Radiation Therapy-Induced Toxicity in a Breast Cancer Patient With Variance of Unknown Significance in the Ataxia Telangiectasia Gene

Abstract

Abstract Breast conservation has been an effective part of the multimodality treatment of localized breast cancer. Appropriate candidates for breast conservation include patients with early stage disease. However, there are certain absolute contraindications for breast cancer, including radiation during pregnancy, multiple positive margins, and homozygosity mutations in the ataxia telangiectasia mutated (ATM) gene. ATM, an autosomal-recessive disorder, is associated with the childhood onset of neurologic impairment, immunodeficiency, and ocular and cutaneous telangiectasias. Typically, patients with heterozygous ATM mutations remain candidates for breast conservation. However, ATM mutations have been linked to increased sensitivity to radiation therapy and, in some cases, to severe toxicity. We present a case of a 51-year-old woman with variance of unknown significance (VUS) in her ATM gene, who was treated with adjuvant radiation and subsequently developed fibrosis, reduced shoulder movement, and telangiectasias. Thus, our case highlights the need for patients with VUS to be appropriately counseled on radiotoxicity.