Drug treatment for advanced cancer

Several types of medicines can be used to treat advanced cancer.

Chemotherapy

Chemotherapy (chemo) uses drugs to kill cancer cells. Usually the drugs are given into a vein or taken by mouth. Once the drugs enter the bloodstream, they go throughout the body. This treatment is often useful for cancer that is widespread. By shrinking the cancer, it can relieve symptoms. It can even prolong life in some patients with advanced cancer.

Chemo kills cancer cells. But these drugs can also harm some of the normal, healthy cells. This can cause side effects, such as:

• Nausea and vomiting
• Loss of appetite
• Hair loss (the hair grows back after treatment ends)
• Mouth sores
• Diarrhea
• Increased chance of infection (from low numbers of white blood cells)
• Bleeding or bruising after small cuts or injuries (from low numbers of platelets)
• Feeling tired (from low numbers of red blood cells)
• Feeling weak

Your cancer care team can suggest many things to ease side effects. For example, there are drugs to help prevent or reduce nausea and vomiting. Sometimes it will help for the doctor to change the dose or the time of day you take your medicines. It is always important to balance any side effects you have against the symptoms you are trying to relieve. To learn more about chemo, please see Understanding Chemotherapy: A Guide for Patients and Families.

Targeted therapy

Targeted therapy is a newer type of cancer treatment that uses drugs that attack specific parts of cancer cells (or other cells that help them grow). These drugs work differently from standard chemo drugs. They can be used alone or along with other treatments.

Most targeted drugs do not affect normal cells as much as chemo drugs do, so they may not cause as many side effects. But even though they mainly target the cancer cells, these drugs are not perfect – they can still cause side effects and sometimes serious reactions.

Hormone therapy

Hormone therapy uses drugs to block the actions of certain hormones or reduce how much is made. For example, estrogen is a hormone that causes many breast cancers to grow. Drugs such as tamoxifen can block the effect of estrogen on breast cancer cells, which may stop growth and even cause many cancers to shrink. Likewise, male sex hormones (called androgens), like testosterone, cause most prostate cancers to grow. Some drugs can help stop or slow this growth.

Side effects of these drugs depend on the type of hormone therapy used but can include hot flashes, blood clots, and loss of sex drive.

Immunotherapy

Immunotherapy is a treatment that boosts the body's immune system or uses man-made versions of immune system proteins to kill cancer cells. Several types of immunotherapy are used to treat patients with advanced cancer, including cytokines, monoclonal antibodies, and tumor vaccines. These treatments are discussed in detail in our document called Immunotherapy.

Drugs to treat cancer spread to the bones

Some types of drugs can be especially helpful if cancer has spread to the bones. (For more information, see our document, Bone Metastasis.)

Bisphosphonates: Bisphosphonates are a group of drugs that work by slowing down the action of bone cells called osteoclasts. These cells normally dissolve small bits of bones to help remodel them and keep them strong. But osteoclasts are often overactive when cancer spreads to the bones, which can cause problems.

Bisphosphonates used to treat cancer in the bones, such as zoledronic acid (Zometa^®) and pamidronate (Aredia^®) are given as an injection into a vein (IV), about once a month. They can often slow bone damage, lower the risk of broken bones, and reduce bone pain. People given these drugs are usually advised to take a supplement containing calcium and vitamin D to prevent problems with low calcium levels.

Still, these drugs can cause problems, too. The most common side effects are fatigue, fever, nausea, vomiting, and bone or joint pain. Some patients develop damage to their jawbone, known as osteonecrosis of the jaw (ONJ), which can be serious. Many doctors have their patients get a thorough dental check-up before they start treatment to help prevent this. These drugs can cause kidney damage, so they should not be given to people with severe kidney problems.

Denosumab (Xgeva^™): This is another drug that can help when cancer spreads to bone. Like the bisphosphonates, this drug keeps osteoclasts from being turned on, but it does so in a different way, by blocking a substance called RANKL.

This drug is injected under the skin every 4 weeks. Patients given this drug may need to take a supplement containing calcium and vitamin D to prevent problems with low calcium levels.

Common side effects include nausea, diarrhea, and feeling weak or tired. Like the bisphosphonates, denosumab can cause ONJ, so doctors recommend taking the same precautions (such as having tooth and jaw problems treated before starting the drug). Unlike the bisphosphonates, this drug is safe to give to patients with kidney problems.

Radiopharmaceuticals: This group of drugs has radioactive elements. The drugs are injected into a vein and settle in areas of bone that contain cancer. The radiation they give off kills the cancer cells and relieves some of the pain caused by bone metastases. If cancer has spread to many bones, these drugs often work better than trying to aim external beam radiation at each affected bone.

The major side effect of this treatment is lower blood cell counts (mainly white blood cells and platelets), which could put you at increased risk for infections or bleeding. This is more of a problem if your counts are already low before treatment.