Screening with whole-body MRI (WB-MRI) in pediatric patients with Li Fraumeni syndrome (LFS).

Abstract

10071 Background: LFS is a rare hereditary cancer syndrome characterized by a high risk of developing a wide range of malignancies. Germline mutations in the tp53 gene confer approximately a 12-fold risk of developing cancer by age 20. Given the potential for diverse malignancies, cancer surveillance in LFS patients is challenging. We piloted the use of WB-MRI for pediatric LFS patients as a cancer screening tool. Methods: Eligibility included: documented tp53 mutation, or obligate carrier status based upon family history/genetic testing, and no recent cancer diagnosis. WB-MRI was performed as a research test, in conjunction with recommended clinical screening based upon family history and clinician recommendation. Our primary aim was to determine the feasibility (defined as 87% completion rate) of obtaining two planned annual MRI scans in 15 pediatric LFS patients. Our secondary aim was to calculate the incidence and describe the characteristics of primary cancers detected. Results: Nine pediatric patients from 5 families have been enrolled and all have successfully completed one WB-MRI. Seven patients were known carriers, and 2 underwent genetic testing in order to enroll in the study. Median age was 12 years, range 6 to 15. Scan time was 60-90 minutes and 2 patients required anesthesia with propofol. There were no acute scan complications. Six of the 9 (67%) scans demonstrated incidental findings (T2 cerebral cortex abnormality, L5-S1 synovial cyst, thoracic syrinx, T12 hemangioma, 2 ovarian cysts, and degenerative disc disease). Only one patient underwent a dedicated follow-up imaging study for an abnormality on WB-MRI. None of the patients required biopsy. All patients had normal screening laboratory work. These results are being presented early to foster collaboration. Conclusions: All patients enrolled on our study tolerated WB-MRI; none were diagnosed with a new malignancy. Although preliminary, our results to date are in contrast to previous reports documenting a high incidence of cancers detected during screening of LFS patients. WB-MRI may be a promising approach to screening; a large multi-center trial will be needed to determine its efficacy in detecting incident cancers and true test characteristics.