How long does the therapy last?
How long the entire therapy lasts depends on which therapeutic options are used. Almost every breast cancer is operated on today, and in most cases with breast-conserving surgery. After this operation, the remaining breast tissue must be irradiated.
In the case of radiation therapy, the entire dose is not applied at once, but divided into several sessions over a few weeks. Chemotherapy can be given before the operation or after it. The various chemotherapy regimens, including the breaks in between, last between 18 and 24 weeks.
Patients whose breast cancer has a receptor for a specific growth factor (HER2) receive targeted antibody therapy for 12 months in addition to chemotherapy. This therapy should be started no later than four months after the end of chemotherapy. The last major pillar of therapeutic options is anti-hormone therapy. This is used in patients whose tumor has, among other things, a positive receptor for estrogens and counteracts tumor growth. This therapy should last for at least five years, with acceptable side effects it can even be used for 10 years.
What are typical side effects in the treatment of breast cancer?
In the drug therapy of breast cancer, a distinction is made between three pillars: Chemotherapy, antibody therapy and anti-hormone therapy. Each therapy group has its specific side effects.
- The effect of chemotherapy is that it kills rapidly dividing cells.
In addition to tumor cells, however, there are also the body’s own cells that divide quickly and from this one can derive the side effects. The stomach and intestinal mucosa are attacked and infections and diarrhoea can occur there. In addition, the bone marrow is suppressed by the chemotherapy, so that bleeding, infections and fatigue due to a lack of the red blood pigment can occur.
In addition, hair loss, vomiting and disorders of the sexual organs are side effects of chemotherapy. Specific side effects of frequently used chemotherapeutic agents in breast cancer are damage to the heart and bloody urinary tract infections, as well as an increased risk of developing bladder carcinoma with the active substance cyclophosphamide.
- Antibody therapy with trastuzumab (antibody drugs) can also cause damage to the heart and must therefore not be given together with chemotherapeutic drugs, which can also damage the heart.
- The drug tamoxifen is often used in antihormone therapy. It can induce hot flushes and vomiting and increases the risk of thrombosis (see Tamoxifen).
Another drug is the so-called GnRH analogue, which reduces the oestrogen level by stimulating the pituitary gland. Side effects here are menopausal symptoms such as hot flushes and constipation. The third group of drugs used in antihormone therapy are aromatase inhibitors, which can be associated with nausea, vomiting and osteoporosis.