Radiotherapy is a safe treatment and follows strict rules to reduce risks at every stage (1). Knowing about your risk of developing a second cancer will help you make the right treatment choices for you and your future.
The benefits of radiotherapy treatment nearly always outweigh the risk. Your treatment team will carefully consider any risks to you, before they offer you radiotherapy. The technology in radiotherapy is improving all the time, aiming to reduce radiation exposure to healthy tissues and the risk of second cancers.
In rare cases, radiotherapy treatment for cancer can contribute to patients developing a second cancer later in life.
Talk to your clinical team about your risk of developing another cancer in the years following treatment to get a better understanding.
Radiotherapy plays a part in just one in twenty treatment-related second cancers (2).
Solid tumour second cancers
Most of these second cancers are solid tumours and develop 10 years or more after radiotherapy (3). The chance of getting a solid tumour second cancer in later life depends on:
- The dose of radiation used in your treatment. In general, the risk of developing a solid tumour after radiotherapy goes up as the dose increases. Some cancers need larger doses of radiation than others, and certain treatment techniques use more radiation.
- The part of your body getting treatment. The area treated is also important, as these cancers tend to develop in or near the area that was treated with radiation. Certain organs, such as the breast and thyroid, seem to have a higher risk for developing cancers after exposure to radiation than other organs.
- Your age and general health. Every patient is unique, but in general, the risk of a solid tumour second cancer is higher for those who were treated during childhood and teenage years, than those treated as adults. The older you are at the time of treatment, the lower the risk of getting a solid tumour second cancer.
- Other anti-cancer treatments you were given, like chemotherapy.
Other factors in second cancers
There are other factors that contribute to the likelihood of a second cancers. These can be more important than the risk of radiation:
- Lifestyle choices: People who continue to smoke during and after treatment are more likely to get second cancers. They also run the risk of experiencing more severe side effects from treatment. You can access support to stop smoking here: Quit smoking – Better Health – NHS
- Environmental factors: We all get exposed to radiation in different ways as we go through life. From natural sources from the atmosphere, in soil and food and also from artificial sources like medical X-rays, which most of us will have at some point.
- Genes: Your genetics can play a part in your risk of getting a second cancer.
Conclusion
Radiotherapy plays a part in just one in twenty treatment-related second cancers. It is a very safe treatment and follows strict rules to reduce risks at every stage. Knowing about your risk of developing a second cancer will help you make the right treatment choices for you and your future.
- Radiotherapy – what patients need to know | IAEA
- Radiation induced secondary malignancies: a review article – PMC
- Second Cancers Related to Treatment | American Cancer Society
