The Results of Surgery for Renal Cell Carcinoma Metastases in the Pancreas

Study design. The study is a single-center study and includes all patients from the age of 18 who underwent a pancreatic resection due to metastasis from RCC from 1. January 2011 to 31. December 2021. Patients, who underwent additional pancreatic resection after surgery for metastatic RCC, were excluded. The follow-up period ended 31. December 2022.

Data collection. Data are collected from a prospectively maintained database of pancreatic operations, from the electronic hospital record systems Orbit and EPIC, the Danish National Pathology Data Registry, and from the National Register of Death. All Danish Nationals have a unique Central Person Registration number that enables searching of health data.

Outcome. Extracted data included patient demographics, date, and site of nephrectomy, Leibovich score, type of pancreatic resection, 30-days postoperative complications according to the Clavien-Dindo classification system, procedure specific complications (pancreatic fistula or biliary leak) according to the International Study Group on Pancreatic Surgery (ISGPS), pathology of resected pancreatic specimen. Postoperative data included time and site of disease recurrence after pancreatic resection, disease free survival (DS) and overall survival (OS). The postoperative follow-up included standard imaging surveillance with computed tomography scan (CT) of the chest and abdomen at specific intervals depending on the Leibovich score.

Statistics. Clinicopathologic characteristics were summarized using descriptive statistics. Data are presented as median and range if not otherwise stated. Categorial data are presented as numbers or percentage and were analysed with Fisher's exact test. The Kaplan-Meier method was used to estimate survival. Post-pancreatectomy survival was defined as date of pancreatic resection to death. Post-pancreatectomy disease free survival was defined as the median time from the date of pancreatic resection to the date of detection of recurrence of disease, expressed in months. Statistical analysis was performed using GraphPad Version 9.5.1 La Holla, CA. The study was reported according to the STROCSS guidelines.

Ethics The study is a register study and was conducted in accordance with the principles stated in the Declaration of Helsinki. No approval was required according to the Danish National Health Board. The use of register data followed the General Data Protection Regulation of the European Union and was approved by the Danish Data Protection Agency (RH -2015-07, nr. 03616) and patients' consent.