International Tumor Budding Consensus Conference criteria determine the prognosis of oesophageal adenocarcinoma with poor response to neoadjuvant treatment

Background: Neoadjuvant therapy regimens followed by surgery represent the current standard treatment of locally advanced oesophageal adenocarcinomas. Tumour regression determines prognosis, but more than half of patients do have more than 10% residual tumour after neoadjuvant therapy. In these cases, classical histopathological parameters for the determination of prognosis are of limited value. Therefore, we investigated whether tumour budding could be an additional prognostic factor for tumours with poor response to neoadjuvant therapy. Methods: Tumour budding was assessed according to a standardized consensus quantification method as proposed by the International Tumor Budding Consensus Conference (ITBCC) in H&E-stained whole tissue slides of 278 formalin-fixed paraffin-embedded (FFPE) resected oesophageal adenocarcinomas with a poor response (> 10% vital residual tumour) to neoadjuvant therapy. Results: We could demonstrate a strong positive correlation (p < 0.05) between the budding group, ypN stage and UICC tumour stage. Further, high numbers of tumour buds were a significant and independent negative prognostic marker for OS in all studied patients (HR = 1.039 (95% CI 1.012-1.066), p = 0.004). ITBCC budding groups were an independent prognostic parameter. Conclusions: Tumour budding assessed in accordance with the ITBCC criteria may aid in the prognostic stratification of locally advanced oesophageal adenocarcinoma with poor response to neoadjuvant treatment.