What is Chemoprevention

November 12, 2012
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In this podcast, you'll receive a definition of chemoprevention, what these medications can and cannot do, and how they are being studied. We'll also look at some examples of chemoprevention that are being used or studied for their potential benefit in preventing cancer.


You’re listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the world’s leading professional organization for doctors that care for people with cancer.

Today we’ll discuss chemoprevention.

Chemoprevention is the use of drugs or other substances to help prevent or delay the development of a possible future cancer. It is not used to treat an existing cancer. In this podcast, you’ll hear about what these medications can and cannot do, as well as  how they are being studied. We’ll also look at the risks and benefits of chemoprevention to lower your risk for cancer.

Chemoprevention drugs-- or agents--can help slow down or prevent the processes in a person’s body that can lead to cancer. Cancer begins when cells become abnormal, invade healthy tissue, and grow uncontrollably. The change from a healthy cell to a cancerous one usually takes many years and can be affected by a person’s genetics, diet, and behavior. Chemoprevention is typically used by people who have a higher risk of developing cancer, those with a previous cancer, an inherited cancer syndrome, or a family history of cancer.

Next, let’s discuss how chemoprevention drugs are being studied. Chemoprevention drugs are studied in clinical trials, which are research studies in people. A new chemopreventive agent is studied to learn whether it is safe, effective and actually delays or prevents cancer.

Clinical trials have shown that chemoprevention lowers the risk for some cancers. Let’s briefly review two examples.

Hormone therapy is a type of medication that blocks the body's production of certain hormones. For instance, tamoxifen  reduces the risk of breast cancer by blocking estrogen production. Another hormone therapy is finasteride (fi NAS teer ide), a drug used to lower the risk of prostate cancer by reducing the amount of a male hormone produced by the body.

In the second example, cancer researchers are looking at the use of nonsteroidal anti-inflammatory drugs, or NSAIDs (EN-seds) for short. Aspirin and other NSAIDS can lower the risk of many types of cancer in people with an average risk of cancer.

Clinical trials often show that chemopreventive agents don’t work for every person. When evaluating the results of any chemoprevention clinical trial, it’s important to look at the group of participants. These drugs are often studied in people with known, increased risks for cancer, so the results of the study may not apply to everyone. It’s also important to note that although cancer may be delayed with chemoprevention, cancer could still develop in the future.

As with any drug or medication, talk with your doctor about the risks and benefits of chemoprevention. Lowering the risk of cancer is often a benefit, but side effects are a risk. People with a higher risk of developing cancer may be willing to accept the possibility of side effects, while a person at average risk may not. Also discuss your risk of developing cancer, your preferences for taking a medication, and your current health.

For more information on chemoprevention, contact your doctor or visit www.cancer.net. Cancer.Net is supported by the Conquer Cancer Foundation, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high-quality cancer care. Thank you for listening to this Cancer.Net podcast.