Neoadjuvant chemotherapy in non-metastatic breast cancer: a study on practice trends in a regional cancer treatment service

Background Neoadjuvant chemotherapy (NACT) is increasingly used for managing locally advanced and high risk non-metastatic breast cancer. Aims To describe trends in NACT use, assess compliance to best practice recommendations and determine treatment response rates in a regional cancer treatment service. Methods In this retrospective cross- sectional study, electronic records of patients who underwent NACT in centres covered by the MidCentral Regional Cancer Treatment Service in 2013 and 2017 were reviewed. Data pertaining to patient demographics, disease status, compliance to best practice recommendations and treatment outcomes were extracted and analysed. Results Of a total of 502 referrals for non-metastatic breast cancer, 34 underwent NACT with the estimated NACT rate rising from 3.85% (2013) to 9.92% (2017). Compliance to practice recommendations improved in all domains (pre-treatment tumour and axillary evaluation, marker placement, multidisciplinary discussion). Overall, NACT was well tolerated with only three patients experiencing treatment limiting toxicity. Response rates mirror published data (complete response: 29.4%, partial: 61.8%) with higher responses registered in HER2 positive and triple negative subtypes. Discordance between radiological and pathological response was 28%, with imaging overestimating response in five out of seven cases. Of the 11 (32%) patients who initially underwent breast conserving surgery, six required a second surgery. Conclusion NACT is increasingly used in the Regional Cancer Treatment Service, with improving compliance to practice recommendations. These results are reassuring and can be used to help patients develop a realistic expectation towards NACT.