Efficacy and safety of standardized allergen-removed Rhus verniciflua Stokes extract in patients with advanced or metastatic pancreatic cancer: A Korean single-center experience

Background: Pancreatic cancer has the worst prognosis because of poor response to conventional therapy. We investigated the clinical feasibility of the standardized allergen-removed Rhus verniciflua Stokes (aRVS) extract as a potential therapeutic agent for advanced or metastatic pancreatic cancer. Patients and Methods: From July 2006 to June 2010, patients with advanced or metastatic pancreatic adenocarcinoma were checked in our institution. After applying inclusion/exclusion criteria, 42 patients were eligible for the final analysis. Overall survival, clinical benefit and adverse events of these patients treated with aRVS in the aftercare period were determined. Results: In May 2011, 39 patients had died and the remaining 3 patients were alive with evidence of disease. The mean RVS administration period was 3.86 months (95% confidence interval 2.52-5.20). The median overall survival for the entire population was 7.87 months (95% confidence interval 5.14-10.59), and the 1-year survival rate was 26.2%, which is compatible with external controls. Using univariate and multivariate analyses, aRVS treatment including performance status and prognostic index significantly affected overall survival. A clinical benefit response was also shown by aRVS treatment which was not dependent on concurrent chemotherapy. Adverse reactions to aRVS treatment were mostly mild and self-limiting. Conclusions: The standardized aRVS extract might be beneficial for patients with advanced or metastatic pancreatic cancer since it positively affected overall survival and clinical symptoms without significant adverse effects.