Intrathoracic Lymph Node Microcalcifications are Associated With a High Prevalence of Malignancy and Anaplastic Lymphoma Kinase Rearrangement: The "Calce" Study.

BACKGROUND: Microcalcifications are acknowledged as a malignancy risk factor in multiple cancers. However, the prevalence and association of intrathoracic lymph node (ILN) calcifications with malignancy remain unexplored. METHODS: In this cross-sectional study, we enrolled patients with known/suspected malignancy and an indication for endosonography for diagnosis or ILN staging. We assessed the prevalence and pattern of calcified ILNs and the prevalence of malignancy in ILNs with and without calcifications. In addition, we evaluated the genomic profile and PD-L1 expression in lung cancer patients, stratifying them based on the presence or absence of ILN calcifications. RESULTS: A total of 571 ILNs were sampled in 352 patients. Calcifications were detected in 85 (24.1%) patients and in 94 (16.5%) ILNs, with microcalcifications (78/94, 83%) being the predominant type. Compared with ILNs without calcifications (214/477, 44.9%), the prevalence of malignancy was higher in ILNs with microcalcifications (73/78, 93.6%; P<0.0001) but not in those with macrocalcifications (7/16, 43.7%; P=0.93). In patients with lung cancer, the high prevalence of metastatic involvement in ILNs displaying microcalcifications was independent of lymph node size (< or >1 cm) and the clinical stage (advanced disease; cN2/N3 disease; cN0/N1 disease). The anaplastic lymphoma kinase (ALK) rearrangement was significantly more prevalent in patients with than in those without calcified ILNs (17.4% vs. 1.7%, P<0.001), and all of them exhibited microcalcifications. CONCLUSION: ILN microcalcifications are common in patients undergoing endosonography for suspected malignancy, and they are associated with a high prevalence of metastatic involvement and ALK rearrangement.

A systematic review and dose-response meta-analysis of prospective cohort studies on coffee consumption and risk of lung cancer.

Studies on the association between coffee consumption and risk of lung cancer have been conflicting. The aim of this study was to systematically review the current evidence on the association between coffee consumption and risk of lung cancer and to quantify this association by performing a meta-analysis. A comprehensive systematic search was performed on online databases up to July 2023 investigating the association between coffee consumption and risk of lung cancer. All prospective cohort studies reporting odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) in this context were included. The overall effect size was calculated using the random-effects model and statistical between-studies heterogeneity was examined using Cochrane's Q test and I2. A total of 14 prospective cohort studies were included in this systematic review and meta-analysis. We found a significant positive association between coffee consumption and risk of lung cancer (RR: 1.28; 95% CI: 1.12, 1.47). This association remained significant when we included a pooled analysis paper and excluded 5 cohort studies (RR: 1.37; 95% CI: 1.12, 1.66). We observed no proof of significant publication bias using Egger's test (P = 0.58). Moreover, dose-response analysis showed that each one cup/day increase in coffee consumption was related with a 6% higher lung cancer risk (RR: 1.06; 95% CI: 1.03, 1.09). In conclusion, we found a significant positive association between coffee consumption and risk of lung cancer.

Clinical investigation of former workers exposed to asbestos: the health surveillance experience of an Italian University Hospital.

Background: The need for health surveillance of former workers exposed to asbestos was provided by law in Italy after the asbestos ban in 1992. Objectives: We describe the results of the health surveillance of former workers exposed to asbestos, conducted over 27 years, from 1994 to 2020, at the Operative Unit of Occupational Medicine of the University Hospital of Bari. Materials and methods: We adopted the health surveillance protocol, which was validated at the national level in 2018. Results: A total of 1,405 former workers exposed to asbestos were examined. We proceeded with diagnosing pathologies in 339 cases (24% of the cohort subjected to surveillance), with diagnoses of some cases involving multiple pathologies. Specifically, pleural plaques were diagnosed in 49.2% of the 339 cases, asbestosis in 35.9%, malignant pleural mesothelioma (MPM) in 20.3%, mesothelioma of the vaginal tunic of the testis (MTVT) in 9.1%, lung cancer in 5.8%, and laryngeal cancer in 0.8%. Conclusion: Despite the 1992 asbestos ban, asbestos-related diseases remain a serious public health issue. It is important to establish criteria that ensure the health surveillance of formerly exposed workers minimizes costs, reduces the number of invasive examinations, and optimizes achievable results.

Beyond lung cancer: air pollution and bladder, breast and prostate cancer incidence.

BACKGROUND: The carcinogenicity of air pollution and its impact on the risk of lung cancer is well known; however, there are still knowledge gaps and mixed results for other sites of cancer. METHODS: The current study aimed to evaluate the associations between ambient air pollution [fine particulate matter (PM2.5) and nitrogen oxides (NOx)] and cancer incidence. Exposure assessment was based on historical addresses of >900 000 participants. Cancer incidence included primary cancer cases diagnosed from 2007 to 2015 (n = 30 979). Cox regression was used to evaluate the associations between ambient air pollution and cancer incidence [hazard ratio (HR), 95% CI]. RESULTS: In the single-pollutant models, an increase of one interquartile range (IQR) (2.11 µg/m3) of PM2.5 was associated with an increased risk of all cancer sites (HR = 1.51, 95% CI: 1.47-1.54), lung cancer (HR = 1.73, 95% CI: 1.60-1.87), bladder cancer (HR = 1.50, 95% CI: 1.37-1.65), breast cancer (HR = 1.50, 95% CI: 1.42-1.58) and prostate cancer (HR = 1.41, 95% CI: 1.31-1.52). In the single-pollutant and the co-pollutant models, the estimates for PM2.5 were stronger compared with NOx for all the investigated cancer sites. CONCLUSIONS: Our findings confirm the carcinogenicity of ambient air pollution on lung cancer and provide additional evidence for bladder, breast and prostate cancers. Further studies are needed to confirm our observation regarding prostate cancer. However, the need for more research should not be a barrier to implementing policies to limit the population's exposure to air pollution.

KRAS and BRAF genetic alterations in lung cancer: A case - control study.

CONTEXT: Lung cancer (LC) is one of the most critical neoplastic abnormalities, having globally a high mortality rate. Knowledge about its genetic mutations and their association with clinically pathological features of LC is very important. Here, we describe the epidemiological molecular study of genetic mutations in KRAS and BRAF genes and their relationship with the demographic and clinical characteristics of Pakistani patients with lung adenocarcinoma. AIM: To analyze the mutations of KRAS and BRAF in LC patients among Pakistani population. SETTINGS AND DESIGN: The study has been carried out at universities and health institutes of Islamabad, Pakistan. METHODS AND MATERIAL: Deoxyribonucleic acid (DNA) was extracted from the patient samples by using the standard protocol and amplified by using the specific primers. Later on, the Polymerase Chain Reaction (PCR) products were examined with the help of single stranded conformational polymorphism (SSCP). STATISTICAL ANALYSIS: Relationship between KRAS, BRAF mutations, and LC risk was accessed by conditional logistic regression using SPSS version 24.0. Results were illustrated by odds ratio (OR), 95% confidence interval (CI), and P value. RESULTS: LC is more common in male population and smoking is one of the leading risk factors for (p < 0.0001) LC. KRAS and BRAF mutations were found to be contributing factors toward LC development and showed statistically significant results along with conformation through computational analysis. CONCLUSIONS: It can be concluded that smoking is lethal and cancer causing. The concomitant mutations found in KRAS and BRAF were infrequent, and they probably have a very unusual effect on the clinical management of Pakistani patients with lung adenocarcinoma.

[County differences in incidence and mortality of malignant neoplasms in Hungary between 2005 and 2019]. / A rosszindulatú daganatos betegségek incidenciájának és mortalitásának vármegyénkénti különbségei Magyarországon 2005 és 2019 között.

The objective of our study was to map county differences in incidence and mortality by cancers and examine their changes over time. Based on the database of National Cancer Registry and Central Statistical Office, age-standardized incidence and mortality rates per 100,000 person-years were calculated for each county for 15 cancer types and 3 time periods. East-West divide was apparent in incidence and mortality of lung cancer, with larger weight in East (Borsod-Abaúj-Zemplén, Heves, Jász-Nagykun-Szolnok, Békés counties). Concentration of lip and oral cavity malignancies was identified in the northeastern periphery (Borsod-Abaúj-Zemplén, Szabolcs-Szatmár-Bereg counties). Breast cancer incidence was the highest in Budapest. As a conclusion, changes in cancer incidence and mortality over time were similar to developed countries; however, values were higher. Differences in spatial distribution follow territorial pattern of social deprivation, which correspond to higher prevalence of health risk factors. Our study contributes to planning of public health programs by pinpointing regional inequalities in different cancer types.

[The pitfalls of lung cancer coding practices based on the evaluation of the National Cancer Registry]. / A tüdorákhoz kötodo kódolási gyakorlat buktatói a Nemzeti Rákregiszter felmérése alapján.

The quality of input data determines the reliability of epidemiological assessments. Thus, the verification of cases reported to the National Cancer Registry is required. The objective of our study was evaluating the reliability of cases diagnosed by lung cancer, exploring the patterns of erroneous reports. The validation of the 11,750 lung cancer cases reported to the Cancer Registry in 2018 was performed with the involvement of the recording hospitals, analyzing the characteristics of reports by gender, age and attributes of the reporting institutions. 81.3 percent of the reported cases was confirmed, in 40.4 percent of the false reports, malignancy was not present at all. Among the erroneous cases women and the elderly age group were overrepresented. The highest deleted rate occurred in Borsod- Abaúj-Zemplén county. As a conclusion, there is a strong need for the improvement of the efficiency in encoding lung cancer. The most common errors: confusion of malignant-benign, cancerous-non-cancerous and primary-metastatic lesions. The reliability is not affected by the role of individual institutions in the hierarchy of health care. The availability of reliable epidemiological data is crucial in the fight against cancer, which requires broad professional cooperation.

Projection of the prevalence of tracheal, bronchus, and lung cancer incidence using cigarette smoking prevalence in Iran from 1990 to 2018: a comparison of latent period-based models with standard forecasting models.

BACKGROUND: Smoking is the major risk factor for tracheal, bronchus, and lung (TBL) cancers. We investigated the feasibility of projecting TBL cancer incidence using smoking incidence rates by incorporating a range of latent periods from the main risk factor exposure to TBL cancer diagnosis. METHODS: In this ecological study, we extracted data on TBL cancer incidence rates in Iran from 1990 to 2018 from the Global Burden of Disease (GBD) database. We also collected data on Iranian cigarette smoking patterns over the past 40 years through a literature review. The weighted average smoking incidence was calculated using a fixed-effects model with Comprehensive Meta-Analysis (CMA) software. Using these data, the five-year TBL cancer incidence in Iran was projected through time series modeling with IT Service Management (ITSM) 2000 software. A second model was developed based on cigarette smoking incidence using linear regression with SPSS (version 22), incorporating different latent periods. The results of these two models were compared to determine the best latent periods. RESULTS: An increasing trend in TBL cancer incidence was observed from 2019 to 2023 (first model: 10.30 [95% CI: 9.62, 10.99] to 11.42 [95% CI: 10.85, 11.99] per 100,000 people). In the second model, the most accurate prediction was obtained with latent periods of 17 to 20 years, with the best prediction using a 17-year latent period (10.13 to 11.40 per 100,000 people) and the smallest mean difference of 0.08 (0.84%) per 100,000 people using the standard forecasting model (the ARIMA model). CONCLUSION: Projecting an increase in TBL cancer incidence rates in the future, an optimal latent period of 17 to 20 years between exposure to cigarette smoke and TBL cancer incidence has implications for macrolevel preventive health policymaking to help reduce the burden of TBL cancer in upcoming years.

Allostatic Load/Chronic Stress and Cardiovascular Outcomes in Patients Diagnosed With Breast, Lung, or Colorectal Cancer.

BACKGROUND: Cardiovascular disease and cancer share a common risk factor: chronic stress/allostatic load (AL). A 1-point increase in AL is linked to up to a 30% higher risk of major cardiac events (MACE) in patients with prostate cancer. However, AL's role in MACE in breast cancer, lung cancer, or colorectal cancer remains unknown. METHODS AND RESULTS: Patients ≥18 years of age diagnosed with the mentioned 3 cancers of interest (2010-2019) and followed up at a large, hybrid academic-community practice were included in this retrospective cohort study. AL was modeled as an ordinal measure (0-11). Adjusted Fine-Gray competing risks regressions estimated the impact of AL precancer diagnosis on 2-year MACE (a composite of heart failure, ischemic stroke, acute coronary syndrome, and atrial fibrillation). The effect of AL changes over time on MACE was calculated via piecewise Cox regression (before, and 2 months, 6 months, and 1 year after cancer diagnosis). Among 16 467 patients, 50.5% had breast cancer, 27.9% had lung cancer, and 21.4% had colorectal cancer. A 1-point elevation in AL before breast cancer diagnosis corresponded to a 10% heightened associated risk of MACE (adjusted hazard ratio, 1.10 [95% CI, 1.06-1.13]). Similar findings were noted in lung cancer (adjusted hazard ratio, 1.16 [95% CI, 1.12-1.20]) and colorectal cancer (adjusted hazard ratio, 1.13 [95% CI, 1.08-1.19]). When considering AL as a time-varying exposure, the peak associated MACE risk occurred with a 1-point AL rise between 6 and 12 months post- breast cancer, lung cancer, and colorectal cancer diagnosis. CONCLUSIONS: AL warrants investigation as a potential marker in these patients to identify those at elevated cardiovascular risk and intervene accordingly.

Trends in primary care blood tests prior to lung and colorectal cancer diagnosis-A retrospective cohort study using linked Australian data.

INTRODUCTION: Abnormal results in common blood tests may occur several months before lung cancer (LC) and colorectal cancer (CRC) diagnosis. Identifying early blood markers of cancer and distinct blood test signatures could support earlier diagnosis in general practice. METHODS: Using linked Australian primary care and hospital cancer registry data, we conducted a cohort study of 855 LC and 399 CRC patients diagnosed between 2001 and 2021. Requests and results from general practice blood tests (six acute phase reactants [APR] and six red blood cell indices [RBCI]) were examined in the 2 years before cancer diagnosis. Poisson regression models were used to estimate monthly incidence rates and examine pre-diagnostic trends in blood test use and abnormal results prior to cancer diagnosis, comparing patterns in LC and CRC patients. RESULTS: General practice blood test requests increase from 7 months before CRC and 6 months before LC diagnosis. Abnormalities in many APR and RBCI tests increase several months before cancer diagnosis, often occur prior to or in the absence of anaemia (in 51% of CRC and 81% of LC patients with abnormalities), and are different in LC and CRC patients. CONCLUSIONS: This study demonstrates an increase in diagnostic activity in Australian general practice several months before LC and CRC diagnosis, indicating potential opportunities for earlier diagnosis. It identifies blood test abnormalities and distinct signatures that are early markers of LC and CRC. If combined with other pre-diagnostic information, these blood tests have potential to support GPs in prioritising patients for cancer investigation of different sites to expedite diagnosis.

Exposure to second-hand smoke and risk of lung cancer among Iranian population: A multicenter case-control study.

OBJECTIVE: Despite the implementation of the WHO Framework Convention on Tobacco Control (FCTC) program in Iran, the regulation of second-hand smoke (SHS) exposure-an often-overlooked hazard-, still requires improvement. We employed a multi-center case-control study to investigate the association between exposure to secondhand smoke (SHS) from various tobacco products (cigarettes, water-pipes, pipes, and chopogh), opium use, and the risk of lung cancer. METHOD: We included 627 lung cancer cases and 3477 controls. Exposure to SHS tobacco and SHS opium was collected through a questionnaire. We used mixed-model logistic regressions to estimate odds ratios (ORs) and 95% confidence intervals (CI). RESULT: Among the overall population exposed to second-hand tobacco smoke (SHTS), the odds ratio (OR) compared to those never exposed was 1.35 (95% CI: 1.08-1.71). Never smokers who were ever exposed to second-hand tobacco smoke (SHTS) had 1.69-fold risk of lung cancer compared to those who were never exposed (95% CI: 1.13-2.52). Exposure to SHTS between 2-3 per day (OR = 2.27, 95% CI: 1.13-4.53) and more than three hours per day (OR = 2.29, 95% CI: 1.20-4.37) can increase the risk of lung cancer compared with the no exposure group (P-trend <0.01). We did not observe any association between exposure to second-hand opium smoke (SHOS) and the risk of lung cancer, either in the overall population or among never-smokers. CONCLUSION: Our study estimates the impact of second-hand tobacco smoke (SHTS) on lung cancer risk in both the overall population and never-smokers. Additional studies are required to evaluate the association between exposure to second-hand smoke from opium and other type of tobacco, including water-pipe and the risk of lung cancer.

Exploring the causal association between uric acid and lung cancer in east Asian and European populations: a mendelian randomization study.

BACKGROUND: Lung cancer still ranks first in the mortality rate of cancer. Uric acid is a product of purine metabolism in humans. Its presence in the serum is controversial; some say that its high levels have a protective effect against tumors, others say the opposite, that is, high levels increase the risk of cancer. Therefore, the aim of this study was to investigate the potential causal association between serum uric acid levels and lung cancer. METHODS: Mendelian randomization was used to achieve our aim. Sensitivity analyses was performed to validate the reliability of the results, followed by reverse Mendelian analyses to determine a potential reverse causal association. RESULTS: A significant causal association was found between serum uric acid levels and lung cancer in East Asian and European populations. Further sublayer analysis revealed a significant causal association between uric acid and small cell lung cancer, while no potential association was observed between uric acid and non-small cell lung cancer, squamous lung cancer, and lung adenocarcinoma. The sensitivity analyses confirmed the reliability of the results. Reverse Mendelian analysis showed no reverse causal association between uric acid and lung cancer. CONCLUSIONS: The results of this study suggested that serum uric acid levels were negatively associated with lung cancer, with uric acid being a potential protective factor for lung cancer. In addition, uric acid level monitoring was simple and inexpensive. Therefore, it might be used as a biomarker for lung cancer, promoting its wide use clinical practice.

Risk of lung diseases in patients with previous carbon monoxide poisoning: a nationwide population-based cohort study in the Republic of Korea.

INTRODUCTION: Carbon monoxide poisoning is associated with severe damage to various organs. In this study, we aimed to determine if previous carbon monoxide poisoning was associated with an increased risk of lung diseases. METHODS: The study population was derived from the National Health Insurance Service database of Korea between 1 January 2002 and 31 December 2021. Adults with carbon monoxide poisoning, with at least one visit to medical facilities between 2002 and 2021, were included. For comparison, an equal number of matched controls with the same index date were selected from the database. RESULTS: A total of 28,618 patients with carbon monoxide poisoning and 28,618 matched controls were included in this study. Approximately 42.8 per cent of the patient and control groups were female, with a mean age of 51.3 years. In patients with carbon monoxide poisoning, there was a significant increase in the risk of lung cancer (adjusted hazard ratio, 1.84; 95 per cent confidence interval, 1.42-2.39; P < 0.001), chronic obstructive pulmonary disease (adjusted hazard ratio, 1.60; 95 per cent confidence interval, 1.36-1.89; P < 0.001), pulmonary tuberculosis (adjusted hazard ratio, 1.46; 95 per cent confidence interval, 1.13-1.88; P = 0.003), and non-tuberculous mycobacterial infection (adjusted hazard ratio, 1.54; 95 per cent confidence interval, 1.01-2.36; P = 0.047). DISCUSSION: In this retrospective cohort study, previous carbon monoxide poisoning was associated with an increased risk of lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection. Further studies are needed to confirm such an association in other populations and the risk of lung diseases due to the toxic effect of carbon monoxide from different sources. CONCLUSIONS: Previous carbon monoxide poisoning was associated with an increased risk of lung diseases, but the relative importance of the causes and sources of exposure was not known. The long-term management of survivors of acute carbon monoxide poisoning should include monitoring for lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection.

The associations between dysregulation of human blood metabolites and lung cancer risk: evidence from genetic data.

BACKGROUND: Metabolic dysregulation is recognized as a significant hallmark of cancer progression. Although numerous studies have linked specific metabolic pathways to cancer incidence, the causal relationship between blood metabolites and lung cancer risk remains unclear. METHODS: Genomic data from 29,266 lung cancer patients and 56,450 control individuals from the Transdisciplinary Research in Cancer of the Lung and the International Lung Cancer Consortium (TRICL-ILCCO) were utilized, and findings were replicated using additional data from the FinnGen consortium. The analysis focused on the associations between 486 blood metabolites and the susceptibility to overall lung cancer and its three major clinical subtypes. Various Mendelian randomization methods, including inverse-variance weighting, weighted median estimation, and MR-Egger regression, were employed to ensure the robustness of our findings. RESULTS: A total of 19 blood metabolites were identified with significant associations with lung cancer risk. Specifically, oleate (OR per SD = 2.56, 95% CI: 1.51 to 4.36), 1-arachidonoylglyceropholine (OR = 1.79, 95% CI: 1.22 to 2.65), and arachidonate (OR = 1.67, 95% CI: 1.16 to 2.40) were associated with a higher risk of lung cancer. Conversely, 1-linoleoylglycerophosphoethanolamine (OR = 0.57, 95% CI: 0.40 to 0.82), ADpSGEGDFXAEGGGVR, a fibrinogen cleavage peptide (OR = 0.60, 95% CI: 0.47 to 0.77), and isovalerylcarnitine (OR = 0.62, 95% CI: 0.49 to 0.78) were associated with a lower risk of lung cancer. Notably, isoleucine (OR = 9.64, 95% CI: 2.55 to 36.38) was associated with a significantly higher risk of lung squamous cell cancer, while acetyl phosphate (OR = 0.11, 95% CI: 0.01 to 0.89) was associated with a significantly lower risk of small cell lung cancer. CONCLUSION: This study reveals the complex relationships between specific blood metabolites and lung cancer risk, highlighting their potential as biomarkers for lung cancer prevention, screening, and treatment. The findings not only deepen our understanding of the metabolic mechanisms of lung cancer but also provide new insights for future treatment strategies.

[Interpretation on the report of global cancer statistics 2022].

In April 2024, the World Health Organization/International Agency for Research on Cancer (IARC) published the global cancer statistics 2022 in the CA: Cancer Journal for Clinicians. This report focuses on the incidence and mortality of 36 cancers in 185 countries or territories worldwide, analyzing the differences of gender, geographic region, and the Human Development Index (HDI) level. It is estimated that in the year 2022, there were 19.96 million new cancer cases and 9.74 million cancer deaths worldwide. Lung cancer (2 480 301, 12.4%) was the most frequently diagnosed cancer in 2022, followed by female breast cancer (2 295 686, 11.5%), colorectal cancer (1 926 118, 9.6%), prostate cancer (1 466 680, 7.3%), and gastric cancer (968 350, 4.9%). Lung cancer (1 817 172, 18.7%) was also the leading cause of cancer death, followed by colorectal cancer (903 859, 9.3%), liver cancer (757 948, 7.8%), female breast cancer (665 684, 6.9%), and gastric cancer (659 853, 6.8%). With demographics-based predictions indicating that the number of new cases of cancer will reach over 35 million by 2050. The Beijing Office for Cancer Prevention and Control team has collated this report and briefly interpreted it in combination with the current situation of cancer incidence and mortality in China.

[Epidemiological signatures and surveillance bias in cancer]. / Signatures épidémiologiques et biais de surveillance du cancer.

Surveillance bias occurs when variations in cancer incidence are the result of changes in screening or diagnostic practices rather than increases in the true occurrence of cancer. This bias is linked to the issue of overdiagnosis and can be apprehended by looking at epidemiological signatures of cancer. We explain the concept of epidemiological signatures using the examples of melanoma and of lung and prostate cancer. Accounting for surveillance bias is particularly important for assessing the true burden of cancer and for accurately communicating cancer information to the population and decision-makers.

Le biais de surveillance se produit lorsque les variations d'incidence d'un cancer sont le résultat d'un changement dans les pratiques de dépistage ou de diagnostic plutôt que d'une augmentation de la fréquence réelle de ce cancer. Ce biais est lié au concept du surdiagnostic et peut être appréhendé en examinant les signatures épidémiologiques des cancers. Nous expliquons le concept de signature épidémiologique à l'aide des exemples du mélanome et des cancers du poumon et de la prostate. La prise en compte des biais de surveillance est particulièrement importante pour évaluer le fardeau réel du cancer et communiquer avec précision l'information sur le cancer à la population et aux décideurs.

Lung cancer: a nationwide analysis of sex and age incidence trends from 1980 to 2022.

BACKGROUND: Lung cancer, once rare, has evolved into the global leading cause of cancer-related mortality, primarily driven by widespread cigarette smoking in the 20th century. This study explores the historical trends of lung cancer incidence in Denmark over four decades, emphasizing the impact of smoking prevalence, age, and gender on the observed patterns. MATERIALS AND METHODS: Drawing upon data from the Danish National Patient Register and information on smoking habits provided by the Danish Health Authority, this study investigates lung cancer incidence rates, demographic shifts, and smoking prevalence from 1980 to 2022. RESULTS: Smoking prevalence exhibited a consistent decline in males from 1950 to 2022, whereas female smoking prevalence maintained a stable level from 1950 to 1987, followed by a subsequent decline from 1987 to 2022. A peak in lung cancer crude incidence rates was identified during 2014-2017, with no significant difference observed before and after this period. Over the period, the gender distribution transitioned from a male majority to an equal male-female ratio, and age-specific disparities indicated declines in patients aged 50-59 and increases in those above 80 years. INTERPRETATION: The certainty of a decline in lung cancer incidence in the coming years remains unclear. Based on smoking prevalence, it might still be a decade away. To ensure a sustained decline in lung cancer incidence, targeted interventions are imperative, including customized smoking cessation programs that could be designed favorably for females. Given the modest decline in smoking prevalence over the last decade, legislation aimed at discouraging young individuals from smoking is pivotal. As of now, these efforts have not been implemented in Denmark.