Is There a Link Between Ataxia Telangiectasia, Radiation, and Cancer?
Overall, the risk of a person with ataxia telangiectasia developing any cancer is 37 times higher than that of a person in the general population. The risk of developing lymphoid tumors, which is the most frequently diagnosed cancer in people with this condition, is 100 times higher. People with ataxia telangiectasia have about a 10 percent risk of developing lymphoma or leukemia. Other cancers that commonly occur in people with this disease include:
It is not known whether ataxia telangiectasia carriers are at an increased risk for developing cancer. However, some scientists believe that when compared with the general population, carriers might have a higher risk of certain cancers, such as breast cancer and stomach cancer. In population-based studies, this increase in cancers (when seen) was small. Although case-control studies have suggested a link between the ATM gene and an increased risk of breast cancer, the findings have been inconsistent.
Studies in animals have not supported the theory of increased cancer risks in ataxia telangiectasia carriers. In animal studies of the ATM gene, all of the mice with the disease died of cancer, while none of the mice that were carriers had tumors.
People with ataxia telangiectasia have an increased sensitivity to ionizing radiation, which is the type of radiation used in x-rays. When cultured in the laboratory, the blood and skin cells of these people had a reduced ability to replicate and form cell colonies after they had been exposed to x-rays.
Currently, there is no data from clinical studies to definitively answer the question about the sensitivity of carriers. So it isn't known whether ataxia telangiectasia carriers also have an increased sensitivity to ionizing radiation. When cultured in the laboratory, the blood and skin cells of known ATM gene carriers are less sensitive to x-rays than cells from people with ataxia telangiectasia, but are more sensitive than cells from the general public.