- How Cancer Chemotherapy Works
- Preparing for Cancer Chemotherapy
- What to Expect From Cancer Chemotherapy
- Side Effects of Cancer Chemotherapy
- What to Expect After Chemotherapy
How Cancer Chemotherapy Works
Most chemotherapy (also referred to as ‘chemo’) treatments involve a combination of drugs — sometimes casually referred to as a “cocktail” — tailored to treat the specific type and stage of your cancer. Chemotherapy drugs may also kill healthy cells, but these cells can repair themselves while cancer cells cannot.
Chemotherapy can serve several functions as part of cancer treatment:
- Shrinking a tumor before surgery
- Killing residual cancer cells left behind after surgery
- In combination with other methods (such as radiation therapy)
- Relieve symptoms of advanced cancer
Your chemotherapy can be delivered through several different methods, depending on the type and stage of cancer being treated:
- Intravenous (IV) medication; This is the most common delivery method for chemotherapy, in which the medication is injected (infused) directly into a vein through an IV line. This is sometimes referred to as an IV drip.
- Oral medication; Some chemotherapy can be taken as a pill. You will be able to take it at home, but make sure to follow your doctor’s directions carefully.
- Topical cream or lotion; For certain types of skin cancer, you may be given a cream to rub onto the cancerous patch of skin. This is an example of how chemotherapy can be used as a localized, rather than systemic treatment.
- Direct placement; For some brain tumors the chemotherapy drug may be injected into the spinal fluid (cerebrospinal luid) or directly into the brain via a device placed under the scalp.
Normal cells go through a transformation process to become cancer cells. They then grow into localized tumors and spread throughout the body. At Houston Methodist, we have extensive knowledge about this transformation process from normal to cancerous cells. Targeted therapy disrupts this transformation process, using drugs to attack certain parts of the cancer cell and the signals needed for the cancer to develop and continue growing. These drugs are grouped by how they work and the part of the cell they target.
Today many different types of targeted therapies are used to treat cancer. There are two main types of targeted therapy drugs:
- Antibody drugs are derived from immune system proteins; the body normally makes antibodies to fight harmful invaders like germs (microorganisms). Antibodies can also be used to target cancer cells.
- Small-molecule drugs are able to attach to very specific areas of cancer cells. There are fewer side effects than some other kinds of chemotherapeutic agents because they do not attach to normal cells.
Our bodies produce many types of special proteins (enzymes) that make chemical reactions possible. Enzymes are commonly associated with helping digest food. Other enzymes involve pathways that signal cancer cells to grow. Enzyme inhibitors block these cell signals to keep the cancer from getting larger and spreading. Even if the tumor is not getting smaller, its growth has been interrupted. This may give other treatments a better chance to work. Slowing or stopping growth may be greatly beneficial to you, even without adding other drugs.
All cells have a program inside them to die a natural process that occurs when a cell is triggered to self-destruct. Apoptosis is the medical word for this programmed cell death. Some targeted therapies change proteins within the cancer cells to turn this switch on. These are called apoptosis-inducing drugs and cause or induce cell death.
Many cancer treatments, including radiation and chemotherapy, cause cell changes that lead to apoptosis. However targeted drugs in this group are different, because they are aimed at the control mechanism that induces the cell’s self-destruction. By turning on the cell’s self-destruct switch, these drugs cause cancer cells to die.
Angiogenesis is the process of making new blood vessels. In most cases this is a normal, healthy process. As the human body grows and develops, it needs to make new blood vessels to get blood to all of its cells. Adults do not have the same need for new blood vessels as children, but there are times when angiogenesis is still important. New blood vessels, for instance, help the body heal wounds and repair damage.
In a person with cancer, the tumor can turn on signals that create new blood vessels to give a tumor its own blood supply. This blood brings nutrients that allow the cancer to grow and spread. Angiogenesis inhibitors target and stop (or slow) this process and the tumor stops making new blood vessels. This helps cut off the tumor’s blood supply, and without blood, tumors cannot grow. Many of these drugs work by blocking vascular endothelial growth factor (VEGF). VEGF is a family of protein growth factors made by some tumors that stimulate new blood vessels to form around the tumors.
Preparing for Chemotherapy
Houston Methodist infusion areas are set up to ensure your comfort. There are several things you can do to make sure your infusions go as smoothly as possible, especially before your first treatment:
- If you are having IV chemotherapy, it is a good idea to arrange for transportation to and from the hospital or clinic, at least for the first few appointments.
- You are encouraged to bring someone with you to your appointments, however children are not allowed in the infusion area. There is space for one or two visitors in a sitting area next to your chair. Additional friends and family members can relax in our family room and take turns visiting with you during your treatment.
- You will be prescribed medications to prevent and treat nausea and vomiting before you start treatment. Please have those medications on hand when you go home following your first treatment.
- Depending on the type and dosage of drugs involved in your chemotherapy treatment, your doctor may have specific instructions about eating, drinking, taking medications and other activities before your appointment. Make sure that you understand and follow these instructions closely. If it is consistent with your doctor’s instruction, eat a small meal before your treatment. The infusion area provides snacks and beverages, and you are allowed to eat during the infusion. If you prefer specialty juices or smoothies you are encouraged to bring those with you.
- Bring a sweater or jacket with you, although the infusion area provides warm blankets and pillows.
- Remember to wear a shirt that allows easy access to your infusion port, if applicable.
- The nurse who administers chemotherapy will provide you with discharge instructions, next infusion appointment, and review your post chemotherapy medications if you have any questions.
Certain aspects of your general health may be affected during your chemotherapy. For example, you may be at increased risk of infection, and chemotherapy drugs can damage developing fetuses. To address these concerns, please remember the following ways to protect your health:
- Perform good hand washing at all times.
- Avoid children or persons with colds, cough, fever, or flu-like symptoms.
- Get your flu shot (if your doctor recommends it).
- Stay active and maintain your normal routines and schedule of work (depending on how you feel).
- Women should not get pregnant while undergoing chemotherapy. Pre-menopausal women who are sexually active should use protection.
What to Expect from Chemotherapy
If you are taking chemotherapy orally or as a topical cream, you will be able to take it at home; just make sure to follow your doctor’s instructions exactly.
If your doctor has prescribed IV chemotherapy, you will have your treatments at a clinic or hospital. At your first appointment, a catheter or a port may be inserted and remain in place for the duration of your treatment cycle. This will make it easier for your treatment team to infuse the chemotherapy drugs.
Because there are many different approaches to chemotherapy, make sure you talk to your doctor about exactly what to expect.
Side Effects of Chemotherapy
Depending on the type and dosage of drugs you receive, you may experience one or more of the following side effects from chemotherapy:
- Higher risk of infection due to a low white blood cell count
- High temperature (If you experience a temperature of 100.5 or greater, you MUST call the clinic number immediately.)
- Nausea and vomiting
- Loss of appetite
- Low platelet counts that can lead to bleeding problems
- Irritation or sores in the mouth (mucositis)
- Diarrhea or constipation
- Hair loss (alopecia) over the entire body including scalp and genital areas – eyelashes and eyebrows less affected but may become thinner
- Skin and nail bed changes
- Menstrual irregularities or cessation of menses
- Problems with concentration or short term memory
Your doctor may prescribe medication to manage side effects, most of which usually go away when your chemotherapy treatment is complete.
What to Expect After Chemotherapy
Before your chemotherapy treatments end, ask your doctor what you can expect during the recovery from chemotherapy:
- When you can return to normal activities
- When to schedule a follow-up appointment
- Which tests will need to be done and when
- Whether there are any special dietary instructions
- Warning signs to watch out for
Every person and every cancer are unique. This section provides some general information about treating cancer. You may find it helpful to look at additional information about treating the specific type of cancer you have. Your doctor may also recommend other approaches to treating your cancer before, with, or after chemotherapy.
Receiving a diagnosis of cancer and undergoing chemotherapy can be overwhelming. However, attending a chemotherapy education class will better prepare you for what to expect during treatment. Ask your care team about chemotherapy classes and other support groups offered at Houston Methodist.
The Houston Methodist financial assistance program can ease financial strain that can accompany your treatment. Find out more about our financial assistance program as well as other programs for our patients.
Our continued commitment to research enables us to improve present and future cancer care. Learn about our current cancer-related clinical trials.