BMC Cancer (Apr 2017)

Adjuvant treatment recommendations for patients with ER-positive/HER2-negative early breast cancer by Swiss tumor boards using the 21-gene recurrence score (SAKK 26/10)

  • Bernhard C. Pestalozzi,
  • Christoph Tausch,
  • Konstantin J. Dedes,
  • Christoph Rochlitz,
  • Stefan Zimmermann,
  • Roger von Moos,
  • Ralph Winterhalder,
  • Thomas Ruhstaller,
  • Andreas Mueller,
  • Katharina Buser,
  • Markus Borner,
  • Urban Novak,
  • Catrina Uhlmann Nussbaum,
  • Bettina Seifert,
  • Martin Bigler,
  • Vincent Bize,
  • Simona Berardi Vilei,
  • Christoph Rageth,
  • Stefan Aebi,
  • The Swiss Group for Clinical Cancer Research (SAKK)

DOI
https://doi.org/10.1186/s12885-017-3261-1
Journal volume & issue
Vol. 17, no. 1
pp. 1 – 10

Abstract

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Abstract Background To evaluate the effect of Recurrence Score® results (RS; Oncotype DX® multigene assay ODX) on treatment recommendations by Swiss multidisciplinary tumor boards (TB). Methods SAKK 26/10 is a multicenter, prospective cohort study of early breast cancer patients: Eligibility: R0-resection, ≥10% ER+ malignant cells, HER2–, pN0/pN1a. Patients were stratified into low-risk (LR) and non-low-risk (NLR) groups based on involved nodes (0 vs 1–3) and five additional predefined risk factors. Recommendations were classified as hormonal therapy (HT) or chemotherapy plus HT (CT + HT). Investigators were blinded to the statistical analysis plan. A 5%/10% rate of recommendation change in LR/NLR groups, respectively, was assumed independently of RS (null hypotheses). Results Two hundred twenty two evaluable patients from 18 centers had TB recommendations before and after consideration of the RS result. A recommendation change occurred in 45 patients (23/154 (15%, 95% CI 10–22%) in the LR group and 22/68 (32%, 95% CI 22–45%) in the NLR group). In both groups the null hypothesis could be rejected (both p < 0.001). Specifically, in the LR group, only 5/113 (4%, 95% CI 1–10%) with HT had a recommendation change to CT + HT after consideration of the RS, while 18/41 (44%, 95% CI 28–60%) of patients initially recommended CT + HT were subsequently recommended only HT. In the NLR group, 3/19 (16%, 95% CI 3–40%) patients were changed from HT to CT + HT, while 19/48 (40%, 95% CI 26–55%) were changed from CT + HT to HT. Conclusion There was a significant impact of using the RS in the LR and the NLR group but only 4% of LR patients initially considered for HT had a recommendation change (RC); therefore these patients could forgo ODX testing. A RC was more likely for NLR patients considered for HT. Patients considered for HT + CT have the highest likelihood of a RC based on RS.

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