Efficacy and potential microRNA mechanism for computed tomography-guided percutaneous radiofrequency ablation of primary lung cancer and lung metastasis from liver cancer.

BACKGROUND: The aim of this study was to evaluate comparatively the effectiveness of computed tomography-guided percutaneous radiofrequency ablation (CT-PRFA) for primary non-small cell lung cancer (NSCLC) and lung metastases from hepatocellular carcinoma (HCC) and to explore the potential miRNA mechanisms for the efficacy of CT-PRFA.

METHODS: 14 patients pathologically diagnosed with NSCLC and 12 patients with lung metastases from HCC were enrolled in the study and underwent CT-PRFA. Clinical outcomes were compiled on the basis of review of medical records, imaging follow-up reports, and any biopsy-proved residual or recurrent disease. Real-time RT-PCR was used to quantify the selected miRNAs known to be play key roles in lung cancer.

RESULTS: A total of 21 tumors were treated with umbrella-tip electrodes and spiral-tip electrodes were used for the remaining 8 tumors. The median follow-up was 13.5 months (range, 3-30 months) and no patient was lost to follow-up. The rate of technique efficacy for primary tumors was ∼93% (13 of 14). Treatment was successful in 11 out of 12 (91.7%) lung metastases patients. Overall survival rate was 80.8% at 2 years, and cancer-specific survival rate was 100% at 2 years. The tumor-free survival was 69.2% at 1 year and 26.9% at 2 years. Before PRFA, tumor suppressor let-7a and miR-34a were downregulated whereas oncomiR miR-21 was upregulated in primary tumors, and let-7a and miR-126 levels were downregulated whereas oncomiRs miR-21, miR-155 and miR-17-5p/miR-20b levels were upregulated in secondary tumors. This abnormal expression was normalized by CT-PRFA. Most notably, CT-PRFA failed to normalize the deregulated miRNAs in the non-survivors.

CONCLUSIONS: CT-PRFA is a effective treatment for primary NSCLCs and secondary lung tumors from HCC and the efficacy may be related to its ability to normalize deregulated expression of miRNAs: upregulating tumor suppressor miRNAs and downregulating oncomiRs.