Esters of tocotrienols having pharmacological activities pertinent to the treatment of breast cancer and other forms of cancer are disclosed herein. Among those compounds is (Z)-4-oxo-4-((R)-2,5,7,8-tetramethyl-2-((3E,7E)-4,8,12-trimethyltrideca-3,7,11-trienyl)chroman-6-yloxy)but-2-enoic acid. Tocotrienol esters were used to inhibit the growth and migration of +SA mammary epithelial cells and highly metastatic human breast cancer MDA-MB-231 cells respectively.