Neoadjuvant endocrine therapy (NET) is effective in downstaging tumours and enabling breast-conserving surgery but remains underutilised. This study assessed the impact of short term NET on hormone receptor-positive breast cancer patients, aiming to evaluate its influence on tumour response and adjuvant treatment recommendations. 

A single-centre retrospective cohort study analysed patients treated with NET from January 2022 to December 2023. Data from patient records, radiology, and histopathology were reviewed, focusing on tumour characteristics, including size, lymph node involvement, Ki67 index, and hormone receptor status. Patients were categorised as responders or non responders based on changes in Ki67 levels. 

Among 98 women (101 breast cancers), with a median age of 60 (IQR 51-71.1), all had stage I or II breast cancer. Most tumours 96/101 (95.0%) were grade 1 & 2. All the tumours were ER-positive, 89/101 (88.1%) were PR-positive, and 5/101 (5.0%) were HER2-positive. The median tumour size remained at 15 mm after NET. Lymph nodes were positive in 22/98, 22.4% of cases on postoperative histology. Chemotherapy was de-escalated in 17/98 (17.3%) of patients based on NET response. The differences in the responder and non-responder groups are presented in the table below.

NET significantly impacts treatment decisions, particularly in reducing the need for adjuvant chemotherapy in hormone receptor-positive breast cancer. The differentiation between responders and non-responders, identified by Ki67 changes, supports NET as a predictive tool for tailored treatment. These results suggest that increased adoption of NET may enhance personalised care, though further research is needed to optimise patient selection and integration into clinical practice.

TBA.