During and right after radiation therapy, it may be hard to think ahead to what may happen many years in the future. But depending on the type of treatment and the location of the cancer, there may be long-term side effects from your radiation treatment. (Some of these are described in more detail in the next section.) Even though long-term problems are less common than short-term side effects, they should still be taken into account when making decisions about radiation therapy.

Damage to your body

Radiation can damage normal cells, and sometimes this damage can have long-term effects. For example, radiation to the chest area may affect the lungs or heart. In some people this may cause scarring, which can affect a person’s ability to do things. Radiation to the abdomen (belly) or pelvis can lead to bladder, bowel, or sexual problems in some people. Radiation in certain areas can also lead to fluid build-up and swelling in parts of the body, a condition known as lymphedema.

Risk of another cancer

Another thing some people worry about is a possible increased risk of getting a second cancer some time in the future. This increase in risk is small but real.

The link between radiation and cancer was noted many years ago in studies of atomic bomb survivors, workers exposed to radiation on their jobs, and patients treated with radiation therapy. Young women, for example, who had gotten whole body radiation for the treatment of Hodgkin disease were found to be at increased risk for breast cancer and other cancers later in life. (This treatment is no longer common.) And some cases of leukemia are also related to radiation exposure. The leukemia usually develops within a few years of exposure. The risk peaks about 5 to 9 years after the radiation exposure and then slowly declines. Other types of cancer after radiation exposure take much longer to develop. Most do not happen until at least 10 years after radiation exposure, and some are diagnosed 15 or more years later.

What does this mean to me?

Radiation therapy techniques have steadily improved over the last few decades. Treatments now target the cancers more precisely, and more is known about choosing the best radiation doses. More precise radiation means less damage to nearby, healthy tissues. These advances are also expected to reduce the number of second cancers that result from radiation therapy. The overall risk of second cancers is low and must be weighed against the benefits gained with radiation treatments.

Talk to your doctor before you start radiation treatment to make sure you are aware of the possible long-term effects. This can help you make an informed treatment decision and help you know what symptoms you may need to watch out for after treatment.

Last Medical Review: 12/23/2008
Last Revised: 12/23/2008