Medline ® Abstract for Reference 112
Severe reaction to radiotherapy for breast cancer as the presenting feature of ataxia telangiectasia.
Byrd PJ, Srinivasan V, Last JI, Smith A, Biggs P, Carney EF, Exley A, Abson C, Stewart GS, Izatt L, Taylor AM
Br J Cancer. 2012 Jan;106(2):262-8. Epub 2011 Dec 06.
BACKGROUND: Severe early and late radiation reaction to radiotherapy is extremely rare in breast cancer patients. Such a reaction prompted an investigation into a 44-year-old mother (patient A-T213).
METHODS: A neurological examination was performed and blood lymphocytes and skin fibroblasts were assessed for radiosensitivity chromosomally and by colony-forming assay. The ATM gene was sequenced and ATM mutations modelled by site-directed mutagenesis. The ATM kinase activity was also assessed.
RESULTS: Patient A-T213 was normally ambulant with no ataxia and minimal other neurological features. T lymphocytes and skin fibroblasts were unusually radiosensitive, although less sensitive than in classical ataxia telangiectasia (A-T). A lymphoblastoid cell line and skin fibroblasts expressed ATM protein with some retained kinase activity. One missense ATM mutation c.8672G>A (p.Gly2891Asp) and a c.1A>G substitution were identified. In the modelling system, the p.Gly2891Asp mutant protein was expressed and shown to have residual ATM kinase activity.
CONCLUSION: Patient A-T213 has a milder form of A-T with biallelic ATM mutations, which may have contributed to breast cancer development, and certainly caused the severe radiation reaction. Ataxia telangiectasia should be investigated as a potential cause of untoward severe early and late radiation reactions in breast cancer patients.
School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT, UK.