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