Chemotherapy uses chemical substances to prevent cells from growing and dividing. This includes healthy cells although tumor cells are destroyed faster than healthy ones [1]. This causes side effects which are described later.
Types of Chemotherapy
There are different types of chemotherapy. When powerful drugs are used it is called a standard / traditional / cytotoxic chemotherapy. Newer medcines target the cancer cells more directly. These are called targeted drugs [1]. Click here for more information on targeted therapy and immunotherapy.
Other variants are intravenous chemotherapy (IV), continuous infusion chemotherapy, oral chemotherapy, injected chemotherapy, chemotherapy into an artery, chemotherapy into the peritoneum or abdomen and topical chemotherapy [1]. Their names say how they are applied to the patient.
Goals of Chemotherapy
The goals depend on the type of cancer and its distribution within the body. The main goal is to get rid of all tumor cells and prevent them from coming back. Sometimes this is not possible. Then the goal is a delay or deceleration of the growth, which also ends in fewer symptoms [1].
A chemotherapy can be used to achieve different subgoals. With the neoadjuvant chemotherapy the tumor shall be shriked before surgery or radiation therapy. It can also be used after surgery or radiation therapy to remove remaining tumor cells which is called adjuvant chemotherapy. It is also used as the only treatment for blood or lymph system cancer including leukemia or lymphoma. The last two points are the treatment of recurrent and metastatic cancer [1].
Medicines
For the treatment of brain tumors with any kind of chemotherapy, the active ingredient has to pass the blood-brain barrier. Following medicines are used to treat brain tumors:
| Medicine | Active Ingredient | Application |
|---|---|---|
| Gliadel Wafer | Carmustine | place wafers in the area the tumor was removed during surgery |
| Temodar / Temodal / Temcad | Temozolomide | monthly dose after radiation therapy of glioblastoma |
Gleostine Matulane Vincasar | Lomustine Procarbazine Vincristine | combination of these three used along radiation therapy |
table of often used drugs for brain tumors [2]
Side Effects
The side effects depend on cancer type, cancer location, medicines and doses and the general health.
| Side Effect | Description |
|---|---|
| Fatigue |
|
| Pain |
|
| Mouth and Throat Sores |
|
| Diarrhea |
|
| Nausea and Vomiting |
|
| Constipation |
|
| Blood Disorders |
|
| Nervous System Effects | some drugs cause nerve damage
|
| Changes in Thinking and Memory | cannot think clearly and concentrate (chemo brain) |
| Sexual and Reproductive Issues |
|
| Appetite Loss |
→ weight loss, malnutrition, loss of muscle mass / strength |
| Hair Loss | starts after several weeks |
| Radiation recall |
|
table of side effects [3]
Most side effects disappears after the end of the treatment. Also permanant damage to heart, lungs, liver and / or kidneys. Cognitive changes may last longer [3].