RecruitingPhase 1Drug trialCBD for Breast Cancer Primary TumorsThis is a randomized placebo controlled partially blinded window of opportunity trial. A maximum of 84 patients with invasive breast cancer will be enrolled. Patients will be randomized 2:2:1:1 to either CBD low dose, CBD high dose, matching low dose placebo, or matching high dose placebo using permuted block randomization with random block sizes of 6 or 12. The time window between CBD or placebo initiation and surgery will be between 5 and 56 days.