Improving Outcomes in Patients With HER2+ Metastatic Breast Cancer: Applying Evidence to Clinical Practice - Episode 2

Clinical Case 1: A 41-year-old Patient with HER2+ Metastatic Breast Cancer

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Rita Nanda, MD, leads a discussion of the first clinical scenario, a 41-year-old woman with HER2+ metastatic breast cancer who progressed on docetaxel/trastuzumab/pertuzumab.

Erika Hamilton, MD: Dr.Nanda, will you present the first case for us?

Rita Nanda, MD: Sure. I'd love to. This is a patient of mine. She's a 41-year-old woman who first came to medical attention in September 2019. She experienced a fall and fractured her right arm. She had this repaired, but unfortunately, shortly thereafter she developed swelling and pain in that arm. She initially attributed this to the fall, but subsequent to that, about a month later, she developed a rash in her right breast [that] extended across the midline in her back. She presented to the University of Chicago emergency department in October 2019 with skin breakdown over her right chest wall. She was promptly admitted for a work-up. A CT (computed tomography) scan revealed a right breast that was nearly entirely replaced with tumor, a large mass with invasion into the kidney, adrenal glands, renal vein, and inferior vena cava. A bone scan revealed extensive boney metastases, and her brain MRI (magnetic resonance imaging) was negative. She subsequently had a biopsy [that] revealed a grade 3 infiltrating ductal carcinoma with involvement of the dermis. It was hormone receptor-negative, HER2/3+, and amplified by FISH (fluorescence in situ hybridization).

She began first-line treatment with the CLEOPATRA trial (NCT00567190) regimen [docetaxel, trastuzumab, and pertuzumab] in October 2020. She also received zoledronic acid infusions to reduce the risk of skeletal-related events. She had a dramatic response to the CLEOPATRA regimen. She had resolution of the chest wall lesions. All of those lesions closed up. She had resolution of the abdominal mass. Unfortunately though, after about 11 cycles, in May 2021 she experienced disease progression in the right axilla in new pulmonary nodules. She subsequently began second-line treatment with T-DM1 [trastuzumab emtansine] in June 2021, but unfortunately, after about 5 cycles, [she] experienced debilitating, painful neuropathy. This was really hard to manage, so we actually had to discontinue treatment even though she was responding to T-DM1. Then, in November 2021, she began treatment with capecitabine, tucatinib, and trastuzumab. After 2 cycles, she experienced hand-foot syndrome, which required a dose reduction of her capecitabine. To date, she's completed 6 cycles of the HER2CLIMB trial (NCT02614794) regimen [tucatinib plus trastuzumab and capecitabine] [and] is tolerating this therapy well. [She] has had continued disease control and is due for repeat imaging in July of this year [2022].

Erika Hamilton, MD: That case really strikes me as very realistic as to what we see in the clinic. Unfortunately, she did present with de novo metastatic disease, but we see that more often since a lot of our neoadjuvant and adjuvant patients aren't relapsing. Luckily, she did not have brain metastases.

Transcript has been edited for clarity.