A prospective study on tumour response assessment methods after neoadjuvant endocrine therapy in early oestrogen receptor-positive breast cancer.

"Declarations Ethics approval and consent to participateThe study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines as well as authorized by the Spain Health Authority and the local Ethics Committee. Consent for publicationNot applicable. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding This work was funded by Instituto de Salud Carlos III (ISCIII) grants: PI21/01208, PI20/01253, CP18/00076 and FI19/00193 co-funded by the European Union, Basque Department of Health (2020111040), Fundación SEOM (SEOM Avon Fellowship 2020) and Ikerbasque Basque Research Foundation. The group also received funds from the breast cancer patient’s charity Katxalin and from Roche Farma S.A. JILV is funded by an AECC PhD Fellowship (PRDGI19007LOPE)."