Phospho-Rb (Ser780) as a biomarker in patients with cervical lymph node metastases from an unknown primary tumour: a retrospective cohort study

Abstract

Objectives: Cervical lymph node metastases from an unknown primary tumour are a heterogeneous disease entity with various clinical features. There are many controversies regarding treatment methods and treatment response predictions. Therefore, we examined the prognostic significance of biomarkers in patients with cervical metastasis of unknown primary tumour. Design: A molecular study of retrospective cohorts. Setting: University teaching hospital. Main outcome measures: Metastatic cervical lymph nodes of 36 patients with cervical unknown primary metastasis of squamous cell carcinoma were assessed by in situ hybridisation for human papillomavirus and immunohistochemistry for p16, retinoblastoma protein (phospho-Ser780), hypoxia-inducible factor-1a, glucose transporter 1 and carbonic anhydrase 9 expression. Clinicopathological factors and biomarkers were analysed for their associations with disease-free survival and overall survival. Results: Univariate analysis showed that nodal extracapsular spread was associated with poor overall survival (P = 0.049), nodal-positive retinoblastoma protein staining were significantly associated with poor outcomes of both disease-free survival (P = 0.035) and overall survival (P = 0.019), Multivariate analysis revealed that nodal positivity of retinoblastoma protein and nodal extracapsular spread were the significant predictors of overall survival (P = 0.049, hazard ratio = 6.21, 95% confidence interval = 1.01-38.35 and P = 0.037, hazard ratio = 4.34, 95% confidence interval = 1.09-17.21, respectively). Conclusion: The retinoblastoma protein expression of metastatic lymph nodes represents an independent prognostic indicator in patients with cervical metastasis of unknown primary tumour.