Proportion Of Lung Cancer Cases Research Articles

Pt-Se-Bonded Nanoprobe for High-Fidelity Detection of Non-small Cell Lung Cancer and Enhancement of NIR II Photothermal Therapy.

Non-small cell lung cancer (NSCLC) accounts for a high proportion of lung cancer cases globally, but early detection remains challenging, and insufficient oxygen supply at tumor sites leads to suboptimal treatment outcomes. Therefore, the development of core-shell Au@Pt-Se nanoprobes (Au@Pt-Se NPs) with peptide chains linked through Pt-Se bonds was designed and synthesized for NSCLC biomarker protein calcium-activated neutral protease 2 (CAPN2) and photothermal therapy (PTT) enhancement. The NP can be specifically cleaved by CAPN2, resulting in fluorescence recovery to realize the detection. The Pt-Se bonds exhibit excellent resistance to biologically abundant thiols such as glutathione, thus avoiding "false-positive" results and enabling precise detection of NSCLC. Additionally, the platinum (Pt) shell possesses catalase-like properties that catalyze the generation of oxygen from endogenous hydrogen peroxide within the tumor, thereby reducing hypoxia-inducible factor-1α (HIF-1α) levels and alleviating the hypoxic environment at the tumor site. The Au@Pt-Se NPs exhibit strong absorption bands, enabling the possibility of PTT in the near-infrared II region (NIR II). This study presents an effective approach for the early detection of NSCLC while also serving as an oxygen supplier to alleviate the hypoxic environment and enhance NIR II PTT.

A three-year review of lung cancer patient characteristics in a tertiary hospital

Objective: The study sought to determine clinical characteristics and histologic subtypes of a cohort of lung cancer patients in a tertiary facility.Design: Retrospective review of the medical records of histology-confirmed lung cancer cases at the respiratory clinic over a 3-year period.Setting: Respiratory Clinic, Korle-Bu Teaching Hospital, Accra, GhanaParticipants: All adult patients with histologically diagnosed lung cancer were enrolled.Main outcome measures: Lung cancer histological typesResults: The proportion of lung cancer cases was 12.4%. The majority were women (57.8%) and the mean age at diagnosis was 55.8±16.0 years. The patients were predominantly non-smokers (61%). Common symptoms were chronic cough and chest pain. More than two-thirds of the cases presented in clinical stages III and IV with the pre-dominant histological subtype being adenocarcinoma in smokers and non-smokers. Genetic testing for epidermal growth factor receptor (EGFR) and Anaplastic Lymphoma kinase (ALK) mutations were largely absent.Conclusions: The majority of lung cancer patients presented late with advanced disease. Adenocarcinoma was the predominant histological subtype in a predominantly non-smoking population, with an increased prevalence among women less than 60 years. This should encourage testing for genetic mutations to improve patient survival.

Identidication of novel biomarkers in non-small cell lung cancer using machine learning

Lung cancer is one of the leading causes of cancer-related deaths worldwide, and non-small cell lung cancer (NSCLC) accounts for a large proportion of lung cancer cases, with few diagnostic and therapeutic targets currently available for NSCLC. This study aimed to identify specific biomarkers for NSCLC. We obtained three gene-expression profiles from the Gene Expression Omnibus database (GSE18842, GSE21933, and GSE32863) and screened for differentially expressed genes (DEGs) between NSCLC and normal lung tissue. Enrichment analyses were performed using Gene Ontology, Disease Ontology, and the Kyoto Encyclopedia of Genes and Genomes. Machine learning methods were used to identify the optimal diagnostic biomarkers for NSCLC using least absolute shrinkage and selection operator logistic regression, and support vector machine recursive feature elimination. CIBERSORT was used to assess immune cell infiltration in NSCLC and the correlation between biomarkers and immune cells. Finally, using western blot, small interfering RNA, Cholecystokinin-8, and transwell assays, the biological functions of biomarkers with high predictive value were validated. A total of 371 DEGs (165 up-regulated genes and 206 down-regulated genes) were identified, and enrichment analysis revealed that these DEGs might be linked to the development and progression of NSCLC. ABCA8, ADAMTS8, ASPA, CEP55, FHL1, PYCR1, RAMP3, and TPX2 genes were identified as novel diagnostic biomarkers for NSCLC. Monocytes were the most visible activated immune cells in NSCLC. The knockdown of the TPX2 gene, a biomarker with a high predictive value, inhibited A549 cell proliferation and migration. This study identified eight potential diagnostic biomarkers for NSCLC. Further, the TPX2 gene may be a therapeutic target for NSCLC.

Intratumoral Heterogeneity and Immune Modulation in Lung Adenocarcinoma in Female Smokers and Never Smokers.

Single-cell analysis of healthy lung tissue and lung cancer reveals distinct tumor cell populations, including cells with differential immune modulating capacity between smokers and never smokers, which could guide future therapeutic strategies.

Uniting Latin America Through Research: How Regional Research Can Strengthen Local Policies, Networking, and Outcomes for Patients With Lung Cancer.

Lung cancer represents a considerable global health threat, leading the list in terms of cancer-related deaths worldwide. An important proportion of lung cancer cases occur within Latin America, and current projections show that over the next decade, the number of deaths due to lung cancer will double in the region, underscoring the need to implement evidence-based interventions to improve outcomes. Several challenges have limited the progress in lung cancer research in Latin America for many years, though recently the surge of multidisciplinary, transnational, and transcultural research groups have overcome many of these limitations. The increase in region-specific knowledge has improved cancer care in the area, providing clinicians with a specific demographic and molecular profile for Hispanic patients with lung cancer; as a result, the implementation of precision oncology has benefited from a profound knowledge of the patient profile. Nonetheless, there are still challenges to improve research in Latin America, including stabilizing funding sources to continue independent research, supporting mentoring programs and an early immersion in clinical research for early career fellows, and overcoming barriers for publishing.

Race & sex disparities related to low-dose computed tomography lung cancer screening eligibility criteria: A lung cancer cases review

IntroductionThe United States Preventive Services Task Force (USPSTF) recommendations do not account for race and sex differences in lung cancer risk. We compared the sensitivity for finding lung cancer cases eligible for lung cancer screening (LCS) by USPSTF 2013 recommendations versus the PLCOm2012 model at an equivalent threshold. MethodsUsing Georgetown University Hospital tumor registry, we identified lung cancer cases (≥55 years old) between 2014 and 2018. Medical chart review collected age, sex, race, education, smoking, and clinical characteristics. We compared the percentage meeting eligibility criteria overall, and by race and sex. ResultsThe cases (N = 447) were 36.6% Black and 52.6% female. The PLCOm2012 and USPSTF 2013 criteria identified 71.4% and 45.6% of cases, respectively (p < 0.0001). This difference was consistent across race and sex sub-groups (p < 0.0001). The PLCOm2012 was more sensitive than the USPSTF in Blacks (69.9% vs. 46.6%, p < 0.0001) and in women (69.8% vs. 41.3%, p < 0.0001). The USPSTF had poor sensitivity for both race groups (Black 46.6%, White 45.9%, p = 0.886) and had lower sensitivity in women vs. men (41.3% vs. 51.4%, p = 0.032). The PLCOm2012 had higher sensitivities in women and men, and difference between sexes was not significant (69.8% vs. 72.6%, p = 0.506). ConclusionsCompared to the USPSTF 2013 recommendations, the PLCOm2012 model selected a larger proportion of lung cancer cases in all race-sex strata and removed the sex disparity observed for the USPSTF. The PLCOm2012 risk model could be used to identify those who will benefit from LCS.

Thoracic surgery in Estonia.

Estonia, a small Northern European country with the population of 1.3 million, has two centres of thoracic surgery, both established in 1960s. One is in the capital Tallinn, and another in the university town Tartu. Both departments cover the full spectrum of thoracic surgery, apart from oesophageal cancer surgery, yet including paediatric operations and chest trauma management. However, the focus is on lung cancer surgery. Currently, the proportion of lung cancer cases treated surgically is 20% in Estonia. Between 2000 and 2015 the proportion of lobectomies increased from 53% to 76%, while pneumonectomies decreased from 28% to 8%. Although the absolute number of lung cancer operations in Estonia is small, upon need complex and extended resections are performed. In the last decades a considerable survival gain of lung cancer patients has been observed. Minimally invasive surgery is widely used since its implementation in 1995, with the list of indications constantly evolving. In 2005, first video-assisted thoracoscopic (VATS) thymectomy and lobectomy were performed. VATS as surgical access in lung cancer operations exceeded thoracotomy in 2015 and is currently considered in all cases. In 2018, the first uniportal VATS sleeve-lobectomy was performed. The lung transplant program is functioning together with other solid organ transplant programs only at the Tartu University Hospital. Up to now, 33 lung transplantations have been performed, including lobar transplantations, a paediatric case, a few urgent cases for patients on extracorporeal membrane oxygenation (ECMO), and two re-transplantations. General thoracic surgery is a separate monospeciality in Estonia with an independent 5-year residency program, which is arranged by the Medical Faculty of University of Tartu. In last years, thoracic surgery related research in Estonia has mainly focused on lung cancer detection and management. Currently, a national lung cancer screening program feasibility study is being led by thoracic surgeons.

Salvage surgery following downstaging of advanced non-small cell lung cancer by targeted therapy.

BackgroundAdvanced non‐small cell lung cancer (NSCLC) accounts for a high proportion of lung cancer cases. Targeted therapy improve the survival in these patients, but acquired drug resistance will inevitably occur. If tumor downstaging is achieved after targeted therapy, could surgical resection before drug resistance improve clinical benefits for patients with advanced NSCLC? Here, we conducted a clinical trial showing that for patients with advanced driver gene mutant NSCLC who did not progress after targeted therapy, salvage surgery (SS) could improve progression‐free survival (PFS). Herein, we retrospectively reviewed our former clinical trial and thoracic cancer database in our medical institutions.MethodsWe identified patients with advanced driver gene mutant NSCLC treated with targeted therapy plus SS or targeted therapy alone in our former clinical trial and our thoracic cancer database from July 2016 to July 2019. PFS was compared between the targeted therapy plus SS group and the targeted therapy only group using the log‐rank test.ResultsWe identified 73 patients with driver gene mutant NSCLC who were treated with targeted therapy and 18 treated with targeted therapy plus SS.Among the 18 patients treated with targeted therapy plus SS, there were no obvious perioperative complications and deaths. Targeted therapy followed by SS resulted in a significantly longer PFS compared with targeted therapy alone (23.4 months VS 12.9 months, p = 0.0004).ConclusionsSalvage surgery after tumor downstaging is a promising therapeutic strategy for some patients with advanced (stage IIIB–IV) NSCLC and may offer a new therapeutic option for multidisciplinary comprehensive treatment of lung cancer.

Current lung cancer screening guidelines may miss high-risk population: a real-world study

BackgroundDespite much research published on lung cancer screening, China has had no large-scale study on the missed diagnosis of lung cancer in a health examination population. We therefore did a real-world study using the current lung cancer screening guidelines to a health examination population in China to determine the proportion of lung cancer cases that have been missed.MethodsA real-world cohort study of screening, with the use of low-dose computed tomography, was conducted among people who took yearly health checkup in health management center of West China Hospital between 2006 and 2017. We respectively used current guidelines including lung cancer screening guidelines of the U.S. Preventive Services Task Force (USPSTF) and expert consensus on low dose spiral CT lung cancer screening in China.ResultsIn a total of 15,996 participants with health examination who completed the baseline screening, 6779 (42.4%) subjects had at least one positive finding, and 142 (2.1%) cases of lung cancer were screened positive. The false positive rate was 97.9%. Of 142 lung cancer cases detected in our study, only 9.2% met the lung cancer screening guidelines proposed by the USPSTF, and 24.4% met that of China. The rates of missed diagnosis were as high as 90.8 and 75.6% respectively. In addition, we did an in-depth analysis by gender. We found that among male patients with lung cancer, the proportion of smokers was 75%, and the proportion of young people under 50 was 23.2%. Among female patients with lung cancer, the proportion of smokers was only 5.8%, and the proportion of young people under 50 was up to 33.3%.ConclusionsThe rate of missed diagnosis was as high as 90.8% applying the current lung cancer screening guidelines to the health examination population in China. Further study to determine screening guidelines for targeted populations, is warranted.

Assessing the Number of Annual Lung Cancer Resections Performed in the United States

Background: The number of lung cancer resections performed annually in the United States has not been previously assessed. The objective of this study is to estimate the total number of lung cancer resections performed every year in the U.S. Methods: The number of lung cancer resections performed in the United States in 2016 and 2017 was estimated by using indirect multiplier methods based on the number of lung cancer resections in the National Cancer Data Base (NCDB) and the proportion of lung cancer cases captured by the NCDB using the United States Cancer Statistics Data Set as reference. Results: In 2016, 37,128 lung cancer resections were documented in the NCDB and the NCDB captured 65.2% of incident lung cancer cases in the U.S. In 2017, 36,882 lung cancer resections were documented in the NCDB and the NCDB captured 65.1% of incident lung cancer cases in the U.S. Based on these metrics, an estimated 57,000 lung cancer resections were performed in 2016 and an estimated 56,600 lung cancer resections were performed in 2017 in the U.S. Of these lung cancer resections, an estimated 10,300 (18.2%) wedge resections, 2,800 (4.9%) segmentectomies, 40,000 (70.6%) lobectomies, 80 (0.14%) bronchial sleeve resections, 1,400 (2.5%) extended lobectomies, 1,600 (2.8%) pneumonectomies, and 40 (0.07%) extended pneumonectomies were performed in 2017. Conclusion: Based on this national analysis, an approximately 56,000 to 57,000 lung cancer resections are performed in the U.S. annually. Lobectomies are the most common lung cancer operations performed in the U.S. Funding Information: None. Declaration of Interests: None. Ethics Approval Statement: Approval dated 2/2/21, Massachusetts General Hospital IRB, Institutional Review Board Number: 2020P004110.

The fraction of lung cancer attributable to smoking in the Norwegian Women and Cancer (NOWAC) Study

BackgroundWe examined the association between active and passive smoking and lung cancer risk and the population attributable fraction (PAF) of lung cancer due to active smoking, in the Norwegian Women and Cancer Study, a nationally representative prospective cohort study.MethodsWe followed 142,508 women, aged 31–70 years, who completed a baseline questionnaire between 1991 and 2007, through linkages to national registries through December 2015. We used Cox proportional hazards models, to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). We calculated PAF to indicate what proportion of lung cancer cases could have been prevented in the absence of smoking.ResultsDuring the more than 2.3 million person-years of observation, we ascertained 1507 lung cancer cases. Compared with never smokers, current (HR 13.88, 95% CI 10.18–18.91) smokers had significantly increased risk of lung cancer. Female never smokers exposed to passive smoking had a 1.3-fold (HR 1.34, 95% CI 0.89–2.01) non- significantly increased risk of lung cancer, compared with never smokers. The PAF of lung cancer was 85.3% (95% CI 80.0–89.2).ConclusionMore than 8 in 10 lung cancer cases could have been avoided in Norway, if the women did not smoke.

Regional differences in tobacco smoking and lung cancer in Portugal in 2018: a population-based analysis using nationwide incidence and mortality data

ObjectivesThis study aims to estimate the proportion of lung cancer cases and deaths attributable to tobacco smoking in Portugal in 2018, complemented by trends in incidence and mortality, by sex...

Lung cancer occurrence attributable to passive smoking among never smokers in China: a systematic review and meta-analysis.

BackgroundQuantifying the occurrence of lung cancer due to passive smoking is a necessary step when forming public health policy. In this study, we estimated the proportion of lung cancer cases attributable to passive smoking among never smokers in China.MethodsSix databases were searched up to July 2019 for original observational studies reporting relative risks (RRs) or odds ratios (ORs) for the occurrence of lung cancer associated with passive smoking in Chinese never smokers. The population attributable fraction (PAF) was then calculated using the combined proportion of lung cancer cases exposed to passive smoking and the pooled ORs from meta-analysis. Data are reported with their 95% confidence intervals.ResultsWe identified 31 case-control studies of never smokers and no cohort studies. These comprised 9,614 lung cancer cases and 13,093 controls. The overall percentages of lung cancers attributable to passive smoking among never smokers were 15.5% (9.0–21.4%) for 9 population-based studies and 22.7% (16.6–28.3%) for 22 hospital-based studies. The PAFs for women were 17.9% (11.4–24.0%) for the population-based studies and 20.9% (14.7–26.7%) for the hospital-based studies. The PAF for men was only calculable for hospital-based studies, which was 29.0% (95% CI: 8.0–45.2%). Among women, the percentage of lung cancer cases attributable to household exposure (19.5%) was much higher than that due to workplace exposure (7.2%).ConclusionsWe conclude that approximately 16% of lung cancer cases among never smokers in China are potentially attributable to passive smoking. This is slightly higher among women (around 18%), with most cases occurring due to household exposure.

Identification of Driver Genes in Lung Squamous Cell Carcinoma and Lung Adenocarcinoma

The non-small cell lung cancer (NSCLC), including lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD), accounts for a large proportion of lung cancer cases. However, the mechanisms of LUSC and LUAD are very different, especially the pathogenesis of LUSC remains unclear. At present, the research on the targeted therapeutic sites of LUAD has approached maturity and these targets are of clinical significance. However, effective therapeutic targets have not been identified in LUSC, and at present, the same targeted therapeutic strategy for LUAD is also applied in LUSC treatment. We used the data from The Cancer Genome Atlas program to analyze the driver genes of LUAD and LUSC by two types of algorithms, namely, the OncodriveCLUST and Multi-Dendrix. Our results showed that the driver genes of LUAD concentrates in the KRAS/epidermal growth factor receptor/TP53 pathways, while LUSC involves multiple pathways, including PIK3CA, NFE2L2, and TP53. The results showed that different carcinogenic mechanisms exist between these two types of NSCLC, implying that different therapeutic targets for LUSC deserve our attention. At the same time, the results of survival analysis proved that the driver genes identified using the two algorithms in combination may be more valid and reliable than those identified by solely using MutsigCV.

Honokiol induces apoptosis of lung squamous cell carcinoma by targeting FGF2-FGFR1 autocrine loop.

Lung squamous cell carcinoma (SCC) accounts for a considerable proportion of lung cancer cases, but there is still a lack of effective therapies. FGFR1 amplification is generally considered a promising therapeutic target. Honokiol is a chemical compound that has been proven to be effective against various malignancies and whose analog has been reported to target the mitogen‐activated protein kinase family, members of a downstream signaling pathway of FGFR1. This was an explorative study to determine the mechanism of honokiol in lung SCC. We found that honokiol induced apoptosis and cell cycle arrest in lung SCC cell lines in a time‐ and dose‐dependent manner. Honokiol also restricted cell migration in lung SCC cell lines. Moreover, the expression of FGF2 and the activation of FGFR1 were both downregulated by honokiol. Pharmacological inhibition and siRNA knockdown of FGFR1 induced apoptosis in lung SCC cells. Our in vivo study indicated that honokiol could suppress the growth of xenograft tumors, and this effect was associated with the inhibition of the FGF2‐FGFR1 signaling pathway. In conclusion, honokiol induced cell apoptosis in lung SCC by targeting the FGF2‐FGFR1 autocrine loop.

NSCLC molecular testing in Central and Eastern European countries

BackgroundThe introduction of targeted treatments for subsets of non-small cell lung cancer (NSCLC) has highlighted the importance of accurate molecular diagnosis to determine if an actionable genetic alteration is present. Few data are available for Central and Eastern Europe (CEE) on mutation rates, testing rates, and compliance with testing guidelines.MethodsA questionnaire about molecular testing and NSCLC management was distributed to relevant specialists in nine CEE countries, and pathologists were asked to provide the results of EGFR and ALK testing over a 1-year period.ResultsA very high proportion of lung cancer cases are confirmed histologically/cytologically (75–100%), and molecular testing of NSCLC samples has been established in all evaluated CEE countries in 2014. Most countries follow national or international guidelines on which patients to test for EGFR mutations and ALK rearrangements. In most centers at that time, testing was undertaken on request of the clinician rather than on the preferred reflex basis. Immunohistochemistry, followed by fluorescent in situ hybridization confirmation of positive cases, has been widely adopted for ALK testing in the region. Limited reimbursement is a significant barrier to molecular testing in the region and a disincentive to reflex testing. Multidisciplinary tumor boards are established in most of the countries and centers, with 75–100% of cases being discussed at a multidisciplinary tumor board at specialized centers.ConclusionsMolecular testing is established throughout the CEE region, but improved and unbiased reimbursement remains a major challenge for the future. Increasing the number of patients reviewed by multidisciplinary boards outside of major centers and access to targeted therapy based on the result of molecular testing are other major challenges.

Population attributable risk associated with lung cancer induced by residential radon in Canada: Sensitivity to relative risk model and radon probability density function choices: In memory of Professor Jan M. Zielinski

Indoor radon has been identified as the second leading cause of lung cancer after tobacco smoking. The Population Attributable Risk (PAR) estimates the proportion of lung cancer cases associated with indoor radon exposure. Different relative risk (RR) models have been used in the literature to calculate PAR. The aim of this study is to assess how sensitive PAR is to the relative risk model and radon probability distribution functions choices. MethodsUsing Canadian observed first floor radon data collected by Health Canada during the period October 2010 to March 2011, seven common PAR radon models used for North American miners and dwelling scenarios were applied. The death rates used for this study were from the period 2006–2009. Smoking data (Ever Smoking ES and Never Smoking NS) collected in 2009 was also used in this study. The original discrete radon data for Canada overall and for each of its provinces are estimated using log-normal and Gaussian kernel density estimator distributions. PAR was then calculated for Canada and its provinces using the empirical, log-normal, and Gaussian kernel estimates distributions. Finally, cancer death cases attributable to radon are reported for the constant relative risk model for the three distributions and the reduction in the cases when the action level 200Bq/m3 is applied. ResultsPAR for the Canadian data is sensitive to the model choice, and it varies with a range of 10% for ES and 32% for NS, respectively. There is little difference in results between miners' models and dwelling models. PAR values for ES females are greater than those for ES males, except in Saskatchewan, Northwest Territories, Nunavut, and Yukon. The male-female range overlaps. Gaussian kernel estimator produces PAR estimates similar to the commonly used log-normal distribution. ConclusionMany lung cancer cases could be prevented in Canada by reducing indoor radon. PAR is sensitive to the choice of RR model. Miners' models can be used for residential radon. Empirical, log-normal, and Gaussian kernel density estimation with support [0,∞) can all be applied to radon data.

P1.01-059 Lung Cancer Epidemiology among the Bahraini Population, 2000-2011

Lung cancer is the fourth most common cancer in the Gulf Cooperation Council countries among males and the third among females. It is the commonest cancer among Bahraini males accounting to 16.9% of all cancers and the third in Bahraini females contributing to 5.8 % of all female cancers. The aim of this study was to describe the epidemiology of lung cancer among the Bahraini population during the period 1998-2011. All Bahraini registered lung cancer cases in the national cancer registry from 1 January 1998 to 31 December 2011 were included in the study. Incidence rates were calculated using the CANREG software, in which the annual crude incidence rates, age specific incidence rates and the age standardized incidence rate (ASR) were computed. Six hundred sixty four lung cancer cases (72.4%, males and 27.6% females) were diagnosed during the study period. The annual average number of cases was 47.5 per year. The mean age at diagnosis during the study period was 70.1 years. The average annual ASR was 26.1/ 100,000 among males and 10.0 / 100,000 among females. There was a tendency for a decreased trend of the ASR during 1998-2011 in both sexes. Twenty six percent of lung cancer cases were squamous cell carcinoma and 17.9% adenocarcinoma. The grades of 70.3% were unknown and 13.4% were poorly differentiated. The stage was unknown for 65.0% of the cases, while 18.5% had distant metastasis and 9.8% were localized. The majority (88.9 %) of the lung cancer cases were dead by the end of the study period with a five-year survival rate of 3.0%. A welcomed decline in the incidence of lung cancer has been noted over the past 14 years. However, more efforts should be put to reduce the proportion of lung cancer cases with unknown stage and grade. The incidence of histological types, which are strongly dependent on tobacco smoking, notably small cell, squamous cell and large cell carcinomas, accounted for over one third of lung cancer cases. Future research should be directed towards better understanding of the lung cancer risk factors and the effectiveness of tobacco control measures in in the country.

Time Trends in Epidemiologic Characteristics and Imaging Features of Lung Adenocarcinoma: A Population Study of 21,113 Cases in China.

ObjectivesThis study aims to describe time trends of epidemiologic characteristics and imaging features over 14 years among histologically confirmed lung adenocarcinoma (ADC) in China and to discuss the possible reasons for these changes.Materials and MethodsData of 21,113 pathologically confirmed lung cancer patients from January 1999 to December 2012 were analyzed retrospectively. Preoperative high-resolution computer tomography (HRCT) images were available and reviewed in 5,439 lung ADC patients since 2005. Time trends of the ADC proportion of lung cancer cases, gender distribution, age at diagnosis, the proportion of early-stage ADC and imaging features were investigated.ResultsThe proportion of ADC increased during the 14 years (P = 0.000). The ratio of female to male ADC cases was higher than both squamous cell carcinoma (SQCC) and total lung cancer cases (P = 0.000). The median age at diagnosis of ADC patients was younger than that of both SQCC and total lung cancer during the 14 years (P = 0.000). The proportion of age group 45–59 years increased in total lung cancer cases (P = 0.000). When stratified by lung cancer histopathologic subtypes, this trend was also observed in ADC (P = 0.001) and SQCC (P = 0.007). The proportion of early-stage cases of ADC increased from 2008 to 2012 (P < 0.001). The proportion of subsolid nodules (SSN) in ADC increased (P = 0.001) from 2005 to 2012.ConclusionThe data suggests that the proportion of ADC increased from 1999 to 2012 especially in middle-aged, female patients; early-stage ADC and SSN on HRCT images gradually increased, which may have been caused by a change in smoking habits and increased application of HRCT.

Estimating the Proportion of Cases of Lung Cancer Legally Attributable to Smoking: A Novel Approach for Class Actions Against the Tobacco Industry

The plaintiffs' lawyers for a class action suit, which was launched in Quebec on behalf of all patients with lung cancer whose disease was caused by cigarette smoking, asked us to estimate what proportion of lung cancer cases in Quebec, if they hypothetically could be individually evaluated, would satisfy the criterion that it is "more likely than not" that smoking caused the disease. The novel methodology we developed is based on the dose-response relationship between smoking and lung cancer, for which we use the pack-years as a measure of smoking, and the distribution of pack-years of smoking among cases. We estimated that the amount of smoking required to satisfy the "more likely than not" criterion is between 3 and 11 pack-years. More than 90% of the Quebec cases satisfied even the most conservative of these thresholds. More than 90% of cases of lung cancer in Quebec are legally attributable to smoking. The methodology enhances the ability to conduct class action suits against the tobacco industry.