Multidisciplinary Approach to HER2+ Breast Cancer

Denise A. Yardley, MD:A multidisciplinary approach is key for our HER2-positive patients. Regarding the reason that a multidisciplinary approach is so key, I can think of all these cases that have come through our tumor board, which is really trying to guide what is going be the bird’s-eye view of all the different modalities that are going to touch this patient during the course of her therapy now that we’ve established the diagnosis of a HER2-positive, hormone receptor-negative breast cancer.

When I meet with these patients, I’m already able to talk about potential downstaging with neoadjuvant treatment upfront so that patients may have an ability to forgo a mastectomy and undergo breast-conserving surgery. Sometimes, we consider genetic testing, and that may incorporate a need to think about bilateral mastectomies and reconstructions. Trying to get all those players in up front so that they are able to see the patient during the course of her therapy becomes quite important, so the patient has time to process all these different parameters.

I think it’s also important for this patient to know that there’s a high likelihood or consideration for radiation therapy to follow her surgery; what that looks like in her planning about her life pre-surgery or post-surgery; and how all these key integral pieces are affected by this diagnosis and how we are all part of her team. I think the hardest part is when a patient becomes only focused on neoadjuvant therapy. And then, when we move into the surgical realm and start discussing what the surgical possibilities can be, it’s quite overwhelming for a patient to process all of that.

I think laying out all the players upfront in that multidisciplinary approach and evaluating things at the time of surgery is a very fluid, real-time treatment process. Sometimes things change. I always tell patients, sometimes the toxicity of the therapy just doesn’t match with the patient. Sometimes we move surgery up earlier. Knowing all the particular components that will have an integral part in making sure we give her the best chance to have disease-free and overall survival is key in the multidisciplinary approach.

The surgeons are very upfront with identifying HER2-positive patients, and I think for the most part they immediately pick up the phone in my practice’s community and run the patient by me. Sometimes, I’d say more often than not, they send the HER2-positive patient—whether they’ve communicated with me or not—to discuss the potential of neoadjuvant therapy. I think the benefit from HER2-targeted neoadjuvant therapy is phenomenal. Our surgeons are probably our greatest advocates for medical oncology because they see these patients at surgery and they see those surgical reports that show a complete remission of disease at the time of surgery with a high PCR [pathological complete response] rate. And so, I think they’re believers as well. I think the challenges are, Are there patients who we don’t need to think about a neoadjuvant strategy for? Occasionally, I send one back to them and I say, “This patient just doesn’t have enough volume of disease to make that a really good approach,” for that particular patient.

Transcript edited for clarity.

A 56-Year-Old Woman Receiving Adjuvant Therapy forHER2+ Breast Cancer

• A 56-year-old postmenopausal woman was referred for evaluation of a left-sided spiculated mass (2.4-cm) with scattered microcalcifications, found incidentally on screening mammography. Mammogram 12 months earlier was normal.
• Ultrasound confirmed a hypoechoic mass of approximately 2.4 cm X 2,3 cm by 1.8 cm at the 2 o’clock position in the left breast, 4 cm from the nipple. Axillary ultrasound demonstrated 3 enlarged lymph nodes with cortex thickening.
• Core biopsy of the breast mass revealed poorly differentiated invasive ductal carcinoma, ER/PR-negative, HER2 IHC 3+; lymph node sampling revealed the presence of breast cancer.
• Staging: T2N1M0
• She received neoadjuvant docetaxel and carboplatin with concurrent trastuzumab and pertuzumab.
• Surgical resection scattered microscopic foci of residual disease spanning 4 mm; no involved lymph nodes
  • Re-staging, ypT1aypN0M0