Neuroendocrine Tumors (NETs) are neoplasms (approximately 1% of the neoplasms of the pancreas) that tend to be more benign than regular pancreatic cancer. The biological behavior of Neuroendocrine Tumors (NETs) depends on their malignancy grade (e.g., Grades 1, 2, 3), which is defined by the Ki-67 index. CT- and MRI scans are and will be the basis of the diagnosis. Nowadays, gallium-68 somatostatin receptor scintigraphy is used for increased diagnostic accuracy when NETs need to be detected in other parts of the patient’s body. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is used when a biopsy needs to be performed for NETs; however, it is not always necessary in patients with NETs initially considered resectable.

In the case of NETs, close collaboration among physicians of different specialties is required, as in most pancreatic conditions. This is exactly what our team does too. According to the latest guidelines, treatment is not required for patients with low-grade and non-functional NETs (smaller than 2cm) who have been incidentally diagnosed without suspicious imaging findings. These patients should be monitored through annual CT or MRI scans to ensure that potential changes in the size or the characteristics of NETs are detected on time. 

However, in patients with metastases that cannot be resected initially or in patients with locally advanced pancreatic disease (peripancreatic vascular invasion), neoadjuvant chemotherapy and/or treatment with somatostatin receptor inhibitors (“hormone therapy”) shall be administered preoperatively to shrink the tumor and metastases thus allowing us to perform pancreatectomy and metastasectomy.

Radical primary tumor resection (R0 resection - margin negative resection) is the basis of the surgical treatment of NETs, as it eliminates or minimizes recurrence rates. Therefore, enucleation (local resection of the tumor) is only recommended for superficial and low-grade NETs that are smaller than 2cm. If enucleation is not considered safe or oncologically sufficient, pancreaticoduodenectomy (Whipple procedure) or peripheral pancreatectomy with or without splenectomy must be performed. Our team performs this surgery often laparoscopically or robotically.

Surgical treatment for metastatic disease 

Metastases in patients with NET require aggressive treatments as opposed to metastases in patients with regular pancreatic cancer. The liver is the most common metastatic site (approximately 40% of the cases). When liver metastases are resectable, the patient may undergo hepatectomy with simultaneous pancreatectomy. When multiple liver metastases are present, and both lobes are involved, not all of them may be resected, as this would lead to a significant reduction of the liver and its functional capacity. In such cases, our team moves forward with the resection of as many metastases as safely possible. Remaining metastases undergo local ablation with the use of radiofrequency ablation (RFA) or the use of microwave ablation (MWA) during surgery and the ultrasound guidance of a specialized interventional radiologist. Today, the five-year postoperative survival rate is 77-93%. The postoperative survival rate in patients with resectable liver metastases is 41-100%.