HER2 Two

I met a charming patient in my office this week. A gentleman with advanced gastric cancer. Upon further examination of his cancer, the adenocarcinoma cells were found to be strongly positive for human epidermal growth factor receptor 2 (HER2).

Many of my readers are familiar with this surface receptor, a member of the epidermal growth factor family. It’s discovery, and the subsequent development of treatments directed toward this target, are well described in the literature. While most people are familiar with this protein in breast cancer, it is only in the last several years that we have recognized the importance of HER2 expression in diseases like gastric and esophageal cancer.

Discussing the implications with the patient and his sons, I realized that this attractive therapeutic target might not be available for use due to the patient’s underlying heart disease. One of the toxicities of HER2-targeted therapies is congestive heart failure. As I pondered the dilemma, I was reminded of one of my patients from 16 years earlier.

At that time, a strapping 69-year-old woman arrived in my office with a large, high-grade breast cancer and 13 positive lymph nodes. She was also HER2 positive. The problem was that in 1997, the drug trastuzumab was not widely available and never (not ever), used in the adjuvant setting. With that as a backdrop, I treated the patient based on laboratory analysis using the best combinations I could identify. Now, 16 years later, still free of disease, she represents a rare success for someone afflicted with such aggressive (and yes, HER2-positive) disease.

The reason this former patient came to mind was that her excellent success 16 years earlier had not required the use of HER2-directed therapy. Ingrid Ottesen had done very well using assay-directed therapy chemotherapy without the addition of trastuzumab.  All we needed for Ingrid was the best use of available drugs. Despite the possible contraindication for trastuzumab in this gentleman’s case, we can still hope for a good outcome if we use the available drugs that best meet his need. After all, it worked perfectly for Ingrid.

You can read about Ingrid in Chapter 14 in Outliving Cancer, to be released later this month.