Original contributionHigh tumor budding count is associated with adverse clinicopathologic features and poor prognosis in breast carcinoma

•In ER+/HER2− cancer, tumor budding is significantly associated with distant metastasis.•In TNBC, H-TB is associated with distant metastasis by univariate analysis.•In TNBC, tumor budding is associated with LVI and worse overall survival.•Evaluation of H-TB should be added to the prognostic features of breast carcinoma.

SummaryThis study is to address the significance of tumor budding (TB) in breast carcinoma. Totally 244 estrogen receptor-positive (ER+)/HER2-negative (HER2−) and 131 triple-negative breast carcinoma (TNBC) diagnosed from 2004 to 2014 were analyzed. TB (cluster of up to 5 tumor cells at the invasive front) was evaluated using five 200× high-power fields (HPF) at the hotspot. The highest TB (H-TB) in 1 HPF and average TB (A-TB) in 5 HPFs were correlated with lymph node and distant metastasis, lymphovascular invasion (LVI), local recurrence, overall survival (OS), and disease-free survival (DFS). In ER+/HER2− cancer, H-TB and A-TB were significantly associated with distant metastasis. In TNBC, H-TB was associated with distant metastasis by univariate but not multivariate analysis; H-TB and A-TB were associated with LVI and worse OS (all P < .05). TB is associated with poor prognosis in ER+/HER2− and TNBC cancer. Evaluation of H-TB may be sufficient in breast carcinoma.