HER2+

Today we found out that E.'s cancer is HER2 positive (or HER2+ or HER2 overexpressing).

What's that mean? HER2 is predominantly thought about in regards to breast cancer, but applies to other cancers as well. HER2 stands for Human Epidermal growth factor Receptor 2. (All my HER2 education came from the doctors and the internet, including sites like herceptin.com.)

Normal cells contain HER2 genes, which help normal cells grow and contain information for making HER2 protein (also called HER2 receptors). In normal cells, HER2 proteins help send growth signals which tell the cell to grow and divide.

In HER2+ cancer, the cancer cells have an abnormally high number of HER2 genes per cell. When this happens, there is too much HER2 protein, which is called HER2 protein overexpression. Too much HER2 protein is thought to cause cancer cells to grow and divide more quickly. This is why HER2+ cancers are considered more aggressive forms of cancer.

Herceptin was discovered as a treatment for women with breast cancer whose tumors have too much HER2 protein. Since then, Herceptin was found to also be an effective treatment for other HER2+ cancer patients. But . . . because E. has responded so favorably to the current regimen, his doctor feels like there is no need to add Herceptin at this time. There would be no way to measure if the Herceptin was making a difference or not, since at this point, the PET/CT shows no uptake. Of course, if any future PET/CT shows uptake again, Herceptin would be an additional treatment at that time.

Just thought I'd share what I learned today, as this was all new to me.

S.