Identifying malignant pleural effusion from tubercular pleural effusion by study of cancer ratio and cancer ratio plus

Background: Early detection of malignant pleural effusions (MPE) through routine biochemical tests will go a long way in improving morbidity and mortality of these patients. Aims and Objectives: The current study was aimed to observe the usefulness of cancer ratio (CR) and CR plus to diagnose malignant effusions early in disease evolution. Materials and Methods: The study was a cross-sectional comparative observational study conducted at the indoor and outdoor facility of Respiratory Medicine department of Institute of Post Graduate Medical Education and Research, Kolkata. Results: Sixty-one patients were included in the study. The overall mean CR in our patients was 40.50±19.83. In MPE, tuberculous pleural effusions (TPE) and “Others”, the mean CR were 49.1839±14.698, 19.2874±16.354, and 30.6107±17.342, respectively. CR with levels above 20 showed very strong statistical association with MPE diagnosis in patients of pleural effusion (P<0.001). The mean CR plus in all patients was found to be 54.58±28.14. According to diagnosis, the means were 65.5645±22.576, 27.3255±24.356, and 43.1169±25.622 in MPE, TPE, and “Others,” respectively. Levels above 30 had shown strong association with MPE diagnosis (P<0.001). Both CR and CR plus had sensitivity of 95.12% (95% CI 80.03–98.64), specificity of 80% (95% CI 60.80–91.16), positive predictive value of 90.69, and negative predictive value of 88.88 in diagnosing MPE. Conclusion: CR and CR plus which are easily obtained by routine testing can be used for early detection of MPE.