Predictive role of cancer ratio in combination with pleural fluid cell block analysis in suspected malignant pleural effusion

Abstract Background The Second most common cause of exudative pleural effusion was malignancy. The diagnosis of suspected MPE was challenging, as it required invasive procedures for tissue biopsy. Aim To estimate the specificity and sensitivity of the Cancer ratio in predicting malignant pleural effusion in comparison to pleural fluid cell block analysis and cytology of pleural fluid. Methodology Prospective cross-sectional study in a tertiary care centre. The cancer ratio and HPE of pleural tissue biopsy obtained by thoracoscope were compared to determine the utility of CR in predicting the MPE. Results The majority of patients present with more than three symptoms, including breathlessness, chest pain, and expectorant cough. The cancer ratio cutoff was 24.41 as per ROC and AUC of 0.988{0.973-1.000( p = 0.0005)} of sensitivity and specificity 91.11% and 90.63%. A statistically significant difference was obtained between MPE, TPE, and chronic inflammation using the ANOVA test and a regression model analysis with multicollinearity. Discussion Low levels of pleural fluid ADA and High levels of serum LDH, even when using cancer-specific biomarkers, were used to support the diagnosis of malignancy. However, the sensitivity and specificity of these individual tests were very low, and the cost was high. The combination of CR and cell block analysis improved the sensitivity and specificity to 95.35% and 100%. Verma et al.‘s study and another meta-analysis in China also showed similar results. Hence, the CR was a dependable, convenient, rapid and easy-to-perform test. Conclusion ≥24.41 was the cutoff value for the CR. A combination of two non-invasive tests, CR and cell block analysis, demonstrated an improvement in sensitivity and specificity.