Accuracy of helical computed tomography and [18F] fluorodeoxyglucose positron emission tomography for identifying lymph node mediastinal metastases in potentially resectable non-small-cell lung cancer.

PURPOSE: Computed tomography (CT) and [18F] Fluorodeoxyglucose positron emission tomography (FDG-PET) are considered suitable methods for the noninvasive staging of the mediastinum. Our study was intended to estimate the efficacy of contrast-enhanced helical CT (hCT) and FDG-PET, alone and combined, in the diagnosis of lymph node mediastinal metastases. METHODS: This study was a prospective and blind comparison of the efficacy of hCT and FDG-PET with two alternative reference standards, mediastinoscopy, and mediastinoscopy plus thoracotomy plus a 6-month follow-up to diagnose lymph node mediastinal metastases in 132 consecutive patients with potentially resectable non-small-cell lung cancer (NSCLC). The metastatic disease was assessed histopathologically. Further clinical information was obtained postoperatively after a median follow-up of 42 months. RESULTS: The prevalence of cN2,3 is 0.28. For hCT the sensitivity and specificity are 0.86 (95% CI, 0.70 to 0.93) and 0.67 (95% CI, 0.56 to 0.75), for PET 0.94 (95% CI, 0.81 to 0.98) and 0.59 (95% CI, 0.49 to 0.68), and for hCT and PET combined in-parallel 0.97 (95% CI, 0.84 to 0.99) and 0.44 (95% CI, 0.34 to 0.53), which translate into a negative predicted probability of 0.98 (95% CI, 0.88 to 1.00). The crude diagnostic odds ratio of PET in the total sample studied is 13.1, in the subgroup hCT+ 11.04 (3.0 to 40 0.1), and in the hCT- 3.5 (0.5 to 21.5). Similar results were obtained for hCT stratified by PET. CONCLUSION: hCT and PET perform similarly in the mediastinal staging of NSCLC, both tests are conditionally dependent and provide complementary information, and their diagnostic value mainly resides on the negative results.

Surgical lung cancer. Risk operative analysis.

STUDY OBJECTIVE: To identify those variables that are associated with operative morbidity or mortality in cases of thoracotomy in lung cancer. SETTING: Third level university hospital. PATIENTS: Consecutive patients with thoracotomy due to lung cancer operated on between 1994 and 1997 (n = 115). METHODS: Pre- and postoperative variables potentially associated with operative morbidity or mortality were retrieved prospectively as follows: demographic and clinical characteristics of the patients, cardiopulmonary function characteristics, tumour characteristics, and treatment characteristics. A bivariate analysis of all variables under evaluation was carried out in order to identify those variables associated with operative morbidity and mortality. A multivariable analysis of the selected variables was then conducted using a logistic model. RESULTS: The predicted postoperative product (predicted FEV1 x predicting diffusing capacity of carbon monoxide), the carbon monoxide diffusion coefficient (Kco) and the contralateral pulmonary perfusion are variables that relate to the overall morbidity or mortality (number of events 63, 55%) (-2 log likelihood chi2 = 22.9; R2 = 0.27). For variables associated with postoperative morbidity, the best associative model combines functional variables (diffusion, predicted FEV1), endoscopic variables (obstructed segments to be resected), clinical variables (comorbidity) and an important postoperative variable, the pathological tumoural staging (pN) (number of events 49, 43%) (-2 log likelihood chi2 = 32.9; R2 = 0.36). CONCLUSION: The numerous variables under analysis are poorly associated with morbidity or mortality after thoracotomy in lung cancer. With regard to postoperative morbidity, the best associative models combine information that is known pre- and postoperatively and which is provided by both the patient and the tumour.

Interferon gamma levels in pleural fluid for the diagnosis of tuberculosis.

PURPOSE: To assess the utility of interferon gamma levels, including identification of the best cutoff for the diagnosis of tuberculosis. METHODS: We prospectively studied consecutive patients in a tertiary care, university-affiliated hospital who had pleural effusions. Interferon gamma levels were measured blindly by radioimmunoassay. The diagnosis of tuberculosis was established using prespecified standard criteria. RESULTS: Of the 595 patients with pleural effusions, 82 patients (14%) had tuberculosis. The area under the receiver operating characteristic (ROC) curve for elevated interferon gamma levels in the diagnosis of tuberculosis was 0.99 (95% confidence interval [CI]: 0.97 to 1.00). A cutoff of 3.7 IU/mL yielded a sensitivity of 0.98 (95% CI: 0.91 to 1.00) and a specificity of 0.98 (95% CI: 0.96 to 0.99). The areas under the ROC curves, and the test's sensitivity and specificity, were similar among patients of different ages and by percentage of lymphocytes in the pleural fluid. In 5 of the 28 patients with hematologic malignancies, interferon gamma levels were slightly above the cutoff; no patient with vasculitis or granulomatous diseases had levels higher than 3.7 IU/mL. The 14 immunocompromised patients and the 3 transplantation patients with tuberculosis had interferon gamma levels greater than the cutoff. CONCLUSION: Elevated pleural interferon gamma levels (>3.7 IU/mL) are very valuable in diagnosing pleural tuberculosis. Patients with pleural effusion due to hematologic neoplasms occasionally have levels slightly above the cutoff.

Diagnostic value of CA 549 in pleural fluid. Comparison with CEA, CA 15.3 and CA 72.4.

Several tumor markers have been evaluated in pleural fluid, but their clinical role has not been firmly established. The aim of this study is to determine the diagnostic value of carbohydrate antigen 549 (CA 549) levels in pleural fluid, and to compare it with another previously studied tumor markers: carcinoembryonic antigen (CEA), CA 15.3 and CA 72.4. We prospectively studied 252 patients with pleural effusion: 101 malignant (20 mesothelioma) and 151 of several benign diseases. The levels of the tumor markers were measured by immunoradiometric assays (RIA). CA 549 in pleural fluid has an acceptable sensitivity (0.49), with high specificity (0.99). The best combination of tumor markers for differentiating malignant from benign effusions was CA 549+CEA+CA 15.3, with a sensitivity of 0.65, specificity of 0.99 and accuracy of 0.85. The addition of any one tumor marker assay consistently improved the diagnostic value of cytology. In our study, none of the tumor markers was organ-specific. When mesothelioma and hematological malignancy were ruled-out, the combination of CA 549+CEA+CA 15.3, improved the results up to a sensitivity of 0.77, specificity of 1 and accuracy of 0.92. In conclusion, CA 549 assay has an acceptable sensitivity with high specificity. The best combination of tumor markers in this series with a high relative frequency of mesothelioma and low frequency of breast carcinoma was CA 549+CEA+CA 15.3. Individual tumor markers or their combination increased the sensitivity of pleural cytology.