Assessing the Accuracy of Tumor Biopsies After Chemotherapy to Determine if Patients Can Avoid Breast Surgery

Inclusion Criteria

• •The patient must have signed and dated an Institutional Review Board (IRB)-approved consent form that conforms to federal and institutional guidelines
• •The patient must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• •Patients must have had ER analysis performed on the primary breast tumor collected prior to neoadjuvant therapy according to current American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for hormone receptor testing; if negative for ER, assessment of progesterone receptor (PgR) must also be performed according to current ASCO/CAP Guideline Recommendations for hormone receptor testing. Patients who have a primary tumor that is hormone receptor-positive or hormone receptor-negative are eligible.
• •Patients must have had HER2 testing performed on the primary breast tumor collected prior to neoadjuvant chemotherapy according to the current ASCO/CAP guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer; patients who have a primary tumor that is HER2-positive, HER2-equivocal, or HER2-negative are eligible
• •Patients must have had a biopsy marker placed within the tumor bed with imaging confirmation (preferably mammogram but ultrasound or magnetic resonance imaging \[MRI\] is acceptable) of marker placement prior to neoadjuvant chemotherapy
• •Patients with operable focal or multifocal (T1-T3, stage II or III invasive ductal carcinoma \[all receptor phenotypes\]), and who have completed neoadjuvant chemotherapy with a clinical complete response (by clinical examination)
• •Patients must have achieved a complete or near complete radiologic tumor response on breast imaging with mammogram, ultrasound, and MRI during or after completion of appropriate neoadjuvant chemotherapy defined as:
• •* Mammogram with malignant appearing calcification or mass ≤ 1 cm; or
• •* Ultrasound with a hypoechoic area ≤ 2 cm; or
• •* Breast MRI not demonstrating a residual mass with rapid rise and washout type III kinetics.
• •At the time of consent, the patient's intent must be to undergo breast conserving therapy.
• •Patient must be able to undergo stereotactic-vacuum-assisted breast biopsy with clip placement after completion of neoadjuvant chemotherapy. (The patient must be enrolled on the study before performing the post-neoadjuvant stereotactic-vacuum-assisted breast biopsy.)
• •Patient must have completed neoadjuvant chemotherapy.
• •Patients with HER2-positive tumors must have received neoadjuvant anti-HER2 therapy (either with all or with a portion of the neoadjuvant chemotherapy regimen), unless medically contraindicated.
• •Patients treated with PD-1 or PD-L1 inhibitors, CDK 4/6 inhibitors, or other immune-based therapy are eligible.