Tumour budding evaluated in biopsy specimens is a useful predictor of prognosis in patients with cN0 early stage oral squamous cell carcinoma.

Aims: Oral squamous cell carcinoma (OSCC) prognosis depends upon lymph node metastasis (LNM). We have reported recently that tumour budding is a good predictive factor for LNM in squamous cell carcinoma (SCC) of the tongue and floor of the mouth (FOM). Our aim was to evaluate whether tumour budding is a good prognostic factor in OSCC.

Methods And Results: We examined conventional histopathological assessment and a new factor, tumour budding, in 209 cases of OSCC in incisional biopsy specimens. The relationship of tumour budding with LNM and prognosis was studied. The budding score was evaluated using immunostaining for pan-cytokeratin in all biopsies specimens; the number of budding foci was counted using a ×20 objective lens. Significant factors using univariate analysis (P < 0.05) in association with LNM were the budding score (intermediate or high score ≥3; high score ≥5), tumour grade (2 and 3), tumour depth (≥5 mm), infiltrative pattern (INF), lymphatic invasion and vessel invasion. In multivariate analysis, the budding score, INF and lymphatic invasion were found to be independent risk factors for LNM; in particular, budding score concerning relapse-free survival was statistically significant among patients with T1/2 stage and cN0 cancer using the Kaplan-Meier method and the log-rank test.

Conclusions: The assessment of tumour budding is effective in predicting prognosis in cN0 early stage OSCC. In T1/2 stage and cN0 cancer, prophylactic neck dissection to prevent LNM should be considered when the tumour budding score regarding pre-operative biopsy specimens is intermediate or high.