From:  Estradiol exposure and pancreatic cancer risk: convergent evidence from population-based incidence, pharmacovigilance, and tumor biology

 Standardized incidence ratios (SIRs) for pancreatic cancer following breast cancer diagnosis in SEER (1975–2022).

Latency after breast cancerObserved casesSIR (O/E)95% CIExcess risk*
12–59 months6461~0.92–1.08†~0.00
≥ 60 months2,1471.04~0.99–1.09†~0.18
Overall2,7931.031.00–1.070.15

Pancreatic cancer incidence was evaluated using SEER multiple-primary standardized incidence ratio (MP-SIR) methodology with a 12-month latency exclusion to minimize synchronous detection and surveillance bias. Expected counts were derived from age, calendar year, and registry-specific population rates. *: Excess risk per 10,000 person-years; † :exact CIs available from SEER output; shown approximately here for layout consistency.