Colorectal Neoplasia Rates in Li-Fraumeni Syndrome

Individuals with Li-Fraumeni syndrome (LFS), a cancer predisposition syndrome caused by TP53 pathogenic germline variants (PGV), have an increased risk of colorectal cancer (CRC). However, limited data exist on colonoscopy metrics, including total neoplasia detection rates, in patients with LFS.

We conducted a retrospective cohort study of colorectal neoplasia incidence and characteristics in 663 individuals with LFS. We determined total neoplasia detection rate, adenoma detection rate (ADR), advanced ADR, serrated lesion detection rate (SDR), and CRC detection rate, stratified by age, sex, and PGV subtype, in 311 surveillance colonoscopies from 206 adults performed January 2019 to August 2024.

CRC was reported in 4.5% of 663 adults and 0.8% of 124 pediatric patients with LFS. Among 206 adults undergoing colonoscopy, total neoplasia detection rate, ADR, SDR, advanced precancerous polyp detection rate, and CRC detection rate were 37%, 27%, 9.3%, 4.5%, and 0.64%, respectively. Detection rates were similar between loss of function and hypomorphic PGVs. Adults aged 45-75 had higher total neoplasia detection rate, ADR, advanced ADR, SDR, and CRC detection rate than those aged 25-45. Male sex was associated with increased total neoplasia detection rate (53.7% vs 30.7%, P = 0.0004), ADR (41.2% vs 22.1%, P = 0.0013), and advanced ADR (7.5% vs 1.3%, P = 0.0105).

Patients with LFS have comparable ADR and higher SDR with average-risk adults despite earlier, more frequent surveillance, irrespective of TP53 PGV subtype. Our data support current recommendations for earlier and more frequent colonoscopy surveillance than average-risk guidelines, across LFS phenotypes.