Most common sits at the center of this dementia and brain health question.
Radiation can cause several types of cancer, with some being more common due to the way radiation damages DNA and cells. The most frequent cancers linked to radiation exposure include **thyroid cancer, leukemia, breast cancer, and lung cancer**.
**Thyroid cancer** is particularly sensitive to radiation, especially when exposure occurs during childhood. Ionizing radiation can cause mutations in thyroid cells, leading to papillary thyroid carcinoma, the most common form of thyroid cancer. This type of cancer has been notably observed in populations exposed to radioactive fallout, such as after nuclear accidents. The molecular changes in radiation-induced thyroid cancers often involve gene fusions distinct from those caused by other factors, indicating a direct link to radiation exposure.
**Leukemia**, a cancer of the blood-forming tissues, is another common radiation-induced cancer. Radiation damages the DNA in bone marrow cells, where blood cells are produced, leading to mutations that cause uncontrolled growth of abnormal white blood cells. Different types of leukemia vary in their sensitivity to radiation, but overall, leukemia risk increases with radiation dose, especially when exposure happens at a young age or during prenatal development.
**Breast cancer** risk also rises with radiation exposure, particularly when the breasts are irradiated during early life stages. Studies of atomic bomb survivors and patients who received repeated chest X-rays show that even small doses of radiation can cumulatively increase breast cancer risk. This risk diminishes with age at exposure but remains significant enough to be a major concern.
**Lung cancer** is linked to radiation exposure primarily through inhalation of radioactive particles, such as radon gas or fallout from nuclear tests. Radiation damages lung tissue DNA, increasing the chance of malignant transformation. People living near nuclear test sites or exposed occupationally to radioactive materials have shown higher lung cancer rates.
Radiation causes cancer mainly by damaging DNA directly or indirectly through the creation of reactive oxygen species. This damage can lead to mutations, chromosomal aberrations, and disruptions in cell cycle regulation. The severity and type of cancer depend on the radiation dose, the part of the body exposed, the age at exposure, and the duration of exposure.
Other less common radiation-related cancers include cancers of the stomach, colon, bladder, and salivary glands, but these are less frequently observed compared to the four main types mentioned.
In summary, the most common cancers caused by radiation are thyroid cancer, leukemia, breast cancer, and lung cancer, with risk influenced by dose, timing, and individual susceptibility. Radiation-induced cancers arise from DNA damage that leads to mutations and abnormal cell growth, highlighting the importance of minimizing unnecessary radiation exposure and monitoring those at risk.
For more, see NIH MedlinePlus — cognitive testing.
