Breast cancer: chemo increases survival for patients with recurrence scores of 26-30

  • Park S & al.
  • Breast Cancer Res
  • 16 Oct 2019

  • curated by Miriam Davis, PhD
  • Univadis Clinical Summaries
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Takeaway

  • Adjuvant chemotherapy is associated with up to 42% survival benefit vs no chemotherapy in patients aged ≤70 years with node-negative breast cancer who have the high end of intermediate 21-gene recurrence scores (RS) of 26-30, according to an analysis of the Surveillance Epidemiology and End Results (SEER) database.
  • Chemotherapy has greatest benefit for younger patients or those with grade III tumors.

Why this matters

  • This is the first study of chemotherapy in patients with this subset of intermediate RS.
  • Prior studies of the lower end of intermediate RS (16-25) found no chemotherapy benefits.

Study design

  • Retrospective cohort of 29,137 US patients with RS 26-30 (2004-2015) in SEER database.
  • Funding: None.

Key results

  • Mean follow-up was 32 months.
  • Patients with RS 26-30 (vs patients with RS 18-25) had higher breast cancer-specific mortality (HR, 1.81; 95% CI, 1.46-2.26) and higher mortality (HR, 1.37; 95% CI, 1.19-1.58) after adjusting for treatments and other confounders.
  • Receipt of adjuvant chemotherapy by patients with RS 26-30 (vs no chemotherapy) was associated with 32% lower breast cancer-specific mortality (HR, 0.68; 95% CI, 0.47-0.99) and 42% lower mortality (HR, 0.58; 95% CI, 0.44-0.76).
    • Subgroup analysis found higher chemotherapy benefits for younger patients ≤56 years (log-rank P=.046) or those with grade III tumors (log-rank P=.003).

Limitations

  • Retrospective observational design.