Lung cancer is the leading cause of cancer-related deaths worldwide. Promising new therapies have recently emerged from the development of molecular targeted drugs; particularly promising are those blocking the signal transduction machinery of cancer cells. One of the most widely studied cell signaling pathways is that of EGFR, which leads to uncontrolled cell proliferation, increased cell angiogenesis, and greater cell invasiveness. Activating mutations in the EGFR gene (deletions in exon 19 and mutation L858R in exon 21), first described in 2004, have been detected in approximately 10% of all non-squamous non-small cell lung cancer (NSCLC) patients in Western countries and are the most important predictors of a response to EGFR tyrosine-kinase inhibitors (EGFR-TKIs). Studies of the EGFR-TKIs gefitinib, erlotinib, and afatinib, in comparison with platinum-based regimens, as first-line treatments in chemotherapy-naïve patients have shown that the EGFR-TKIs produce gains in progression-free survival and overall response rates, although only in patients whose tumors harbor activating mutations in the EGFR gene. Clinical trials have also shown EGFR-TKIs to be effective as second- and third-line therapies in advanced NSCLC. Here, we review the main aspects of EGFR pathway activation in NSCLC, underscore the importance of correctly identifying activating mutations in the EGFR gene, and discuss the main outcomes of EGFR-TKI treatment in NSCLC.

Keywords: Molecular targeted therapy; Receptor, epidermal growth factor; Lung neoplasms/drug therapy; Mutation; Oncogenes.

Nitric oxide (NO) is an endogenous vasoactive compound that contributes to pulmonary vascular homeostasis and is produced by three nitric oxide synthase (NOS) isoforms-neuronal NOS (nNOS); inducible NOS (iNOS); and endothelial NOS (eNOS)-all three of which are present in the lung. Studies using pharmacological inhibitors or knockout mice have shown that eNOS-derived NO plays an important role in modulating pulmonary vascular tone and attenuating pulmonary hypertension. However, studies focusing on the role of iNOS have shown that this isoform contributes to the pathophysiology of acute lung injury and acute respiratory distress syndrome. This review aimed at outlining the role played by NO in the control of pulmonary circulation, both under physiological and pathophysiological conditions. In addition, we review the evidence that the L-arginine-NO-cyclic guanosine monophosphate pathway is a major pharmacological target in the treatment of pulmonary vascular diseases.

Keywords: Nitric oxide; Arginine; Nitric oxide synthase; Cyclic GMP; Pulmonary circulation.

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 analyze and compare the mutations in two different regions of the katG gene, which is responsible for isoniazid (INH) resistance. Methods: We analyzed 97 multidrug-resistant Mycobacterium tuberculosis strains isolated in cultures of sputum samples obtained from the Professor Hélio Fraga Referral Center, in Brasília, Brazil. Another 6 INH-sensitive strains did not present mutations and were included as controls. We used PCR to amplify two regions of the katG gene (GenBank accession no. U06258)-region 1, (from codon 1 to codon 119) and region 2 (from codon 267 to codon 504)-which were then sequenced in order to identify mutations. Results: Seven strains were resistant to INH and did not contain mutations in either region. Thirty strains carried mutations in region 1, which was characterized by a high number of deletions, especially at codon 4 (24 strains). Region 2 carried 83 point mutations, especially at codon 315, and there was a serine-to-threonine (AGC-to-ACC) substitution in 73 of those cases. The analysis of region 2 allowed INH resistance to be diagnosed in 81.4% of the strains. Nine strains had mutations exclusively in region 1, which allowed the proportion of INH-resistant strains identified to be increased to 90.6%. Conclusions: The number of mutations at codon 315 was high, which is consistent with cases described in Brazil and in other countries, and the analysis of region 1 resulted in a 9.2% increase in the rate at which mutations were identified.

Keywords: Isoniazid; Mutation; Tuberculosis; Drug resistance, multiple.

Objective: The clinical, functional, radiological and genotypic descriptions of patients with an alpha-1 antitrypsin (A1AT) gene mutation in a referral center for COPD in Brazil. Methods: A cross-sectional study of patients with an A1AT gene mutation compatible with deficiency. We evaluated the A1AT dosage and genotypic, demographic, clinical, tomographic, and functional characteristics of these patients. Results: Among the 43 patients suspected of A1AT deficiency (A1ATD), the disease was confirmed by genotyping in 27 of them. The A1AT median dosage was 45 mg/dL, and 4 patients (15%) had a normal dosage. Median age was 54, 63% of the patients were male, and the respiratory symptoms started at the age of 40. The median FEV1 was 1.37L (43% predicted). Tomographic emphysema was found in 77.8% of the individuals. The emphysema was panlobular in 76% of them and 48% had lower lobe predominance. The frequency of bronchiectasis was 52% and the frequency of bronchial thickening was 81.5%. The most common genotype was Pi*ZZ in 40.7% of participants. The other genotypes found were: Pi*SZ (18.5%), PiM1Z (14.8%), Pi*M1S (7.4%), Pi*M2Z (3.7%), Pi*M1I (3.7%), Pi*ZMnichinan (3.7%), Pi*M3Plowell (3.7%), and Pi*SF (3.7%). We did not find any significant difference in age, smoking load, FEV1, or the presence of bronchiectasis between the groups with a normal and a reduced A1AT dosage, neither for 1 nor 2-allele mutation for A1ATD. Conclusions: Our patients presented a high frequency of emphysema, bronchiectasis and bronchial thickening, and early-beginning respiratory symptoms. The most frequent genotype was Pi*ZZ. Heterozygous genotypes and normal levels of A1AT also manifested significant lung disease.

Keywords: Alpha-1 antitrypsin; Emphysema; Alleles.

Epidemiological studies have demonstrated a causal relationship between smoking and lung cancer. Although most lung cancer cases are linked to smoking, only a minority of heavy smokers develop lung cancer, leading to the notion that genetic factors affect individual susceptibility. The principal molecular changes in lung cancer are seen in tumor suppressor genes, proto-oncogenes, growth factors, telomerase activity, and methylation status of promoters. Well-known agents include angiogenesis-stimulating factors (such as vascular endothelial growth factor), as well as factors related to tumor cell proliferation and apoptosis (epidermal growth factor receptor, p53, K-ras, retinoblastoma and BCL-2). Several of these genetic factors have already been investigated, but no single parameter has yet presented sufficient selectivity regarding prognostic value or therapeutic efficacy. Treatment strategies to cure lung cancer should focus on these early genetic lesions in order to promote their repair or to eliminate these lung cancer cells.

Keywords: Smoking; Lung neoplasms; Genetic markers; Prognosis

Objective: To determine the effects that mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and deletion of the glutathione S-transferase (GST) genes mu-1 (GSTM1) and theta-1 (GSTT1) have on the clinical course of cystic fibrosis (CF) in patients residing in the southeastern region of Brazil. Methods: The study sample consisted of all consecutive CF patients treated at the Hospital de Clínicas School of Medical Sciences of the State University at Campinas between March of 2002 and March of 2005. We included 66 CF patients. Genomic DNA was analyzed by polymerase chain reaction and restriction endonuclease digestion for the identification of the genotypes. Results: The F508 mutation of the CFTR gene was found in 44 patients (66.7%). The null genotypes GSTM1, GSTT1 and GSTM1/GSTT1 were found in 40.9%, 15.2%, and 3.0% of the patients, respectively. The F508 CFTR mutation was more common in patients diagnosed with CF before 2.5 years of age than in those diagnosed later (75.5% vs. 41.2%; p = 0.008). The frequency of the F508 CFTR mutation, as well as of the GSTM1 and GSTT1 genotypes, was not found to be associated with gender, ethnicity, pulmonary disease status, or pancreatic disease status. Conclusions: When the patients were stratified by clinical and epidemiological features, the frequencies of the GSTM1 and GSTT1 null genotypes were similar, suggesting that the inherited absence of these enzymatic pathways does not alter the course of CF. However, the high frequency of the F508 CFTR mutation found in younger children suggests that it influences the age at diagnosis of CF in this region of Brazil.

Keywords: : Cystic fibrosis; Cystic fibrosis transmembrane conductance regulator; Glutathione transferase.

Objective: To investigate the applicability of ultrasound imaging of the diaphragm in interstitial lung disease (ILD). Methods: Using ultrasound, we compared ILD patients and healthy volunteers (controls) in terms of diaphragmatic mobility during quiet and deep breathing; diaphragm thickness at functional residual capacity (FRC) and at total lung capacity (TLC); and the thickening fraction (TF, proportional diaphragm thickening from FRC to TLC). We also evaluated correlations between diaphragmatic dysfunction and lung function variables. Results: Between the ILD patients (n = 40) and the controls (n = 16), mean diaphragmatic mobility was comparable during quiet breathing, although it was significantly lower in the patients during deep breathing (4.5 ± 1.7 cm vs. 7.6 ± 1.4 cm; p < 0.01). The patients showed greater diaphragm thickness at FRC (p = 0.05), although, due to lower diaphragm thickness at TLC, they also showed a lower TF (p < 0.01). The FVC as a percentage of the predicted value (FVC%) correlated with diaphragmatic mobility (r = 0.73; p < 0.01), and an FVC% cut-off value of < 60% presented high sensitivity (92%) and specificity (81%) for indentifying decreased diaphragmatic mobility. Conclusions: Using ultrasound, we were able to show that diaphragmatic mobility and the TF were lower in ILD patients than in healthy controls, despite the greater diaphragm thickness at FRC in the former. Diaphragmatic mobility correlated with ILD functional severity, and an FVC% cut-off value of < 60% was found to be highly accurate for indentifying diaphragmatic dysfunction on ultrasound.

Keywords: Diaphragm/ultrasonography; Lung diseases, interstitial; Respiratory muscles; Respiratory function tests.

Surgical resection is the primary treatment option for early-stage non-small cell lung cancer, lobectomy being considered the standard of care. In elderly patients, physiological characteristics can limit the suitability for surgery and the extent of resection. Sublobar resection (SLR) can be offered as an alternative. The aim of this real-world analysis was to compare lobectomy and SLR in terms of recurrence and survival rates in patients over 70 years of age.

Keywords: Carcinoma, non-small-cell lung/mortality; Carcinoma, non-small-cell lung/surgery; Recurrence; Aged; Aged, 80 and over.

Objective: Adjuvant chemotherapy (AC) improves survival of patients with resected non-small cell lung cancer (NSCLC). However, the cisplatin-vinorelbine regimen has been associated with a significant risk of clinically relevant toxicity. We sought to evaluate the effectiveness, safety, and feasibility of AC for NSCLC patients in a real-world setting. Methods: This was a single-center, retrospective cohort study of patients with stage I-III NSCLC undergoing surgery with curative intent between 2009 and 2018. AC was administered at the discretion of physicians. The patients were divided into two groups: AC group and no AC (control) group. Study outcomes included overall survival (OS) and recurrence-free survival (RFS), as well as the safety profile and feasibility of the cisplatin-vinorelbine regimen in a real-world setting. Results: The study involved 231 patients, 80 of whom received AC. Of those, 55 patients received the cisplatin-vinorelbine regimen. Survival analyses stratified by tumor stage showed that patients with stage II NSCLC in the AC group had better RFS (p = 0.036) and OS (p = 0.017) than did those in the no AC group. Among patients with stage III NSCLC in the AC group, RFS was better (p < 0.001) and there was a trend toward improved OS (p = 0.060) in comparison with controls. Of those who received the cisplatin-vinorelbine regimen, 29% had grade 3-4 febrile neutropenia, and 9% died of toxicity. Conclusions: These results support the benefit of AC for NSCLC patients in a real-world setting. However, because the cisplatin-vinorelbine regimen was associated with alarming rates of toxicity, more effective and less toxic alternatives should be investigated.

Keywords: Lung neoplasms; Chemotherapy, adjuvant; Cisplatin/toxicity; Vinorelbine/toxicity.

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 evaluate the efficacy of the joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the sampling of mediastinal lymph nodes in patients with non-small cell lung cancer (NSCLC) and candidates for pulmonary resection. Methods: Sixty-two patients diagnosed with NSCLC were submitted to cervical mediastinoscopy and video-assisted thoracoscopy. The samples obtained (from paratracheal chains, anterior and posterior subcarinal chains, paraesophageal chains and pulmonary ligament) were submitted to frozen section analysis. The following variables were also evaluated: age; gender; weight loss; diagnostic method; tomographic findings; histological type; staging; and location and size of the primary tumor. Results: In 11 patients, mediastinoscopy showed no involvement of the subcarinal chain, whereas such involvement was identified when video-assisted thoracoscopy was used: positive predictive value = 88.89% (95% CI: 51.75-99.72); negative predictive value = 94.34% (95% CI: 84.34-98.82); prevalence = 17.74% (95% CI: 9.2-29.53); sensitivity = 72.73% (95% CI: 39.03-93.98); and specificity = 98.77% (95% CI: 93.31-99.97). In 60% of the patients with involvement of the posterior subcarinal chain, the primary tumor was in the right inferior lobe. (p = 0.029) Conclusions: The joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the evaluation of posterior mediastinal lymph nodes proved to be an efficacious method. When there is no access to posterior chains by means of ultrasound with transbronchial or transesophageal biopsy, which dispenses with general anesthesia, this should be the method of choice for the correct evaluation of mediastinal lymph nodes in patients with NSCLC.

Keywords: Neoplasm staging; Mediastinoscopy; Biopsy; Lymphatic metastasis.

Multiple respiratory abnormalities can be found in anxiety disorders, especially in panic disorder (PD). Individuals with PD experience unexpected panic attacks, characterized by anxiety and fear, resulting in a number of autonomic and respiratory symptoms. Respiratory stimulation is a common event during panic attacks. The respiratory abnormality most often reported in PD patients is increased CO2 sensitivity, which has given rise to the hypothesis of fundamental abnormalities in the physiological mechanisms that control breathing in PD. There is evidence that PD patients with dominant respiratory symptoms are more sensitive to respiratory tests than are those who do not manifest such symptoms, and that the former group constitutes a distinct subtype. Patients with PD tend to hyperventilate and to panic in response to respiratory stimulants such as CO2, triggering the activation of a hypersensitive fear network. Although respiratory physiology seems to remain normal in these subjects, recent evidence supports the idea that they present subclinical abnormalities in respiration and in other functions related to body homeostasis. The fear network, composed of the hippocampus, the medial prefrontal cortex, the amygdala and its brain stem projections, might be oversensitive in PD patients. This theory might explain why medication and cognitive-behavioral therapy are both clearly effective. Our aim was to review the relationship between respiration and PD, addressing the respiratory subtype of PD and the hyperventilation syndrome, with a focus on respiratory challenge tests, as well as on the current mechanistic concepts and the pharmacological implications of this relationship.

Keywords: Panic disorder; Anxiety; Respiration; Hyperventilation; Carbon dioxide.

Objective: To describe the mortality trends for lung cancer, cancer of the trachea, and bronchial cancer in relation to gender and age brackets in Brazil. Methods: Data related to mortality between 1980 and 2003 were collected from the Brazilian Mortality Database. A trend analysis of mortality was carried out, nationwide and in selected states, using the LOWESS technique for rate smoothing and model adjustments. Results: In Brazil, the standardized mortality rate for lung cancer, cancer of the trachea, and bronchial cancer increased from 7.21/100,000 inhabitants in 1980 to 9.36/100,000 inhabitants in 2003. Specific mortality rates decreased in males in the 30-49 and 50-59 age brackets. In the 60-69 age bracket, the rates for males increased from 1980 to 1995 and declined thereafter. There was a trend toward higher mortality rates in males over 70, as well as in females over 30, throughout the period evaluated. Conclusions: The decrease in the mortality rates in younger males might have resulted from recent national interventions aimed at reducing the prevalence of smoking and reducing exposure in younger cohorts. High mortality rates in older populations remained constant due to prior tobacco use. Increased mortality rates in females are a worldwide trend and are attributable to the recent increase in smoking prevalence in females.

Keywords: Lung neoplasms/epidemiology; Mortality/trends; Brazil.

Objective: To present an alternative method of detecting micrometastases in lymph nodes previously testing negative for non-small cell lung cancer (NSCLC) by routine hematoxylin-eosin staining. Methods: A total of 77 hilar and mediastinal lymph nodes resected from 18 patients with NSCLC were investigated for the presence of micrometastases using a combination of microarray analysis and immunohistochemistry. Results: Micrometastases were detected by identifying cytokeratin- and chromogranin-positive cells in lymph node microarrays. Of the 18 patients initially staged as pN0 through routine hematoxylin-eosin staining, 9 (50%) were restaged as N1, and the prognoses were re-evaluated in terms of histological and clinical parameters. The comparison of the survival curves revealed that survival was higher in the patients without micrometastases than in those with micrometastases. In addition, in the multivariate analysis adjusted for age, gender, histological type, and restaging, the presence of micrometastases proved to be an independent predictor of survival. Among patients who had been previously staged as pN0, the risk of death was found to be 7-times greater for those later diagnosed with micrometastases than for those in whom no micrometastases were identified. Conclusion: The combination of microarray analysis and immunohistochemistry might represent a low-cost and less time-consuming alternative for identifying occult micrometastases and predicting prognoses in surgically resected patients with pN0 NSCLC. Larger randomized, prospective studies are needed in order to determine the accuracy of this method.

Keywords: Lung neoplasms; Microarray analysis; Chromogranin A; Survival analysis.

Background: Lung cancer is the leading cause of cancer-related death worldwide. Objective: To determine the time spent diagnosing, staging and surgically treating lung cancer in a university hospital. Method: Between January 1990 and December 1998, 69 (53 male, 16 female) patients were diagnosed with lung cancer and underwent surgery. The hospital records of these patients were reviewed to evaluate clinical and histological data, dates of outpatient visits, hospital admission, tests and procedures, as well as to determine if the patients were examined as inpatients or as outpatients. Results: The 15 patients investigated as outpatients were designated as group I, the 28 examined as both inpatients and outpatients as group II, and the 26 investigated as inpatients as group III. Age ranged from 43 to 79 years (mean ± SD; 61 ± 10). Of the 69 patients, 43 were smokers and 23 were ex-smokers. The mean time from onset of symptoms to the first outpatient visit was 110 days and 33 days from the first outpatient visit until diagnosis. There was a lapse of 25 days between diagnosis and surgery. The mean total elapsed time between the first outpatient visit and surgery was 58 days. The mean total time was 72 days for group I, 72 days for group II, and 35 days for group III (p < 0.01). There was no significant difference regarding total time in relation to the different stages of the disease (p = 0.16). Conclusions: The results show that patients waited too long before seeking medical assistance and that medical treatment of lung cancer was further delayed when patients were examined in an outpatient setting.

Keywords: Lung neoplasm/surgery. Disease progression.