Nabilone Effect on the Attenuation of Anorexia, Nutritional Status and Quality of Life in Lung Cancer Patients

Overview

Anorexia is common symptom in cancer patients and is associated with increased morbidity and mortality. However timely detection with objective tools is necessary to establish the diagnosis of anorexia and to assess the magnitude of change over time. The anorexia pathophysiology is not clearly understood and treatment options are limited. Anecdotal historical benefits of smoking marijuana on nausea, pain and anorexia led to studies with marijuana and synthetic cannabinoids from Δ-9-tetrahydrocannabinol, the main active agent in marijuana. The endogenous cannabinoid system with its receptors CB1 and CB2 regulate appetite in four functional levels: (1) limbic system (hedonistic quality), (2) hypothalamus (appetite stimulant), (3) intestinal, and (4) tissue adipose. Nabilone, a synthetic analogue of THC approved in Mexico for nausea and vomiting induced by chemotherapy is also used in palliative care units for clinical improvement in increased appetite patients in terminal stages, however, there are no clinical trials demonstrating this benefit.

Background: Lung cancer is the leading cause of cancer death in Mexico and the world. Malnutrition is often associated with this type of cancer appearing in about 40-50% of patients the diagnosis made, affecting the quality of life and prognosis, as well as increased toxicity to cancer treatment. Cancer anorexia is characterized by loss of appetite and is the main cause of reduced food consumption in lung cancer patients. Anorexia occurs in up to 25% of cases. Unfortunately, current therapies available to treat anorexia and / or cachexia associated with cancer provide only partial results, mainly because the intervention is delayed and the development of an early and effective intervention is still looking. In most patients, malnutrition is associated with a hyporexia secondary to the production of pro-inflammatory cytokines such as tumor necrosis factor (TNF), leading to an increase in metabolism and appetite loss. Nabilone is a synthetic cannabinoid derivative that is widely used in oncology for its antiemetic and adjuvant effect of pain. Although widely used for the treatment of anorexia in palliative care, no randomized clinical trials demonstrating an effect on cancer-associated anorexia, however, in animal models, stimulation of cannabinoid receptors, mainly through CB1 receptor can modulate hypothalamic circuits in the brain stem, which in turn regulate food intake and satiety. Moreover cannabinoids are able to block the effects of TNF in the nervous system, which is associated with appetite changes in cancer patients. Additionally, agonists of cannabinoid receptors attenuated weight loss in murine models of anorexia. Additionally, to diagnosis anorexia The Anorexia-Cachexia scale (A/CS-12) from The Functional Assessment of Anorexia-Cachexia therapy (FAACT) questionnaire relates differences in symptoms and severity, assigning a value of 0-4 for each of 12 items. A 2010 consensus of special interest group of CACS from ESPEN (The European Society for Clinical Nutrition and Metabolism) in order to unify criteria, proposed that a score ≤24 of the A/CS-12 would be enough to establish a diagnosis of anorexia. The administration of Nabilone in patients with anorexia associated with Non-Small Cell Lung Cancer (NSCLC) is expected to increase appetite, nutritional status and quality of life. Methods: randomized double-blind clinical trial assessing Nabilone effect in non-small cell lung cancer (NSCLC) patients with unresectable stage III/IV NSCLC, ECOG performance status (ECOG PS) 1-2 and anorexia (main criteria: score of Anorexia Cachexia scale (AC/S-12) from Functional Assessment of Anorexia Cachexia Therapy ≤24). Patients are randomized to Nabilone at 0.5mg to 1mg, or placebo, given daily orally for 8 weeks. Changes are evaluated from baseline to week 2, 4, and 8. Time Assessment Dose T0 Baseline 0.5mg T1 2 weeks 1 mg T2 4 weeks 1 mg T3 8 weeks 1 mg Sample size: To determine the sample size is considered the effect of cannabinoid (dronabinol, 2.5 mg / 22 days) in appetite in cancer patients by a difference in proportions of 34% more than placebo, requiring 32 patients per group plus 20% of loss gives us a total of 39 patients per group, with a power of 90% and an α of 0.05