A 28-year-old man from Delhi is found to have a heterozygous TP53 mutation (Li-Fraumeni syndrome) on genetic screening performed after his sister was diagnosed with rhabdomyosarcoma at age 6. He is currently asymptomatic with normal imaging. What is the most appropriate next step?

Explanation

## Li-Fraumeni Syndrome (LFS) Overview Li-Fraumeni syndrome is an autosomal dominant cancer predisposition syndrome caused by germline TP53 mutations. TP53 is a critical tumor suppressor encoding the "guardian of the genome." **Key Point:** TP53 mutations confer a lifetime cancer risk of ~90% in heterozygotes, with diverse malignancy types (breast, sarcoma, brain, adrenal, leukemia) and early age of onset. ## Surveillance Strategy for Asymptomatic TP53 Mutation Carriers Once a TP53 mutation is identified, the standard of care is **intensive surveillance**, NOT chemoprevention or reassurance: | Modality | Frequency | Rationale | |----------|-----------|----------| | Clinical examination | Every 3–6 months | Early detection of palpable masses | | Whole-body MRI | Annual (or 6-monthly if high-risk family) | Detects soft-tissue and CNS tumors | | Chest/abdominal imaging | Baseline + annual | Lung, liver, adrenal cancers | | Dermatologic exam | Annual | Melanoma and other skin cancers | | Colonoscopy | Age 40–50 onwards | Colorectal cancer screening | **High-Yield:** The goal is early detection while tumors are still localized and surgically resectable. Surveillance does NOT prevent cancer but improves outcomes through stage-shift. **Clinical Pearl:** TP53 carriers should AVOID unnecessary radiation (including CT scans when possible) because ionizing radiation increases cancer risk in this population — use MRI preferentially. **Mnemonic:** LFS = **L**ifelong **F**requent **S**urveillance (not prophylactic treatment). [cite:Robbins 10e Ch 7]