Pancreas Cancer Risk During Intraductal Papillary Mucinous Neoplasm Surveillance - A SEER-Based Comparison.

OBJECTIVE

To compare the incidence of pancreatic adenocarcinoma (PDAC) during surveillance for intraductal papillary mucinous neoplasm (IPMN) to a Surveillance, Epidemiology, and End Results (SEER) matched cohort.

BACKGROUND

IPMN are pre-malignant lesions and prescribed lifelong surveillance. Many still develop PDAC despite annual imaging, while others never demonstrate cyst progression. The true magnitude of PDAC risk attributable to IPMN remains unclear.

METHODS

Retrospective review of patients under surveillance for IPMN at a high-volume center was performed using an institutional cyst database which includes demographics, serial radiographic cyst features, and pathological outcomes. Standardized incidence ratio (SIR) for PDAC was derived from age and year matched SEER group compared to the study cohort.

RESULTS

Overall, 1494 patients underwent 11,107 scans with median surveillance of 55.3 months for 7,681 person-years at risk. Median age was 66 years, 64% were female, and median index cyst size was 1.4 cm. Cumulative incidence of malignancy at 60 months was 0.97% (CI:0.53%-1.70%). Compared to SEER population, PDAC risk was 10-fold higher (CI:7.2-15.6) during surveillance with 26 events (16 IPMN-HGD, 10 PDAC) compared to 2.44 expected. Highest risk was noted with MPD dilation ≥5 mm (SIR:26.5, CI:11-64), and BMI ≥30 (SIR:20.6, CI:11.4-37). Whereas IPMN ≤1 cm (SIR:3.28, CI:0.82-13.1), and age<60 (SIR:6.27, CI:1.58-24.9) were closest to the population risk. Cysts <3 cm and without MPD dilation or solid component (guideline-negative), had SIR:8.40 (CI: 5.15-13.7).

CONCLUSION

Risk of malignancy with IPMN is significantly higher than the general population but varies by demographics and cyst features. A personalized surveillance approach may improve early detection in high-risk patients and reduce imaging burden in low-risk groups.