Mistletoe extract in patients with advanced pancreatic cancer: Health-related quality of life in a double-blind, randomized, placebo-controlled trial (MISTRAL)

BACKGROUND: Mistletoe extract is a widespread complementary therapy mainly used for quality-of-life improvement in cancer patients. Advanced pancreatic cancer is associated with poor quality of life and better therapies for symptomatic relief are highly needed. AIM: MISTRAL aimed to assess the impact of mistletoe extract on quality of life, body weight, observed costs and blood biomarkers in patients with advanced pancreatic cancer. DESIGN: MISTRAL was an investigator-initiated, phase III, randomized, double-blind, placebo-controlled, parallel-group, superiority, multicenter, clinical trial with a nested biomarker study. Registration EudraCT 2014-004552-64, NCT02948309. SETTING AND PARTICIPANTS: At 9 oncology centers, 290 participants were randomized to standard treatment (palliative chemotherapy or best supportive care) plus subcutaneous mistletoe extract or placebo. Main inclusion criteria were advanced pancreatic cancer, performance status 0-2, main exclusion criteria neuroendocrine pancreatic tumor. EORTC-QLQ-C30, EORTC-QLQ-PAN26, body weight, cost parameters and biomarkers were assessed from baseline up until 9 months. RESULTS: No statistically significant differences for quality of life and weight were evident between treatment arms. Parameters for observed costs for supportive and inpatient care (days at hospital, parenteral nutrition infusions, nutritional supplement drinks, number of visits of palliative home care teams, symptom-relieving medication) were similar in both arms. Thus, calculation of costs was not performed. No effect on explored biomarkers (differential blood count, lymphocyte subpopulations, C-reactive protein, albumin and Ca19-9) was found except for a statistically significant increase of eosinophils in the mistletoe arm without association to clinical effect. CONCLUSIONS: Since no benefit was observed, there is no clinical reason to recommend mistletoe extract in patients with advanced pancreatic cancer.