Her2-positive breast cancer means that there is an increased amount of her2 protein on the surface of the cancer cells, which leads to increased cell division and tumor growth.
Her2-positive breast cancer may be either hormone sensitive, or lack estrogen and / or progesterone receptors.
Today, all breast cancer tumors are tested to see if they are her2-positive through tissue samples from the tumor.
Treatment of her2-positive breast cancer is often focused on the her2 protein, so-called targeted antibody treatment. The targeted treatment is usually given in combination with chemotherapy.
Source: Breast Cancer Association, Regional Cancer Center
Treatment with the drug trastuzumab deruxtekan, sold under the name Enhertu, may become a new standard treatment for a large group of women with advanced breast cancer, writes Today’s Medicine.
This means a greatly improved prognosis for patients with so-called her2-positive cancer, according to Jonas Bergh, professor of oncology at Karolinska Institutet.
– This is a very convincing result and one of the most important things that has happened in the field of breast cancer in ten years, he says to Dagens Medicin.
In the study, researchers tested a treatment that combines two drugs. A cytostatic has been linked to a monoclonal antibody that targets the protein her2.
The treatment has been given to patients with tumors that do not have much of her2. This group accounts for almost half of all breast cancer tumors and has so far not been treated with drugs targeting her2.
Six months
The study included 577 patients who had undergone other treatments but who had relapsed into their disease. These were drawn to receive either chemotherapy or the new treatment. The main analysis concerned the majority of participants who had hormone-sensitive tumors.
Here, the time before the disease worsened was 10.1 months among those who received trastuzumab deruxtecan, compared with 5.4 months in the control group.
Median survival was also better in the trastuzumab deruxtecan group: 23.9 compared with 17.5 months.
Around 500 patients
Jonas Bergh estimates that around 500 patients in Sweden would be eligible for treatment with Enhertu each year.
– Since the drug is already available, they would have liked to offer it immediately, but according to recent years’ order, a green light is needed from the European Medicines Agency, EMA, says Jonas Bergh to Dagens Medicin.
The study was presented at the Asco Cancer Congress in the United States. The results are also published in the journal New England Journal of Medicine.
Jonas Bergh, professor of oncology at Karolinska Institutet and until recently chairman of the national care program group for breast cancer. Stock Photography.