Cancer Caused by Radiation Therapy

Medically Reviewed by Jennifer Robinson, MD on November 06, 2022
2 min read

If you have cancer, your doctor may recommend radiation therapy. This uses high-energy beams to kill cancer cells.

It’s rare, but these high doses of radiation could trigger another cancer called second primary cancer. It typically doesn’t show up until years after treatment. Here’s what you need to know.

The strength of this treatment can damage your DNA and kill healthy cells and tissues. This can lead to cancer. But since it’s rare, the many benefits of radiation treatment usually outweigh this risk.

There are a few steps you can take to manage your concerns if you’re worried you might get another type of cancer after radiation therapy. They include:

Talk to your doctor. Cancer affects everyone differently. Ask them which types you may be at risk for based on your past cancer and radiation therapy.

Schedule checkups. This will help your doctor check for possible complications from your original cancer and watch for signs of new cancers. Ask them how often you should come in.

Watch for new symptoms. Let your doctor know right away if you have any new problems or possible side effects related to cancer.

Radiation therapy can cause early side effects, which happen shortly after treatment. These usually don’t last very long and tend to be minor and treatable. They include:

Fatigue. Radiation may make you mentally and physically tired. This usually happens after a few weeks of treatment. That’s because of the harm to your healthy cells. Your sleepiness may get more intense as you continue with therapy.

Skin changes. Your skin may look red, tanned, or irritated in the area you get radiation therapy. This could cause it to become itchy, flaky, and dry later. It should go away over time after your treatment ends, but in some cases your skin may stay more sensitive or discolored in that area.

Low blood counts. While it’s rare, your blood count levels could change. These are the cells that help you stop bleeding and fight infections. If this happens, your doctor may suggest taking a break from treatment so your levels can go back to normal.

Hair loss. You may lose your hair or notice it’s thinner after treatment. This could happen in the specific area where you get therapy, like your head. Your hair will grow back after treatment ends.

In addition to second primary cancer, you could have other late side effects that may take months or years to show up. These changes depend on where you had radiation and the amount your doctor used. They’ll plan your treatment very carefully to try to avoid severe long-term side effects of radiation.