Chemotherapy and medicine-based treatments
Chemotherapy, targeted therapy, immunotherapy and hormone therapy are the four medicine-based ways to treat cancer. Here you can read in plain language how they differ, how they are given and what their common side effects are.
What is medicine-based cancer treatment?
When a medicine travels through the body and reaches cancer cells wherever they are, it is called medicine-based or systemic treatment. The four main groups of these treatments are:
- Chemotherapy: medicines that kill fast-growing cells or stop them growing. Because healthy fast-growing cells, such as those in the mouth, the bowel and the hair roots, can also be harmed, side effects such as mouth sores, nausea and hair loss occur.
- Targeted therapy: medicines that aim at specific proteins that help cancer cells grow and spread. Unlike chemotherapy, which affects every fast-growing cell, the aim here is more specific. Usually the “target” has to be tested for in the cancer cells before a medicine is chosen (a biomarker test).
- Immunotherapy: treatment that helps the immune system recognize and fight the cancer better. It comes in types such as immune checkpoint inhibitors and laboratory-made antibodies.
- Hormone therapy: it slows or stops the growth of cancers that need hormones to grow, that is, some breast and prostate cancers.
This page only introduces the methods. None of them suits every cancer, and no one should go looking for a medicine without the doctor’s advice.
Who are these treatments for?
The type of cancer, how far it has advanced, biomarker tests, earlier treatment and other conditions such as diabetes and heart disease all play a part in choosing treatment. These treatments are often combined with surgery or radiotherapy: sometimes before them to shrink the tumor, and sometimes after them to destroy remaining cells. They are also used for blood cancers.
How are they diagnosed and chosen?
Before starting, the doctor works out the type and stage of the cancer from the pathology report and imaging. For targeted therapy and immunotherapy, a biomarker test on a sample of the tumor or blood may be needed, because some medicines work only when the cancer cells have a particular marker. Your overall condition, blood tests and other conditions are also reviewed.
How is treatment given?
- How the medicine is given: chemotherapy is mostly given through a drip (intravenously), but it may be taken by mouth, injected, or given by other routes. Targeted therapy is often a tablet or capsule, and some types are given intravenously. Immunotherapy is usually intravenous, and sometimes taken by mouth or applied locally. For repeated drips, a catheter or a port (a small disc under the skin) may be placed.
- Place: chemotherapy and immunotherapy may be given in a hospital or as outpatient care in treatment centers. Many sessions are outpatient and do not need an overnight stay. Ask the treatment team where and how your sessions will be done.
- Schedule: the timetable varies a great deal. Treatment is often given in cycles: a period of treatment, then a period of rest so the body can recover. Do not skip a session on your own; if a side effect occurs, the doctor adjusts the plan.
- Combination: cancer cells may become resistant to one targeted medicine. For this reason several medicines or treatments are sometimes combined.
Common side effects and follow-up
- Chemotherapy: tiredness (the most common side effect), nausea, mouth sores, hair loss, eating problems. There are medicines to prevent nausea; ask the treatment team. A drop in white blood cells raises the risk of infection, and blood tests are done to monitor it.
- Targeted therapy: diarrhea and liver problems are the most common. High blood pressure, skin and nail problems, mouth sores, tiredness, and problems with clotting and wound healing are also possible. Targeted therapy is not necessarily milder than chemotherapy.
- Immunotherapy: many side effects occur when the immune system becomes overactive and attacks healthy tissue. So tell the team about any new symptom.
- Hormone therapy: for example hot flashes, tiredness, nausea, mood changes, and in men with prostate cancer reduced sexual desire and ability and weaker bones; in women vaginal dryness and changes in periods.
A few important points:
- Side effects are not a sign that treatment is working.
- Many side effects get better after treatment ends, although tiredness may last for months.
- Many people can work during chemotherapy.
- Tell the treatment team about every medicine, supplement or herbal product before taking it.
For care at home, see the site’s patient guide.
When to call
- A fever of 38 degrees or higher, chills, a cough or sore throat, burning when passing urine, or redness and swelling at the catheter site: call the treatment team at once. An infection during treatment can be serious. Ask before taking a fever-reducing medicine, because it may hide a sign of a bigger problem.
- Severe vomiting or diarrhea that stops you from drinking fluids, or signs of dehydration (dry mouth, little dark urine, dizziness).
- Bleeding that will not stop, bruising without a reason, or black stools.
- Mouth sores that make eating, drinking or sleeping hard.
- Emergency (115, Iran’s emergency number): severe or sudden shortness of breath, chest pain, fainting, weakness on one side of the body or trouble speaking.
Every patient’s treatment plan is different; ask your doctor about your own situation.
Frequently asked questions
Does chemotherapy always cause hair loss?
No. Some chemotherapy medicines cause hair loss and some do not. Ask what applies to your medicine. If hair falls out, it usually grows back within a few months after treatment ends, although it may at first be thinner or a little different in color or texture.
Do severe side effects mean the treatment is working better?
No. You cannot tell from the severity of side effects whether the treatment is working. The doctor measures the effect with examination, blood tests and imaging.
Are targeted therapy and immunotherapy free of side effects?
No. These treatments also have side effects, and some are serious. In targeted therapy, diarrhea and liver problems are the most common, and in immunotherapy the immune system may attack healthy tissue. Each has a monitoring plan and a list of symptoms that must be reported.
Can I work during chemotherapy?
Many people can, as long as they fit their work to how they feel. You may need to cut your hours or work from home on hard days. It depends on the type of treatment and your side effects.
Can I take herbal medicines or supplements alongside treatment?
Always tell the treatment team before taking any medicine, supplement or herbal product. Some of them may change the effect of treatment. So far no study has shown that a diet, vitamin or supplement can cure cancer or stop it from coming back.
Does medicine-based treatment always mean a cure?
The goal of treatment differs from patient to patient. It may be to destroy the cancer or reduce the chance of it returning, or to slow its growth, or to ease symptoms. Ask the doctor what the goal of treatment is in your case.