Clinical benefit of locoregional therapy for oligometastasis after surgery for pancreatic cancer: a single center retrospective study

Background The prognosis of patients with pancreatic cancer (PC) is generally poor. However, favorable outcomes have recently been reported in selected patients with metastatic PC who receive multidisciplinary treatment. Oligometastasis (OM) represents a limited metastatic state and may be associated with better prognosis than multiple metastases (MM). The clinical role of locoregional therapy (LT) for postoperative OM remains unclear. Methods We included all consecutive patients with pancreatic malignancies who underwent macroscopically curative resection between 2013 and 2018. Patients with postoperative recurrence were divided into OM and MM groups. Survival outcomes and treatment after recurrence were compared between the groups. Results In total, 150 patients were evaluated. Postoperative recurrence was classified as OM in 29 patients and MM in 71 patients. Among the patients with OM, 10 underwent LT. Overall survival and survival after recurrence were significantly longer in the OM group than in the MM group. Among patients with OM, those who underwent LT showed longer survival after recurrence than those who received chemotherapy alone. Conclusions Patients with postoperative OM after pancreatic cancer surgery showed more favorable survival outcomes than those with MM. In carefully selected patients with postoperative OM, LT combined with chemotherapy was associated with longer survival after recurrence. However, because of the retrospective single-center design, small number of treated patients, and potential selection bias, LT should be regarded as a possible treatment option rather than an established therapeutic strategy.