ECE2020 Audio ePoster Presentations Pituitary and Neuroendocrinology (217 abstracts)
1Erasmus University Medical Center, Department of Internal Medicine, Section of Endocrinology, Rotterdam, Netherlands; 2Erasmus University Medical Center, Department of Radiology & Nuclear Medicine, Rotterdam, Netherlands; 3Erasmus University Medical Center, Department of Surgery, Rotterdam, Netherlands; 4Erasmus University Medical Center, Department of Pathology, Rotterdam, Netherlands; 5Amsterdam University Medical Centers, Department of Surgery, Amsterdam, Netherlands
Introduction: Pancreatic neuroendocrine neoplasm (pNEN) patients often present with locally advanced or metastatic disease. The objective response rate of peptide receptor radionuclide therapy (PRRT) in pNENs is 55%. Therefore, PRRT may be a possibility for patients who are not eligible for upfront curative surgery.
Aims: To assess the potency of PRRT to render locally advanced or oligometastatic pNENs resectable and to evaluate the effect of surgery after early PRRT on survival.
Material and Methods: A single-center retrospective analysis was performed on 50 pNEN patients, treated between 2000 and 2019 with 177Lu-DOTATATE with a neoadjuvant or downstaging intent. Patients had resectable, borderline resectable or unresectable locoregional disease and/or metastatic disease.
Results: After PRRT, 26 patients underwent surgery with curative intent. Surgical and non-surgical patients had equal tumor diameters and metastatic sites at baseline. Patients in the surgical group had more grade 1 tumors than those in the non-surgical group (P = 0.001) and more often completed the intended PRRT dose of 29.6 GBq (P = 0.007). In 54% and 46% of the surgical and in 21% and 63% of the non-surgical patients, best responses were partial response and stable disease, respectively (P = 0.02). One patient died due to surgical complications. Median progression free survival was 28 months for the non-surgical group and 68 months for the surgical group (P = 0.009). Median overall survival was 66 months for the non-surgical group compared to 177 months for the surgical group (P = 0.002).
Conclusions: This study shows the favorable long-term outcomes of pNEN patients that underwent surgery after neoadjuvant PRRT. Early PRRT followed by surgical evaluation is an option for patients with unresectable or oligometastatic pNEN.
Keywords: neoadjuvant, peptide receptor radionuclide therapy, neuroendocrine, pancreas, surgery.