Can Radiation for Cancer Increase the Risk of Developing Another Cancer?

Radiation therapy for one type of cancer can increase risk of developing another type later on. Learn more about how radiation affects healthy cells & how to manage your concerns.

Can Radiation for Cancer Increase the Risk of Developing Another Cancer?

Doctors have long been aware that radiation can cause cancer, and research has demonstrated that radiation therapy for one cancer can raise the risk of developing another cancer later on. Factors that may influence this risk include the amount of radiation used and the area that was treated. Much of what we know about the health effects of radiation comes from studying survivors of atomic bomb explosions in Japan, as well as workers in certain jobs that included radiation exposure and patients treated with radiation therapy for cancer and other diseases. Radiation not only kills or slows the growth of cancer cells, but it can also affect healthy cells nearby, leading to side effects.

If you are worried that you may have another type of cancer after radiation therapy, there are some steps you can take to manage your concerns. For many types of cancer at higher risk among certain cancer survivors, such as lung and stomach cancer, no known screening method can affect prognosis. Talk to your doctor if you think you may be at risk for cancer because you were exposed to radiation. Radiation can disassemble atoms and damage the DNA of cells, resulting in potentially serious side effects, including cancer.

When brachytherapy was compared to patients with external beam RT (EBRT), there were lower rates of second solid cancers overall (RR %3D 0.92; 95% CI, 0.83—1.0; significantly lower rates of second colon cancer (RR %3D 0.52; 95% CI, 0.37—0.7, and leukemia (RR %3D 0.60; 95% CI, 0.40—0.8). A cohort of British Childhood Cancer Survivor Study found that the absolute excess risk for all types of second malignancy was 19% (95% CI, 11.7— 26.3%) after a median follow-up of 24.3 years. Studies in this cohort have revealed that most second RT cancers occur in the volume irradiated by the primary radiation field, where the dose exceeds 2.5 Gy. Myelodysplastic syndrome (MDS), a bone marrow cancer that can develop into acute leukemia, has also been linked to radiation exposure in the past. Many factors contribute to the development of RISM, such as the age at which radiation is received, the dose and volume of the irradiated area, the type of organ and tissue irradiated, the radiation technique, and the individual and family history of cancer. Prostate cancer is a good example of radiation-induced secondary cancers since surgery and RT are equally effective for treatment.

After adjusting for age, patients diagnosed with cervical cancer at an early age had a higher risk of developing a second cancer. This will help the doctor detect possible complications from the original cancer and watch for signs of new cancers. However, the incidence of secondary lung cancer and sarcomas in the radiation field also increased (lung received, 0.5 Gy). Some drugs used to treat cancer are called targeted therapy drugs because they are designed to detect and attack certain genes or proteins found in specific types of cancer.