Cancer Therapies: An Easy-to-Understand Guide

Cancer treatment varies depending on your cancer type and stage, overall condition, and treatment goal. Your treatment may include one or more of the following :

• Surgery
• Chemotherapy
• Radiation therapy
• Stem cell transplant
• Hormonal therapy
• Targeted therapy
• More and more, several types of treatment are used together at the same time or one after the other to prevent the cancer from coming back (recurring). This is called multimodality (multimethod) treatment .

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. More than half of all people diagnosed with cancer receive chemotherapy. Patients may be treated with a single drug or a combination of drugs. These drugs can be given through a vein, injected into a body cavity, or delivered orally in pill form.

Unlike surgery or radiation, chemotherapy can kill or eliminate cancer cells in parts of the body that are far from the original cancer. That’s because the cancer-fighting drugs circulate in the blood to places in the body where the cancer may have spread. As a result, chemotherapy affects the entire body; this type of treatment is referred to as "systemic."  

Being informed about chemotherapy and its potential side effects can help you manage your own care and help optimize your treatment and outcome. Things you may need to know include:

How is Chemotherapy Delivered?

Managing Chemotherapy Side Effects

Most Frequently Asked Questions about Chemotherapy

Surgery

Surgery is used to diagnose and treat cancer and determine its stage. One common type of surgery that is used to diagnose cancer is a biopsy, or removal of a tissue sample from the suspected cancer for examination by a specialist. A biopsy is often performed in the physician’s office or in an outpatient surgery center. A positive biopsy indicates the presence of cancer; a negative biopsy may indicate that no cancer is present in the sample.

Many types of cancer are treated by surgical resection. In this procedure, the surgeon removes the cancer and some of the normal tissue surrounding the cancer. Sometimes, the surgeon also takes out the nearby lymph nodes (small organs that help the body fight infection) in case they contain cancer cells.

Recently, doctors have started using surgical procedures that remove less healthy tissue, involve smaller incisions (cuts), and usually allow the patient to recover more quickly than surgical resection. In laparoscopic surgery, for example, the surgeon inserts a laparoscope, or tiny telescope connected to a video camera, into the patient's body near the tumor. The laparoscope shows a magnified view of the cancer on a monitor. The surgeon inserts other small instruments to take out the cancer.

In addition, many women with breast cancer are now treated successfully with a lumpectomy, or surgery to remove only the breast cancer and a small amount of normal tissue around the cancer. This is less invasive than mastectomy, in which part or all of the breast is removed.

Another promising new surgical procedure is radiofrequency ablation, in which the physician inserts a thin needle through the skin and into the tumor. The doctor delivers electrical energy through the needle. This energy heats and destroys the tumor.

For information about care after surgery, go to the following link:

Postsurgical Care

Radiation Therapy

Radiation therapy destroys cancer cells and prevents them from reproducing and growing. This form of treatment is usually administered in the form of high-energy beams that deposit the radiation dose in the body where cancer cells are located. Thanks to modern advances in technology, the radiation can be delivered externally or internally. 

For a few kinds of cancer (such as cervical and prostate cancer), radiation is sometimes the only treatment used. More often, radiation therapy is given before, after, or at the same times as other therapies. The use of several different kinds of therapy to treat cancer is becoming increasingly common.

Unlike chemotherapy, which works throughout the body (systemic), radiation therapy is considered a local treatment because thecancer cells are killed only at the location in the body where the radiation is delivered. This is called the radiation field. If cancer exists outside the radiation field, those cancer cells are not destroyed by the radiation.

Radiation therapy is designed to kill enough cancer cells to maximize the probability of cure and minimize side effects. The treatment is also sometimes used as palliation, or palliative care, to reduce symptoms but not cure underlying disease.

Learning more about radiation will help you participate more fully in your treatment plan.

Frequently Asked Questions About Radiation Therapy

Prevention and Management of Radiation Side Effects

Side Effects of Radiation Therapy

Techniques for Delivering Radiation Therapy

What to Expect During Radiation Treatment

Stem Cell Transplant

A stem cell transplant is the delivery of healthy stem cells to your body after you finish your chemotherapy and radiation therapy. This procedure is sometimes used to treat people with leukemia or lymphoma whose radiation therapy or chemotherapy treatment destroyed their bone marrow, which the body needs to make blood cells. If the procedure is successful, the healthy stem cells begin producing blood cells in your body. Stem cell transplant is also called bone marrow transplant.

The stem cells used for this procedure may come from someone (often a relative) whose tissue type is almost the same as yours. In other cases, the doctor might remove your own stem cells from your bone marrow or blood before your radiation and chemotherapy treatment. These cells can often be frozen until they are needed.

Hormone Therapy

Hormones are chemical substances formed in an organ (known as a gland) in one part of the body that affects another part of the body. When cancer starts in the breast or prostate, the body's own hormones may help the cancer grow and spread. Therefore, drugs that block hormone production or change the way the hormones work, and/or removal of organs that produce hormones, such as the ovaries or testicles, are ways of fighting cancer.

One well-known hormone therapy that's often used to treat breast cancer, for example, is tamoxifen. This drug stops the hormone estrogen from binding to tumor cells and helping tumors grow. It can also prevent women at high risk of breast cancer from developing the disease. Aromatase inhibitors are another hormone therapy used to treat breast cancer. They block the aromatase enzyme, which the body needs to produce estrogen.

Hormone therapy is used to reduce levels of male hormones, or androgens, in men with prostate cancer because androgens stimulate prostate cancer cell growth. When hormone treatments lower androgene levels, prostate cancers often shrink or grow more slowly. Hormone therapies for prostate cancer include drugs to decrease androgen levels and orchiectomy, or surgical removal of the testicles, which make most androgens.

Hormone therapy, like chemotherapy, is a systemic treatment because it may affect cancer cells throughout the body. Hormone therapy is also known as antihormone therapy.

Targeted Therapies

A targeted therapy is one that is designed to treat only the cancer cells and minimize damage to normal, healthy cells. Conventional cancer treatments, such as chemotherapy and radiation therapy, cannot distinquish between cancer cells and healthy cells and often damage healthy cells, resulting in side effects. In contrast, treatments that “target” cancer cells produce fewer treatment-related side effects and better outcomes.

Some targeted therapies are known as biologic therapies or immunotherapies. These treatments use the body's immune system to help kill cancer cells. Biologic therapies include monoclonal antibodies and vaccines.

Advances in science and technology have led to the development of several different types of targeted therapies. Each of these new treatments targets cancer in different ways:

• Antiangiogenic drugs (also known as angiogenesis inhibitors) stop cancer cells from making the new blood cells that they need to survive and grow. 
• Gene therapy involves the use of genes to treat cancer. In some cases, healthy copies of missing or damaged genes are given to patients to change the genetic makeup of certain cells. Genes are also used to stop cancer cells from making new blood vessels, which stops the cells from growing.
• Monoclonal antibodies can locate and attach to certain receptors on the outside of cancer cells. This stops the cells from sending a signal to divide. Treatments that block receptors are also called receptor antagonists.
• Proteasome inhibitors stop the action of certain enzymes (proteasomes) that break down proteins. This can stop cancer cells from growing or kill them.
• Tyrosine kinase inhibitors stop the enzyme (protein) tyrosine, which is part of a complex signaling system that helps some cancers grow out of control. 
• Vaccines are used to treat existing cancers (therapeutic vaccines) or prevent the development of cancer (prophylactic vaccines). Therapeutic vaccines strengthen the body's natural defenses against cancer. This can prevent the further growth of an existing cancer, prevent a treated cancer from recurring, or kill cancer cells that are still left after previous treatments. Prophylactic vaccines prevent healthy people from infection with cancer-causing viruses.