Chronic immunosuppression does not potentiate the malignant progression of mucinous pancreatic cystic lesions.

BACKGROUND

Premalignant mucinous pancreatic cystic lesions (mPCLs) are increasingly identified.

AIMS

In this study, we aim to assess the effect of selected immunosuppressive therapies on the progression of mPCLs, including side-branch intraductal papillary mucinous neoplasms and mucinous cystic neoplasms.

METHODS

We performed a retrospective cohort study of patients with mPCLs diagnosed over a 24-year period who received chronic immunosuppression. Controls were matched on age at cyst diagnosis (±11 yrs) and cyst size (±8 mm). Measured outcomes included increase in cyst size, development of "worrisome features" as defined by consensus guidelines, progression to malignancy, and rate of surgical resection.

RESULTS

39 patients (mean age 60 yrs) with mPCLs were on immunosuppression. Leading indications for immunosuppression were solid organ transplant (n = 14), inflammatory bowel disease (n = 6), and rheumatoid arthritis (n = 5). 33% were on biologics, 77% on antimetabolites and 79% on multiple medications. Mean cyst size increased from 12.6 mm to 17.8 mm over a median of 16.5 months. 6 patients elected for surgical resection, and none ultimately developed malignancy. 26 cases with follow-up were matched to control subjects, with no significant differences among cases and controls in initial cyst size (12.8 mm vs 11.9 mm, P = 0.69), mean size increase (6.9 mm vs 5 mm, P = 0.47), follow-up interval (24.3 months vs 21.5 months, P = 0.44). No significant differences in the rate of worrisome features, malignancy, or surgical resection.

CONCLUSIONS

Patients with mPCLs exposed to immunosuppressive medications did not have higher rates of malignancy or development worrisome features in the short term. This suggests that patients with mPCLs can be initiated or maintained on these agents without changes to surveillance practices.