Tumour budding is a useful predictor to identify high-risk stage II colon cancer patients after curative surgery

Aim Although it is now accepted in the literature that tumour budding (BD) is a useful survival indicator in colon cancer (CC), there are still uncertainties about daily use. Here we methodologically examined the role of BD on survival in CC. Methods In our study, we analyzed CC patients operated on between 2005 and 2012. BD was calculated separately using different comprehensive methodological methods. Results We first investigated an optimal evaluation method. The relationship with prognostic factors was better (lymphatic invasion [p = 0.001], advanced PT [p = 0.003], perineural invasion [p = 0.040], MSS [p = 0.016], advanced size [p = 0.001], tumour perforation [p = 0.005], and margin involvement [p = 0.043]) in Method-1 (invasive margin focus & hot-spot area & deeply invasive block). Similarly, with the same method, the success of the cut-off value, the correlation of BD data (r = 0.724), and the repeatability of the method (Κappa = 0.53 − 0.75) were quite good (ROC = 0.816 [0.707–0.925]). Then, survival analysis was performed using the best three methods, including this method. In univariate analysis using Method-1, survival analyses were worse in high BD patients (RFS: 81%, p < 0.001; OS: 84%, p < 0.001). Multivariate analyses using the same method confirmed that high BD for RFS and OS was an independent poor prognostic parameter for survival (p = 0.002, Hazard ratio [HR]: 1.42 [1.13–1.80]) and OS (p = 0.014, HR: 1.38 [1.07–1.79]). Conclusions With our study, we showed that BD calculated by the standard method is a very valuable prognostic parameter in stage II CC and can contribute to the detection of patients with poor prognosis in stage II CC.