Personalized screening strategies for R337H carriers: a retrospective cohort study of tumor spectrum in Li-Fraumeni syndrome adult carriers.

BACKGROUND

Li-Fraumeni Syndrome (LFS) is a predisposition associated with early onset malignant tumors caused by germline pathogenic variants in the gene. Although rare worldwide, LFS is prevalent in Southern Brazil due to the founder pathogenic variant R337H. Here, we assessed tumor patterns and temporal trends, cancer risk, and sex differences of adult R337H carriers and carriers of other LFS-associated variants.

METHODS

We retrospectively analyzed 708 adults, combining data from two sources: the Brazilian Li-Fraumeni Syndrome Study cohort and the NCI TP53 database. We assessed the clinical characteristics of 303 adults with R337H and compared them with those associated with 405 carriers of other TP53 variants.

FINDINGS

R337H carriers, compared to adult carriers of other variants typical of LFS, had a lower cumulative risk of developing cancer (54% vs 78%). Female R337H carriers were at a higher risk than males (65% vs 30%) and had a higher risk of developing a second primary cancer, underscoring a strong sex bias not observed in carriers of other variants. The most common cancers were breast cancer and soft tissue sarcoma in females, and soft tissue sarcoma and prostate cancer in males. Common second malignancies were breast cancer in females and lung cancer in males.

INTERPRETATION

This study shows that R337H is associated with a lifetime risk of multiple LFS-spectrum cancers but with incomplete penetrance, particularly in males. Our findings suggest that R337H carriers would benefit from tailored surveillance and risk reduction strategies.

FUNDING

São Paulo Research Foundation, Conselho Nacional de Pesquisa, and Hospital Sírio-Libanês.