What is the Significance of Indeterminate Pulmonary Nodules in Patients Undergoing Resection for Pancreatic Adenocarcinoma?

The significance of indeterminate pulmonary nodules (IPNs) in patients undergoing resection of pancreatic ductal adenocarcinoma (PDAC) is unknown. We sought to define the prevalence and impact of IPN in such patients. We studied all patients who underwent surgical resection of PDAC between 1980 and 2013. IPN was defined as a parts per thousand yen1 well-defined lung nodule(s) less than 3 cm in diameter. Survival was assessed using univariate and multivariate Cox models. Of the 2306 resected patients, 374 (16.2 %) had a preoperative chest computed tomography (CT) scan. Of these patients, 183 (49 %) had a parts per thousand yen1 IPN. Demographic and clinicopathological characteristics were similar among patients with or without IPN (all P > 0.05). Median survival was comparable among patients who did (15.6 months) or did not (18.0 months) have IPN (P = 0.66). Of the 183 patients with IPN, 29 (16 %) progressed to clinically recognizable metastatic lung disease compared to 13 % without IPN (P = 0.38). The presence of > 1 IPN was associated with the development of lung metastasis (relative risk 1.58, 95 % CI 1.03-2.4; P = 0.05). However, lung metastasis was not associated with survival (P = 0.24). An IPN proved to be a lung metastasis in only one of six patients with PDAC undergoing surgical resection in this study. Survival was not impacted, even among patients who developed lung metastasis. Patients with PDAC who have IPN should not be precluded from surgical consideration.