Ki-67 Assessment Data in Breast Carcinoma: Core Needle Biopsy vs. Resection Specimens (2020–2025, Medica Ruse University Hospital, Bulgaria)
Description
This dataset contains fully anonymized clinicopathological data from 63 cases of breast carcinoma diagnosed between 2020 and 2025 at Medica Ruse University Hospital, Ruse, Bulgaria. For each case, both core needle biopsy (CNB) and resection specimens were available, and the Ki-67 proliferation index was independently assessed by two pathologists. Along with Ki-67 indices, the dataset includes patient sex, age at diagnosis, TNM stage, and detailed tumor characteristics such as histological type, molecular subtype, receptor status, focality, grade, size, presence/absence of necrosis, stromal elastosis, and desmoplastic reaction. Abbreviations: M = Rater 1 D = Rater 2 C = Core needle biopsy R = Resection specimen CM = Ki-67 index on core needle biopsy assessed by Rater 1 CD = Ki-67 index on core needle biopsy assessed by Rater 2 RM = Ki-67 index on resection specimen assessed by Rater 1 RD = Ki-67 index on resection specimen assessed by Rater 2 NST = Invasive breast carcinoma of no special type ILC = Invasive lobular carcinoma ER = Estrogen receptor PR = Progesterone receptor HER2 = Human epidermal growth factor receptor 2 Exclusion criteria: Cases that had received neoadjuvant therapy or showed noticeable morphological heterogeneity, including intertumoral heterogeneity in multifocal tumors, were excluded from this dataset. Purpose and use: The dataset supports research on interobserver variability in Ki-67 scoring and the comparison of Ki-67 indices between CNB and resection specimens. Anonymization statement: All patient information has been removed in compliance with GDPR, HIPAA, and Elsevier’s patient consent policy. No identifying details are included.
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Steps to reproduce
Clinical information was retrieved from the hospital information system of Medica Ruse University Hospital to identify suitable patients. Inclusion criteria were: breast carcinoma diagnosed by core needle biopsy (CNB), followed by surgical resection at the same hospital (so that both CNB and resection specimens were available). Exclusion criteria included prior neoadjuvant therapy and noticeable morphological heterogeneity, including intertumoral heterogeneity in multifocal tumors. In cases of multifocal carcinomas representative tissue block from resection specimen of the tumor coresponding to the preoperative biopsy site was included. Formalin-fixed, paraffin-embedded tissue blocks and hematoxylin and eosin (H&E) stained slides were obtained from the hospital archives. The H&E slides were reviewed under the microscope, and tumor characteristics such as tumor cellularity, presence of necrosis, elastosis and desmoplasia were assessed. Immunohistochemistry (IHC) for Ki-67 was performed on 3 µm thick sections using the ONCORE Pro autostainer (Biocare, USA) with a rabbit monoclonal antibody, clone SP6 (Biocare, USA), and the ONCORE Pro Rabbit HRP Detection System (Biocare, USA), according to the manufacturer’s protocol. Proliferation index was assessed on each IHC stained slide by manual image-based counting, using the microscope camera and ImageJ software. A minimum of 500 tumor cells was evaluated whenever possible. Both hot spots and cold spots were included when present. The Ki-67 index was calculated as the percentage of positively stained nuclei relative to the total number of tumor cells counted.
Institutions
- Meditsinski universitet - Pleven