What is chemotherapy?
Chemotherapy is the term used by doctors to describe the treatment of malignant tumors with so-called cytostatic drugs. These drugs intervene in the reproduction cycle of cells and inhibit their division (cytostasis = cell arrest). The faster the cells multiply, the greater the effect of the cytostatic drugs. And since cancer cells have a particularly high division rate, they are particularly susceptible to cytostatic drugs.
However, there are also other (healthy) cell types in our body that multiply rapidly, for example those of the blood-forming bone marrow or the mucous membrane. They also feel the effects of the cytostatic drugs during chemotherapy, which explains the often numerous side effects of the therapy.
Chemotherapy can be carried out either as part of an inpatient hospital stay or as an outpatient treatment. The patient receives outpatient chemotherapy either in an oncology practice or in the hospital outpatient clinic.
Chemotherapy phases
There are basically three phases of chemotherapy that the patient goes through:
- Induction phase: intensive chemotherapy until the tumor regresses
- Consolidation phase: chemotherapy with a reduced dose to stabilize the tumour regression
- Maintenance phase: less aggressive therapy that is administered over a longer period of time to prevent tumor growth from recurring
Neoadjuvant chemotherapy and adjuvant chemotherapy
Neoadjuvant chemotherapy is the term used by doctors to describe chemotherapy that is administered prior to surgical removal of a tumor. The aim is usually to shrink the tumor and counteract the early spread of tumor cells (metastasis). The aim is to ensure that the surgical procedure does not have to be so radical. In international parlance, neoadjuvant chemotherapy is also referred to as “primary chemotherapy”.
Curative or palliative chemotherapy?
If the aim of chemotherapy is to cure the patient of their cancer, this is referred to as curative intent. Unfortunately, there are also situations in which a cure is no longer possible, for example if the tumor has already spread to other organs: Palliative chemotherapy is then considered. The aim is to alleviate the symptoms and prolong the patient’s survival.
How long does chemotherapy last?
It is not possible to say in general terms how long a patient must receive cytostatic drugs. The duration of chemotherapy depends on the type and stage of the cancer, the patient’s general state of health and the chosen combination of drugs (chemotherapy usually involves a combination of different cytostatic drugs).
Chemotherapy is generally carried out in several treatment cycles. This means that the patient receives cytostatic drugs on one or more days. A break is then taken for a few weeks to allow the cocktail of active substances to take effect and the body to recover from the side effects. A new treatment cycle then begins.
When is chemotherapy administered?
Chemotherapy for lung cancer
Chemotherapy is currently the most important treatment method, especially for small cell lung cancer. Lung cancer of the non-small cell type tends to be removed surgically. Chemotherapy with platinum-containing cytostatics is only used here as a supplement, if at all.
Chemotherapy for breast cancer
Chemotherapy is also used to treat breast cancer. For example, experts recommend additional chemotherapy (adjuvant chemotherapy) after surgical removal of a tumor with many HER2 receptors (docking sites for growth factors) on the surface of the cancer cells. Breast cancer patients under the age of 35 are also often treated with cytostatic drugs after tumor surgery.
Chemotherapy for stomach cancer
A malignant tumor of the stomach or the transition from the oesophagus to the stomach is also often treated with chemotherapy – usually in addition to surgical removal. Sometimes perioperative chemotherapy is recommended. This means that the administration of cytostatic drugs is started before the tumor is surgically removed and continued afterwards.
In other cases, neoadjuvant chemotherapy is used to try to shrink the tumor so that less tissue needs to be cut away afterwards.
If the stomach cancer is so advanced that a cure is no longer possible, palliative chemotherapy can be used to try to alleviate the symptoms caused by the tumor and prolong survival.
Advanced colon cancer is usually treated with surgery and subsequent chemotherapy. If surgical removal of the tumor no longer offers a chance of cure, chemotherapy alone can still be useful – namely by increasing the quality of life and survival time of those affected.
Patients with rectal cancer are often recommended a combination of radiotherapy and chemotherapy (radiochemotherapy) before surgery. This is intended to shrink the tumor and thus simplify the subsequent operation.
Chemotherapy: Leukemia
Intensive chemotherapy (high-dose chemotherapy) is the most important therapy for acute leukemia. It should be started as soon as possible after diagnosis.
Chronic lymphocytic leukemia (CLL) progresses very slowly. In the early stages, as long as no symptoms occur, the “wait and see” strategy is therefore usually chosen. In advanced stages or when symptoms occur, however, treatment is initiated – very often a combination of chemotherapy and antibody therapy (chemoimmunotherapy).
What is chemotherapy used for?
During chemotherapy, the doctor administers cytostatic drugs to the patient, which attack the tumor cells and thus shrink the tumor or inhibit its growth.
Between cycles, the doctor checks whether the cancer is responding to the cytostatics. This is indicated by whether the tumor has become smaller or whether cancer cells have regressed. If the treatment has no effect, there is no point in continuing the chemotherapy according to the previous schedule.
Chemotherapy: tablets or infusion?
The doctor therefore usually administers the cytostatic drugs to the patient as an infusion into a vein, through which they reach the heart. This then pumps the medication into the entire body (systemic effect).
If, on the other hand, the chemotherapy is not to have a systemic effect, but only on the organ affected by the tumor, cytostatic drugs can be injected into an artery that supplies the affected area. This is known as regional chemotherapy.
In the case of brain or spinal cord tumors, the cytostatic drugs are administered directly into the cerebrospinal fluid (intrathecal administration).
Chemotherapy: Port
Once the port has been inserted, it can withstand around 1,500 to 2,000 needle pricks, after which it usually needs to be replaced. Once chemotherapy has been completed, the patient can – in consultation with the doctor – have the port removed again, which only requires a minor outpatient surgical procedure.
What are the risks of chemotherapy?
Most cytostatic drugs cannot distinguish between pathological cancer cells and healthy body cells. They particularly attack cells with a high division rate – for example bone marrow, mucous membrane and hair root cells. This leads to typical side effects such as
- Increased risk of infection
- blood clotting disorder
- Reduced performance and fatigue
- Nausea and vomiting
- diarrhea
- Urinary tract infections
- Damage to liver, heart, kidney and nerve tissue
When cytostatic drugs are administered via blood vessels, so-called extravasations are particularly feared. This means that the drug does not run into the vein, but next to it. This can lead to severe damage to the surrounding tissue and, in the worst case, to the death of the cells there. If necessary, the damaged tissue must then be removed during an operation.
You can read about the side effects that can occur and how they are treated in the article Chemotherapy: side effects.
What do I need to consider after chemotherapy?
Inform your doctor immediately if you notice any symptoms, in particular
- fever
- Bleeding (bleeding from the gums or nose, blood in the stool or urine)
- shortness of breath
- dizziness
- Diarrhea
Nutrition during chemotherapy
Many patients suffer from a loss of appetite during treatment – not least due to the numerous side effects. In order to maintain your weight, you should eat several small meals a day. Whole foods or light whole foods are permitted, adapted to your individual preferences. If necessary, you can seek advice from a specially trained dietician.
Late effects of chemotherapy
Most of the side effects you suffer during chemotherapy will subside after the treatment has been completed. However, there are also long-term effects that can occur a long time after treatment:
- Second tumors (years or decades later)
- Damage to nerves (impairment of fine motor skills, sense of touch and feel)
- Premature menopause in women
- Infertility
- States of exhaustion (fatigue)
Please also bear in mind that once you have survived cancer that has been successfully treated with chemotherapy, among other things, it does not protect you from developing another, independent tumor in the course of your life. You should therefore continue to go for regular cancer screening examinations.
