Familial Lung Cancer: A Brief History from the Earliest Work to the Most Recent Studies

KIR-HLA gene diversities and susceptibility to lung cancer

Killer-cell immunoglobulin-like receptors (KIR) are essential for acquiring natural killer (NK) cell effector function, which is modulated by a balance between the net input of signals derived from inhibitory and activating receptors through engagement by human leukocyte antigen (HLA) class I ligands. KIR and HLA loci are polygenic and polymorphic and exhibit substantial variation between individuals and populations. We attempted to investigate the contribution of KIR complex and HLA class I ligands to the genetic predisposition to lung cancer in the native population of southern Iran. We genotyped 16 KIR genes for a total of 232 patients with lung cancer and 448 healthy controls (HC), among which 85 patients and 178 HCs were taken into account for evaluating combined KIR-HLA associations. KIR2DL2 and 2DS2 were increased significantly in patients than in controls, individually (OR 1.63, and OR 1.42, respectively) and in combination with HLA-C1 ligands (OR 1.99, and OR 1.93, respectively). KIR3DS1 (OR 0.67) and 2DS1 (OR 0.69) were more likely presented in controls in the absence of their relative ligands. The incidence of CxTx subset was increased in lung cancer patients (OR 1.83), and disease risk strikingly increased by more than fivefold among genotype ID19 carriers (a CxTx genotype that carries 2DL2 in the absence of 2DS2, OR 5.92). We found that genotypes with iKIRs > aKIRs (OR 1.67) were more frequently presented in lung cancer patients. Additionally, patients with lung cancer were more likely to carry the combination of CxTx/2DS2 compared to controls (OR 2.04), and iKIRs > aKIRs genotypes in the presence of 2DL2 (OR 2.05) increased the likelihood of lung cancer development. Here we report new susceptibility factors and the contribution of KIR and HLA-I encoding genes to lung cancer risk, highlighting an array of genetic effects and disease setting which regulates NK cell responsiveness. Our results suggest that inherited KIR genes and HLA-I ligands specifying the educational state of NK cells can modify lung cancer risk.

Lung cancer in never smokers: Tumor immunology and challenges for immunotherapy

Lung cancer is the second most common and the most lethal malignancy worldwide. It is estimated that lung cancer in never smokers (LCINS) accounts for 10-25% of cases, and its incidence is increasing according to recent data, although the reasons remain unclear. If considered alone, LCINS is the 7th most common cause of cancer death. These tumors occur more commonly in younger patients and females. LCINS tend to have a better prognosis, possibly due to a higher chance of bearing an actionable driver mutation, making them amenable to targeted therapy. Notwithstanding, these tumors respond poorly to immune checkpoint inhibitors (ICI). There are several putative explanations for the poor response to immunotherapy: low immunogenicity due to low tumor mutation burden and hence low MANA (mutation-associated neo-antigen) load, constitutive PD-L1 expression in response to driver mutated protein signaling, high expression of immunosuppressive factors by tumors cells (like CD39 and TGF-beta), non-permissive immune TME (tumor microenvironment), abnormal metabolism of amino acids and glucose, and impaired TLS (Tertiary Lymphoid Structures) organization. Finally, there is an increasing concern of offering ICI as first line therapy to these patients owing to several reports of severe toxicity when TKIs (tyrosine kinase inhibitors) are administered sequentially after ICI. Understanding the biology behind the immune response against these tumors is crucial to the development of better therapeutic strategies.

A Multi-Omics Study of Familial Lung Cancer: Microbiome and Host Gene Expression Patterns

Background

Inherited susceptibility and environmental carcinogens are crucial players in lung cancer etiology. The lung microbiome is getting rising attention in carcinogenesis. The present work sought to investigate the microbiome in lung cancer patients affected by familial lung cancer (FLC) and indoor air pollution (IAP); and further, to compare host gene expression patterns with their microbiome for potential links.

Methods

Tissue sample pairs (cancer and adjacent nonmalignant tissue) were used for 16S rRNA (microbiome) and RNA-seq (host gene expression). Subgroup microbiome diversities and their matched gene expression patterns were analyzed. Significantly enriched taxa were screened out, based on different clinicopathologic characteristics.

Results

Our FLC microbiome seemed to be smaller, low-diversity, and inactive to change; we noted microbiome differences in gender, age, blood type, anatomy site, histology type, TNM stage as well as IAP and smoking conditions. We also found smoking and IAP dramatically decreased specific-OTU biodiversity, especially in normal lung tissue. Intriguingly, enriched microbes were in three categories: opportunistic pathogens, probiotics, and pollutant-detoxication microbes; this third category involved Sphingomonas, Sphingopyxis, etc. which help degrade pollutants, but may also cause epithelial damage and chronic inflammation. RNA-seq highlighted IL17, Ras, MAPK, and Notch pathways, which are associated with carcinogenesis and compromised immune system.

Conclusions

The lung microbiome can play vital roles in carcinogenesis. FLC and IAP subjects were affected by fragile lung epithelium, vulnerable host-microbes equilibrium, and dysregulated immune surveillance and response. Our findings provided useful information to study the triple interplay among environmental carcinogens, population genetic background, and diversified lung microbiome.

Molecular pathogenesis of hereditary lung cancer: a literature review

Among all cancer types, pulmonary cancer has the highest mortality rate. Tobacco consumption remains the major risk factor for the development of lung cancer. However, many studies revealed a correlation between inherited genetic variants and predisposition to lung cancer, especially in nonsmokers. To date, genetic testing for the detection of germline mutations is not yet recommended in patients with lung cancer and testing is focused on somatic alterations given their implication in the treatment choice. Understanding the impact of genetic predisposition on the occurrence of lung cancer is essential to enable the introduction of accurate guidelines and recommendations that might reduce mortality. In this review paper, we describe familial lung cancer, and expose germline mutations that are linked to this type of cancer. We also report pathogenic genetic variants linked to syndromes associated with lung cancer.

Germline variation networks in the PI3K/AKT pathway corresponding to familial high-incidence lung cancer pedigrees

Background

There were scarcely germline variants of familial lung cancer (LC) identified. We conducted an study with whole-exome sequencing of pedigrees with familial lung cancer to analyze the potential genetic susceptibility.

Methods

Probands with the highest hereditary background were identified by our large-scale epidemiological study and five ones were enrolled as a learning set. The germline SNPs (single-nucleotide polymorphisms) of other five similar probands, four healthy individuals in the formerly pedigrees and three patients with sporadic LC were used as a validation set, controlled by three healthy individuals without family history of any cancer. The network of mutated genes was generated using STRING-DB and visualized using Cytoscape.

Results

Specific and shared somatic mutations and germline SNPs were not the shared cause of familial lung cancer. However, individual germline SNPs showed distinct protein-protein interaction network patterns in probands versus healthy individuals and patients with sporadic lung cancer. SNP-containing genes were enriched in the PI3K/AKT pathway. These results were validated in the validation set. Furthermore, patients with familial lung cancer were distinguished by many germline variations in the PI3K/AKT pathway by a simple SVM classification method. It is worth emphasizing that one person with many germline variations in the PI3K/AKT pathway developed lung cancer during follow-up.

Conclusions

The phenomenon that the enrichments of germline SNPs in the PI3K/AKT pathway might be a major predictor of familial susceptibility to lung cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07528-3.

COPD-dependent effects of genetic variation in key inflammation pathway genes on lung cancer risk

Genome-wide association studies (GWAS) have identified several loci contributing to lung cancer and COPD risk independently; however, inflammation-related pathways likely harbor additional lung cancer risk-associated variants in biologically relevant immune genes that differ dependent on COPD. We selected single nucleotide polymorphisms (SNPs) proximal to 2,069 genes within 48 immune pathways. We modeled the contribution of these variants to lung cancer risk in a discovery sample of 1,932 lung cancer cases and controls stratified by COPD status and validation sample of 953 cases and controls also stratified by COPD. There were 43 validated SNPs in those with COPD and 60 SNPs in those without COPD associated with lung cancer risk. Furthermore, 29 of 43 and 28 of 60 SNPs demonstrated a statistically significant interaction with COPD in the pooled sample. These variants demonstrated tissue-dependent effects on proximal gene expression, enhanced network connectivity and resided together in specific immune pathways. These results reveal that key inflammatory related genes and pathways, not found in prior GWAS, impact lung cancer risk in a COPD-dependent manner. Genetic variation identified in our study supplements prior lung cancer GWAS and serves as a foundation to further interrogate risk relationships in smoking and COPD populations.

Inherited lung cancer: a review

Lung cancer is the most common cancer worldwide and has high rates of mortality. The major risk factor associated with this disease is tobacco smoke, but approximately 10%-25% of all lung cancer cases occur in patients who have never smoked. Data suggest that lung cancer in never-smokers has a different molecular profile, tumour microenvironment and epidemiology than that in smokers. Several risk factors have been associated with its occurrence, and the possibility of inherited predisposition is becoming clearer. A better understanding of this disease is essential for the future development of personalised screening, diagnosis and treatment approaches, with consequent reduction of mortality. In this review, we discuss historical studies of lung cancer in never-smokers and the currently available evidence of inherited predisposition to this disease.

MUC16 in non-small cell lung cancer patients affected by familial lung cancer and indoor air pollution: clinical characteristics and cell behaviors

Background

Inherited susceptibility and environmental carcinogens are crucial players in lung cancer etiology, and both exhibit population heterogeneity. MUC16 is overexpressed in various cancers and often associated with poor prognosis. Present work was to investigate the clinical significance of MUC16 in non-small cell lung cancer patients affected by familial lung cancer (FLC) and indoor air pollution caused by coal use.

Methods

Clinicopathologic characteristics and MUC16 expression were analyzed and evaluated in our subject population. Vectors were constructed for MUC16 gene knockout and overexpression, then we examined how MUC16 affected lung cancer cell behaviors, including proliferation, migration, invasion and chemoresistance.

Results

FLC showed significant association with early-onset (P<0.01) and later stage (P<0.01). Indoor air pollution was associated with younger age (P<0.01), later stage (P<0.05) and AD histology type (P<0.05). Interestingly, two age peaks were observed in our FLC and sporadic group respectively, possibly suggesting multiple major contributors to lung cancer in our subject population. MUC16 overexpression was significantly associated with FLC (P<0.05), indoor air pollution (P<0.01) and later stage (P<0.01), additionally more metastasis cases were observed in patients with up-regulated MUC16 (18.1% vs. 10.3%). Taken together, elevated MUC16 may potentially be one molecular character of FLC in local residents. Intriguingly, patients with more MUC16 up-regulation seemed to have a lower number of white blood cells, especially neutrophils, this reflected MUC16's role in immune regulation. In cell behavior experiments, high MUC16 level could contribute to lung cancer cell proliferation, migration, invasion and chemoresistance, but there were variations among cell lines.

Conclusions

MUC16 plays crucial roles in lung cancer pathogenesis, progression and chemoresistance. Interestingly, its association with FLC and indoor air pollution highlights the complexity of lung cancer etiology. Our findings provide useful information to study the intricate interaction between environmental carcinogens and population genetic background.

Lung cancer and family-centered concerns

BACKGROUND

Genetic and environmental interactions predispose certain groups to lung cancer, including families. Families or caregiving units experience the disease interdependently. We have previously evaluated the concerns and preferences of patients in addressing the lung cancer experience and cancer risks in their families. This qualitative study evaluates the concerns and preferences of family members and caregivers of patients with lung cancer in the lung cancer experience and familial cancer risks.

METHODS

We held focus groups to discuss the format and timing of addressing these preferences and concerns. Qualitative data generated was analyzed using a grounded theory approach.

RESULTS

Five focus groups totaling 19 participants were conducted. Seven themes were identified: (1) journey to lung cancer diagnosis has core dimensions for patient and family, (2) importance of communication between patients, families, and providers, (3) challenges for caregivers and family, (4) mixed perceptions of lung cancer causation among relatives, (5) discussion of cancer risk with relatives has complex dynamics, (6) impact of diagnosis on family health behaviors and screening, (7) role of genetic counseling.

CONCLUSIONS

Family members of patients with lung cancer are interested in discussing risk factors, prevention, and diagnoses and also would like access to other supportive services do learn about and cope with some of the stresses and barriers they experience in the family lung cancer journey. The diagnosis represents a potential teachable moment with the opportunity to reduce the risk of LC development or improve early detection in LC patient's family members.

Lung cancer family history and exposure to occupational/domestic coal combustion contribute to variations in clinicopathologic features and gene fusion patterns in non-small cell lung cancer

BACKGROUND

Both genetic and environmental factors contribute to the development of cancer and its mutant spectrum. Lung cancer has familial aggregation. Lung cancer caused by non-tobacco factors has unique pathological and molecular characteristics. The interaction between genetic lung cancer susceptibility and carcinogens from coal burning remains complex and understudied.

METHODS

We selected 410 non-small cell lung cancer (NSCLC) patients with a family history of lung cancer (FLC) and exposure to coal combustion between 2014 and 2017. Clinicopathologic parameters were analyzed. Reverse transcription-PCR was performed to detect ALK, ROS1, RET, and NTRK1 rearrangement.

RESULTS

Among the 410 NSCLC patients, 192 had FLC and 204 (49.8%) were exposed to occupational or domestic coal combustion. FLC patients had the same characteristics regardless of gender and coal exposure: younger age, high female ratio, adenocarcinoma, increased metastasis, later stage at diagnosis, and higher frequency of gene fusion. Sixty-seven patients (16.3%) had gene rearrangement: 51 (12.4%) harbored EML4-ALK fusions and 16 ROS1 fusions (3.9%). The highest gene fusion rate (35.1%, 33/94) occurred in patients with both FLC and high tobacco and coal exposure. ALK fusions and total gene rearrangement were closely associated with women, never smokers, younger age, FLC, and coal exposure.

CONCLUSION

FLC and exposure to coal combustion have an important impact on the clinicopathological characteristics and gene fusion mode of NSCLC, particularly in cases of higher levels of carcinogens, and genetic susceptibility has a greater impact. Our findings may help evaluate the effect of FLC and coal exposure on the pathogenesis of lung cancer.

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.

Characteristics of Familial Lung Cancer in Yunnan-Guizhou Plateau of China

Background: Lung cancer has inherited susceptibility and show familial aggregation, the characteristics of familial lung cancer exhibit population heterogeneity. Despite previous studies, familial lung cancer in China's Yunnan-Guizhou plateau remains understudied. Methods: Between 2015 and 2017, 1,023 lung cancer patients (residents of Yunnan-Guizhou plateau) were enrolled with no limitation on other parameters, 152 subjects had familial lung cancer. Clinicopathologic parameters were analyzed and compared, 4,754 lung cancer patients from NCI-GDC were used to represent a general population. Results: Familial lung cancer (FLC) subjects showed unique characters: early-onset; increased rate of female, adenocarcinoma, stage IV and other cancer history; unbalance in anatomic sites; all ruling out significant difference in smoking status. Unbalanced distribution of co-existing diseases or symptoms was also discovered. FLC patients were more likely to develop benign lesions (polyps, nodules, cysts) early in life, especially early-growth of multiple pulmonary nodules at higher frequency. Typical diseases with family history like diabetes and hypertension were also increased in FLC population. Compared to GDC data, our subject population was younger: the age peak of our FLC group was in 50-59; our sporadic group had an age peak around 60; while GDC patients' age peak was in 60-69. Importantly, the biggest difference happened in age 40-49: our FLC group and sporadic group had 3 times and 2 times higher ratio than GDC population, respectively. Moreover, the age peaks of our FLC males and FLC females were both in 50-59; while our sporadic females had the age peak in 50-59, much earlier than sporadic males (around 60-69); reflecting gender-specific or age-specific characters in our subject population. Conclusions: Familial lung cancer in China's Yunnan-Guizhou plateau showed unique clinicopathologic characters, differences were found in gender, age, histologic type, TNM stage and co-existing diseases or symptoms. Identification of hereditary factors which lead to increased lung cancer risk will be a challenge of both scientific and clinical significance.

Genome-wide association study of familial lung cancer

To identify genetic variation associated with lung cancer risk, we performed a genome-wide association analysis of 685 lung cancer cases that had a family history of two or more first or second degree relatives compared with 744 controls without lung cancer that were genotyped on an Illumina Human OmniExpressExome-8v1 array. To ensure robust results, we further evaluated these findings using data from six additional studies that were assembled through the Transdisciplinary Research on Cancer of the Lung Consortium comprising 1993 familial cases and 33 690 controls. We performed a meta-analysis after imputation of all variants using the 1000 Genomes Project Phase 1 (version 3 release date September 2013). Analyses were conducted for 9 327 222 SNPs integrating data from the two sources. A novel variant on chromosome 4p15.31 near the LCORL gene and an imputed rare variant intergenic between CDKN2A and IFNA8 on chromosome 9p21.3 were identified at a genome-wide level of significance for squamous cell carcinomas. Additionally, associations of CHRNA3 and CHRNA5 on chromosome 15q25.1 in sporadic lung cancer were confirmed at a genome-wide level of significance in familial lung cancer. Previously identified variants in or near CHRNA2, BRCA2, CYP2A6 for overall lung cancer, TERT, SECISPB2L and RTEL1 for adenocarcinoma and RAD52 and MHC for squamous carcinoma were significantly associated with lung cancer.

Genetic predisposition to lung cancer: comprehensive literature integration, meta-analysis, and multiple evidence assessment of candidate-gene association studies

More than 1000 candidate-gene association studies on genetic susceptibility to lung cancer have been published over the last two decades but with few consensuses for the likely culprits. We conducted a comprehensive review, meta-analysis and evidence strength evaluation of published candidate-gene association studies in lung cancer up to November 1, 2015. The epidemiological credibility of cumulative evidence was assessed using the Venice criteria. A total of 1018 publications with 2910 genetic variants in 754 different genes or chromosomal loci were eligible for inclusion. Main meta-analyses were performed on 246 variants in 138 different genes. Twenty-two variants from 21 genes (APEX1 rs1130409 and rs1760944, ATM rs664677, AXIN2 rs2240308, CHRNA3 rs6495309, CHRNA5 rs16969968, CLPTM1L rs402710, CXCR2 rs1126579, CYP1A1 rs4646903, CYP2E1 rs6413432, ERCC1 rs11615, ERCC2 rs13181, FGFR4 rs351855, HYKK rs931794, MIR146A rs2910164, MIR196A2 rs11614913, OGG1 rs1052133, PON1 rs662, REV3L rs462779, SOD2 rs4880, TERT rs2736098, and TP53 rs1042522) showed significant associations with lung cancer susceptibility with strong cumulative epidemiological evidence. No significant associations with lung cancer risk were found for other 150 variants in 98 genes; however, seven variants demonstrated strong cumulative evidence. Our findings provided the most updated summary of genetic risk effects on lung cancer and would help inform future research direction.

Screening and Early Detection of Lung Cancer

OBJECTIVE

To review current risk factors for lung cancer, identify screening and early detection guidelines while describing new approaches that use genomic technologies.

DATA SOURCES

Published scientific literature, clinical literature, and published lung cancer screening guidelines from the United States and Canada.

CONCLUSION

Nurses are caring for lung cancer patients who, historically, do not live for long periods after diagnosis. Research is revealing promising screening methodologies that can detect lung cancer 1 to 4 years earlier than the current approaches.

IMPLICATIONS FOR NURSING PRACTICE

Current knowledge about screening for lung cancer is a vital tool for nurses working with persons at high risk for this potentially aggressive and life-threatening malignancy. While old methods remain the standard of care, new detection methods use a variety of genomic-based technologies. These developing approaches emphasize the need for nurses at all levels of practice to have a working knowledge of genetics to educate patients and conference with colleagues.