Assessing the Utility of a Proposed System for Routine Assessment of Tumour Budding in Core Biopsies of Breast Cancer, a Robust Adjunct to Conventional Grading to Improve Prediction of Stage, Response to Neoadjuvant Chemotherapy and Prognosis

Abstract

Background Tumour budding is a predictor lymph node metastasis and prognosis in colon cancer. Recent studies suggest that tumor budding can be useful in prognostication of breast cancer. We determined the utility of a proposed system that relies on combined assessment Tumour Budding and Nest Size (B-TBNS) for grading breast cancers on core biopsy as a predictor of prognosis. We assessed the relationship between B-TBNS grade and tumour characteristics such as traditional grade, stage, molecular type, and response to neoadjuvant chemotherapy. Methods A descriptive, cross-section study design, with a retrospective review of breast core biopsy (H&E) slides from January 2020 to December 2021 was carried out. B-TBNS grades were determined on core biopsy samples by three pathologists independently and related to tumour characteristics on core biopsy and matched excision with axillary lymph node dissection. Data were analysed with SPSS v 20.0. Descriptive statistics of frequencies and percentages were used to describe categorical variables. Cross-tabulation and chi-square test was done at 95% confidence interval with significance established at p < 0.05. Results A total of Eighty-five (85) cases were included in the study with mean age at 52.74 ± 14.443 years. There was a statistically significant relationship between, nest size (NS) of tumour buds in core biopsy samples and size of tumour at excision (p < 0.039), ER (p < 0.026), HER-2 (p < 0.035), Receptor status (ER & or PR) (p < 0.011), Molecular subtype (p < 0.019), HER-2 enriched (p < 0.008). There was also a significant association between Tumour budding activity and tumour size (p < 0.001). Conclusion Tumour budding and nest size in breast core biopsies are related to tumour characteristics such as size, lymph node involvement, molecular subtype, and response to neoadjuvant chemotherapy. Simple hematoxylin and eosin morphology-based systems such as our B-TBNS grading system that assess tumour budding and nest size on initial core biopsies will help better stratify patients into risk categories for management and ensure improved prognosis.