Breast cancer: meta-analysis identifies best target volume for regional node irradiation

  • Haussmann J & al.
  • Radiat Oncol
  • 11 Jun 2019

  • curated by Emily Willingham, PhD
  • Univadis Clinical Summaries
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Takeaway

  • In breast cancer, after axillary node dissection, radiation field expansion to include the supraclavicular nodes and axillary apex yields no overall or cancer-specific survival advantage.
  • Survival benefit is seen with inclusion of the internal mammary chain.  

Why this matters

  • Because of various difficulties, nodal irradiation often includes only the supraclavicular nodes and axillary regions, although the additional benefit their inclusion offers is unclear.
  • Trials have targeted different volumes, including these nodes, the internal mammary chain, or breast or chest wall only. 

Key results

  • In this network meta-analysis of 4 studies, vs whole breast/chest wall irradiation alone, HRs for OS with addition of:
    • Internal mammary chain: 0.88 (95% CI, 0.78-0.99; P=.036).
    • Supraclavicular node/axillary apex: 0.99 (95% CI, 0.86-1.14; P=.89).
  • Similar results for breast cancer-specific survival:
    • Internal mammary chain added: HR, 0.82 (95% CI, 0.72-0.92; P=.002).
    • Supraclavicular node/axillary apex added: HR, 0.96 (95% CI, 0.79-1.18; P=.69).
  • PFS improved with addition of internal mammary chain (OR, 0.83; 95% CI, 0.71-0.97; P=.019), as did distant metastasis-free survival (HR, 0.84; 95% CI, 0.75-0.94; P=.002).

Study design

  • Network meta-analysis of 4 studies (3 randomized, n=7243; 1 prospective cohort, n=3377), median follow-up, 8 years.
  • Funding: None.

Limitations

  • No trial included that assessed supraclavicular target alone.
  • Cohort study inclusion could create bias risk.