title: A randomized controlled trial of oral melatonin supplementation and breast cancer biomarkers.
abstract: We examined compliance with and the effects of melatonin supplementation on breast cancer biomarkers (estradiol, insulin-like growth factor I (IGF-1), insulin-like growth factor-binding protein 3 (IGFBP-3), and the IGF-1/IGFBP-3 ratio) in postmenopausal breast cancer survivors. In a double-blind, placebo-controlled study, postmenopausal women with a prior history of stages 0-III breast cancer who had completed active cancer treatment (including hormonal therapy) were randomly assigned to either 3 mg oral melatonin (n = 48) or placebo daily for 4 months. Plasma samples were collected at baseline and after the completion of the intervention. The primary endpoints were compliance and change in estradiol and IGF-1/IGFBP-3 levels. Ninety-five women were randomized (48 to melatonin and 47 to placebo). Eighty-six women (91%) completed the study and provided pre- and postintervention bloods. Melatonin was well tolerated without any grade 3/4 toxicity and compliance was high (89.5%). Overall, among postmenopausal women with a prior history of breast cancer, a 4-month course of 3 mg melatonin daily did not influence circulating estradiol, IGF-1, or IGFBP-3 levels. Compliance was comparable between the two groups. Short-term melatonin treatment did not influence the estradiol and IGF-1/IGBBP-3 levels. Effects of longer courses of melatonin among premenopausal women are unknown. Low baseline estradiol levels in our study population may have hindered the ability to detect any further estradiol-lowering effects of melatonin.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115, USA. eva.schernhammer@channing.harvard.edu
authors.forename: E S
authors.initials: ES
authors.lastname: Schernhammer
authors.forename: A
authors.initials: A
authors.lastname: Giobbie-Hurder
authors.forename: K
authors.initials: K
authors.lastname: Gantman
authors.forename: J
authors.initials: J
authors.lastname: Savoie
authors.forename: R
authors.initials: R
authors.lastname: Scheib
authors.forename: L M
authors.initials: LM
authors.lastname: Parker
authors.forename: W Y
authors.initials: WY
authors.lastname: Chen
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000008:administration & dosage*; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood*; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism; D008550:Melatonin / Q000008:administration & dosage*; D008875:Middle Aged
chemical_list: D000975:Antioxidants; D014408:Biomarkers, Tumor; C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D008550:Melatonin