Outcomes following pancreatic metachronous metastatic renal cell carcinoma resection and comparisons with pancreatic neuroendocrine tumours

Background: The aim of this study was to investigate perioperative findings ofpancreatic metachronous metastatic renal cell carcinoma (PmmRCC) and pancreatic neuroendocrine tumours and long-term survival outcomes of PmmRCC in a high-volume single centre. Methods: : The clinicopathological data of 29 PmmRCC patients treated in our centre from January 2013 to December 2021 were collected retrospectively. We analysed demographics, diagnoses, surgical information, 30-day morbidity data, and long-term survival outcomes. Preoperative characteristics and diagnosis were also compared with patients who had pancreatic neuroendocrine tumours during the same period in our centre. Results: : PmmRCC patients were older ( P < 0.001), less symptomatic ( P = 0.017), more likely to appear hyper-vascular in imaging studies ( P = 0.023), had more multiple nodules in the pancreas ( P = 0.002), and had a larger tumour size ( P = 0.046) than patients with pancreatic neuroendocrine tumours. No metastatic lymph nodes were detected, and 34.5% of PmmRCC cases were preoperatively misdiagnosed. At the last follow-up, 13 patients had tumour progression, and five died (two within 30 days postoperatively). Conclusions: : Clinical characteristics and imaging results exhibited some differences between PmmRCC and pancreatic neuroendocrine tumours. Patients could benefit from PmmRCC surgery with an acceptable co-morbidity. No metastatic lymph nodes were found, even though suspected on imaging examination or detected intraoperatively. However, elucidating the surgical role and necessity of lymphadenectomy requires larger-sample studies.