This review emphasizes the following critical topics, selected as likely closest to affecting standards of breast cancer care and representative of the myriad range of neurotransmitter impacts on breast cancer: epinephrine, norepinephrine, and adrenergic activation; acetylcholine; serotonin; dopamine; histamines; gamma-aminobutyric acid (GABA); and neurotensin; and drugs, such as beta blockers and monoamine oxidase inhibitors, impacting pathways mediated by these neurotransmitters (Table 3). Here, NTS is linked to breast cancer.