skip to main content

ATM Mutation — SCE Medical Oncology MCQ

Instant feedback + full explanation. One question, done properly.

HardCancer GeneticsATM MutationSCE Medical Oncology

A 45-year-old woman is found to have a germline ATM mutation on panel testing after a breast cancer diagnosis. What cancer risks are associated with ATM mutations, and does it affect treatment selection?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — ATM heterozygous carriers have a moderately increased breast cancer risk (~20-40% lifetime)

Heterozygous germline ATM mutations confer a moderate breast cancer risk (approximately 2-3× population risk, lifetime risk ~20-40%). ATM functions in the DNA damage response, and ATM-deficient tumours may exhibit homologous recombination deficiency (HRD) biology. Emerging data suggest sensitivity to PARP inhibitors and platinum chemotherapy, though the evidence is less robust than for BRCA1/2. Radiation sensitivity is a concern with homozygous ATM loss (ataxia-telangiectasia) but heterozygous carriers can receive standard radiotherapy.

Reference: https://www.nice.org.uk/guidance/conditions-and-diseases/cancer