New drugs are constantly being developed for breast cancer. In the future, artificial intelligence will be used to assess individual risk for cancer. Liquid biopsy, on the other hand, reveals the risk of cancer recurrence.
- Text Ulla Kaltiala | Photos Raija Törrönen and Riikka Myöhänen
Breast cancer is the most common cancer in women. In Finland, around 5,000 women are diagnosed with breast cancer every year, and one in eight women will get breast cancer at some point in their lives. However, the prognosis of a patient in Finland is one of the best in Europe: 85% of those with breast cancer will be alive ten years after the diagnosis.
Breast cancer is not one single disease, but a group of different subtypes. Based on the biological properties of the tumour, breast cancer is divided into luminal hormone-dependent breast cancer, HER2-positive breast cancer or triple negative breast cancer.
Most cases of breast cancer are hormone dependent and slow-growing
In hormone-dependent breast cancer, there are hormone receptors on the surface of cancer cells to which the female hormones oestrogen and progesterone are bound, thus contributing to cancer growth. This cancer type is the most common, usually the slowest to progress, and the one with best prognosis. In HER2 positive breast cancer, there is an abundance of HER2 growth factor receptors on the cell surface, promoting cancer growth. In triple negative breast cancer, there are no hormone or HER2 receptors on the cancer cell surface. HER2 positive and triple negative breast cancer are typically aggressive; however, HER2 positive breast cancer can nowadays be treated with effective precision drugs.
“HER2 antibodies have been a major improvement in the treatment of this type of cancer. More and more of them have been introduced in the past 5–10 years, and they are nowadays routinely used in treatment,” says Päivi Auvinen, Service Director and Chief of Department at the Cancer Centre of Kuopio University Hospital.
Breast cancer is primarily treated by surgery. When necessary, surgery is followed by radiation therapy and drugs, i.e., cytostatics that destroy cancer cells and, depending on the cancer type, also hormone therapy that blocks the action of female hormones, or precision drugs. Sometimes, drug therapy is initiated already before surgery to, for example, improve tumour operability.
Pre-surgery drug therapy is known as neoadjuvant treatment.
“For the treatment of HER2 positive breast cancer, for example, we have several new drugs whose effectiveness has been studied specifically before surgery, so they will be used in hospitals as neoadjuvant treatment for larger or more widespread tumours. They are an interesting addition to treatment, although actual comparative studies before versus after surgery are unfortunately scarce. The clinical impression nevertheless is that neoadjuvant treatment would be associated with fewer cases of cancer recurrence.”