Isolated lung metastases from pancreatic ductal adenocarcinoma (PDAC): Diagnostic and therapeutic challenges of a different disease.

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, mostly due to the high rate of distant dissemination. However, growing evidence shows that isolated lung recurrence or metastases (ILM) from PDAC are not only less common, but also correlated with a better prognosis. Lung-only recurrence after surgery occurs later in time and is associated with more favorable prognostic characteristics of the primary tumor. Moreover, recent findings suggest that this specific site of metastases is characterized by an immunologically "hot" microenvironment and a more favorable molecular profile that could possibly justify its clinical behavior. Thus, ILM from PDAC emerge as a distinct entity, that might also benefit from a different therapeutic approach, possibly with the integration of surgery and de-intensified chemotherapy regimens, especially in selected patients. In this review we delve into the current scientific evidence on the clinical and biological characteristics of isolated LM from PDAC, also focusing on concerns with their diagnostic process and the therapeutic options for the management of this subset of patients.