Long-term recurrence of PDAC after resection for IPMN: A narrative review of the literature on clinical and biologic predictors.

Recurrence of IPMNs after surgical resection is defined as the reappearance of new cystic lesions, invasive carcinoma, or metastases, either in the remnant pancreas or other distant sites. The median 5-year cumulative incidence of residual pancreatic lesions is 10 % (range, 0-21 %) and this risk continues to increase even after five years, especially in patients with the presence of HGD at first surgery and a family history of pancreatic ductal adenocarcinoma (PDAC). The management algorithm for all IPMNs is described in the latest guidelines on IPMNs; the patient's general condition, comorbidities, and life expectancy should be considered as well in the surgical decision. All patients operated for IPMN, have a risk of developing metachronous pancreatic lesions, which may require further surgery. Therefore, postoperative surveillance should be continued until the patient is surgically fit. The primary objective of this review is to evaluate the current scientific evidence regarding the management and surveillance strategies in patients who have undergone surgery for IPMN. Secondarily, we assessed the definitions of recurrence after surgery and explored the clinical, pathological, and biomolecular factors which may influence the biologic behavior of IPMNs. The optimal surveillance strategy for resected IPMN remains a topic of ongoing debate. The presence of an enlarging mass, the increase of ductal diameter, extrapancreatic disease observed during postoperative CT scans were previously taken into account as possible recurrence indicators. Additionally, positive resection margins, tumor invasiveness, and lymph node involvement were previously correlated with recurrence, while the role of molecular biomarkers still needs to bevalidated. This underscores the importance of rigorous, long-term follow-up, with multimodal approach as recurrent IPMNs can be detected even more than five years post-surgery.