BRCA+ women: higher overall mortality even after risk-reducing surgery

  • Öfverholm A & al.
  • Genes (Basel)
  • 16 Dec 2019

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

  • Risk-reducing surgery for BRCA-positive women is tied to substantially reduced incidence of breast and/or ovarian cancer, but not to decreased overall mortality, according to a retrospective cohort study.

Why this matters

  • BRCA-positive women considering risk-reducing mastectomy (RRM) and/or salpingo-oophorectomy (RRSO) should be informed about this divergence in benefit between overall mortality and incidence reduction.
  • Further research is warranted.

Study design

  • 20-year retrospective, population-based cohort in Western Sweden, all BRCA1/2-positive women who were cancer-free at the time of registration, 1995-2016 (N=253).
  • Incidence and mortality data from Swedish Cancer Register were compared with the general population.
  • Funding: Swedish government and city councils.

Key results

  • Standard incidence ratio (SIR) for breast cancer:
    • Until RRM: 14.0 (95% CI, 9.42-20.7). 
    • After RRM: 1.93 (95% CI, 0.48-7.7).
  • SIR for ovarian cancer:
    • Until RRSO: 124.6 (95% CI, 59.4-261.3).
    • After RRSO: 13.5 (95% CI, 4.34-41.8).
  • Standard mortality ratio (SMR):
    • Before risk-reducing surgery: 5.56 (95% CI, 2.09-14.8). 
    • After both RRM and RRSO: 4.32 (95% CI, 1.62-11.5).

Limitations

  • Number of deaths was low for statistical purposes (n=16).
  • The study does not reflect the effect of new prophylactic medications or new medications for breast or ovarian cancer.