Study of tumor budding and its association with clinicopathological parameters in breast carcinoma.

Objective: Tumor budding is a phenomenon in which the tumor cells detach from the main mass and are present at the invasive front. The present study was conducted to study tumor budding in invasive breast carcinoma and to correlate it with clinicopathological parameters and molecular subtypes.

Methods: The study was conducted over a period of 1 year, and tumor budding was studied as a single or group of cells at the invasive front of breast carcinoma counted in a high-power field (40×). The grading was statistically correlated with tumor size, grade, lymph node status, lymphovascular invasion, pathological TNM staging, molecular subtype, and survival of patients.

Results: A total of 50 cases of invasive breast carcinoma were included, out of which 66% (n=33) showed high-grade tumor budding, which was statistically significantly higher in grade 2 invasive ductal carcinoma (p<0.05). High tumor budding was associated with lymphovascular invasion, lymph node metastasis, and a high Ki-67 proliferative index. All cases showing low-grade budding were alive until 6 months of diagnosis, but there was no statistically significant association between stage and budding.

Conclusion: Tumor buds are significantly higher in grade 2 invasive ductal carcinoma with lymphovascular invasion, lymph node metastasis, and a high Ki-67 proliferative index. Immunohistochemistry may prove helpful in distinguishing tumor buds from their mimickers. Further studies with extended follow-up are recommended to predict tumor budding as a prognostic marker in breast carcinoma, which may play an important role in cancer therapy.