P116. The impact of neoadjuvant hormone monotherapy in deferral of surgery during the SARS-COV-2 pandemic

Topping, Jonathan; Zabkiewicz, Catherine; Holland, Phillip

Introduction: The Cov-Sars-2 pandemic required rapid re-evaluation of breast cancer management, with national recommendation that oestrogen receptor (ER) positive, HER2 negative early-stage patients defer surgery with hormone treatment (HT). We reviewed the impact of this approach for our ER+ patients. Methods: 33 ER positive HER2 negative patients were initiated on HT at diagnosis. Data was collected on age, Allred score, time to surgery from diagnosis, operation undertaken, tumour grade on biopsy and final pathology. Comparison was to 33 patients matched for age, receptor status, surgery, and initial tumour grade. Results: Mean age of both groups was 62.4 years (range 34 to 90). Length of HT ranged from 29 to 204 days (mean of 87). Both groups had mean initial biopsy grade 1.9, and final pathology mean grade 1.8 (median 2). There was no statistically significant change in tumour grade in the HT or control groups (paired t test p=0.06 and 0.5 respectively). In the HT group, 9 of 33 (27%) patients had reduction in tumour grade, compared to 6 (18%) in the control group. 3 (9%) of the HT and 4 (12%) of the control group increased in tumour grade. These differences did not reach statistical significance (p=0.6 fishers exact test). Conclusion: This data demonstrates that delaying surgery and temporising with neoadjuvant hormone treatment did not result in significant detriment to the biology of the disease and shows there was a trend towards reduction in tumour grade, in keeping with recent literature suggesting neoadjuvant hormone monotherapy as a viable low toxicity option in these patients ER+ HER2- early disease patients.