Multidisciplinary Treatment of Pancreatic Neuroendocrine Tumors - Episode 3
The liver is the predominant metastatic site for patients with neuroendocrine tumors (NETs) and represents as a unique challenge for systemic and localized therapies. Control of hepatic metastases is essential, since liver failure can be as serious as the hormonal symptoms caused by the disease itself, notes Rodney Pommier, MD. Moreover, hormonal symptoms decrease dramatically with proper cytoreduction, further emphasizing the importance of local control.
If plausible, all of the sites of disease should be fully resected, states Pommier. However, unlike other kinds of tumors where the criteria for eligibility of liver resection are very strict, the threshold for debulking remains unclear for patients with pancreatic NETs. In most cases, the typical guidelines for liver resection are inappropriate when assessing patients with NETs, since many patients with pancreatic NETs have multiple metastases or bilobar metastases that preclude them from being candidates for liver-directed surgery.
When considering patients with NETs and liver metastases for surgery, extrahepatic involvement should not prevent resection, Pommier advises. Moreover, since these tumors do not infiltrate, enucleation is an option for a larger number of tumors, which results in very little blood loss and minimal loss of hepatic parenchyma.
If the tumor is located in an unfavorable place in the pancreas, it has the potential to obstruct the bile duct, portal vein, mesenteric vessel, or splenic vein, making it critical to resect if possible, states J. Philip Boudreaux, MD. Without resection, patients may face serious problems, such as recurring bleeding gastric varices or recurrent gastrointestinal bleeds. Patients may suffer extreme complications from gut failure due to ischemic intestines from vessels being squeezed.
When considering hepatic therapies, the sequence of treatment is important, specifically for embolization and surgery, comments Boudreaux. It is vital to perform embolic therapy before a Whipple procedure, to prevent encountering complications.