Diagnostic role of cancer ratio in suspected malignant pleural effusion

Background: The Second most common complication of various cancers was malignant Pleural Effusion (MPE). 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 diagnosing malignant pleural effusion. Methodology: Prospective cohort study in a tertiary care centre. The cancer ratio and HPE of tissue biopsy obtained by thoracoscope were compared to determine the diagnostic utility of CR in diagnosing MPE. Observation: The majority of patients present with more than three symptoms, 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%. The ANOVA test, followed by Tukey's Post Hoc analysis, demonstrated a statistically significant difference between malignant pleural effusion, tubercular pleural effusion, and chronic inflammation. 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 cancer ratio and cell block analysis tests 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 and easy-to-perform test. Conclusion: ≥24.41 was the cutoff value for the cancer ratio. A combination of two non-invasive tests, cancer ratio and cell block analysis, demonstrated an improvement in sensitivity and specificity.