MiR-221, a potential prognostic biomarker for recurrence in papillary thyroid cancer.

BACKGROUND: Many studies have reported several transcriptionally deregulated microRNAs (miRNAs) in papillary thyroid cancer (PTC) tissue in comparison with benign thyroid nodules and normal thyroid tissues. However, the correlation between miRNA expressions and PTC recurrence still remains unclear.

METHODS: The PTC patients who scheduled to undergo total thyroidectomy by the same surgical team in Ningbo NO.2 Hospital from March 1998 to March 2008 were enrolled in this study. The clinical and pathological characteristics of each patient were recorded in detail. The selected miRNA expressions were detected using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Potential predictive factors for cancer recurrence were evaluated by univariate and multivariate Cox proportional hazard analysis.

RESULTS: A total of 78 patients were enrolled with 49 females at a mean age of 45.8 years. Enrolled patients were divided into two groups: nonrecurrent group (n = 54) and recurrent group (n = 24). The results from the univariate Cox proportional hazard analysis revealed that primary tumor size, TNM stage, extrathyroid extension, miR-221, and miR-222 expressions were significantly associated with PTC recurrence (P < 0.05). The tissue expression of miR-221 was the only independent risk factor for PTC recurrence (HR 1.41; 95%CI 1.14-1.95, P = 0.007) by multiple Cox proportional hazard analysis.

CONCLUSIONS: This study identified the potential role of miR-221 as a prognostic biomarker for the recurrence in PTC.