Li-Fraumeni syndrome (LFS) is associated with a high lifetime cancer risk, particularly sarcoma, breast cancer and glioblastoma. Current cancer early detection strategies in adults are annual Magnetic Resonance (MR) whole-body and brain imaging. Here we report our single-centre experience in 75 adults over 12 years. WB-MRI detected 9 out of 17 cancers diagnosed throughout the study, (7/9 had stage 1/2 disease) with a negative predictive value of 97.4%. Benign incidental findings were identified in 27.4% of WB-MRI scans prompting 53 further imaging investigations. We discuss the high level of cancer exclusion but significant burden of additional tests with this strategy. (By Peter Sodde, https://jmg.bmj.com/content/early/2025/06/30/jmg-2025-110704 )