Factors associated with discordance between pathological and radiological tumor size and risk of re-excision in breast-conserving surgery: a post-hoc analysis within a randomized trial
In brief
Re-excisions occurred in 2.7% of non-palpable cancers, driven by tumor biology not MRI
In a post-hoc analysis of 414 patients undergoing breast-conserving surgery, only 11 (2.7%) needed a second operation, and this was linked to high-grade, small, or lobular tumors rather than the use of pre-operative MRI. MRI tended to over-size most cancers but improved measurement of invasive lobular carcinoma, yet it did not lower re-excison rates, highlighting the need to combine imaging with biological risk factors in surgical planning.
- Journal
- Breast cancer research and treatment (Q1)
- Published
- 13 August 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Christos Kollatos, Eirini Pantiora, Allan Jazrawi, Fredrik Wärnberg, Staffan Eriksson, Andreas Karakatsanis
- PMID
- 42593693
- DOI
- 10.1007/s10549-026-08052-x
Why clinicians should know about it
- Picked for Breast and Endocrine Surgery (top studies of the week, 16 August 2026): Factors linked to radiology‑pathology discordance and re‑excision
- Picked for Radiology, Radiation Oncology, Nuclear Medicine, Medical Physics and Imaging (top studies of the week, 16 August 2026): Post‑hoc analysis of RCT, imaging‑pathology size discordance
Abstract
PURPOSE: Accurate preoperative radiological assessment is essential in breast-conserving surgery (BCS) to achieve clear margins while minimizing unnecessary healthy tissue excision. Discrepancies between radiological and pathological tumor size may contribute to re-excision. This study evaluated factors associated with radiology-pathology discordance and their impact on re-excision. METHODS: This post hoc analysis of the MagTotal randomized trial included patients with non-palpable breast cancer undergoing BCS with lesion localization and sentinel lymph node dissection. The Pathology-to-Radiology Ratio (PRR) quantified discordance between size on preoperative imaging and specimen pathology. Primary outcomes were predictors of PRR and re-excision. A multivariable model was used to construct a nomogram for predicting PRR. RESULTS: Among 414 patients (median age 65 years; median tumor size 10.3 mm), MRI was performed in 24.4%. Median PRR was 1.25, suggesting systematic underestimation. MRI consistently overestimated tumor size in most subtypes but provided more accurate estimates for invasive lobular carcinoma (ILC), compared with conventional imaging. Independent predictors of discordance included ILC, high grade, and small tumor size. Eleven patients (2.7%) required re-excision, which was associated with tumor biology and mismatches between imaging and pathology but not with MRI use. CONCLUSION: Re-excision in non-palpable breast cancer is primarily driven by tumor biology and radiology-pathology mismatch. Although MRI improved size assessment in ILC, it did not reduce re-excision rates. Integrating imaging with biological factors, supported by predictive tools such as a nomogram, may refine surgical planning in BCS.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.