Neoplasia USMLE Step 1 Practice Question
A 19-year-old woman with history of osteosarcoma presents with a newly diagnosed early-onset breast cancer (ER/PR negative on immunohistochemistry). Vital signs are stable; mammography shows a 2-cm mass. Her father died of a glioblastoma at age 32. She takes no medications. Family history suggests Li-Fraumeni syndrome with suspected germline TP53 mutation. Which of the following best describes the normal role of p53?
Answer choices
- ADetects DNA damage and can induce cell cycle arrest or apoptosisCorrect answer
- BMediates mismatch repair in microsatellites
- CActivates telomerase to maintain chromosomal ends
- DPromotes angiogenesis through VEGF upregulation
- EStimulates cyclin dependent kinases to promote S phase entry
- FRepairs double-strand breaks through homologous recombination
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