Phytocannabinoids for the Treatment of Chronic Chemotherapy-Induced Peripheral Neuropathy in Breast and Colon Cancer Survivors

PRIMARY OBJECTIVE: I. Assess the ability of CBD and THC:CBD to reduce CIPN symptoms as compared to placebo using the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group (FACT/GOG)-Neurotoxicity (Ntx) subscale among breast and colon cancer survivors. SECONDARY OBJECTIVES: I. Evaluate the impact of CBD and THC:CBD as compared to placebo on quality of life using the Functional Assessment of Cancer Therapy General (FACT-G) among breast and colon cancer survivors with chronic CIPN. II. Document the utilization of neuropathic and pain medications by cancer patients with chronic CIPN during treatment with CBD and THC:CBD as compared to placebo. III. Describe the side effects of CBD and THC:CBD treatment. EXPLORATORY OBJECTIVES: I. Assess neurological symptoms and function with the Neuropathy Pain Scale (NPS), Total Neuropathy Sccore - clinically based (TNSc), quantitative sensory testing (QST), Grooved Pegboard Test (GPT), and Unipedal Stance balance test (USBT) among patients with chronic CIPN treated with CBD and THC:CBD as compared to placebo. II. Evaluate for predictors of response to CBD and THC:CBD for chronic CIPN. OUTLINE: This is a dose-escalation study of CBD and THC. Patients are randomized to 1 of 3 arms. ARM I: Patients receive CBD orally (PO) on study. ARM II: Patients receive CBD PO + THC PO on study. ARM III: Patients receive placebo PO on study.