The Association Between Radiation-Induced miR-208a, Cancer Recurrence and Death Risk in Patients with Non-Small Cell Lung Cancer.

Background: Existing experimental evidence suggested that the miR-208a expression in tumor tissue from non-small cell lung cancer (NSCLC) was significantly high after radiotherapy in vitro and in vivo, indicating a potential role for predicting NSCLC progression or recurrence. However, its prognostic value has not been fully confirmed among patients with NSCLC. Aim: We explored the association of serum miR-208a level with adverse events including cancer recurrence and/or metastasis and cancer death during a follow-up for 36 months after radiotherapy. Methods: We identified the serum level of miR-208a from 46 patients before and after surgical treatment combined with radiotherapy in NSCLC patients. The association between serum miR-208a and risk for the cancer recurrence and/or metastasis and cancer death among these patients were examined by Kaplan-Meier and multivariable Cox analysis. Results: The comprehensive outcomes during the follow-up period for 3 years including cancer recurrence and/or cancer metastasis and cancer death were 13 (28.3%) and 8 (17.4%), respectively. Kaplan-Meier analysis suggested that a high serum miR-208a level after radiotherapy tended to have a higher rate of cancer recurrence and/or cancer metastasis and a higher risk of cancer death than those with a low level of serum miR-208a. Furthermore, our multivariable Cox analysis suggested that elevated serum miR-208a levels were associated with an increased risk for cancer recurrence and/or cancer metastasis (HR=7.5, 95% CI: 2.5-24.9, P<0.01) and cancer death risk (HR=5.3, 95% CI: 1.7-18.5, P<0.05) after age, gender, smoking, drinking and tumor node metastasis (TNM) stage were controlled for. Conclusion: This study further provided evidence that elevated serum miR-208a levels after radiotherapy were associated with a high risk for cancer recurrence and/or metastasis and death among NSCLC patients.