HER2-TARGETED THERAPIES

Presentation and Diagnosis

James is a 62-year-old male patient who was diagnosed with rectal cancer with metastatic disease to his lungs.

Treatment

James was initially treated with FOLFOX and cetuximab and achieved a partial remission. He then was started on 5-FU/cetuximab, stopped for a treatment break, and restarted treatment after 2 months due to signs of progression. James also received radiation therapy, along with 5-FU for bulky local disease, FOLFIRI/bevacizumab, and FOLFIRI/cetuximab, the latter of which was discontinued after he experienced neuropathy. James was started on 5-FU/cetuximab again, but after progressing again, James’s advanced practitioner (AP) recommended palliative radiation and trastuzumab 2 mg/kg weekly with lapatinib 1000 mg.

Cardiovascular Toxicity Mitigation and Management

Before starting the trastuzumab/lapatinib therapy, James underwent an echocardiogram, which indicated left ventricular ejection fraction (LVEF) of 40% to 45% of unclear cause. Due to his older age and lower baseline LVEF, James’s AP collaborated with cardiology for close follow-up and to ensure he received LVEF assessments every 3 months during treatment with trastuzumab. 

After 6 months of treatment, although James had no symptoms of heart failure, his LVEF continued declining (35%-40%). His AP decided to hold the trastuzumab/lapatinib treatment, and after 6 months, James’s LVEF had increased to 65%. Due to his metastatic disease and evidence of mixed response to treatment on recent CT, the AP started James back on the trastuzumab/lapatinib treatment. His LVEF continues to be normal, and James continues to be followed closely by cardiology.