Age-specific pancreatic cancer risk in Italian CDKN2A families

Background: Pancreatic cancer (PC) risk in carriers of germline CDKN2A pathogenic variants (PV) is among the highest, with a standardized incidence ratio (SIR) of 20 and cumulative incidence >20% by age 70 in Dutch cohorts, informing surveillance protocols with promising results in CDKN2A-positive families. Prospective, lifetime, variant-specific estimates are missing in Italy. Patients and methods: We assessed SIR and cumulative incidence of PC in 202 kindreds carrying germline CDKN2A PV, mostly melanoma-selected and followed for up to 25 years. Results: PC occurred in about one-third of families, with median age at diagnosis of 66 years. Compared with regional cancer registry PC incidence rates, SIR was 34.26 [95%CI= 27.12-42.7]. Cumulative incidence was <1% until age 52, 10% by 70, and 19% after 90. Variant-specific estimates were higher for E27X than G101W (SIR 38.68 and 31.17; cumulative incidence 22% and 18%, respectively). Conclusion: In this Italian cohort, SIR approached Dutch estimates, with similar cumulative incidence, but at older ages. Incorporating region-specific risk and age of onset may help tailor PC screening in high-risk individuals, improving efficacy, adherence and sustainability. Our data support the inclusion of all CDKN2A PV carriers in surveillance programs, starting not earlier than age 40.