Predictive power of tumour budding for lymph node metastasis in colorectal carcinomas: A retrospective study

BACKGROUND & OBJECTIVES: Tumour budding is a feature of epithelial-to-mesenchymal transformation that is characterized histologically within the tumour stroma by the presence of isolated cells or clusters of less than five cells which are different from the other malignant cells. This could be present around the invasive margin of the tumour, called peritumoural budding, or in the bulk of the tumour, called intratumoural budding. The aim of this study was to assess the predictive power of tumour budding for lymph node metastasis and its relationship with other features of tumour progression in colorectal carcinoma (CRC). METHODS: Preoperative colonoscopic biopsies and consecutive resection specimens from 80 patients of colorectal cancer were taken. In the biopsy, intratumoural budding was looked for and graded. In the resection, peritumoural budding was seen and graded along with other features such as grade of the tumour, lymphovascular emboli and tumour border configuration. RESULTS: Intratumoural budding was seen in 23 per cent (18/80) and peritumoural in 52 per cent (42/80) of cases. Intratumoural budding was associated with the presence of lymphovascular emboli (P=0.002) and irregular tumour border configuration (P=0.004). Peritumoural budding was also significantly associated with the presence of lymphovascular emboli and irregular margins (P<0.001). Both intra- and peritumoural budding were not associated with the grade of the tumour. Both intra- and peritumoural budding had a significant association with lymph node metastasis (LNM) (P<0.001). INTERPRETATION & CONCLUSIONS: Our findings indicate that tumour budding in preoperative biopsy and resection specimens may predict a possibility of finding LNM in patients with CRC.