Silica is one of the main occupational agents associated with lung cancer. It is classified by the International Agency for Research on Cancer (IARC) as a Group 1 substance, i.e., carcinogenic for humans, since 1996. The objective of this paper is to report two cases of workers previously exposed to silica who developed lung cancer, seen in an out-patient clinic, focusing on important points of the current literature on the subject.

Lung cancer is a multifactorial disease. Hereditary, genetic, and environmental factors interact in its genesis. The principal risk factor for lung cancer is smoking. However, the workplace provides an environment in which there is a risk of exposure to carcinogens. The International Agency for Research on Cancer currently lists 19 substances/work situations/occupations that have been proven to be associated with lung cancer (group 1). Thorough occupational history taking is not widely practiced in patients with lung cancer, which has a negative impact on the investigation of causality and, consequently, on the identification of cases of occupational cancer. The objectives of this review were to list the agents that are recognized as causes of lung cancer, to discuss the contribution of occupation to the development of the disease, to cite national studies on the subject, and to propose a list of procedures that are essential to the appropriate investigation of causality between lung cancer and occupation.

Keywords: Lung neoplasms; Occupational diseases; Occupations; Carcinogens.

Objective: Silicosis is a pneumoconiosis characterized by fibrosis of the lung parenchyma caused by the inhalation of silica particles. Silica dust inhalation is associated with inflammation and induction of oxidative stress in the lungs. This oxidative stress affects telomeres, which are short tandem DNA repeats that cap the end of linear chromosomes. We aimed to determine whether telomere length (TL) correlates with silicosis or severity of silicosis in silica-exposed workers in Brazil. Methods: We included 200 men in southeastern Brazil: 100 with silicosis and 100 who had not been exposed to silica. We extracted DNA from buccal cells and assessed TL by multiplex quantitative polymerase chain reaction. Results: The median TL was significantly shorter in the patients with silicosis than in the unexposed controls (p < 0.0001), although it did not differ between the patients with simple silicosis and those with complicated silicosis (p = 0.961). We also found that, in patients with silicosis, TL was influenced by smoking (p = 0.034) and by a history of personal protective equipment use in the workplace (p = 0.002). Conclusions: Silica exposure appears to have an impact on TL, which was found to be shorter in patients with silicosis than in unexposed controls. Further studies are needed in order to confirm the impact that oxidative stress caused by silica inhalation has on telomeres.

Keywords: Silicosis; Oxidative stress; Inflammation; Telomere.

Background: The primary work-related lung disease in Brazil is silicosis. Its pathogenic agent is the dust of crystalline free silica (SiO2; silicon dioxide). The inflammatory process of silicosis is not yet well understood. Objective: To analyze, through immunologic laboratory evaluation, including nonspecific and specific immunity, the profile of IgG, IgM, IgA, C3, C4 and autoantibodies in the serum of workers, with or without silicosis, exposed to silica. Methods: Fifty-eight male workers were studied. All had been exposed to silica. Immunologic, radiologic and functional evaluations were made. The immunoglobulins IgG, IgA, and IgM, the complement system components C3 and C4, and the autoantibodies were assessed. Results: Chest X-rays were normal in 20 of the 58 workers and compatible with silicosis in 38. Among the 38 who were positive, IgG values were, on average, higher than in the group with normal X-rays (p < 0.05). There were no significant differences in average values of IgA, IgM, C3 or C4 (p > 0.05). The percentage of autoantibody positivity was higher in the silicosis group than in the group with normal X-rays. Conclusion: The increased levels of IgG in patients with silicosis constitutes an important discovery. It may represent continuity of the granulomatous reaction, even when the individual is no longer being exposed to silica. However, further studies are necessary in order to increase understanding of the mechanism involved in the silicosis immunologic process.

Keywords: Lung diseases. Silicosis. Occupational diseases. Immunoglobulins

Recent advances in genetics and molecular biology lead to the identification of genes and protein products overexpressed by tumors. Such products, called tumor markers, were previously used only as diagnostic and prognostic tools, but are currently being the target of extensive research, with growing evidence that some of them may have an important role in the development of new treatment modalities, targeting the tumor cell biological cycle. In this article, the authors review the role of some of the traditionally known tumor markers (CEA, p53, NSE, K-ras), and describe the prevalence and the role of the epidermal growth factor receptor (EGFR) overexpression and its protein product, p185neu. New drugs have been developed, aiming at the blockade of the signaling process initiated by the EGFR. Among these, the authors highlight ZD1839 (Iressa), a new orally administered drug that reversibly and selectively inhibits the EGFR tyrosine-kinase activity. This drug has demonstrated good results in the treatment of non-small-cell lung cancer, as an isolated drug or in combination with other chemotherapy agents. Targeting the EGFR could represent a significant contribution to cancer therapy, mainly the non-small-cell lung cancer.

Keywords: Lung neoplasms. Tumor markers. Receptor epidermal growth factor.

Exposure to radon can impact human health. This is a nonsystematic review of articles written in English, Spanish, French, or Portuguese published in the last decade (2013-2023), using databases such as PubMed, Google Scholar, EMBASE, and SciELO. Search terms selected were radon, human health, respiratory diseases, children, and adults. After analyzing the titles and abstracts, the researchers initially identified 47 studies, which were subsequently reduced to 40 after excluding reviews, dissertations, theses, and case-control studies. The studies have shown that enclosed environments such as residences and workplaces have higher levels of radon than those outdoors. Moreover, radon is one of the leading causes of lung cancer, especially in nonsmokers. An association between exposure to radon and development of other lung diseases, such as asthma and COPD, was also observed. It is crucial to increase public awareness and implement governmental control measures to reduce radon exposure. It is essential to quantify radon levels in all types of buildings and train professionals to conduct such measurements according to proven efficacy standards. Health care professionals should also be informed about this threat and receive adequate training to deal with the effects of radon on human health.

Keywords: Radon; Lung neoplasms; Risk factors.

Objective: To evaluate the radiological characteristics of conglomerate masses using high-resolution computed tomography of the chest. Methods: From among the patients treated between 1986 and 2004 at the Antonio Pedro University Hospital, 75 patients with silicosis and massive fibrosis, most working in the field of sandblasting, were selected for study. These patients were submitted to a clinical evaluation, chest X-ray and high-resolution computed tomography of the chest. Results: In more than half of the patients with accelerated silicosis, the chest X-ray revealed large type B and C opacities, denoting the severity of the disease in those patients. In 1 case, a unilateral mass simulating lung cancer was observed. High-resolution computed tomography scans of the chest were acquired for 44 patients. In most cases (88.6%), the masses were located in the superior and posterior thirds of the lung. Common findings within the masses included air bronchograms (in 70.4%) and calcifications (in 63.6%). A history of tuberculosis was reported by 52% of the patients. Conclusion: In the vast majority of cases, the masses were bilateral, predominantly located in the superior and posterior regions of the lung, featuring air bronchograms and interposed calcifications. Concomitant calcification of the mediastinal and hilar lymph nodes was another common finding. Exposure to high concentrations of dust and having a history of tuberculosis were considered significant risk factors for the development of progressive massive fibrosis.

Keywords: Pulmonary fibrosis; Silicosis; Silicon dioxide; Occupational diseases; Environmental exposure;

Introduction: Silicosis is the most prevalent pneumoconiosis in Brazil, with most of the registered cases occurring in the State of Minas Gerais. Although it is a preventable disease, silicosis is still epidemic in some areas. Objective: To describe the profile of workers seen at the Clinics Hospital of the Federal University of Minas Gerais. Patients and methods: 300 medical records of silica-exposed workers in different occupations, seen between 1989-2000, were reviewed. Clinical and occupational information, radiographic and spirometric data were analyzed. Statistical methods included univariate analyses with chi-square and t tests. Results and conclusion: The mean age of the exposed patients was 51 years, with mean exposure duration of 15.6 years. 126/300 (42%) were radiologically classified as cases of silicosis. Increasing grades of profusion were associated with lower spirometric indices and more frequent associations with tuberculosis and chronic airflow limitation. Most of the workers were regularly registered employees and the main occupational activity was mining, accounting for the exposure of 197 (66%) workers. Non-registered workers presented more severe radiological grades of silicosis, suggesting, possibly, worse conditions of silica exposure in this group of workers.

We present the case of a 60-year-old female patient who had been in menopause for 14 years and presented a pulmonary nodule on chest X-ray diagnosed in the postoperative follow-up evaluation of breast cancer. The patient had a history of mastectomy and ipsilateral axillary lymphadenectomy for invasive ductal breast carcinoma, as well as of hormone therapy, chemotherapy, and adjuvant radiotherapy. After thoracoscopic nodulectomy, the frozen section analysis revealed a pulmonary hamartoma. Recent studies show that 75% of patients who undergo surgery for pulmonary nodules after a curative mastectomy for breast cancer present lung metastases, 11.5% present primary lung cancer, and 13.5% present benign lesions, including hamartoma.

Keywords: Hamartoma; Breast neoplasms; Lung neoplasms; Neoplasm metastasis.

Objective: To determine the diagnostic accuracy of positron emission tomography/computed tomography (PET/CT) using fluorine- 18‑deoxyglucose ([18F]-FDG) for the evaluation of a solitary pulmonary nodule (SPN). Methods: Prospective analysis of 53 consecutive patients submitted to PET/CT between March 2005 and May 2007 for the evaluation of an SPN. Of those, 32 met the criteria for inclusion in the present study. The lesions were evaluated for location, size, radiotracer uptake and maximum standardized uptake value (SUV). The FDG-PET/CT results were correlated with other predictors of malignancy (age, gender, smoking status, nodule size and nodule location). The definitive diagnosis was established through histopathology or through clinical/radiological follow-up for at least one year. Results: Fourteen malignant SPNs were found. Through analysis of the receiver operating characteristic curve, we established an SUV of 2.5 as the most appropriate cut-off point, since it correctly identified 13 of the 14 malignant SPNs. The results below that point revealed one false positive for neoplasia out of a total of 14. The semiquantitative method presented a sensitivity of 92.9%, specificity of 72.2%, positive predictive value of 72.2%, negative predictive value of 92.9% and accuracy of 81.2%. The multivariate analysis showed a statistically significant association with SPN malignancy only for nodule location in the upper lobes (p = 0.048) and SUV (p = 0.007). Conclusions: The results obtained suggest that the SUV of [18F]-FDG is a useful predictor of neoplasia in SPN, with a high negative predictive value, which allows malignancy to be safely ruled out, showing its relevance in the diagnostic approach to pulmonary nodules.

Keywords: Positron-emission tomography; Coin lesion, pulmonary; Lung neoplasms.

BACKGROUND: In agreement with other reported studies, wehad previously found a possible association between gender and prognosis in stage I non-small cell lung cancer (NSCLC), showing a higher survival rate among females. OBJECTIVES: The purpose of this study was to further clarify the role of gender as a possible prognostic factor in NSCLC. METHOD: In a retrospective cohort study, we examined the survival of 163 NSCLC patients who underwent curative surgical treatment at the Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) Hospital between 1990 and 1997. Data was analyzed using Kaplan-Meier plots. Additionally, we used the Mann-Whitney test for comparing group survival rates and the Cox regression model to adjust for potential confounding factors. RESULTS: Were included 124 (76.07%) males and 39 (23.93%) females, whose median survival was of 32.3 and 60.6 months, respectively. The 5-year survival was 38.0% for men and 55.4% for women (P=0.030). Considering only stage I patients, survival rates were 44.4% and 81.8% for men and women, respectively (P=0.009). Effect of gender continued after adjustment for several factors (age, hemoglobin, histology, tumor size, type of surgery and postoperative complications). CONCLUSION: This study confirms our previous findings that women live longer after NSCLC surgery when compared to men. This result is only observed at an early stage and persists after adjustment of several factorsP

Keywords: Carcinoma, bronchogenic [surgery]; Carcinoma, bronchogenic [epidemiolgy]; Prognosis; Sex distribution; Disease - free survival.

Objective: To estimate and compare the frequency of CYP1A1*2A gene polymorphisms in a Brazilian population and determine the possible contribution of these genetic variations to lung cancer risk. Methods: The study population included 200 patients with lung cancer, and the control group consisted of 264 blood donors. Genomic DNA was obtained from peripheral blood samples. The PCR-RFLP method was used for analysis of the CYP1A1*2A gene. Results: There was no statistically significant difference between the lung cancer patients and the controls in terms of the distribution of CYP1A1*2A polymorphisms (p = 0.49). A multivariate logistic regression model analysis by ethnic group revealed that, within the lung cancer group, the CYP1A1*2A genotype CC plus TC was more common among the African-Brazilian patients than among the White patients (adjusted OR = 3.19; 95% CI: 1.53‑6.65). Conclusions: The CYP1A1*2A gene cannot be linked with lung cancer risk in Brazilian patients at this time. Larger epidemiologic studies are needed in order to establish whether the CC plus TC polymorphism increases the risk of lung cancer in African-Brazilians.

Keywords: Lung neoplasms; Polymorphism, genetic; Metabolism.

Objective: To evaluate the evolution of clinical and epidemiological data, as well as data related to diagnosis, staging, treatment, and survival, among patients undergoing curative surgery for lung cancer at a tertiary referral center in the city of São Paulo, Brazil. Methods: This was a retrospective study of cases in the International Association for the Study of Lung Cancer database. We selected only cases of patients undergoing curative surgery between January of 2011 and April of 2018. We determined overall and disease-free survival at 36 months and compared the data between two periods (2011-2014 and 2015-2018). Results: Comparing the two periods (N = 437 cases), we observed trends toward increases in the number of female patients, as well as in the proportions of former smokers (44.09% vs. 53.59%), of patients diagnosed with adenocarcinoma (52.21% vs. 59.72%), and of patients diagnosed at an earlier pathological stage, together with a decrease in 30-day mortality (4.05% vs. 2.39%). There were significant increases in the proportions of cases diagnosed at an earlier clinical stage (p = 0.002) or incidentally (p = 0.003). Although lobectomy was the main surgical technique employed, there was a proportional increase in segmentectomies (2.67% vs. 7.11%; p = 0.026). Overall and disease-free survival rates were 79.4% (95% CI: 74.0-83.9%) and 75.1% (95% CI: 69.1-80.1%), respectively. The difference in overall survival between the periods lost statistical significance when adjusted for pathological stage, the only factor that affected survival (log-rank: p = 0.038 to p = 0.079). Conclusions: The clinical and epidemiological evolution presented in this study corroborates global trends. The decrease in 30-day mortality was probably due to better patient selection and improved surgical techniques.

Keywords: Lung neoplasms/surgery; Lung neoplasms/epidemiology; Lung neoplasms/therapy; Survival analysis; Thoracic surgery; Thoracic surgery, video-assisted.

Objective: To assess cost differences between EBUS-TBNA and mediastinoscopy for mediastinal staging of non-small cell lung cancer (NSCLC). Methods: This was an economic evaluation study with a cost-minimization analysis. We used a decision analysis software program to construct a decision tree model to compare the downstream costs of mediastinoscopy, EBUS-TBNA without surgical confirmation of negative results, and EBUS-TBNA with surgical confirmation of negative results for the mediastinal staging of NSCLC. The study was conducted from the perspective of the Brazilian public health care system. Only direct medical costs were considered. Results are shown in Brazilian currency (Real; R$) and in International Dollars (I$). Results: For the base-case analysis, initial evaluation with EBUS-TBNA without surgical confirmation of negative results was found to be the least costly strategy (R$1,254/I$2,961) in comparison with mediastinoscopy (R$3,255/I$7,688) and EBUS-TBNA with surgical confirmation of negative results (R$3,688/I$8,711). The sensitivity analyses also showed that EBUS-TBNA without surgical confirmation of negative results was the least costly strategy. Mediastinoscopy would become the least costly strategy if the costs for hospital supplies for EBUS-TBNA increased by more than 300%. EBUS-TBNA with surgical confirmation of negative results, in comparison with mediastinoscopy, will be less costly if the prevalence of mediastinal lymph node metastasis is = 38%. Conclusions: This study has demonstrated that EBUS-TBNA is the least costly strategy for invasive mediastinal staging of NSCLC in the Brazilian public health care system.

Keywords: Lung Neoplasms; Neoplasm Staging; Costs and cost analysis; Bronchoscopy; Mediastinoscopy.