PP083: Oncogenic microRNA-31 as prognostic potential biomarker in histologically negative surgical margins of head and neck cancer patients

The development of locoregional recurrence is the main reason for treatment failure in head and neck squamous cell carcinomas (HNSCC) and the remaining of tumor cells in surgical margins is associated with recurrence. Surgical margins are considered negative based on histologic assessment of the pathological specimen. However, this method lacks sensitivity in identifying cells that already started malignant transformation but have not yet developed a pathologic phenotype. We investigated the usefulness of assessing the expression of microRNA-31 for the detection of molecular alterations in histologically negative surgical margins (HNSM) and determine the correlation of these tumor-related alterations with clinical and prognostic parameters.. MicroRNAs are endogenously expressed non-coding RNAs that have important biological and pathological functions. The microRNA-31 was found markedly upregulated in different malignancies, including HNSCC. The microRNA-31 expression was determined by qRT-PCR in HNSCC ( n  = 19), HNSM ( n  = 37) and normal mucosa ( n  = 10). According to our results, 76% of tumor samples and 30% of the HNSM specimens were positive for microRNA-31 overexpression. Moreover, the overexpression of this microRNA in the HNSM was associated with perineural invasion ( p p These findings demonstrate that the overexpression of microRNA-31 in histologically negative surgical margins is a frequent event. The use of qRT-PCR may be an useful tool in detecting actually negative HNSCC surgical margins and the overexpression of microRNA-31 in these margins could be helpful in the identification of patients with worst outcome.