Are Staging Computed Tomography (CT) Scans of the Chest Necessary in Pancreatic Adenocarcinoma?

Background: There is no consensus on the use of chest imaging in pancreatic ductal adenocarcinoma (PDAC) patients. Among PDAC patients, we examined the use of chest computed tomography (CT) over time and determined whether the use of chest CT led to a survival difference or change in management via identification of indeterminate lung nodules (ILNs). Methods: Retrospective clinical data was collected for patients diagnosed with PDAC from 1998 to 2014. We examined the proportion of patients undergoing staging chest CT scan and those who had ILN, defined as ≥ 1 well-defined, noncalcified lung nodule(s) ≤ 1 cm in diameter. We determined time to overall survival (OS) using multivariate Cox regression. We also assessed changes in management of PDAC patients who later developed lung metastasis only. Results: Of the 2710 patients diagnosed with PDAC, 632 (23%) had greater than one chest CT. Of those patients, 451 (71%) patients had ILNs, whereas 181 (29%) had no ILNs. There was no difference in median overall survival in patients without ILNs (16.4 [13.6, 19.0] months) versus those with ILN (14.8 [13.6, 15.8] months, P = 0.18). Examining patients who developed isolated lung metastases (3.3%), we found that staging chest CTs did not lead to changes in management of the primary abdominal tumor. Conclusions: Survival did not differ for PDAC patients with ILNs identified on staging chest CTs compared with those without ILNs. Furthermore, ILN identification did not lead to changes in management of the primary abdominal tumor, questioning the utility of staging chest CTs for PDAC patients.