Randomized double-blind 2x2 trial of low-dose tamoxifen and fenretinide for breast cancer prevention in high-risk premenopausal women

Decensi, Andrea and Robertson, Chris and Guerrieri-Gonzaga, Aliana and Serrano, Davide and Cazzaniga, Massimiliano and Mora, Serena and Gulisano, Marcella and Johansson, Harriet and Galimberti, Viviana and Cassano, Enrico and Moroni, Simona M. and Formelli, Franca and Lien, Ernst A. and Pelosi, Giuseppe and Johnson, Karen A. and Bonanni, Bernardo (2009) Randomized double-blind 2x2 trial of low-dose tamoxifen and fenretinide for breast cancer prevention in high-risk premenopausal women. Journal of Clinical Oncology, 27 (23). pp. 3749-3756. ISSN 0732-183X (http://dx.doi.org/10.1200/JCO.2008.19.3797)

Full text not available in this repository.Request a copy

Abstract

Tamoxifen and fenretinide are active in reducing premenopausal breast cancer risk and work synergistically in preclinical models. The authors assessed their combination in a two-by-two biomarker trial. A total of 235 premenopausal women with pT1mic/pT1a breast cancer (n = 21), or intraepithelial neoplasia (IEN, n = 160), or 5-year Gail risk > or = 1.3% (n = 54) were randomly allocated to either tamoxifen 5 mg/d, fenretinide 200 mg/d, their combination, or placebo. We report data for plasma insulin-like growth factor I (IGF-I), mammographic density, uterine effects, and breast neoplastic events after 5.5 years. During the 2-year intervention, tamoxifen significantly lowered IGF-I and mammographic density by 12% and 20%, respectively, fenretinide by 4% and 10% (not significantly), their combination by 20% and 22%, with no evidence for a synergistic interaction. Tamoxifen increased endometrial thickness principally in women becoming postmenopausal, whereas fenretinide decreased endometrial thickness significantly. The annual rate of breast neoplasms (n = 48) was 3.5% +/- 1.0%, 2.1% +/- 0.8%, 4.7% +/- 1.3%, and 5.2% +/- 1.3% in the tamoxifen, fenretinide, combination, and placebo arms, respectively, with hazard ratios (HRs) of 0.70 (95% CI, 0.32 to 1.52), 0.38 (95% CI, 0.15 to 0.90), and 0.96 (95% CI, 0.46 to 1.99) relative to placebo (tamoxifen x fenretinide adverse interaction P = .03). There was no clear association with tumor receptor type. Baseline IGF-I and mammographic density did not predict breast neoplastic events, nor did change in mammographic density. Despite favorable effects on plasma IGF-I levels and mammographic density, the combination of low-dose tamoxifen plus fenretinide did not reduce breast neoplastic events compared to placebo, whereas both single agents, particularly fenretinide, showed numerical reduction in annual odds of breast neoplasms. Further follow-up is indicated.