- 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.
- 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).
- Network meta-analysis of 4 studies (3 randomized, n=7243; 1 prospective cohort, n=3377), median follow-up, 8 years.
- Funding: None.
- No trial included that assessed supraclavicular target alone.
- Cohort study inclusion could create bias risk.