Tumor Budding as a Useful Prognostic Marker in T1-Stage Squamous Cell Carcinoma of the Esophagus

BACKGROUND Establishing a new prognostic factor for early-stage cancer may seem difficult due to the small number of disease-specific deaths. Tumor budding has been recognized as a useful microscopic finding reflecting biological activity of the tumor. METHODS Tumor budding stand for isolated single cancer cells and cell clusters scattered beyond the tumor margin at the invasive front. It was searched for in the resected esophagus with T1 squamous cell carcinoma (SCC), and the correlation between the tumor budding, patient survival, and various pathologic factors were analyzed to verify whether tumor budding is a prognostic factor in superficial esophageal cancer. RESULTS Seventy-nine patients undergoing curative esophagectomy were assigned to frequent (n = 29) and rare (n = 50) groups according to the microscopically observed frequency of tumor budding in the tumor. Three-year survival rates after esophagectomy were 48.8% for the frequent group and 94.5% for the rare group. Multivariate analysis using the Cox proportional hazards model identified this morphological variable as a significant independent prognostic factor. CONCLUSIONS Tumor budding reflects the biological activity of the tumor and may be a useful prognostic indicator even in early-stage SCC of esophagus.