Chemotherapy

Chemotherapy is the use of potent drugs or chemicals, often in combinations or intervals, to kill or damage cancer cells in the body. Chemotherapy drugs are often called anticancer agents. The drugs must be toxic enough to kill leukemic cells, which is why chemotherapy can be hard on your body; the drugs' toxicity can harm your healthy cells as well. However, successful chemotherapy depends on the fact that cancerous cells are more sensitive to the chemicals in the drug than normal cells are.

The progress in treatment and survival for patients with blood cancers is largely due to the development of chemotherapy drugs over the past 40 years. Today's treatments for leukemia, lymphoma and myeloma sometimes combine chemotherapy with radiation therapy. Very high dose chemotherapy followed by stem cell transplantation can also be used.

The goal of chemotherapy is to damage or kill cancer cells so there's either no sign of illness (remission) or the disease's progress is slowed. Chemotherapy can produce long-term remission or outright cure for many persons, depending on the cancer type and its extent.

How Does Chemotherapy Work?

Normal, healthy cells divide and grow in a controlled pattern. As each cell divides, a replica is produced. Cancer cells, on the other hand, grow uncontrollably and rapidly with no pattern. When a cancer cell comes into contact with a normal cell, the cancer cell takes over and copies itself many times, overburdening the body with cancer cells.

All chemotherapy drugs interfere with cancer cells' ability to grow or multiply. Different groups of drugs harm cancer cells in different ways. That's why it's essential that the disease be accurately diagnosed: Certain chemotherapy drugs are used only for certain disease cell types.

Attacking DNA and RNA

Both new chemotherapy drugs and new ways to attack cancer cells continue to emerge as research progresses. Many chemotherapy drugs attack cancer cells by interacting with the cancer cell's DNA or RNA (genetic makeup). This interaction changes the DNA in such a way that it kills the cancer cell or prevents it from growing or dividing. Chemotherapy drug types that act directly to impair DNA include:

• DNA-damaging agents. These drugs, referred to as alkylating agents, damage the DNA so severely that the cancer cell is killed. Examples of alkylating agents are chlorambucil (Leukeran®), cyclophosphamide (Cytoxan®) and melphalan (Alkeran®). Other DNA-damaging agents, such as carboplatin (Paraplatin®), attach to the DNA and prevent the cancer cell from growing.

• Antitumor antibiotics. By inserting themselves into a cancer cell's DNA, these drugs prevent the DNA from functioning normally and often kill the cancer cell. Examples are daunorubicin (Cerubidine®), doxorubicin (Adriamycin®, Doxil®), idarubicin (Idamycinv®) and mitoxantrone (Novantrone®).

• Antimetabolites. These drugs mimic the substances that the cancer cell needs to build DNA and RNA. When the cancer cell uses the antimetabolite instead of the natural substances, it can't produce normal DNA or RNA and the cell dies. Examples are methotrexate (Rheumatrex®, Trexall®), fludarabine (Fludara®) and cytarabine (cytosine arabinoside, ara-C, Cytosar-U®).

• DNA-repair enzyme inhibitors. Repair of DNA damage is a normal and vital process in the cell. Without this repair process, the cancer cell is much more susceptible to damage and is prevented from growing. These agents attack the cancer cell proteins that normally repair DNA damage. Examples are etoposide (VP16, Etopophos®, Toposar®, VePesid®) and topotecan (Hycamtin®).

Other Modes of Attack

• Hormones such as prednisone and dexamethasone (Decadron®) in high doses can kill lymphoma or lymphocytic leukemia cells.

• Antimitotic drugs such as vincristine (Oncovin®) or vinblastine (Velban®) damage cancer cells by blocking a process called mitosis (cell division), preventing cancer cells from dividing and multiplying.

• Antibodies made specifically to attach to cancer cells interfere with a cancer cell's function and kill the cell. Some antibodies are combined with a toxin or radioactive substance.

Radiation

Radiation therapy, also called radiotherapy or irradiation, can be used to treat leukemia, lymphoma, myeloma and myelodysplastic syndromes.

Radiotherapy works by damaging the genetic material (DNA) within cells, which prevents them from growing and reproducing. Although the radiotherapy is directed at cancer cells, it can also damage nearby healthy cells. However, current methods of radiotherapy have been improved upon, minimizing “scatter” to nearby tissues. Therefore its benefit (destroying the cancer cells) outweighs its risk (harming healthy cells).

When radiotherapy is used for blood cancer treatment, it's usually part of a treatment plan that includes drug therapy. Radiotherapy can also be used to relieve pain or discomfort caused by an enlarged liver, lymph node(s) or spleen.

Radiotherapy, either alone or with chemotherapy, is sometimes given as conditioning treatment to prepare a patient for a blood or marrow stem cell transplant. The most common types used to treat blood cancer are external beam radiation (see below) and radioimmunotherapy.

External Beam Radiation

External beam radiation is the type of radiotherapy used most often for people with blood cancers. A focused radiation beam is delivered outside the body by a machine. The machine moves around the body to deliver radiation from various angles.

Most radiation therapy machines use photon beams from a machine called a linear accelerator, or linac for short. The same type of radiation is used for x-rays, but x-rays use lower doses. This is the most common type of external beam radiation.

At some cancer centers, proton beam radiation may be an option. Protons are particles with a positive charge. Proton beam radiation can be more targeted than photon beam radiation. This helps to minimize damage to healthy tissues and organs and may decrease the risk of long-term and late effects. This type of radiation therapy is newer and requires a special machine.

The dose (total amount) of radiation used during treatment depends on various factors regarding the patient, disease and reason for treatment, and is established by a radiation oncologist. You may receive radiotherapy during a series of visits, spread over several weeks (from two to 10 weeks, on average). This approach, called dose fractionation, lessens side effects. External beam radiation does not make you radioactive.

Before Treatment

You'll need to prepare for radiotherapy by undergoing a "simulation" so the technician can determine the most effective ways to direct the radiation and position you during treatment.

For the simulation, members of the radiation oncology team measure your body and sometimes mark your skin to ensure the radiation is aimed at the same part of your body during each treatment session. These marks are small dots usually made with semipermanent ink. You can choose to have the marks removed (by surgery or laser treatment) after radiotherapy is completed. However, some doctors encourage patients to keep the marks to show the exact site(s) of initial therapy if additional radiotherapy is needed in the future. Instead of marking the skin, a radiation therapist may mark an immobilization device — a mold, cast or similar object — used to help you remain still during the treatment sessions.

During Treatment

You shouldn't feel any pain or discomfort during an external beam radiation treatment session. However, you may need to stay in one position for several minutes during a session, which is uncomfortable for some patients. Shields protect certain parts of your body, such as the testes or ovaries, from radiation. You'll likely spend 20 to 30 minutes in the treatment area even though actual radiation exposure lasts only a few minutes.

When you receive the radiation, the treatment team leaves the room and stands behind a protective barrier to protect them from repeated exposure. They can still hear you and see you through a window or closed-circuit television camera. You can talk to them during the treatment and report any discomfort or special needs.

In between sessions, let your treatment team know about any discomfort you experience so they can make changes if needed.

After Treatment

During and after radiotherapy, you need to get plenty of rest and follow a nutritious diet. Eating well during and after cancer therapy can help you cope with side effects, fight infection, rebuild healthy tissue and maintain body weight and energy. Above all, a nutritious diet combined with regular exercise promotes overall wellness.

Follow your doctor's advice about caring for skin exposed to radiation. To help damaged skin heal:

• Shower or bathe with warm water

• Protect the damaged area from the sun

• Wear loose clothes

• Get medical guidance before using skincare products on the affected area(s)

To cope with side effects such as fatigue, seek support from healthcare professionals and other patients who've had similar treatment.

Immunotherapy

Immunotherapy is a type of cancer treatment that helps your immune system fight cancer. The immune system helps your body fight infections and other diseases. It is made up of white blood cells and organs and tissues of the lymph system.

Immunotherapy is a type of biological therapy. Biological therapy is a type of treatment that uses substances made from living organisms to treat cancer.

How does immunotherapy work against cancer?

As part of its normal function, the immune system detects and destroys abnormal cells and most likely prevents or curbs the growth of many cancers. For instance, immune cells are sometimes found in and around tumors. These cells, called tumor-infiltrating lymphocytes or TILs, are a sign that the immune system is responding to the tumor. People whose tumors contain TILs often do better than people whose tumors don’t contain them.

Even though the immune system can prevent or slow cancer growth, cancer cells have ways to avoid destruction by the immune system. For example, cancer cells may:

• Have genetic changes that make them less visible to the immune system.

• Have proteins on their surface that turn off immune cells.

• Change the normal cells around the tumor so they interfere with how the immune system responds to the cancer cells.

Immunotherapy helps the immune system to better act against cancer.

What are the types of immunotherapy?

Several types of immunotherapy are used to treat cancer. These include:

• Immune checkpoint inhibitors, which are drugs that block immune checkpoints. These checkpoints are a normal part of the immune system and keep immune responses from being too strong. By blocking them, these drugs allow immune cells to respond more strongly to cancer.

  Learn more about immune checkpoint inhibitors.

• T-cell transfer therapy, which is a treatment that boosts the natural ability of your T cells to fight cancer. In this treatment, immune cells are taken from your tumor. Those that are most active against your cancer are selected or changed in the lab to better attack your cancer cells, grown in large batches, and put back into your body through a needle in a vein.

  T-cell transfer therapy may also be called adoptive cell therapy, adoptive immunotherapy, or immune cell therapy.

  Learn more about T-cell transfer therapy.

• Monoclonal antibodies, which are immune system proteins created in the lab that are designed to bind to specific targets on cancer cells. Some monoclonal antibodies mark cancer cells so that they will be better seen and destroyed by the immune system. Such monoclonal antibodies are a type of immunotherapy.

  Monoclonal antibodies may also be called therapeutic antibodies.

  Learn more about monoclonal antibodies.

• Treatment vaccines, which work against cancer by boosting your immune system’s response to cancer cells. Treatment vaccines are different from the ones that help prevent disease.

  Learn more about cancer treatment vaccines.

• Immune system modulators, which enhance the body’s immune response against cancer. Some of these agents affect specific parts of the immune system, whereas others affect the immune system in a more general way.

  Learn more about immune system modulators.

Which cancers are treated with immunotherapy?

Immunotherapy drugs have been approved to treat many types of cancer. However, immunotherapy is not yet as widely used as surgery, chemotherapy, or radiation therapy. To learn about whether immunotherapy may be used to treat your cancer, see the PDQ® adult cancer treatment summaries and childhood cancer treatment summaries.

What are the side effects of immunotherapy?

Immunotherapy can cause side effects, many of which happen when the immune system that has been revved-up to act against the cancer also acts against healthy cells and tissues in your body.

Learn more about immunotherapy side effects.

How is immunotherapy given?

Different forms of immunotherapy may be given in different ways. These include:

• Intravenous (IV)
  The immunotherapy goes directly into a vein.

• Oral
  The immunotherapy comes in pills or capsules that you swallow.

• Topical
  The immunotherapy comes in a cream that you rub onto your skin. This type of immunotherapy can be used for very early skin cancer.

• Intravesical
  The immunotherapy goes directly into the bladder.

Where do you go for immunotherapy?

You may receive immunotherapy in a doctor’s office, clinic, or outpatient unit in a hospital. Outpatient means you do not spend the night in the hospital.

How often do you receive immunotherapy?

How often and how long you receive immunotherapy depends on:

• Your type of cancer and how advanced it is

• The type of immunotherapy you get

• How your body reacts to treatment

You may have treatment every day, week, or month. Some types of immunotherapy given in cycles. A cycle is a period of treatment followed by a period of rest. The rest period gives your body a chance to recover, respond to the immunotherapy, and build new healthy cells.

How can you tell if immunotherapy is working?

You will see your doctor often. He or she will give you physical exams and ask you how you feel. You will have medical tests, such as blood tests and different types of scans. These tests will measure the size of your tumor and look for changes in your blood work.