In 1986, the Noble Prize in medicine was awarded to two scientists, Rita Levi-Montalcini and Stanley Cohen, for their discovery of growth factors that cause cancer cells to grow.
Their research and work by many other scientists led to the discovery of genes and molecules on the surface of cells called Epidermal Growth Factor Receptors (EGFR).
Nearly a quarter of all patients with breast cancer have a type of EGFR, called HER-2, on the surface of the cancer cells. It is one of the drivers or triggers of cancer growth in these cells. It was known for quite some time that if a patient's cancer cell had an overactive HER-2, that patient was expected to do very poorly and have a very short survival.
In the 1980s, many centers across the world started looking in to drug development to somehow switch these receptors off. The majority of this research was carried out at the U.S. National Cancer Institute, University of California Los Angeles and by the pharmaceutical company Genentech. Eventually, scientists at Genentech were able to make an antibody called Herceptin that blocked this receptor and, for the first time, showed that this could cause these fast-growing cells to slow down tremendously. This was a major breakthrough in cancer research.
In the 1990s, many studies were conducted using Herceptin and chemotherapy in patients with breast cancer in whom cancer had spread widely in the body. The results were amazing and, in 1998, FDA allowed use of this medication in patients with HER-2 positive metastatic breast cancer.
By this time, we knew that Herceptin worked very well in patients with metastatic breast cancer. But did it work just as well in patients who have an early stage of breast cancer? Patients who have early-stage breast cancer typically have surgery to remove this cancer and then many have chemotherapy. To answer this question, many trials were conducted in the United States and throughout the world in patients with early stage breast cancer. In these studies, Herceptin was given with many commonly used chemotherapies. The results were unprecedented; this medication increased the survival rate of patients by nearly 50 percent. In the world of oncology, this is nothing short of magic. Once again, FDA approved this drug for use — this time, in early HER-2 breast cancer.
Over the past few years, there have been many developments in this field. We have many more drugs in this family that act by suppressing HER-2. Some are newer antibodies (Perjeta and Kadcyla), while others are small molecules that act by getting inside the cells and shut off the receptor from inside the cell (Tykerb). There are many more drugs that are still in the experimental phase. The results are getting better than ever before.
HER-2 breast cancer was one of the worst kinds of breast cancer and, now, thanks to scientists and thousands of patients who participated in these studies, it has become one of the more treatable types of breast cancer. Nowadays, our patients with this disease have excellent survival and they are living well with good quality of life. Hopefully, in years to come as newer treatments are developed, we can beat this cancer into oblivion.