Effects of a Phytoestrogen Intervention and Estrogen Receptor β Genotype on Prostate Cancer Proliferation and PSA Concentrations-A Randomized Controlled Trial

• Published in: Nutrition and cancer Vol. 77; no. 1; pp. 124 - 138
• Main Authors: Ahlin, Rebecca, Josefsson, Andreas, Nybacka, Sanna, Landberg, Rikard, Stranne, Johan, Steineck, Gunnar, Hedelin, Maria
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 2025; Taylor & Francis Ltd
• Subjects: Aged; blood; Cancer and Oncology; Cancer och onkologi; Cell Proliferation - drug effects; confidence interval; Diet; Estrogen Receptor beta - genetics; Estrogen Receptor beta - metabolism; Estrogen receptors; Estrogens; Flax; Gene polymorphism; genes; Genotype; Genotype & phenotype; genotyping; Glycine max - chemistry; Humans; Ki-67 Antigen - genetics; Ki-67 Antigen - metabolism; linseed; Male; Middle Aged; Phytoestrogens; Phytoestrogens - pharmacology; plant estrogens; Polymorphism; Prostate cancer; Prostate-specific antigen; Prostate-Specific Antigen - blood; Prostatectomy; Prostatectomy - methods; prostatic neoplasms; Prostatic Neoplasms - genetics; Prostatic Neoplasms - pathology; Prostatic Neoplasms - surgery; Receptors; risk; Soybeans; surgery; Tumors
• ISSN: 0163-5581; 1532-7914; 1532-7914
• DOI: 10.1080/01635581.2024.2407007

A phytoestrogen-rich diet has been suggested to reduce tumor proliferation among men with prostate cancer, and the effect may differ between men with different polymorphisms of the estrogen receptor-beta gene (ERβ). Patients with low- or intermediate-risk prostate cancer scheduled for radical prostatectomy were randomized to an intervention group (n = 71) provided with soybeans and flaxseeds (∼200 mg phytoestrogens/day) to eat until surgery (approximately 6 wk) or to a control group (n = 69). Tumor proliferation was assessed using Ki-67 indexes, prostate-specific antigen (PSA) concentrations were analyzed in blood, and ERβ polymorphism was genotyped in all subjects. The intervention group had a 13% unit lower risk [95% confidence interval (CI): −28%, 1.8%] of a higher Ki-67 index compared to controls, but the effect was most pronounced among TT carriers of ERβ [risk difference (RD) −19%, 95% CI: −45%, 6.8%]. Subjects with genotype TC/CC had a lower risk (RD −29%, 95% CI: −46%, −1.2%) and TT genotype a higher risk (RD 25%, 95% CI: 8.7%, 42%) of increased PSA concentration, comparing the intervention group to controls. In conclusion, a phytoestrogen-rich diet may cause lower tumor proliferation and concentration of PSA in men with prostate cancer with a specific genetic upset of ERβ.