Chemotherapy, often referred to as just chemo, is a type of cancer treatment that uses drugs to destroy cancer cells. Chemotherapy is used to treat many types of cancer and more than 100 chemotherapy drugs are used today, either alone or in combination with other treatments. Unlike radiation therapy and surgery, which are considered local treatments because they act only in one area of the body, chemo is almost always used as a systemic treatment. This means the drug travels throughout the entire body to reach cancer cells, wherever they may be. Chemo works by stopping or slowing the growth of cancer cells, which rapidly grow and divide. Depending on the type and advancement of cancer, chemotherapy can be used in one of three ways: to cure the cancer, control the cancer, or ease cancer symptoms (also called palliative care). Some uses for chemo include shrinking a tumor before surgery or radiation therapy, destroying cancer cells that remain after surgery, or destroying cancer cells that have recurred and spread to other parts of the body.
How is chemotherapy given?
To decide if chemotherapy is right for a patient, doctors consider many factors. These factors can include the type of cancer, whether the patient has undergone chemotherapy before, and any other health risks, such as diabetes or heart disease, the patient may have. Chemotherapy drugs can be divided into several groups based on their chemical structure, relationship to other drugs, and success rate. Some chemotherapy drugs are phase-specific, meaning they only work in one phase of the cell cycle. This helps oncologists plan exactly when chemotherapy will be most effective. Oncologists know how each drug works, which helps them to predict when each drug should be given, which drugs will work together, and related side effects for each drug.
Chemotherapy treatments are divided into two categories: systemic therapy and regional therapy.
Drugs used for total body chemotherapy (systemic), can be given:
- Orally – taken by mouth, usually in pill form
- Subcutaneously (SQ) – injected under the skin
- Intravenously (IV) – drugs are infused through a vein, often using a port, catheter, or pump
- IV therapy may be given through a catheter placed in a vein in the arm or hand, called a “peripheral line”, or in a larger vein in the chest or neck, known as “central line” or central venous catheter (CVC). CVCs are used for frequent treatments, long-term therapy, continuous infusion chemo, to give several drugs at one time or give drugs that can cause serious damage to skin and muscle if leaked. The type of CVC used is based on the duration of treatment, how long it takes to infuse each dose, the doctor’s preferences, the patient’s preferences and the cost of treatment. There are many types of CVCs available, so it is best to discuss all options with your doctor before consenting to a vascular access device.
Regional therapy is used when a specific area of the body requires high doses of chemo. This form of chemotherapy directs the drugs into specific parts of the body with cancer, and is used to get more of the drug to the cancer while minimizing side effects. Although regional chemo keeps side effects to a minimum, they will often still occur because the drugs can be partly absorbed into the bloodstream, and travel throughout the body.
Some forms of regional chemotherapy:
- Intra-arterial – drugs are injected into an artery that goes to a certain part of the body
- Intravesical – chemotherapy drugs are infused into the patient’s bladder
- Intrapleural – drugs are infused into the chest cavity, between the lung and chest wall
- Intraperitoneal – drugs are infused into the abdomen around the intestines and other organs
- Intrathecal – drugs are infused into the central nervous system, via the spinal fluid
- Intralesional/Intratumoral – drugs are injected directly into the tumor
- Topical – chemotherapy drugs are applied to the skin as a cream or lotion
Like other cancer treatments, there are side effects to chemotherapy. Chemotherapy works to kill cancer cells, but often healthy cells are damaged in the process. The normal cells most likely to be damaged are ones that divide rapidly, such as bone marrow and blood cells, cells of hair follicles, cells lining the digestive tract and cells lining the reproductive tract. Chemotherapy side effects are most often caused by the damage done to healthy cells during treatment. Side effects of various chemotherapy drugs also differ based on the dose, the way the drug is given, and how the drug affects the patient individually.
Common side effects during chemotherapy treatment:
- Hair loss
- Loss of appetite
- Mouth Sores
- Bruising easily
Many of these can be prevented or treated during chemotherapy, and most subside after treatment ends. Some chemotherapy drugs can cause side effects that aren’t noticeable until months or years after treatment.
Late side effects vary depending on the drugs, but can include:
- Damage to lung tissue
- Heart problems
- Kidney problems
- Nerve damage
- Risk of a second cancer
When suggesting chemotherapy, the oncologist first carefully weighs the known risks of treatment against the potential benefits for each patient. These benefits include relief of symptoms, shrinking a tumor, and potential cures. In some cases, patients undergo scans and tests regularly to monitor the cancer during treatment to give the doctor an idea of how the cancer is responding to treatment. Oncologists also discuss side effects experienced during treatment, since many can be controlled with medications. Discuss chemotherapy with your doctor to determine the best form of treatment for you.
The specialists at Southeastern Medical Oncology Center are fellowship trained and board certfied in oncology. Ask your physician for a referral to one of our specialists for your chemotheraphy treatment, which is administered on-site in our chemotheraphy suite.
The American Cancer Society
The National Cancer Institute at the National Institutes of Health