Interventional Therapy for Pancreatic Cancer

Palliative therapy and primarily chemoradiotherapy are the mainstream treatments in patients with locally advanced or metastatic pancreatic cancer (PC). Conventional endoscopy and endoscopic ultrasound (EUS)-guided interventional therapy has emerged as an important procedure for PC management. In this review, the progress in conventional endoscopy and EUS for PC management is discussed.

For local palliative therapy against PC, EUS-guided fine needle injection (FNI) could deliver different kinds of agents, such as radioactive seeds and fiducials. Although their feasibility and safety have been proven, the long-term efficiency of EUS-FNI is still not established. For pain, EUS-celiac plexus neurolysis (CPN) is effective. However, CPN can only relieve the pain to a limited degree, with short duration. Endoscopy-guided stent placement is the preferred strategy for biliary and duodenal obstruction. Plastic and metal stents are equally effective for the relief of obstructive jaundice. The functional times of metal stents are longer than those of a plastic stent.

For biliary obstruction, a metal stent is the first choice. The long-term efficiency of EUS-FNI still needs further study.

Endoscopy and EUS-guided interventions have gradually become the mainstream method for local treatment of PC due to mini-invasiveness and real-time observation. PC is the second most common gastrointestinal malignancy and the sixth leading cause of cancer mortality in the United States, leading to about 4.0% of all cancer deaths [Siegel et al: CA Cancer J Clin 2014;64:9-29]. The only curative approach for patients with PC is surgical resection, but unfortunately 80-90% of patients have a surgically inoperable disease, with 53% having local metastases at the time of diagnosis [Weinberg et al: Oncology (Williston Park) 2015;29:809-820, 886]. Therefore, palliative therapy and primarily chemoradiotherapy are the mainstream of treatment in patients with locally advanced or metastatic PC. Although overall survival has improved from 6 to 8.5-11 months (some of them even survived for a year or more), the overall survival rate has not improved, and the 5-year survival is less than 4% [Weinberg et al: Oncology (Williston Park) 2015;29:809-820, 886; Greenlee et al: CA Cancer J Clin 2001;51:15-36; Zhang et al: Gastroenterol Res Pract 2016;2016:8962321]. Hence, it is crucial to develop more effective local treatment strategies for tumor tissue and symptom palliation. At present, endoscopy has gradually become the mainstream method for local treatment of gastrointestinal cancer due to mini-invasiveness and real-time observation. Conventional endoscopy can be used to manage the complication caused by PC, including endoscopic biliary stent placement for obstructive jaundice, and duodenal stent placement for duodenal obstruction. In addition, in those cases in whom obstructive jaundice failed to be relieved by endoscopic biliary stent placement, EUS-guided biliary drainage has emerged as an alternative procedure. Furthermore, antitumor agents can be delivered into tumor tissue or celiac plexus directly under interventional EUS guided to manage the tumor or the pain caused by the tumor. In this review, the progress in conventional endoscopy and EUS for PC management is discussed.