title: A pilot study comparing the effect of flaxseed, aromatase inhibitor, and the combination on breast tumor biomarkers.
abstract: Use of complementary approaches is common among breast cancer survivors. Potential interactions between aromatase inhibitors (AI) and high phytoestrogen foods, such as flaxseed (FS), are not often described. We conducted a pilot 2 × 2 factorial, randomized intervention study between tumor biopsy and resection, in 24 postmenopausal women with estrogen receptor positive (ER+) breast cancer, to assess the effects of FS and anastrozole, and possible interactions between them, on serum steroid hormone and tumor-related characteristics associated with long-term survival (Roswell Park Cancer Institute, 2007-2010). The effect of each treatment vs. placebo on outcomes was determined by linear regression adjusting for pretreatment measure, stage, and grade. Although not statistically significant, mean ERβ expression was approximately 40% lower from pre- to postintervention in the FS + AI group only. We observed a statistically significant negative association (β ± SE -0.3 ± 0.1; P = 0.03) for androstenedione in the FS + AI group vs. placebo and for DHEA with AI treatment (β ± SE -1.6 ± 0.6; P = 0.009). Enterolactone excretion was much lower in the FS + AI group compared to the FS group. Our results do not support strong effects of FS on AI activity for selected breast tumor characteristics or serum steroid hormone levels but suggest AI therapy might reduce the production of circulating mammalian lignans from FS.
authors.affiliation: a Department of Cancer Prevention and Control , Roswell Park Cancer Institute , Buffalo , New York , USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: McCann
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Edge
authors.forename: David G
authors.initials: DG
authors.lastname: Hicks
authors.forename: Lilian U
authors.initials: LU
authors.lastname: Thompson
authors.forename: Carl D
authors.initials: CD
authors.lastname: Morrison
authors.forename: Gerald
authors.initials: G
authors.lastname: Fetterly
authors.forename: Christopher
authors.initials: C
authors.lastname: Andrews
authors.forename: Kim
authors.initials: K
authors.lastname: Clark
authors.forename: John
authors.initials: J
authors.lastname: Wilton
authors.forename: Swati
authors.initials: S
authors.lastname: Kulkarni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077384:Anastrozole; D047072:Aromatase Inhibitors / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000097:blood*; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D005260:Female; D019597:Flax / Q000737:chemistry*; D012739:Gonadal Steroid Hormones / Q000097:blood; D006801:Humans; D017705:Lignans / Q000652:urine; D016014:Linear Models; D008875:Middle Aged; D009570:Nitriles / Q000494:pharmacology; D010865:Pilot Projects; D016896:Treatment Outcome; D014230:Triazoles / Q000494:pharmacology; D055815:Young Adult
chemical_list: D047072:Aromatase Inhibitors; D014408:Biomarkers, Tumor; D047629:Estrogen Receptor beta; D012739:Gonadal Steroid Hormones; D017705:Lignans; D009570:Nitriles; D014230:Triazoles; D000077384:Anastrozole