Abstract B95: Is ethanol required for cyst ablation in patients with premalignant type pancreatic cysts?

Background: Mucinous pancreatic cystic lesions have the propensity to progress into pancreatic cancer. Currently radiographic surveillance or surgical resection is recommended for this premalignant type of cyst, both of which have significant limitations. Recently, endoscopic ultrasound-guided cyst ablation has emerged as an innovative and promising alternative treatment approach. Previous studies have shown that EUS-guided ethanol lavage of pancreatic cysts is safe and results in complete cyst resolution in 1/3 of patients. Subsequent studies demonstrated marked increases in rates of ablation with infusion of paclitaxel following ethanol lavage, which raises the question of whether alcohol is necessary for effective ablation. This is important, since ethanol extravasation is felt to have caused two complications in previous trials, abdominal pain and pancreatitis. This study hypothesizes that the removal of alcohol lavage prior to chemotherapy infusion will not impair ablation rates and will decrease complication rates. A secondary aim of this study is to assess whether a custom chemoablation cocktail tailored to pancreatic neoplasia (paclitaxel+gemcitabine) will improve ablation rates overall. Gemcitabine was chosen because it dilutes paclitaxel for injection and has been the standard in pancreatic cancer chemotherapy. Recently, the combination of paclitaxel and gemcitabine was shown to improve response rates and progression-free survival when compared with gemcitabine alone. Methods: Patients with mucinous or indeterminate type pancreatic cysts of 1-5cm’s without signs of malignancy were randomized to undergo either EUS-guided lavage with 80% alcohol or normal saline followed by infusion of 3 mg/ml paclitaxel + 19mg/ml gemcitabine (both arms). 9 patients were enrolled in this initial pilot study and evaluated post op, at 72 hours, with two week lab tests and by CT scan at 3, 6, and 12 months to assess response rates and for any complications. Results: The initial 9 patients of this trial (expected to have an N of 78 when complete) were randomized for this pilot study with 8 patients then able to be treated. Pancreatic cysts ranged in maximum diameter from 2.2cm to 3.8 cm (mean 2.9 cm). Location included body (n=4), head (n=2), neck (n=1) and tail (n=1). The overall reduction in cyst surface area was 67% at 3 months and 82% at 6 months. At 6 months size reduction was 81% in the alcohol infusion arm and 83% in the alcohol-free arm. Complications were mild abdominal pain (1) in the alcohol free arm (12.5%), moderate abdominal pain (1), and mild pancreatitis (1) in the alcohol arm (25%). Conclusion: The treatment of mucinous type pancreatic cysts with either alcohol or saline lavage followed by gemicitabine-paclitaxel infusion is feasible and safe in this limited pilot study. Initial results indicate that alcohol-free ablation does not impair ablation efficacy and is associated with fewer complications although the full sample size will be required to prove this hypothesis with any certainty. Citation Format: Matthew T. Moyer, Setareh Sharzehi, Charles E. Dye, Wafik El-Deiry, Thomas J. McGarrity, Abraham Mathew, Niraj Gusani, Raquel E. Davila, Brooke Ancrile. Is ethanol required for cyst ablation in patients with premalignant type pancreatic cysts? [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B95.