The role of immunohistochemistry is to recognize antigens and, consequently, to identify and classify specific cells within a cell population whose morphology is heterogenous or apparently homogenous. The visualization of the antigen-antibody complex is made possible through the addition of either a fluorochrome conjugate or an enzyme to the antibody, which is then viewed under microscopy. Immunohistochemistry can be used in the routine diagnosis of lung cancer, in order to identify biological markers (diagnostic and prognostic). The essential immunohistochemistry panels will be discussed in this review.

Keywords: Immunohistochemistry; Tumor markers, biological; Lung neoplasms.

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.

Biological markers are cellular, structural and biochemical components that can define cellular as well as molecular changes in both normal and neoplastic cells. There are two types of biological markers: 1) intermediate markers that evaluate cellular and molecular alterations before malignancy occurs; and 2) diagnostic markers, present in association with malignancy. The identification and validation of biological markers for clinical use are performed in stages: initial identification in cell cultures of the tumor;
testing of the marker in tissues obtained in biopsies of patients with an established diagnosis of the tumor;
testing of biopsies of normal tissues and tissues with an inflammatory process;
sputum, blood or urine tests for validation as a non-invasive test that can be used in high-risk populations. Sorologic and histopathologic biological markers are cellular, structural and biochemical components found in both normal and neoplastic cells that can be quantitatively assessed by biochemical, immunological and molecular methods in the body fluids or tissues, respectively, and may be associated with malignancies and, possibly, with the neoplastic organ. Biological markers are studied in diverse primary neoplasms. However, few of them proved to be clinically valuable. The role of biological markers in lung cancer patients remains unclear because only a small number of markers has been properly identifiassessed. The aim of this paper is to understand the role of sorologic and histologic biological markers in the prognosis and survival of lung cancer patients based on our previous works. Furthermore, we present a future perspective of the early detection of lung cancer on the basis of the role of intermediate biological markers.

Keywords: Biologic markers. Lung cancer. Prognosis. Survival. Morphometric method.

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.

Objective: To determine the demographic and clinical characteristics of patients with non-small cell lung cancer (NSCLC), as well as their disease course, by age group and gender. Methods: This was a retrospective cohort study of patients diagnosed with NSCLC from 2000 to 2012 and followed until July 2015 in a tertiary referral hospital in the city of São Paulo, Brazil. Based on the 25th and 75th percentiles of the age distribution, patients were stratified into three age groups: < 55 years; ≥ 55 and < 72 years; and ≥ 72 years. Survival time was evaluated during the follow-up period of the study. Functions of overall and gender-specific survival stratified by age groups (event: all-cause mortality) were calculated using the Kaplan-Meier method. Differences among survival curves were assessed via the log-rank test. Results: We included 790 patients with the following age distribution: < 55 years, 165 patients; ≥ 55 and < 72 years, 423; and ≥ 72 years, 202. In the entire sample, there were 493 men (62.4%). Adenocarcinoma was the most common histological pattern in the < 72-year age groups; 575 patients (73%) presented with advanced disease (stages IIIB-IV). The median 5-year survival was 12 months (95% CI: 4-46 months), with no significant differences among the age groups studied. Conclusions: NSCLC remains more common in men, although we found an increase in the proportion of the disease in women in the < 55-year age group. Adenocarcinoma predominated in women. In men, squamous cell carcinoma predominated in the ≥ 72-year age group. Most patients presented with advanced-stage disease at diagnosis. There were no statistical differences in survival between genders or among age groups.

Keywords: Lung neoplasms; Age groups, Sex; Survival.

Background: Transbronchial needle aspiration (TBNA) with a flexible bronchoscope has been used for many years in the United States of America to diagnose bronchogenic carcinoma. However little information on the subject is available in Brazil. Objective: Assess the effectiveness of transbronchial needle aspiration for diagnosis and staging of lung cancer. Method: A retrospective review was made of 74 TBNA performed at the National Cancer Institute, in Rio de Janeiro, Brazil. a thoracic computerized tomography had oreviouslbeen made of all patients. Eleven (15%) patients exhibited mediastinal masses and 63 (85%) hilar masses. Seventy six endoscopic alterations were detected: enlargement of the main carina in 44 (59%) patients; enlargement of the secondary carina in 12 (16%); paratracheal compression in 5 (7%); posterior tracheal wall compression in 3 (4%); main bronchus compression in 5 (7%) AND BRONCHOSCOPY was normal in 5 (7%) patients. Results: Specimens were satisfactory for diagnosis in 42 (57%) patients and in 34 (46%) diagnosis was confirmed. Malignancy was confirmed in 30 of 34 patients (88%): as follows: small cell undifferentiated carcinoma in 10 of 30 (33%); squamous cell lung cancer in 7 of 30 (23%); adenocarcinoma 7 of 30 (23%); and non-small cell lung cancer in 6 of 30 (20%). Four of 30 (12%) were diagnosed as bearers of benign disease: tuberculosis 2 of 4 (50%) and sarcoidosis 2 of 4 (50%). No complications related to the method were perceived. Conclusion: This preliminary experience with TBNA in 74 patients indicated that this method is safe, easy to perform with a minimum of complications and useful for the diagnosis and staging of pulmonary neoplasms.

Keywords: Bronchoscopy/methods. Carcinoma, bronchogenic/diagnosis. Aspiration/methods.

Objective: To evaluate the contribution of a new coefficient, the FEF50%/0.5FVC ratio, obtained from the maximal expiratory flow-volume curve, to the diagnosis of obstructive lung disease (OLD); to test this coefficient in differentiating among patients considered normal, those with OLD and those with restrictive lung disease (RLD); and to determine cut-off points for each functional diagnosis, as well as the probability for each diagnosis based on individual values. Methods: A prospective, cross-sectional study analyzing the pulmonary function of patients referred to the Porto Alegre Hospital de Clínicas, in Porto Alegre, Brazil, between January and December of 2003. We collected demographic and spirometric data. The patients were divided into three groups: normal; OLD; and RLD. We calculated the FEV1/FVC and FEF50%/0.5FVC ratios, and we compared the mean FEF50%/0.5FVC values among the groups. We used Pearson's correlation test in order to compare FEF50%/0.5FVC with FEV1/FVC. The patients were again divided into two groups: those with OLD and those without OLD. We calculated the likelihood ratio for different cut-off points. Results: The mean age of the patients was 55.8 ± 14.7 years. There were significant differences among the groups in terms of the mean FEF50%/0.5FVC (2.10 ± 0.82, 2.55 ± 1.47 and 0.56 ± 0.29, respectively, for normal, RLD and OLD; p < 0.001). There was a positive correlation between FEF50%/0.5FVC and FEV1/FVC in the OLD group (r = 0.83). We found that an FEF50%/0.5FVC < 0.79 strongly suggests OLD, whereas an FEF50%/0.5FVC > 1.33 practically excludes this diagnosis. Conclusions: The FEF50%/0.5FVC ratio is a potentially useful parameter in the differential diagnosis of OLD and correlates positively with the FEV1/FVC ratio.

Keywords: Pulmonary disease, chronic obstructive; Spirometry; Respiratory function tests.

Carcinoma of the lung can present in a number of guises and a number of possible and often complementary diagnostic approaches are available. The choice of procedure should reflect the presentation of the tumor, local expertise, intended management and patient preference. There are different methods of investigation: sputum cytology, fiberbronchoscopy, transbronchial biopsy, transbronchial needle aspiration, transthoracic fine needle aspiration, etc. The association of all of these methods increases the power of diagnosis. Staging is the measurement of the anatomical extent of a tumor in any given patient. The staging of cancer began with Denoix's TNM classification system, and, although several modifications were developed, it remains the basis of lung cancer staging systems up to now. Assigning patients to a particular TNM stage allows choosing the most appropriate therapy and provides prognostic information. Also, the impact of new therapeutic methods can be evaluated for efficacy and a comparison of the expected survival rates can be predicted.

Introduction: Bronchoscopy is useful in the diagnosis of tuberculosis suspects with a "negative" sputum smear. The objectives of this study were: to assess yield of bronchoalveolar lavage (BAL) and of transbronchial biopsy (TBB) both in HIV-positive patients (group 1) and immunocompetent individuals (group 2), based on simple and most available laboratory techniques in clinical practice. Patients and methods: The authors performed 319 bronchoscopies in 302 patients. BAL and TBB were sequentially performed in the same lung in all cases. Tuberculosis was diagnosed based on the results of acid-fast stains (AFS) from the lavage (ZN), culture for mycobacteria (LJ), and histological examination of biopsies (HE and ZN). Results: Tuberculosis was the final diagnosis in 28 exams of group 1 (n = 214) and in 35 of group 2 (n = 105). There were abnormal endoscopic findings respectively in 3 and 10 patients. In group 1, AFS were positive in 7 cases, culture of BAL in 14, and TBB in 19. In group 2, AFS were positive in 13 cases, culture in 17, and biopsies in 31. TBB results compared to BAL were in concordance for group 1 (p = 0.823) and different for group 2 (p = 0.022). Immediate results (AFS and TBB) compared to later positive results of culture were similar for group 1 (p = 0.066) but not for group 2 (p = 0.001). There were eight episodes of pneumothorax (2.5%) and one death (0.36%). Conclusions: Both BAL and TBB should be performed whenever possible, aiming towards a higher yield of bronchoscopy in the diagnosis of tuberculosis. Both methods complement each other in immunocompetent patients, whereas TBB establishes a faster diagnosis for HIV-infected patients if associated to AFS.

Keywords: Bronchoscopy/methods. Smear-negative tuberculosis/diagnosis. Opportunistic infections related to AIDS/diagnosis.

Objective: To analyze the relationship between one-minute sit-to-stand test (1MSTST) parameters and a diagnosis of post COVID-19 condition in a cohort of patients who previously had COVID-19. Methods: This was a prospective cohort study of patients with post COVID-19 condition referred for body plethysmography at a tertiary university hospital. Post COVID-19 condition was defined in accordance with the current WHO criteria. Results: Fifty-three patients were analyzed. Of those, 25 (47.2%) met the clinical criteria for post COVID-19 condition. HR was lower in the patients with post COVID-19 condition than in those without it at 30 s after initiation of the 1MSTST (86.2 ± 14.3 bpm vs. 101.2 ± 14.7 bpm; p < 0.001) and at the end of the test (94.4 ± 18.2 bpm vs. 117.3 ± 15.3 bpm; p < 0.001). The ratio between HR at the end of the 1MSTST and age-predicted maximal HR (HRend/HRmax) was lower in the group of patients with post COVID-19 condition (p < 0.001). An HRend/HRmax of < 62.65% showed a sensitivity of 78.6% and a specificity of 82.0% for post COVID-19 condition. Mean SpO2 at the end of the 1MSTST was lower in the patients with post COVID-19 condition than in those without it (94.9 ± 3.6% vs. 96.8 ± 2.4%; p = 0.030). The former group of patients did fewer repetitions on the 1MSTST than did the latter (p = 0.020). Conclusions: Lower SpO2 and HR at the end of the 1MSTST, as well as lower HR at 30 s after initiation of the test, were associated with post COVID-19 condition. In the appropriate clinical setting, an HRend/HRmax of < 62.65% should raise awareness for the possibility of post COVID-19 condition.

Keywords: COVID-19; Post-acute COVID-19 syndrome; Heart rate; Respiratory function tests.

Objective: To evaluate confirmed cases of lung cancer, reviewing epidemiological variables, clinical variables, staging and treatment. Methods: The cases of 263 patients were studied. All of the patients had been treated at the Universidade Federal do Paraná (Federal University of Paraná) Hospital de Clínicas or at the Hospital Erasto Gaertner, two institutions that, together, serve a significant portion of the patients seeking treatment in the city of Curitiba, located in the state of Paraná. This was a retrospective study, involving the administration of questionnaires. The descriptive analysis of the data obtained was performed using the Epi-Info program. Results: There was a predominance of male patients (76%). At the time of diagnosis, the majority of patients (90%) were smokers or former smokers. In 87% of the cases, there was no history of lung disease. The most common initial symptoms were cough (142 cases) and chest pain (92 cases). Non-small cell lung cancer was found in 87% of the patients, and the most common histological type was spinocellular carcinoma, which was found in 49% of all of the patients. Smoking was found to be the most significant predisposing factor. Conclusion: The characteristics of lung cancer progression, such as the nonspecificity of the initial symptoms, the duration of tumor growth and the course of the tumor, together with the lack of tracking programs, are the principal factors that hinder the early detection of lung cancer, making it difficult to treat lung cancer patients and to increase their survival.

Keywords: Lung neoplasms/diagnosis; Lung neoplasms/epidemiology; Lung neoplasms/surgery; Early diagnosis; Neoplasms staging

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.

Introduction: The diagnosis of diffuse lung disease is still a challenge for the pediatric intensive care physician. Routine clinical examinations and laboratory tests are frequently negative. The objective of this study was to evaluate the diagnostic potential, the impact on therapy and the rate of complications of open lung biopsy in children with undiagnosed diffuse lung disease, respiratory failure and inappropriate response to initial therapy. Methods: From January 1987 to January 1997, 29 children with diffuse pulmonary disease of unknown etiology, respiratory failure (PaO2 /FiO2 < 300) and no response to previous treatments were considered for open lung biopsy. Newborns, children with known chronic pulmonary disease and children with untreatable shock or coagulopathy were excluded. All biopsies were performed by a thoracic surgeon by a microthoracotomy in the lung shown to be the most affected by X-ray examination. Tissue samples were analyzed in terms of cultures, light microscopy, electron microscopy and immunofluorescence microscopy, according to the pathologist's decision. Results: All biopsies (100%) resulted in at least one histological diagnosis and in 20 patients (68.9%) it was obtained a specific diagnosis. The most frequent histological patterns found were: non-specific interstitial pneumonitis with variable degrees of fibrosis in 18 cases; bronchiolitis in eight cases and pulmonary hypertension in three cases. Regarding the most frequent specific diagnosis, six children were found with cytomegalovirus infection, three with Pneumocystis carinii, three with adenovirus and three with respiratory syncytial virus infection. These data induced a change in therapy in 20 children (68.9%). The most frequent changes in therapy were the use of corticosteroids in 14 children and a review of the antibiotic regimen in six patients. Seven patients (24.1%) presented with complications that were easily resolved. There were 13 deaths, probably due to the critical conditions of these patients, all unrelated to the procedure. Conclusions: Open lung biopsy, though an invasive procedure, should be considered in the evaluation of selected children with undiagnosed diffuse lung disease, respiratory failure and with no satisfactory response to previous therapies.