How does chemotherapy work?
Chemotherapy kills rapidly-dividing cells in a variety of ways, depending on the drug. Since there are many different types of cancers that all grow differently, many chemotherapy drugs have been developed to target these various growth patterns. Each drug has a different way of working and is effective at a specific time in the life cycle of the cell it targets. For example, some chemotherapy drugs work by:
- Damaging DNA,
- Preventing cells from dividing, or
- Disrupting cellular metabolism or other critical functions.
How is chemotherapy given?
Chemotherapy can be given:
- Intravenously (IV),
- By mouth in the form of a pill,
- With a shot (injection), or
- By intrathecal and intraventricular injection (meaning into the spinal fluid surrounding the spinal cord or brain).
Many types of chemotherapy can be given at home. Through instruction, you and your family members can learn how to administer chemotherapy in pill form or by injection with small syringes and needles similar to those that people with diabetes use to administer insulin. In some cases, a nurse will administer chemotherapy in an outpatient clinic. In other cases, it may be necessary to go to the hospital to receive treatment.
Chemotherapy is typically given in cycles, which is a treatment followed by a period of rest. A cycle can last one or more days, but is usually one, two, three, or four weeks long. A course of chemotherapy is comprised of multiple cycles. Each course is different, but generally consists of four to six cycles. It may take a relatively short period of time to receive some chemotherapy drugs, while others take hours. It all depends on the treatment regimen that your doctor recommends.
If your chemotherapy is given through an IV, your doctor may suggest an implanted venous access device (VAD) such as a Hickman® catheter or Port-a-Cath. VADs are surgically placed in a large vein near the heart and can stay in place for long periods of time. By using a VAD, you will not have to have smaller catheters repeatedly placed in your arm veins.
How often will I receive chemotherapy?
Generally, treatments are given daily, weekly, or monthly. How often you receive chemotherapy depends on the type of cancer and which drug or combination of drugs you receive. Your doctor will help you determine the most effective treatment schedule for you. Chemotherapy is usually given in cycles with rest periods between each administration.
Chemotherapy may be used in combination with surgery. When chemotherapy is given before surgery it is referred to as neoadjuvant chemotherapy. The goal of neoadjuvant chemotherapy is to shrink the cancer before it is surgically removed. If the chemotherapy is given after surgery, it is referred to as adjuvant chemotherapy. The goal of adjuvant chemotherapy is to kill any cancer cells left in the body after surgery. Regardless of whether it is given before or after surgery, chemotherapy will still be administered in cycles that depend on the type of cancer and which drug or combination of drugs.
What chemotherapy will I receive?
You will receive chemotherapy that is best suited to achieve your goals of therapy. When selecting a treatment or treatments, your doctor will consider:
- Your diagnosis
- How far along your cancer is in its development
- The expected behavior of the cancer
- Where the cancer originated
- Your age
- Other medical problems you may have
- Any potential side effects from the treatment.
How is my chemotherapy scheduled?
Chemotherapy is typically given in cycles, which is a treatment followed by a period of rest. A cycle can last one or more days, but is usually one, two, three or four weeks long. A course of chemotherapy is comprised of multiple cycles. Each course is different, but generally consists of four to six cycles. The actual administration of the chemotherapy drugs may take minutes to several hours, depending on the drug or drugs given.
If your chemotherapy is given through an IV, your doctor may suggest an implanted venous access device (VAD) or Port-a-Cath. VADs are surgically placed in a large vein near the heart and can stay in place for long periods of time. By using a VAD you will not have to have smaller catheters repeatedly placed in arm veins.
What are the side effects of chemotherapy?
Chemotherapy works by destroying cancer cells; unfortunately, it cannot tell the difference between a cancer cell and a healthy cell. The delivery of cancer therapy often affects the body’s normal tissues or organs that are not affected by cancer. Side effects, or complications of treatment are the undesired consequence of affecting normal cells.
Side effects of treatment may cause inconvenience, discomfort, and occasionally even fatality to patients. Additionally and perhaps more importantly, side effects may prevent delivery of the full dose of chemotherapy on schedule. This is extremely important to understand since your expected outcome from chemotherapy is based on delivering treatment at the full dose and schedule prescribed in the treatment plan Because the expected outcome from therapy is based on delivering treatment at the prescribed dose and schedule, a change from the treatment plan may reduce your chance of achieving an optimal outcome. . This is extremely important to understand. In other words, side effects not only cause discomfort and unpleasantness, but may also compromise your chance of cure by preventing the delivery of therapy at its optimal dose and time.
The most common side effects of chemotherapy are low blood counts, nausea, vomiting, hair loss, and fatigue. Some side effects may be temporary and merely annoying. Others, such as infection or a low white blood count, can be life-threatening. For example, one of the most serious potential side effects of chemotherapy is a low white blood cell count – a condition called neutropenia (new-truh-pee-nee-ah) – which can put you at risk for severe infections or treatment interruptions.
Fortunately, last 20 years has brought a great deal of progress in the development of treatments to help prevent and control the side effects of cancer therapy. These developments have
- Led to vast improvements in the management of symptoms associated with cancer treatment
- Allowed for greater accuracy and consistency concerning the administration of cancer treatment
- Made many cancer treatments more widely available to patients throughout the world.
Why am I so tired?
Many people who receive chemotherapy experience fatigue. Fatigue has many causes but frequently occurs because of anemia caused by the chemotherapy. Your daily activities should be planned according to how you feel, and you should take rest periods throughout the day as often as you feel necessary. Anemia can be effectively treated. To learn more, go to fatigue.
Will my chemotherapy make me sick?
Without receiving special anti-nausea medications, most patients will experience some nausea after treatment with chemotherapy. Nausea and vomiting may last 24-48 hours. The severity of nausea and vomiting mainly depends on which chemotherapy drugs were used. A number of very effective medications called anti-emetics or anti-nausea drugs are now available to help lessen or prevent nausea and vomiting. These medications may be given to you intravenously during your chemotherapy, or you may be given a prescription medication to take at home. To learn more, go to nausea and vomiting.
What tests will be performed?
Your doctor determines what kinds of tests are needed. If you are receiving chemotherapy, you may have blood work done anywhere from the day of or up to 7 days before your scheduled treatment. This blood work will include a complete blood count (CBC), chemistry profile, and any necessary cancer markers. A blood sample for a complete blood count (CBC) will also be collected seven to fourteen days following your chemotherapy. It is important to be aware of possible symptoms of reduced red blood cell (RBC), white blood cell (WBC), or platelet (PLT) production. Be sure to report any of the following:
- Fever (over 101º F), congestion, or a cold.
- A rash, blister, easily bruised skin, signs of bleeding, an infected cut, itching or burning in the genital area.
- Weakness, fatigue, or shortness of breath.
Why is my complete blood count (CBC) tested after treatment?
Chemotherapy destroys rapidly dividing cells, a characteristic of cancer cells. However, red blood cells, white blood cells, and platelets also divide rapidly and are frequently damaged by chemotherapy. Your red blood cell count, white blood cell count, and platelet count may all go down. Your doctor monitors these counts to determine the toxicity of treatment and to predict your risk for complications, as well as to plan future therapy. For more information, see section on Understanding and Monitoring Your Blood Counts.
Will I lose my hair because of my treatment?
Hair loss occurs with some, but not all, chemotherapy drugs. The amount of hair loss varies from a slight thinning to complete baldness and affects the scalp, eyelashes and eyebrows, legs, armpits, and pubic area.
Hair loss will typically begin two or three weeks after your first treatment. The amount of hair that you lose will depend on the type of chemotherapy drug you are taking. Hair typically begins to grow back approximately 2-3 weeks after treatment is finished. The hair may grow back differently than it was before treatment. For example color or texture (curly or straight) may be different.
Remember that hair loss associated with chemotherapy is temporary and the hair WILL grow back. In the meantime, here are a few tips to help you cope with the loss:
- You may wish to cut your hair before it starts falling out. The experience of losing the hair is sometimes worse than dealing with it once it’s gone. If you expect to lose all or a lot of your hair, cutting it first may be easier to cope with.
- Plan ahead; shop for a wig before your hair is gone, especially if you wish to match your natural color. Or, take this opportunity to try something different.
- Try hats or head scarves; these are good alternatives or a compliment to a wig.
- Remember to cover your head or use sunscreen on your scalp. Skin that has been covered with hair may be particularly sensitive to UV rays of the sun.
- Ask your insurance company if they cover the cost of the wig.
- Treat your new hair gently once it grows back. Avoid chemicals, bleach, peroxide, or colors.
Things you may need to know include the following topics:
How is chemotherapy delivered?
Managing Chemotherapy Side Effects
Understanding and Monitoring Your Blood Count
When to Call Your Doctor
Frequently Asked Questions