NOSTRA-Feasibility Study: A Study Looking at Ultrasound Guided Biopsies for Breast Cancer

Inclusion Criteria: * Patient with histological diagnosis of operable HER2-positive, ER-negative, early stage invasive breast cancer * Tumour size ≥ 1cm and visible on US (T1c to T4d) * Patient fit and willing to receive, or is already receiving and has received no more than five cycles of a NOSTRA-Feasibility Study approved treatment regimen, in the opinion of the responsible clinician * Eastern Co-operative Group (ECOG) performance status of 0 or 1 * Women of child-bearing potential, prepared to adopt highly effective contraceptive measures if sexually active for at least 6 months after completion of study medication * Female, 18 years or older * Able to provide informed consent for the study * Availability of embedded paraffin tumour blocks from pre-chemotherapy biopsy * The radiology team are able and willing to perform the tumour bed core biopsies Exclusion Criteria: * Previous ipsilateral invasive breast cancer or Ductal Carcinoma in Situ (DCIS) * Unequivocal evidence of distant metastatic disease at registration * Multi-focal disease at diagnosis * Active malignancy * Previous chemotherapy * Prior extensive radiotherapy (as judged by the Investigator) to bone marrow * Risk factors precluding the safe administration of the intended cytotoxic chemotherapy regimen * Patient unsuitable for the planned dual-targeted anti-HER2 treatment in opinion of the Investigator * Prior diagnosis of cardiac failure * Uncontrolled hypertension, coronary heart disease or other significant cardiac abnormality * Bleeding diathesis * Any evidence of other disease which in the opinion of the Investigator places the patient at high risk of treatment related complications * Pregnant (female patients of child bearing potential must have a urine or blood Human Chorionic Gonadotropin test performed to rule out pregnancy prior to study entry) * Patient lactating * Patients who have received live vaccine within 4 weeks of the date of study entry * Any concomitant medical or psychiatric problems which in the opinion of the Investigator would prevent completion of treatment or follow-up * Patient unfit and/or unwilling to undergo surgery * Patient unwilling or unable to comply with scheduled visits, treatment plan and study procedures * Patient has started protocol non-compliant neo-adjuvant chemotherapy * Patient has started approved neoadjuvant chemotherapy but insufficient data is available to complete relevant CRFs * Patient has already received more than five cycles of approved neoadjuvant chemotherapy Additional Inclusion Criteria for ctDNA Sub-Study * Patient has not yet started neoadjuvant treatment * Patient is willing and able to give blood samples as per ctDNA Sub-Study Guidelines