NSABP P-2, or STAR Trial

  • The NSABP P-2, or STAR trial:
    • Enrolled 19, 747 postmenopausal women with:
      • A 5-year Gail risk assessment score:
        • Of equal or greater 1.66% for the development of invasive breast cancer at 5 years
    • The women were randomized to:
      • Receive 20 mg of tamoxifen plus placebo or 60 mg of raloxifene plus placebo
  • In the updated results of the STAR trial:
    • Median follow-up 81 months
    • There were more cases of invasive breast cancer:
      • In the raloxifene group than the tamoxifen group:
        • Risk ratio [RR]: 1.24; 95% confidence interval [CI]: 1.05–1.47):
          • Demonstrating that raloxifene is about:
            • 76% as effective as tamoxifen in reducing breast cancer risk
          • There were significantly fewer cases of:
            • Invasive uterine cancer with raloxifene compared to tamoxifen:
              • RR: 0.55; 95% CI, 0.36–0.83
          • Thromboembolic events occurred less often in the raloxifene group (RR: 0.75; 95% CI: 0.6–0.93) and there were fewer cataracts and cataract surgeries in the women taking raloxifene (RR: 0.79; 95% CI: 0.68–0.92)
        • Importantly:
          • There was no significant difference in mortality between the two groups
  • References:
    • Mamounas EP, Wicherham DL, Fisher B, Geyer CE, Julian TB, Wolmark N. The NSABP experience. In: Kuerer HM, ed. Kuerer’s Breast Surgical Oncology. New York, NY: McGraw-Hill Companies; 2010:475-508.
    • Vogel VG. The NSABP Study of Tamoxifen and Raloxifene (STAR) trial. Expert Rev Anticancer Ther. 2009;9:51-60.
    • Vogel VG, Costantino JP, Wickerham DL, et al; for the National Surgical Adjuvant Breast and Bowel Project (NSABP). Effects of tamoxifen vs raloxifene on the risk of developing invasive breast cancer and other disease outcomes: the NSABP Study of Tamoxifen and Raloxifene (STAR) P-2 trial. JAMA. 2006;295:2727-2741.