Molecular profile of driver genes in lung adenocarcinomas of Brazilian patients who have never smoked: implications for targeted therapies.

INTRODUCTION: Lung cancer in never-smoker (LCINS) patients accounts for 20% of lung cancer cases, and its biology remains poorly understood, particularly in genetically admixed populations. We elucidated the molecular profile of driver genes in Brazilian LCINS. METHODS: The mutational and gene fusion status of 119 lung adenocarcinomas from self-reported never-smoker patients, was assessed using targeted sequencing (NGS), nCounter, and immunohistochemistry. A panel of 46 ancestry-informative markers determined patients' genetic ancestry. RESULTS: The most frequently mutated gene was EGFR (49.6%), followed by TP53 (39.5%), ALK (12.6%), ERBB2 (7.6%), KRAS (5.9%), PIK3CA (1.7%), and less than 1% alterations in RET, NTRK1, MET∆ex14, PDGFRA, and BRAF. Except for TP53 and PIK3CA, all other alterations were mutually exclusive. Genetic ancestry analysis revealed a predominance of European (71.1%), and a higher African ancestry was associated with TP53 mutations. CONCLUSION: Brazilian LCINS exhibited a similar molecular profile to other populations, except the increased ALK and TP53 alterations. Importantly, 73% of these patients have actionable alterations that are suitable for targeted treatments.

Lung Cancer in Never Smokers: Delving into Epidemiology, Genomic and Immune Landscape, Prognosis, Treatment, and Screening.

Lung cancer in never smokers (LCINS) represents a growing and distinct entity within the broader landscape of lung malignancies. This review provides a comprehensive overview of LCINS, encompassing its epidemiologic trends, risk factors, distinct genomic alterations, clinical outcomes and the ongoing initiative aimed at formulating screening guidelines tailored to this unique population. As LCINS continues to gain prominence, understanding its intricate genomic landscape has become pivotal for tailoring effective therapeutic strategies. Moreover, LCINS does not meet the criteria for lung cancer screening as per the current guidelines. Hence, there is an urgent need to explore its heterogeneity in order to devise optimal screening guidelines conducive to early-stage detection. This review underscores the vital importance of detailed research to elucidate the multifaceted nature of LCINS, with the potential to shape future clinical management and screening recommendations for this unique and growing patient cohort.

OSCC in Never-Smokers and Never-Drinkers Is Associated with Increased Expression of Tumor-Infiltrating Lymphocytes and Better Survival.

The aim of this study was to investigate the clinical, histopathologic, and immunologic differences of oral squamous cell carcinoma of never-smokers/never-drinkers and smokers/drinkers. Immunohistochemical staining for CD4, CD8, FoxP3, CD1a, and p16 was performed in 131 oral squamous cell carcinomas from smokers/drinkers and never-smokers/never-drinkers. Associations of smoking/drinking status with clinicopathologic data, immunohistochemical antibody expression, and survival were examined. Oral squamous cell carcinoma in never-smokers/never-drinkers was associated with the female gender (p < 0.001). Never-smokers/never-drinkers were older at diagnosis than smokers/drinkers (p < 0.001). Never-smokers/never-drinkers had more tumors in the maxilla, mandible, and tongue (p < 0.001). Pre-existing oral potentially malignant disorders appeared to be more common in never-smokers/never-drinkers (p < 0.001). Perineural invasion was more common in smokers/drinkers (p = 0.039). Never-smoking/never-drinking was associated with better overall survival (p = 0.004) and disease-specific survival (p = 0.029). High CD4+ T cell infiltration was associated with never-smoking/never-drinking (p = 0.008). Never-smokers/never-drinkers also showed increased CD8+ T cell infiltration (p = 0.001) and increased FoxP3+ Treg infiltration (p = 0.023). Furthermore, the total group of tumor-infiltrating lymphocytes was associated with never smoking/never drinking (p = 0.005). To conclude oral squamous cell carcinoma of the never-smokers/never-drinkers appears to be a distinct type of tumor, as it appears to have unique clinical and pathologic features and a more immunogenic microenvironment.

Identification of Germline Mutations in East-Asian Young Never-Smokers with Lung Adenocarcinoma by Whole-Exome Sequencing.

Recently, an increasing number of young never-smokers are diagnosed with lung cancer. The aim of this study is to investigate the genetic predisposition of lung cancer in these patients and discover candidate pathogenic variants for lung adenocarcinoma in young never-smokers. Peripheral blood was collected from 123 never-smoking east-Asian patients diagnosed with lung adenocarcinoma before the age of 40. Whole-exome sequencing (WES) was conducted on genomic DNA extracted from peripheral blood cells. As a result, 3,481 single nucleotide variants were identified. By bioinformatical tools and the published gene list associated with genetic predisposition of cancer, pathogenic variants were detected in ten germline genes: ATR, FANCD2, FANCE, GATA2, HFE, MSH2, PDGFRA, PMS2, SDHB, and WAS. Patients with pathogenic variants were more likely to occur in females (9/10, 90.0%) and have stage IV lung adenocarcinoma (4/10, 40%). Furthermore, germline mutations in 17 genes (ASB18, B3GALT5, CLEC4F, COL6A6, CYP4B1, C6orf132, EXO1, GATA4, HCK, KCP, NPHP4, PIGX, PPIL2, PPP1R3G, RRBP1, SALL4, and TTC28), which occurred in at least two patients, displayed potentially pathogenic effects. Gene ontology analysis further showed that these genes with germline mutations were mainly located in nucleoplasm and associated with DNA repair-related biological processes. The study provides spectrum of pathogenic variants and functional explanation for genetic predisposition of lung adenocarcinoma in young never-smokers, which sheds a light on prevention and early diagnosis of lung cancer. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-022-00062-1.

First-Line Treatment of Driver-Negative Non-Small Cell Lung Cancer.

Immunotherapy-based regimens are an established standard of care for the first-line treatment of driver-negative (EGFR/ALK/ROS WT) advanced non-small cell lung cancer. With multiple immune-based regimens approved in the first-line setting, clinicians are faced in practice with a variety of treatment choices. This article summarizes the most up-to-date trial data on treatments for driver-negative advanced non-small cell lung cancer, including immunotherapy monotherapy, chemoimmunotherapy, and combination immunotherapy, providing a framework for clinicians based on PD-L1 and smoking status. A multibiomarker assay that may best predict immunotherapy response remains an active area of research.

Female reproductive and hormonal factors and lung cancer mortality among never-smokers: A prospective cohort study of 287 408 Chinese women.

There is growing, but inconsistent evidence suggesting oestrogen may play a key role in lung cancer development, especially among never-smoking women for whom lung cancer risk factors remain largely elusive. Using the China Kadoorie Biobank, a large-scale prospective cohort with 302 510 women aged 30 to 79 years recruited from 10 regions in China during 2004 to 2008, we assessed the risk of lung cancer death among self-reported never-smoking women who were cancer-free at baseline, in relation to age at menarche, age at menopause, time since menopause, prior use of oral contraceptives (OCP), number of livebirths, breastfeeding and age at first livebirth. Women were followed up to December 31, 2016 with linkage to mortality data. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression, adjusting for key confounders including several socio-demographic, environmental and lifestyle factors. Among 287 408 never-smoking women, 814 died from lung cancer with a median follow-up of 10.3 years. Women who had used OCP within 15 years prior to baseline had a significantly higher hazard of lung cancer death compared with never-users: HR = 1.85 (95% CI: 1.14-3.00) and risk increased by 6% with each additional year of use: HR = 1.06 (1.01-1.10). Among parous women, the hazard of lung cancer death increased by 13% with each single livebirth: HR = 1.13 (1.05-1.23); and among post-menopausal women, the risk increased by 2% with each year since menopause: HR = 1.02 (1.01-1.04). These results suggest that reproductive factors which were proxies for lower endogenous oestrogen level, for example, longer duration of OCP use, could play a role in lung cancer development.

No survival benefit in never-smoker never-drinker patients with oral cavity cancer.

BACKGROUND: Although strongly associated with tobacco and alcohol use, many oral cavity squamous cell carcinoma (OCSCC) cases occur in patients without exposure to either, known as "never-smoker, never-drinkers" (NSND). We aimed to compare clinical outcomes between NSND and tobacco/alcohol-exposed populations and to define demographic characteristics of NSND. METHODS: We performed a retrospective, single-institution cohort study of 672 OCSCC patients. Cox models were used to estimate differences in overall survival (OS) and recurrence-free survival (RFS) between NSND and tobacco/alcohol-exposed patients while adjusting for confounders. RESULTS: NSND represented 25.6% of our cohort and were older, more female, and more economically advantaged. Among NSND, oral tongue tumors dominated in younger patients, while alveolar ridge tumors dominated in elderly patients. Multivariate survival analysis revealed no differences in OS or RFS between NSND and tobacco/alcohol-exposed patients. CONCLUSION: When adjusted for independent biologic features, clinical outcomes in OCSCC are similar between NSND and tobacco/alcohol-exposed patients.

Isoflavone and soy food intake and risk of lung cancer in never smokers: report from prospective studies in Japan and China.

PURPOSE: Evidence from several cohorts has suggested that a higher intake of isoflavone is associated with lower risk of lung cancer in never smokers, but the association has not been investigated by histologic type of lung cancer. Adenocarcinoma is a common histologic type found in never smokers. We hypothesized that a higher intake of isoflavone is associated with a lower risk of lung adenocarcinoma among never smokers. Here, we examined the associations of isoflavone and soy food intake with lung cancer and its histologic types in never smokers. METHODS: We performed a pooled analysis using data from the Japan Public Health Center-based Prospective Study, Shanghai Women's Health Study and Shanghai Men's Study with 147,296 never smokers aged 40-74 years with no history of cancer. During 1,990,040 person-years of follow-up, 1247 lung cancer cases were documented. Dietary isoflavone and soy food intake were assessed using a food-frequency questionnaire. Multivariable Cox proportional hazards models assessed the associations between isoflavone and soy intake with incidence of lung cancer by histologic type. RESULTS: A higher intake of dietary isoflavone and soy food were associated with reduced risk of lung adenocarcinoma. The multivariable hazard ratios (HRs) (95% CI) of risk of lung adenocarcinoma for the highest versus lowest intakes of isoflavone and soy food were 0.74 (0.60-0.92) and 0.78 (0.63-0.96), respectively. The multivariable HRs of risk of lung adenocarcinoma associated with each 10 mg/day increase in isoflavone and each 50 g/day increase in soy food intake were 0.81 (0.70-0.94) and 0.84 (0.73-0.96), respectively. CONCLUSION: Higher intake of isoflavone and soy food was associated with lower risk of lung adenocarcinoma in never smokers.

Association of exposure to environmental tobacco smoke at home and risk of mortality among US never smokers by race/ethnicity, education, and income.

Environmental tobacco smoke (ETS) increases the risk of mortality among nonsmokers. Yet, few studies have examined this association among racial/ethnic minorities or among people with less education or income. We assessed self-reported ETS exposure at home among never smoking participants (n = 110,945) of the 1991-2010 National Health Interview Surveys. Deaths through 2015 were identified by the National Death Index. Hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality were estimated using Cox proportional hazards regression models with age as the underlying time metric and adjusted for sex, race/ethnicity, education, household income, body mass index, region of residence, and survey year. We further stratified all-cause mortality analyses by race/ethnicity, household income, and education. Relative to no ETS at home, every day exposure was associated with higher risk of all-cause mortality (HR = 1.33, 95%CI: 1.23, 1.45), with similar HRs observed across strata of education and income. HRs were similar among non-Hispanic Black (HR = 1.28, 95%CI: 1.08, 1.53) and non-Hispanic White adults (HR = 1.34, 95%CI: 1.21, 1.48) although somewhat higher among Hispanic adults (HR = 1.65, 95%CI: 1.29, 2.10; P for pairwise comparison = 0.04). ETS exposure at home is an important contributor to mortality across strata of race/ethnicity, education, and income in the US.

Comprehensive genomic profiling of Finnish lung adenocarcinoma cohort reveals high clinical actionability and SMARCA4 altered tumors with variable histology and poor prognosis.

INTRODUCTION: Lung adenocarcinoma is the most common type of lung cancer and typically carries a high number of mutations. However, the genetic background of the tumors varies according to patients' ethnic background and smoking status. Little data is available on the mutational landscape and the frequency of actionable genomic alterations in lung adenocarcinoma in the Finnish population. MATERIALS AND METHODS: We evaluated the gene alteration frequencies of 135 stage I-IV lung adenocarcinomas operated at Turku University Hospital between 2004 and 2017 with a large commercial comprehensive genomic profiling panel. Additionally, we correlated the alterations in selected genes with disease outcomes in 115 stage I-III patients with comprehensive follow-up data. The genomic alterations in a sub-cohort of 30 never-smokers were assessed separately. RESULTS: Seventy percent of patients in the overall cohort and 77% in the never-smoker sub-cohort harbored an alteration or a genomic signature targetable by FDA and/or EMA approved drug for non-small cell carcinoma, respectively. In multivariable analysis for disease-specific survival, any alteration in SMARCA4 (DSS; HR 3.911, 95%CI 1.561-9.795, P=0.004) exhibited independent prognostic significance along with stage, tumor mutation burden, and predominant histological subtypes. CONCLUSIONS: Over two thirds of our overall cohort, and especially never-smokers had an actionable genomic alteration or signature. SMARCA4 alterations, detected in 7.4% of the tumors, independently predicted a shortened overall and disease-specific survival regardless of the alteration type. Most SMARCA4 alterations in our cohort were missense mutations associated with differentiated predominant histological subtypes and immunohistochemical SMARCA4/BRG1 and TTF-1 positive status.

Implications of the Immune Landscape in COPD and Lung Cancer: Smoking Versus Other Causes.

Cigarette smoking is reported in about one third of adults worldwide. A strong relationship between cigarette smoke exposure and chronic obstructive pulmonary disease (COPD) as well as lung cancer has been proven. However, about 15% of lung cancer cases, and between one fourth and one third of COPD cases, occur in never-smokers. The effects of cigarette smoke on the innate as well as the adaptive immune system have been widely investigated. It is assumed that certain immunologic features contribute to lung cancer and COPD development in the absence of smoking as the major risk factor. In this article, we review different immunological aspects of lung cancer and COPD with a special focus on non-smoking related risk factors.

Narrative review: association between lung cancer development and ambient particulate matter in never-smokers.

Objective: To review the association and pathophysiological link between lung cancer in never smokers and ambient particulate matter (PM). Background: Although the association between exposure to PM and lung cancer development is well known, the pathophysiological background is yet to be studied in depth. Never smokers comprise a large proportion of newly diagnosed lung cancer cases and account for 25% of all cases. Considering the carcinogenic nature of ambient PM and the fact that many patients with lung cancer are never smokers, it is necessary to evaluate the interrelation and possible clinical background, in order to effectively prevent lung cancer development in this subgroup. Methods: An online search of literature was conducted. The National Center for Biotechnology Information (NCBI), PubMed, Google Scholar, Cochrane Library and EMBASE were searched. Conclusions: In never smokers, the risk of lung cancer was dose-dependent with the concentration of ambient air pollutants. Regarding the pathophysiological link, involvement of epithelial mesenchymal transition (EMT) and chronic inflammation has been mentioned, but further studies are necessary to enable therapeutic interventions to prevent cancer development. Considering the significant burden of PM on lung cancer development, both public and clinical approaches to cancer prevention are essential. To prevent lung cancer more effectively, clinicians should develop a more individualized approach in patients, focusing on gender and genetic background.

Endogenous sex hormones, aromatase activity and lung cancer risk in postmenopausal never-smoking women.

Although reproductive factors have been repeatedly associated with lung cancer risk, no study to date has directly evaluated the relationship with endogenous sex hormones nor with aromatase activity in postmenopausal never-smoking women. A case-control study of 397 incident lung cancer cases and their individually matched controls, nested within the Shanghai Women's Health Study, was conducted among postmenopausal women who were lifetime never smokers. Prediagnostic concentrations of sex hormones was quantitated using LC-MS/MS assays in plasma. The product-substrate molar ratio of estrone to androstenedione was used as an index of aromatase activity (IAA). Multivariable conditional logistic regression models were used to calculate odds ratios (ORs) for lung cancer. Baseline concentrations of estradiol, free testosterone and IAA were inversely associated with subsequent risk of lung cancer in multivariable-adjusted models. When further adjusted for body mass index, the inverse association with estradiol was attenuated and no longer statistically significant, but the association with free testosterone and IAA remained. In analyses confined to participants having never used menopausal hormone therapy in 376 case-control pairs, the inverse association with free testosterone and IAA was slightly strengthened. OR for the highest vs the lowest quartile of free testosterone was 0.55 (95% CI = 0.34-0.90; Ptrend  = .03), and the corresponding OR for IAA was 0.57 (95% CI = 0.34-0.96; Ptrend  = .04). Our study, for the first time, suggests that higher levels of circulating free testosterone and estimated aromatase activity may be associated with lower lung cancer risk in postmenopausal never-smoking women.

Risk factors for chronic obstructive pulmonary disease in never-smokers: A systematic review.

INTRODUCTION: Relatively little is known about the risk factors for chronic obstructive pulmonary disease (COPD) in never-smokers, and these factors have not yet been fully characterised. This study therefore sought to analyse COPD risk factors in never-smokers by conducting a systematic review of the literature on the topic. MATERIALS AND METHODS: We performed a search in PubMed (Medline) and Embase from 2000 onwards, to locate studies on COPD in never-smokers. For literature search and evidence synthesis purposes, we used the PRISMA guidelines and drew up a specific quality scale to quantify the evidence of each study included. RESULTS: The bibliographic search retrieved a total of 557 papers, 20 of which fulfilled the designated inclusion criteria (two case-control studies, four cohort studies and 14 cross-sectional studies). These studies were undertaken in Europe, the United States, Latin America, Asia and Africa. The risk factors for never-smokers were varied and ranged from exposure to biomass, occupational exposure and passive smoking to having a history of asthma, tuberculosis or respiratory infections during childhood. The effect of residential radon was unclear. The highest risk was obtained for previous respiratory diseases of any type, with a magnitude much higher than that observed for other risk factors. CONCLUSIONS: There are few studies on COPD risk factors in never-smokers. More purpose-designed studies in this subpopulation are thus called for, including well-designed studies to specifically assess if indoor radon has any role on COPD onset.

Gene-gene interaction of AhRwith and within the Wntcascade affects susceptibility to lung cancer.

BACKGROUND: Aberrant Wnt signalling, regulating cell development and stemness, influences the development of many cancer types. The Aryl hydrocarbon receptor (AhR) mediates tumorigenesis of environmental pollutants. Complex interaction patterns of genes assigned to AhR/Wnt-signalling were recently associated with lung cancer susceptibility. AIM: To assess the association and predictive ability of AhR/Wnt-genes with lung cancer in cases and controls of European descent. METHODS: Odds ratios (OR) were estimated for genomic variants assigned to the Wnt agonist and the antagonistic genes DKK2, DKK3, DKK4, FRZB, SFRP4 and Axin2. Logistic regression models with variable selection were trained, validated and tested to predict lung cancer, at which other previously identified SNPs that have been robustly associated with lung cancer risk could also enter the model. Furthermore, decision trees were created to investigate variant × variant interaction. All analyses were performed for overall lung cancer and for subgroups. RESULTS: No genome-wide significant association of AhR/Wnt-genes with overall lung cancer was observed, but within the subgroups of ever smokers (e.g., maker rs2722278 SFRP4; OR = 1.20; 95% CI 1.13-1.27; p = 5.6 × 10-10) and never smokers (e.g., maker rs1133683 Axin2; OR = 1.27; 95% CI 1.19-1.35; p = 1.0 × 10-12). Although predictability is poor, AhR/Wnt-variants are unexpectedly overrepresented in optimized prediction scores for overall lung cancer and for small cell lung cancer. Remarkably, the score for never-smokers contained solely two AhR/Wnt-variants. The optimal decision tree for never smokers consists of 7 AhR/Wnt-variants and only two lung cancer variants. CONCLUSIONS: The role of variants belonging to Wnt/AhR-pathways in lung cancer susceptibility may be underrated in main-effects association analysis. Complex interaction patterns in individuals of European descent have moderate predictive capacity for lung cancer or subgroups thereof, especially in never smokers.

Cost-effectiveness and health impact of lung cancer screening with low-dose computed tomography for never smokers in Japan and the United States: a modelling study.

BACKGROUND: Never smokers in Asia have a higher incidence of lung cancer than in Europe and North America. We aimed to assess the cost-effectiveness of lung cancer screening with low-dose computed tomography (LDCT) for never smokers in Japan and the United States. METHODS: We developed a state-transition model for three strategies: LDCT, chest X-ray (CXR), and no screening, using a healthcare payer perspective over a lifetime horizon. Sensitivity analyses were also performed. Main outcomes were costs, quality-adjusted life-years (QALYs), life expectancy life-years (LYs), incremental cost-effectiveness ratios (ICERs), and deaths from lung cancer. The willingness-to-pay level was US$100,000 per QALY gained. RESULTS: LDCT yielded the greatest benefits with the lowest cost in Japan, but the ICERs of LDCT compared with CXR were US$3,001,304 per QALY gained for American men and US$2,097,969 per QALY gained for American women. Cost-effectiveness was sensitive to the incidence of lung cancer. Probabilistic sensitivity analyses demonstrated that LDCT was cost-effective 99.3-99.7% for Japanese, no screening was cost-effective 77.7% for American men, and CXR was cost-effective 93.2% for American women. Compared with CXR, LDCT has the cumulative lifetime potential for 60-year-old Japanese to save US$117 billion, increase 2,339,349 QALYs and 3,020,102 LYs, and reduce 224,749 deaths, and the potential for 60-year-old Americans to cost US$120 billion, increase 48,651 QALYs and 67,988 LYs, and reduce 2,309 deaths. CONCLUSIONS: This modelling study suggests that LDCT screening for never smokers has the greatest benefits and cost savings in Japan, but is not cost-effective in the United States. Assessing the risk of lung cancer in never smokers is important for introducing population-based LDCT screening.

Phytoestrogens and lung cancer risk: a nested case-control study in never-smoking Chinese women.

BACKGROUND: Since several lines of evidence suggest that estrogens may be involved in lung carcinogenesis, it has been hypothesized that intake of phytoestrogens, similar in molecular structure to mammalian estrogens, may be associated with lung cancer development. OBJECTIVE: The aim was to prospectively evaluate the association between phytoestrogen exposure and lung cancer risk in never-smoking women. METHODS: We conducted a nested case-control study within a population-based prospective cohort study of women. A total of 478 incident lung cancer cases and their individually matched controls were identified among never-smoking women after a mean follow-up of 15.6 years. Habitual intake of and internal exposure to phytoestrogens were assessed by repeated dietary surveys and urinary biomarkers, respectively. ORs and 95% CIs for lung cancer were estimated in conditional logistic regression models. RESULTS: After adjustment for potential confounders, a moderate intake of dietary isoflavones was inversely associated with lung cancer risk in never-smoking women, with the OR for the second quartile vs. the lowest quartile of intake being 0.52 (95% CI: 0.35, 0.76). Further increasing intake did not convey additional benefits, with ORs (95% CI) for the third and fourth quartiles of 0.53 (0.36, 0.78) and 0.47 (0.31, 0.72), respectively (P-overall < 0.001 and P-nonlinearity = 0.006). A similar association was seen when exposure to isoflavones was assessed by urinary biomarkers. ORs (95% CI) for the second, third, and fourth quartiles compared with the lowest quartile of urinary isoflavone excretion were 0.57 (0.39, 0.83), 0.64 (0.44, 0.92), and 0.60 (0.41, 0.86), respectively. The inverse association reached a plateau beyond the second quartile, with P-overall = 0.04 and P-nonlinearity = 0.15. Urinary excretion of gut-microbiota-derived metabolites of lignans was not related to lung cancer risk. CONCLUSIONS: This study suggests that moderately increasing intake of isoflavone-rich foods is associated with lower risk of lung cancer in never-smoking women.

Results of 10-year mobile low-dose computed tomography screenings for lung cancer in Shimane, Japan.

BACKGROUND: Some randomized controlled trials have evaluated the effects of low-dose computed tomography (CT) screening on lung cancer mortality in heavy smokers. Based on the results of those trials, our CT screening program recommended screening for people aged ≥40 years with a history of smoking. This retrospective study aimed to verify the validity of our CT screening program and elucidate the current state of CT screening program. METHODS: We retrospectively examined lung cancer detection in 25,189 participants who underwent chest CT screening by a mobile low-dose CT screening unit in the 10-year period from April 2009 to March 2019. Participants were recruited at Japan Agricultural Cooperatives (JA) Shimane Kouseiren. Participants requested CT screening for lung cancer. CT images were read by two pulmonologists. RESULTS: Lung cancer was identified in 82 of the 25,189 participants over 10 years, an overall lung cancer detection rate (percentage of lung cancers detected among all participants) of 0.33%. Lung cancer among never smokers accounted for 54.9% of the detected cases. The lung cancer detection rate was similar for smokers versus never smokers. The stage IA detection rate (percentage of stage IA lung cancers among all lung cancers detected) was 62%, while the stage Ⅳ detection rate was 10%. CONCLUSIONS: Chest CT detected lung cancer in never smokers as well as current or former smokers. Our CT screening program was not effective for never smokers; thus, further study of the effectiveness of CT screening in never smokers is needed.

Lung cancer symptom appraisal, help-seeking and diagnosis - rapid systematic review of differences between patients with and without a smoking history.

BACKGROUND: Lung cancer is the leading cause of cancer death in the world. A significant minority of lung cancer patients have never smoked (14% in the UK, and ranging from 10% to 25% worldwide). Current evidence suggests that never-smokers encounter delays during the diagnostic pathway, yet it is unclear how their experiences and reasons for delayed diagnoses differ from those of current and former smokers. This rapid review assessed literature about patient experiences in relation to symptom awareness and appraisal, help-seeking, and the lung cancer diagnostic pathway, comparing patients with and without a smoking history. METHODS: MEDLINE, PsychINFO and Google Scholar were searched for studies (2010-2020) that investigated experiences of the pathway to diagnosis for patients with and without a smoking history. Findings are presented using a narrative synthesis. RESULTS: Analysis of seven quantitative and three qualitative studies revealed that some delays during symptom appraisal and diagnosis are unique to never-smokers. Due to the strong link between smoking and lung cancer, and low awareness of non-smoking related lung cancer risk factors and symptoms, never-smokers do not perceive themselves to be at risk. Never-smokers are also likely to evaluate their experiences in comparison with other non-smoking related cancers, where prognosis is likely better, potentially leading to lower satisfaction with healthcare. CONCLUSION: Never-smokers appear to have different experiences in relation to symptom appraisal and diagnosis. However, evidence in relation to help-seeking, and what is driving diagnostic delays for never-smoker patients specifically is lacking.