Can Radiation Therapy Cause Cancer?

Radiation therapy has been used for many years to treat cancer, but there is a small risk of developing a second cancer due to radiation therapy. Learn more about this risk and how to manage your concerns.

Can Radiation Therapy Cause Cancer?

Radiation therapy has been used for many years to treat cancer, and it is well known that it can cause damage to healthy cells and tissues. However, the benefits of radiation therapy often outweigh the risks, and most side effects go away after treatment. But there is a small risk of developing a second cancer due to radiation therapy, which is known as radiation-induced secondary malignancy (RISM).Studies have found that most second cancers occur in the area that was irradiated by the primary radiation field, where the dose exceeds 2.5 Gy. It is estimated that each Gray (Gy) of radiation increases the rate of solid cancers by approximately 35% in men and 58% in women.

It is not possible to predict who might have a second cancer, but certain factors can put a person at higher risk for a second cancer. The American Cancer Society offers programs and services to help people during and after cancer treatment. It is important to be aware of the risks associated with radiation therapy, and to take steps to manage any concerns about developing another type of cancer after radiation therapy. A non-threshold linear dose-response relationship (LNT) is used to describe the relationship between radiation dose and cancer onset, but it is not fully understood why certain people and tissues are susceptible to cancers caused by radiation. Radiation therapy has been considered a double-edged sword, as it has a well-established role in the treatment of solid cancers, but unfortunately it is likely to induce cancers years after treatment. Myelodysplastic syndrome (MDS), a bone marrow cancer that can develop into acute leukemia, has also been linked to radiation exposure in the past.

Prostate cancer is a good example of radiation-induced secondary cancers, since surgery and RT are equally effective for treatment.