What Is Chemotherapy and How Does It Work?

Chemotherapy is the use of medicines (or drugs) to treat disease. Cancer chemotherapy (usually just called "chemotherapy" or "chemo") refers to medicines which treat cancer. While surgery and radiation therapy destroy or damage cancer cells in a specific area, chemotherapy works throughout the body. It can destroy cancer cells that have metastasized (spread) to parts of the body far away from the primary (original) tumor.

Today, about 80 chemotherapy drugs are used. Although a single drug can be used to treat cancer, generally chemotherapy drugs are more powerful when used in combination with other drugs. Your chemotherapy treatment probably will consist of more than one drug. This is called combination chemotherapy. A combination of drugs with different actions can work together to kill more cancer cells and reduce the chance that you will develop a resistance to one particular drug.

Which Chemotherapy Drugs Will Be Used?

You and your doctor will decide which drug or combination of drugs, dosages, method of administration, and frequency and length of treatment are best for you. All of these decisions will depend on the type of cancer, its location, the extent of its growth, how it is affecting your normal body functions, and your general health.

What Can Chemotherapy Achieve?

Depending on the type of cancer and its stage of development, chemotherapy can be used to cure cancer, to keep the cancer from spreading, to slow the cancer's growth, to kill cancer cells that may have spread to other parts of the body from the original tumor, or to relieve symptoms caused by the cancer. Your doctor will discuss with you the goal of your chemotherapy before you start treatment.

Will Chemotherapy Be My Only Treatment for Cancer?

Sometimes chemotherapy is the only treatment a patient receives. More often, chemotherapy is used in addition to surgery and/or radiation therapy.

There are several reasons why chemotherapy may be given in addition to other treatment methods. For instance, chemotherapy may be used to shrink a tumor before surgery or radiation therapy; it may be used after surgery or radiation therapy to help destroy any remaining cancer cells; or it may be used with other treatments if your cancer returns. When chemotherapy is given following surgery to destroy any cancer cells that may still be present, it is called adjuvant therapy. When chemotherapy is used to shrink a tumor before surgery or radiation therapy, it is called neoadjuvant therapy.

What Should I Know About Chemotherapy?

Before choosing chemotherapy as a treatment option, you should understand the expected benefits, side effects, and risks. Consider asking your doctor or nurse the following questions. The answers should provide you with important information about your treatment and realistic expectations about the outcome.

• What is the goal of chemotherapy for my cancer?
• Will I be treated surgically and/or with radiation? If so, when and why? What are the expected results of each type of treatment?
• If chemotherapy is to follow surgery and/or radiation, will it destroy any remaining cancer cells? Could chemotherapy alone be used?
• What are the chances that the chemotherapy will work?
• After chemotherapy, will I be cured, in remission, or relieved of my symptoms?
• Are there other ways to achieve the same goals?
• How will I know if the chemotherapy is working?
• If the chemotherapy is not effective, are there other treatments for me?
• What are the potential risks and side effects of the anticancer drug(s) I will be taking? How do they (the side effects) compare with other treatments?
• How will I receive chemotherapy, how often, and for how long? Where will I be given the drugs?
• Are there ways to help me prepare for treatment and decrease the chance of side effects?
• Will my diet be restricted in any way? My activities? My work? Exercise? Sexual activities?
• How much will chemotherapy cost and will it be covered by my insurance or health plan?

This list is just a start. Always ask your doctor, nurse, and pharmacist as many questions as you want. If you don't understand their answers, keep asking until you do. Keep a "running list" and jot down each new question as it occurs to you.

To help remember your doctor's answers, take notes during your appointments. Don't feel shy about asking your doctor to slow down when you need more time to write. If you can, use a tape recorder during your visit so you won't miss a thing. Consider taking a friend or relative to your appointment to help you understand what your doctor says during your visit and to refresh your memory afterward.

One way to find out if a suggested treatment is the best for you is to get the opinion of at least two doctors. Your doctor should not mind if you seek a second opinion. In fact, some insurance companies require you to get one. Often, the results of any tests you have taken can be sent to the second doctor, so you probably won't have to repeat any of them. If you belong to a health maintenance organization (HMO), find out about its policy concerning second opinions before you get the second opinion.

Where Will I Get Chemotherapy?

You may be treated with chemotherapy at home, in your doctor's office, in a clinic, in your hospital's outpatient department, or in a hospital. The location depends on which chemotherapy drug or drugs you are getting, the dosages of each drug to be given, your hospital's policies, and you and your doctor's preferences. When chemotherapy treatment begins, you may need a brief hospital stay so that your doctor can monitor and evaluate the medicine's effects and make any adjustments.

How Often Will I Receive Chemotherapy Treatment and How Long Will It Last?

How often you take chemotherapy drugs and how long your treatment lasts depends on the kind of cancer you have, the goals of the treatment, the drugs that are used and how your body responds to them. You may receive treatments daily, weekly, or monthly. But treatments are usually given in on-and-off cycles which allow rest periods so that your body can build healthy new cells and regain its strength.

If your cancer returns, chemotherapy may be used again. This time, different drugs may be given to relieve symptoms or to slow the growth of the disease. Side effects may differ, depending on the drug, the dose, and how it is given.

How Will the Chemotherapy Be Administered?

Most chemotherapy is given intravenously. Depending on the drug and where the cancer is located, your chemotherapy may be given in one or more of the following ways:

• By mouth, orally, per os, PO; You swallow the drug in a pill, capsule, or liquid form just as you do many other medications. This method is usually more convenient and may be less expensive since the drugs can be taken at home. If you take oral chemotherapy drugs, it is very important to take the exact dosage that has been prescribed for you.

• Intravenous, or IV; There are several ways it can be done. The drug can be given quickly over a few minutes, which is called "IV push," or as an infusion, which can last 30 minutes to a few hours. Continuous infusions are sometimes necessary and usually last 1 to 4 days. The drug is given through a tiny plastic tube, or catheter, which is inserted into a vein in the forearm or hand. The drugs are administered through the tube either directly from a syringe, when given as an IV push, or from a mixed drug solution that flows from a plastic bag when given as an infusion.

Catheters and needles can scar or weaken veins after several chemotherapy sessions. An alternative is the vascular access device (VAD). The VAD is a catheter that is surgically implanted under the skin and can remain painlessly in place to provide access to a large vein. Drugs can then be injected directly into the VAD or through an IV connected to the VAD.

• Intrathecal, IT; The drug is injected into the spinal canal. You may either get an injection directly into your spine or into an indwelling cerebrospinal fluid reservoir under your scalp. This method involves placing a small device surgically into the scalp that connects to the cerebrospinal fluid in the spinal cord.

• Intra-arterial, IA; The chemotherapy drug is injected directly into an artery to treat a single area (such as the liver, an arm or leg). This method limits exposure of other parts of the body to the drug.

• Intracavitary, IC;. Chemotherapy drugs are given through a catheter into the abdominal cavity or chest cavity.

• Intramuscular, IM; The drug is given by injection into a muscle.

• Intralesional; The drug is injected directly into a tumor in the skin, under the skin, or in an internal organ.

• Topical; The medication is applied directly to a cancerous area on the skin.

Does Chemotherapy Hurt?

Getting chemotherapy orally, topically, or by injection feels about the same as taking other medications by these methods. Intravenous medications should not hurt after the initial stick to insert the catheter. If you feel any pain, burning, coolness, or other unusual sensations, tell your doctor or nurse immediately.

Can I Take Other Medicines While I Am Getting Chemotherapy?

Some medicines may interfere with the effects of your chemotherapy. To ensure that your treatment is the most effective that it can be, tell your physician about any and all medications you are taking, including aspirin, herbals, vitamins, over-the-counter, and prescription medications. Include the name of each drug, how often you take it, the reason you take it, and the dosage. Your doctor will tell you if you should stop taking any of these medications before you start chemotherapy. After your treatments begin, check with your doctor before taking any new medicines or stopping the ones you already take.

Will I Be Able to Work During Treatment?

Whether a patient can continue work, school, and other activities depends on their type and dose of chemotherapy. For some treatments, a hospital stay of one or more weeks is needed, but most people are able to continue working during treatment. You might be able to schedule your treatments late in the day or right before the weekend so that they interfere with work as little as possible.

If your chemotherapy makes you tired, try to adjust your work schedule for a while. You may be able to arrange a part-time schedule or work at home. Federal and state laws may require some employers to allow you to work a flexible schedule during your treatment.

How Will I Know If My Chemotherapy Is Working?

Your health-care team will measure how well your treatments are working through frequent physical exams, blood tests, scans, and x-rays. Ask your doctor about the test results and what they show about your progress. Side effects are not an indication of whether treatment is effective.

Informed Consent

Informed consent is your written permission to receive chemotherapy based on your understanding of the drugs your oncologist recommends, how they will be administered, how often and for how long, what their side effects are, and how likely it is that the therapy will be successful. Know the answers to all of these questions before you sign the informed consent form.

Although the specifics of the form may vary from state to state, the form usually attests to the fact that your doctor has explained your condition to you, how the chemotherapy will benefit you, the risks, and the other options available to you. Your signature means that you have received this information and that you are willing to be treated with chemotherapy.