Combination of DNA ploidy analysis and miR-21 or miR-24 in screening malignant pleural effusion

Objectives: The study aimed to assess the combination of DNA ploidy analysis (DPA) and the expression of microRNA-21 (miR-21) or microRNA-24 (miR-24) in the detection of malignant pleural effusion (MPE).

Methods: In this prospective research, a total of 40 samples (20 benign and 20 malignant effusions), flexural effusion exfoliated cells and cell-free miR-21 and miR-24 were collected. DPA and exfoliative cytology examinations were conducted to diagnose flexural effusion exfoliated cells. Quantitative reverse transcriptase polymerase chain reaction was carried out to measure the expressions of miR-21 and miR-24. Receiver operating characteristic curve and the area under the curve were applied to evaluate the accuracy rate of different diagnostic approaches on MPE.

Results: In the MPE group, DPA demonstrated a higher rate of accuracy in MPE diagnosis than exfoliative cytology. The expressions of miR-21 and miR-24 were significantly higher in MPE than in benign pleural effusion (P < 0.05). Furthermore, area under the curve, sensitivity and specificity were 0.942, 95% and 90% for the combination of miR-21 and DPA and 0.973, 100% and 80% for the union of miR-24 and DPA, respectively, representing a significant improvement in both accuracy and sensitivity. Therefore, the combination of DPA and miR-21 or miR-24 appears to be a better biomarker for discriminating MPE from benign pleural effusion.

Conclusions: The combination of DPA and miR-21 or miR-24 may function as a promising diagnostic tool of MPE.

Registration number: ChiCTR-TRC-14004719.