To investigate the clinical indications, methods and prognosis of conversion therapy for pancreatic neuroendocrine neoplasm (pNEN).

Clinical data of 1 pNEN patient with local progression complicated with liver metastasis admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine in January 2021 were retrospectively analyzed. The 49-year-old male patient was admitted to hospital due to "a space-occupying liver lesion during physical examination for more than20 d". Physical examination showed no yellow coloration of the skin and sclera, the abdomen was flat and soft, and no mass was palpable. Preoperatively, tumor biomarkers were detected negative. MRI showed a huge tumor in the head of the pancreas, approximately 91 mm×49 mm×95 mm in size, the lesion was significantly enhanced, and a nodule with abnormal signal, with a maximal diameter of 20 mm, was detected in segment Ⅳof the liver. Puncture biopsy prompted the diagnosis of pNEN. Finally, the diagnosis of pNEN with local progression complicated with liver metastasis was confirmed. Preoperatively, oral intake of sulfatinib ata dose of 300 mg was given daily for 2 months. After written informed consent was obtained from the patient and preoperative preparation was made, he underwent total pancreatectomy combined with splenectomy and radiofrequency ablation of liver metastasis under general anesthesia on April 27, 2021.

At2 months after preoperative conversion therapy, partial remission (PR) was evaluated, and primary lesion and liver metastasis were significantly mitigated. Postoperative pathological examination showed G2 pNEN. Immunohistochemistry showed CK(AE1/AE3)(+), Syn(+), CgA(+) and Ki-67 10%(+). Sulfatinib treatment was further delivered after operation. During postoperative 10-month follow-up, enhanced MRI of the liver showed multiple metastases in the liver. PR was evaluated after continuous treatment with octreotide acetate-loaded microspheres for 2 months. The patient was found to be in a disease-free status until the paper submission.

Preoperative sulfatinib conversion therapy contributes to down-grading pNENs with local progression complicated with liver metastasis and improving the complete resection rate. For patients with postoperative liver metastasis and recurrence, sulfatinib combined with octreotide acetate-loaded microspheres can effectively control disease progression and enhance clinical prognosis of patients.