Tumor Budding as a Useful Prognostic Indicator in Early Oral Squamous Cell Carcinoma

Tumor budding, defined as the presence of single cancer cells or small clusters of fewer than five cells at the tumor invasive front, has been reported to be an independent prognostic factor for several cancers together with margin status, depth of invasion, lymph vascular invasion, and lymph node metastasis. Distant metastasis and poor prognosis were significantly more common in the higher budding group. In this short review, we focused on the studies related to tumor budding in several cancers including oral squamous cell carcinoma(OSCC) and showed the association among the intensity of tumor budding, risk of lymph node metastasis, and poor prognosis in OSCC is strongly supported by many studies. Moreover, arguments for the assessment of tumor budding, scoring system, stains to mark budding, specimens, and the association with epithelial mesenchymal transition (EMT) are also discussed.