Bergamot essential oil (BEO) aromatherapy has not been researched as a cancer treatment. It has been investigated as an adjunct to stem cell therapy in children as a possible mitigator for pain, anxiety, and nausea and was found to be worse than no treatment.[1]
While several individual constituents of BEO have been researched as cancer treatments — for example, bergapten and bergamottin, phototoxic furocoumarins present in small quantities in BEO and in other citrus fruits, have been researched in vitro[2][3] — there is no evidence supporting the use of BEO as a cancer treatment.