in Split-Dalmatia County, this malignant neoplasm should occupy a high place within County public health priorities measures of prevention programme, targeting risk factors responsible for their formation.

Potential genetic modifiers for somatic EGFR mutation in lung cancer: a meta-analysis and literature review

BACKGROUND

Accumulating evidence indicates inherited risk in the aetiology of lung cancer, although smoking exposure is the major attributing factor. Family history is a simple substitute for inherited susceptibility. Previous studies have shown some possible yet conflicting links between family history of cancer and EGFR mutation in lung cancer. As EGFR-mutated lung cancer favours female, never-smoker, adenocarcinoma and Asians, it may be argued that there may be some underlying genetic modifiers responsible for the pathogenesis of EGFR mutation.

METHODS

We searched four databases for all original articles on family history of malignancy and EGFR mutation status in lung cancer published up to July 2018. We performed a meta-analysis by using a random-effects model and odds ratio estimates. Heterogeneity and sensitivity were also investigated. Then we conducted a second literature research to curate case reports of familial lung cancers who studied both germline cancer predisposing genes and their somatic EGFR mutation status; and explored the possible links between cancer predisposing genes and EGFR mutation.

RESULTS

Eleven studies have been included in the meta-analysis. There is a significantly higher likelihood of EGFR mutation in lung cancer patients with family history of cancer than their counterparts without family history, preferentially in Asians (OR = 1.35[1.06-1.71], P = 0.01), those diagnosed with adenocarcinomas ((OR = 1.47[1.14-1.89], P = 0.003) and those with lung cancer-affected relatives (first and second-degree: OR = 1.53[1.18-1.99], P = 0.001; first-degree: OR = 1.76[1.36-2.28, P < 0.0001]). Familial lung cancers more likely have concurrent EGFR mutations along with mutations in their germline cancer predisposition genes including EGFR T790 M, BRCA2 and TP53. Certain mechanisms may contribute to the combination preferences between inherited mutations and somatic ones.

CONCLUSIONS

Potential genetic modifiers may contribute to somatic EGFR mutation in lung cancer, although current data is limited. Further studies on this topic are needed, which may help to unveil lung carcinogenesis pathways. However, caution is warranted in data interpretation due to limited cases available for the current study.

Clinical characteristics and survival in non-small cell lung cancer patients by smoking history: a population-based cohort study

Introduction: Approximately, 10-15% of lung cancer patients have never smoked. Previous epidemiological studies on non-tobacco associated lung cancer have been hampered by selected data from a small number of hospitals or limited numbers of patients. By use of data from large population-based registers with national coverage, this study aims to compare characteristics and survival of patients with non-small cell lung cancer (NSCLC) with different smoking histories.Methods: Swedish national population-based registers were used to retrieve data on patients diagnosed with primary NSCLC between 2002 and 2016. The Kaplan-Meier method and Cox proportional hazard models were used to estimate overall survival and lung cancer-specific survival by smoking history.Results: In total, 41,262 patients with NSCLC were included. Of those, 4624 (11%) had never smoked. Never-smokers were more often women and older compared to ever smokers (current and former). Adenocarcinoma was proportionally more common in never-smokers (77%) compared to current (52%) and former smokers (57%). Stage IV disease was more common in never-smokers (57%) than in current (48%) and former smokers (48%). Epidermal growth factor receptor mutation was observed more in never-smokers (37%) compared to current (5%) and former smokers (9%). Both lung cancer-specific and overall survival were higher for never-smokers compared to current smokers.Conclusions: The observed differences in characteristics between never-smokers and smokers, and the higher survival in never-smokers compared to smokers from this large population-based study provide further evidence that lung cancer in never-smokers is clinically different to tobacco-associated lung cancer. The findings from this study emphasise the need for an improved understanding of genetics, pathogenesis, mechanisms and progression of non-tobacco associated lung cancer that may help prevent lung cancer or identify individually targeted treatments.

Contribution of programmed cell death 6 genetic variations, gender, and smoking status to lung cancer

PURPOSE

Programmed cell death 6 (PDCD6) is a calcium sensor participating in T-cell receptor-, Fas-, and glucocorticoid-induced programmed cell death. At the sites of lung tumors, the expression of PDCD6 is higher than that in non-tumor tissues. However, the contribution of variant PDCD6 genotypes to lung cancer is largely unknown. The current study aimed to evaluate the contributions of the PDCD6 rs4957014 and rs3756712 genotypes to the risk of lung cancer.

PATIENTS AND METHODS

The contributions of PDCD6 genotypes to lung cancer risk were examined among 358 patients with lung cancer and 716 age- and gender-matched healthy controls by typical polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology.

RESULTS

The results showed that the GG but not the GT genotype of PDCD6 rs4957014 was associated with a decreased risk of lung cancer (odds ratio (OR) =0.41, 95% confidence interval (CI) =0.23-0.72, p=0.0013). The analysis of allelic frequency distributions showed that the G allele of PDCD6 rs4957014 decreased lung cancer susceptibility (p=0.0090). There was no association between PDCD6 rs3756712 genotypes and lung cancer risk. Interestingly, the GG genotype at PDCD6 rs4957014 significantly decreased the risk of lung cancer among males (adjusted OR =0.29, 95% CI =0.14-0.57) and smokers (adjusted OR =0.34, 95% CI =0.18-0.61) but not among females and non-smokers.

CONCLUSION

The GG genotype of PDCD6 rs4957014 may decrease lung cancer risk in males and smokers and may serve as a practical marker for early detection and the incidence of lung cancer in Taiwan.

Association between Family History of Cancer and Lung Cancer Risk among Japanese Men and Women

Although cigarette smoking is a major risk factor for lung cancer, genetic susceptibility may also affect lung cancer risk. To explore the role of genetic risk, this case-control study investigated the association between family history of cancer at several sites and lung cancer risk. A total of 1,733 lung cancer cases and 6,643 controls were selected from patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2009. Information on family history of cancer was collected using a self-administered questionnaire and odds ratios (ORs) were estimated by unconditional logistic regression. Family history of lung cancer in first-degree relatives was associated with an increased risk of lung cancer among both sexes. According to histology and type of relatives, a parental history of lung cancer was significantly associated with an increased risk of female adenocarcinoma (OR = 1.72). Stratification by smoking status revealed that this significant positive association in women was limited to ever-smokers (OR = 4.13). In men, a history of lung cancer in siblings was significantly associated with an increased risk of small cell carcinoma (OR = 2.28) and adenocarcinoma (OR = 2.25). Otherwise, positive associations between history of breast (OR = 1.99) and total (OR = 1.71) cancers in siblings and the risk of male adenocarcinoma were observed. These results suggest that inherited genetic susceptibility may contribute to the development of lung cancer. In men, shared exposure to environmental factors among siblings may also be responsible for the increase in lung cancer risk.

Apoptosis Induction of Agave lechuguilla Torrey Extract on Human Lung Adenocarcinoma Cells (SK-LU-1)

In this study, an ethanol extract of Agave lechuguilla was evaluated against six carcinogenic cell lines (HCT-15, MCF-7, PC-3, U-251, SK-LU-1 and K-562) with an inhibition of 75.7 ± 2.3% against the SK-LU-1 line. Based on the previous result, the extract was hydrolyzed and fractionated, to which the IC50 was determined; the cell line was more sensitive to the fractionated extract with an IC50 6.96 ± 0.15 µg/mL. Characterization by mass spectrometry showed the presence of kaempferol, quercetin and a flavonoid dimer formed by afzelechin-4β-8-quercetin, according to the generated fragmentation pattern. The fractionated extract presented cell death by apoptosis with 39.8% at 24 h. Molecular docking was performed with the molecules found to try to describe cell death by apoptosis through death receptors such as FasCD95, TNF-R1, DR4/5 and blocking signaling on the EGFR and K-Ras MAPK/ERK pathway, as well as through the intrinsic pathway activating tBID, which promotes the amplification of the apoptotic signal due to the activation of caspase-3, and consequently caspase-7. In addition to the activation of the IIb complex associated with cell death due to necroptosis.

Polymorphism rs3819102 in thymidylate synthase and environmental factors: effects on lung cancer in Chinese population

PURPOSE

Lung cancer is the leading cause of cancer death worldwide, and the predominant risk factor for its development is smoking. Thymidylate synthase (TYMS) is a key enzyme in DNA synthesis that catalyzes the conversion of deoxyuridine monophosphate to dTMP. Rs931794, a single nucleotide polymorphism located in the TYMS gene, was suggested to be associated with cancer risk.

METHODS

To analyze the interaction between rs3819102 and environmental factors on the risk of lung cancer in a Chinese population, single nucleotide polymorphismscan was used to genotype this polymorphism in 974 lung cancer cases and 1005 control subjects.

RESULTS

The frequencies of TT, CT, and CC genotypes of TYMS rs3819102 were 61.8%, 32.9%, and 5.3% in controls, and 53.8%, 38.4%, and 7.8% in cases, respectively. Compared with the TT genotype, the CT (odds ratio [OR], 1.380; 95% confidence interval [CI], 1.131-1.683), and CC (OR, 1.786; 95% CI, 1.213-2.644) genotypes were associated with an increased risk of lung cancer after adjustment for age, gender, smoking status, and family history. The C allele of rs3819102 is the risk allele for lung carcinogenesis in a dominant model (OR, 1.435; 95% CI, 1.188-1.735). In a stratified analysis, the risk effects of both the CT and CC genotypes of rs3819102 were more evident in subgroups of smokers and people without a family history of cancer.

CONCLUSION

The rs3819102 polymorphism in TYMS might increase susceptibility to environmental factors and contribute to the risk of lung cancer. The C allele is a risk allele in lung carcinogenesis.

The epidemiology of lung cancer

The incidence and mortality from lung cancer is decreasing in the US due to decades of public education and tobacco control policies, but are increasing elsewhere in the world related to the commencement of the tobacco epidemic in various countries and populations in the developing world. Individual cigarette smoking is by far the most common risk factor for lung carcinoma; other risks include passive smoke inhalation, residential radon, occupational exposures, infection and genetic susceptibility. The predominant disease burden currently falls on minority populations and socioeconomically disadvantaged people. In the US, the recent legalization of marijuana for recreational use in many states and the rapid growth of commercially available electronic nicotine delivery systems (ENDS) present challenges to public health for which little short term and no long term safety data is available.

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

Genetic susceptibility variants for lung cancer: replication study and assessment as expression quantitative trait loci

Many single nucleotide polymorphisms (SNPs) have been associated with lung cancer but lack confirmation and functional characterization. We retested the association of 56 candidate SNPs with lung adenocarcinoma risk and overall survival in a cohort of 823 Italian patients and 779 healthy controls, and assessed their function as expression quantitative trait loci (eQTLs). In the replication study, eight SNPs (rs401681, rs3019885, rs732765, rs2568494, rs16969968, rs6495309, rs11634351, and rs4105144) associated with lung adenocarcinoma risk and three (rs9557635, rs4105144, and rs735482) associated with survival. Five of these SNPs acted as cis-eQTLs, being associated with the transcription of IREB2 (rs2568494, rs16969968, rs11634351, rs6495309), PSMA4 (rs6495309) and ERCC1 (rs735482), out of 10,821 genes analyzed in lung. For these three genes, we obtained experimental evidence of differential allelic expression in lung tissue, pointing to the existence of in-cis genomic variants that regulate their transcription. These results suggest that these SNPs exert their effects on cancer risk/outcome through the modulation of mRNA levels of their target genes.

Correlation between familial cancer history and epidermal growth factor receptor mutations in Taiwanese never smokers with non-small cell lung cancer: a case-control study

BACKGROUND

Lung cancer is a leading cause of cancer deaths in the world. Cigarette smoking remains a prominent risk factor, but lung cancer incidence has been increasing in never smokers. Genetic abnormalities including epidermal growth factor receptor (EGFR) mutations predominate in never smoking lung cancer patients. Furthermore, familial aggregations of patients with these mutations reflect heritable susceptibility to lung cancer. The correlation between familial cancer history and EGFR mutations in never smokers with lung cancer requires investigation.

METHODS

This was a retrospective case-control study that evaluated the prevalence of EGFR mutations in lung cancer patients with familial cancer history. Never smokers with lung cancer treated at a hospital in Taiwan between April 2012 and May 2014 were evaluated. Inclusion criteria were never smokers with non-small cell lung cancer (NSCLC). Exclusion criteria involved patients without records of familial cancer history or tumor genotype.

RESULTS

This study included 246 never smokers with lung cancer. The study population mainly involved never smoking women with a mean age of 60 years, and the predominant tumor histology was adenocarcinoma. Lung cancer patients with familial cancer history had an increased prevalence of EGFR mutations compared to patients without family history [odds ratio (OR): 5.9; 95% confidence interval (CI): 3.3-10.6; P<0.001]. Specifically, 57 out of 85 cancer patients (67%) with familial cancer history had these mutations, while 41 out of 161 patients (25%) without family history harbored mutations. Subgroup analysis also revealed that patients with familial lung cancer history had stronger association with EGFR mutations (OR: 7.5; 95% CI: 3.4-16.3; P<0.001) compared to patients with family history of non-pulmonary cancers (OR: 5.0; 95% CI: 2.5-10.0; P<0.001).

CONCLUSIONS

The study demonstrated an increased prevalence of EGFR mutations in Taiwanese never smoking lung cancer patients with familial cancer history. Moreover, a sizable proportion of never smoking cancer patients harbored these mutations. These observations have implications for the treatment of lung cancer in never smokers.

Risk factors for head and neck cancer in young adults: a pooled analysis in the INHANCE consortium

BACKGROUND

Increasing incidence of head and neck cancer (HNC) in young adults has been reported. We aimed to compare the role of major risk factors and family history of cancer in HNC in young adults and older patients.

METHODS

We pooled data from 25 case-control studies and conducted separate analyses for adults ≤ 45 years old ('young adults', 2010 cases and 4042 controls) and >45 years old ('older adults', 17700 cases and 22 704 controls). Using logistic regression with studies treated as random effects, we estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The young group of cases had a higher proportion of oral tongue cancer (16.0% in women; 11.0% in men) and unspecified oral cavity / oropharynx cancer (16.2%; 11.1%) and a lower proportion of larynx cancer (12.1%; 16.6%) than older adult cases. The proportions of never smokers or never drinkers among female cases were higher than among male cases in both age groups. Positive associations with HNC and duration or pack-years of smoking and drinking were similar across age groups. However, the attributable fractions (AFs) for smoking and drinking were lower in young when compared with older adults (AFs for smoking in young women, older women, young men and older men, respectively, = 19.9% (95% CI=9.8%, 27.9%), 48.9% (46.6%, 50.8%), 46.2% (38.5%, 52.5%), 64.3% (62.2%, 66.4%); AFs for drinking=5.3% (-11.2%, 18.0%), 20.0% (14.5%, 25.0%), 21.5% (5.0%, 34.9%) and 50.4% (46.1%, 54.3%). A family history of early-onset cancer was associated with HNC risk in the young [OR=2.27 (95% CI=1.26, 4.10)], but not in the older adults [OR=1.10 (0.91, 1.31)]. The attributable fraction for family history of early-onset cancer was 23.2% (8.60% to 31.4%) in young compared with 2.20% (-2.41%, 5.80%) in older adults.

CONCLUSIONS

Differences in HNC aetiology according to age group may exist. The lower AF of cigarette smoking and alcohol drinking in young adults may be due to the reduced length of exposure due to the lower age. Other characteristics, such as those that are inherited, may play a more important role in HNC in young adults compared with older adults.

Joint effects of environmental exposures and familial susceptibility to lung cancer in Chinese never smoking men and women

OBJECTIVES

Previous epidemiological studies had limited power to investigate the joint effects of individual environmental risk factors and familial susceptibility to lung cancer. This study aimed to address this shortcoming.

METHODS

We recruited 345 never smoking lung cancer cases and 828 community referents. We developed a collective environmental exposure index by assigning a value of 1 to subjects at high risks regarding environmental risk factors and 0 otherwise, and then summed over using weights equivalent to the excess odds ratio. Potential additive and multiplicative interactions between environmental exposure index and family cancer history were examined.

RESULTS

Compared with "low environmental exposure and without family cancer history", the odds ratio was 6.80 (95% confidence interval = 3.31-13.98) for males who had high environmental exposures but without family cancer history, whereas it increased to 30.61 (95% confidence interval = 9.38-99.87) if they also had a positive family history. The corresponding associations became weaker in never smoking females. No multiplicative interaction was observed for both genders and an additive interaction was restricted among males.

CONCLUSIONS

This study developed a novel environmental exposure index that offers sufficient interest deserving further studies on the interactions between environmental exposures and familial susceptibility to lung cancer risk.

Identification and validation of PROM1 and CRTC2 mutations in lung cancer patients

Background

Genetic alterations could be responsible lung cancer, the leading cause of worldwide cancer death.

Methods

This study investigated gene mutations in a Han Chinese family of lung cancer using the whole genome exome sequencing and subsequent Sanger sequencing validation and then confirmed alteration of prominin 1(PROM1) and cyclic AMP-response element binding protein-regulated transcription co-activator2 (CRTC2) in blood samples of 343 sporadic lung cancer patients vs. 280 healthy controls as well as in 200 pairs of lung cancer and the corresponding normal tissues using PCR-restriction fragment length polymorphism and directed DNA sequencing of PCR products.

Results

The data showed PROM1 (p. S281R) and CRTC2 (p. R379C) mutations, in 5 and 2 cases of these 343 sporadic lung cancer patients, respectively. Notably, these mutations were absent in the healthy controls. Furthermore, in the 200 lung cancer and the matched normal tissues, PROM1 mutation occurred in 3 patients (i.e., one squamous cell carcinoma and two adenocarcinomas) with a mutation frequency of 1.5%, while CRTC2 mutation occurred in 5 patients (two squamous cell carcinomas and three adenocarcinomas) with a mutation frequency of 2.5%.

Conclusions

The data from the current study demonstrated novel PROM1 and CRTC2 mutations, which could promote lung cancer development.