Article Abstract

RNF8 is associated with radioresistance, nodal stage and extranodal spread in oral cavity squamous-cell carcinoma

Authors: Glenn Jenkins, Duncan Lambie, Derek Richard, Ben Panizza


Background: Oral cavity cancer has an early metastatic profile and poor adjuvant therapy response when compared with other head and neck cancers, which is reflected in more aggressive clinical management. Accurate prognostic prediction is dependent on histological disease staging and extranodal spread, however these parameters are not available in preoperative clinical decision making. E3-ubiquitin ligase RNF8 is involved in the DNA repair cascade and dysregulation has been shown to promote in vitro genomic instability.
Methods: A single-site retrospective series of 53 patients with oral cavity cancer were selected from 2006 to 2012. Clinical data was obtained from chart review, and survival data obtained from the Queensland Cancer Registry. Immunohistochemical analysis for RNF8 was performed against a constructed tissue microarray.
Results: Sixteen (30.3%) tumours stained positive for RNF8 expression. RNF8 negative disease showed a significant survival advantage in patients who did not receive radiotherapy, while a non-significant inverse association was suggested in patients who did receive radiotherapy. RNF8 positivity was associated with increased tumour thickness (P=0.021), nodal extracapsular spread (ECS) (P=0.037) and pathological N-stage (P=0.036).
Conclusions: RNF8 shows significant correlation with established tumour prognostic features of tumour thickness, ECS and nodal stage.