| 10 11 | See page 67 for references · ·Although ATM has been reported with other types of cancers, more research is needed to determine the exact cancer types and possible associated risks, such as colon cancer. Potential management options Management guidelines for ATM mutations are evolving. A thorough family history review is important to better understand cancer risks and to develop an individualized cancer screening plan. For women with ATM mutations, NCCN recommends the following: · ·Annual mammogram with consideration of tomosynthesis and consideration of breast MRI beginning at age 40 or ten years before the youngest breast cancer diagnosis in the family. · ·Additional risk reduction strategies, such as prophylactic mastectomy or the use of medication, may be considered on an individualized basis. However, there is no data on the benefit of risk-reducing mastectomy for women with ATM mutations. There are currently no screening or management recommendations for other possible types of cancers associated with ATM and management is often individualized based on family history. In rare instances, an individual may inherit mutations in both copies of the ATM gene, leading to the autosomal recessive condition ataxia–telangiectasia. Most individuals with AT develop symptoms in early childhood. For individuals who test positive for ATM, it may be appropriate to consider carrier screening for ATM mutations in a spouse/partner. Other considerations · ·There is some evidence to suggest that certain missense mutations in ATM may act in a dominant negative fashion and lead to higher breast cancer risk. The specific mutation c. 7271T>G has been reported to confer up to a 69% risk to develop breast cancer by age 70. · ·Some studies suggest radiation exposure may further increase cancer risk in ATM mutation carriers. However, there is currently insufficient evidence to recommend against radiation therapy for female ATM mutation carriers with breast cancer. ATM gene summary ATM-associated hereditary cancer Gene name ATM Associated syndrome ATM-associated hereditary cancer Primary associated cancers Breast, pancreatic Frequency Varies by ethnicity Inheritance pattern Autosomal dominant Overview · ·ATM is a gene associated with a moderate risk for breast cancer. · ·Because ATM mutations do not always explain all of the cancer risk in a family, family members who test negative for a known familial ATM mutation may still be at increased risk for cancer based on the family history. · ·Cancer risks associated with mutations in ATM vary widely and are influenced by family history, as well as the specific mutation identified. · ·For individuals who test positive for ATM, it may be appropriate to consider carrier screening for ATM mutations in a spouse/partner. About ATM The ATM gene recognizes DNA damage and plays a role in activating DNA repair mechanisms. ATM was initially identified in those affected with a neurodegenerative condition known as ataxia–telangiectasia (AT), which results when an individual inherits a non-working copy of the gene from each parent. Studies on these families identified an increased cancer risk among unaffected female carriers. ATM has since been associated with moderate penetrance and a relative risk of breast cancer of 2 to 4. Absolute cancer risks for individuals who are identified to have an ATM mutation, however, are influenced by family history and the specific mutation identified. Cancer risks · ·Women identified to have a mutation in ATM have a lifetime breast cancer risk of 17%–40%, compared with the general population risk of 12%. · ·The risk for pancreatic cancer in men and women is reported to be increased; however, the specific percentage is not known.