7 Tumor budding as a prognostic marker in head and neck cancer – A systematic review

Abstract

Introduction Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. For the histopathological prognostication of HNSCC, pathologist evaluates characteristics which reveal the biological aggressiveness of tumor. The invasive front (IF) has been suggested as the aggressive part of HNSCC and several histopathological parameters were evaluated at IF. One of these parameters is the tumor budding which defined as presence of single cancer cells or small clusters ( [1] . Later on, our group [2] and other [3] reported a strong prognostic power for tumor budding in tongue carcinoma. This systematic review aims to highlight the importance of tumor budding in HNSCC. Material and methods The term ‘tumor budding’ was searched in the following databases: PubMed, Scopus and Web of Science. The search was limited to the English language literature published before March 2014. Results of the literature searching Of the literature searching: We retrieved 122 citations. However, only 5 studies were eligible for the review process and each of them have studied the tumor budding in the squamous cell carcinoma in one of the following location: larynx, nasopharynx, tongue, oral tongue, and oral cavity. The findings of these reports suggested tumor budding as a marker of many important events in HNSCC which include: epithelial-mesenchymal transition, invasion, metastasis, and subsequent prognosis. Conclusion In HNSCC, there is a strong association between tumor budding and tumor progression, in addition to strong correlation with patient prognosis. Further research is required to better understand the molecular background of budding cells and to standardize the scoring method and the cutoff point.