Smoking Is Not Associated with Severe Dysplasia or Invasive Carcinoma in Resected Intraductal Papillary Mucinous Neoplasms

Introduction: Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are precursor lesions that progress to invasive cancer through progressively worsening dysplasia. Although smoking is an established risk factor for pancreatic adenocarcinoma, potential associations with IPMN grade of dysplasia remain unclear. Methods: Pancreatic resections for IPMN from 1995 to 2013 were retrospectively reviewed. A total of 446 patients in which the smoking status was documented were identified. Results: Smoking history was positive in 47 % of patients. Of smokers, 50 % had branch-duct, 14 % had main-duct, and 36 % had mixed-type IPMN. Patients with main-duct IPMN were more commonly smokers (65 %), compared to smoking history in 46 % with mixed and 44 % with branch-duct IPMN (p = 0.03). High-grade dysplasia occurred in 25 % of smokers and 21 % of nonsmokers (p = 0.32), and invasive carcinoma in 25 % of smokers and 25 % nonsmokers (p = 0.95). On multivariate analysis, duct size was independently associated with high-grade dysplasia (OR = 3.17, 95 %CI = 1.79–5.64, p < 0.001). Presence of mural nodules (OR = 3.34, 95 %CI = 1.82–6.12, p < 0.001), duct size (OR = 3.87, 95 %CI = 2.21–6.75, p < 0.001), and symptoms (OR = 7.10, 95 %CI = 3.80–13.08, p < 0.001), but not smoking history (OR = 1.10, 95 %CI = 0.64–1.88, p = 0.73), were independent predictors of invasive carcinoma. Median overall survival was 70 months for smokers and 88 months for nonsmokers (p = 0.68). Conclusion: Positive smoking history correlated with duct type classification but does not appear to be a risk factor for harboring high-grade dysplasia or invasive carcinoma in IPMNs.