Top Line: One of the biggest questions in breast radiation oncology over the past decade was the role of regional nodal irradiation (RNI).
The Study: Here we have the EBCTCG meta-analysis of randomized trials comparing RNI and no RNI for breast cancer. It included data from over 14,000 patients treated on 16 randomized trials that started enrolling between 1961 and 2008. Such a time span allowed for comparisons across decades. Among patients treated on 8 randomized trials after 1989, the addition of RNI significantly reduced recurrence risk, distant recurrence, breast cancer mortality, and all-cause mortality. In particular, there were no negative effects on non-breast cancer mortality including no increase in cardiac mortality or second malignancies. The same wasn’t true for the older trials where RNI didn’t improve breast cancer mortality and increased non-breast cancer mortality. These findings suggest that newer techniques (at least early 2000’s new) have both improved treatment outcomes and reduced adverse outcomes. The mortality benefit of RNI increased with increasing nodal disease burden. At 15 years, RNI provided a 1.6% absolute reduction for node-negative patients compared to 2.7% for those with 1-3 positive nodes and 4.5% for those with 4 or more nodes.
TBL: Regional nodal irradiation using modern techniques significantly reduces breast cancer mortality without affecting non-breast cancer mortality. For those with 4 or more positive nodes, this translates to a 4.5% absolute reduction in breast cancer mortality at 15 years. | EBCTCG, Lancet 2023
The Study: Here we have the EBCTCG meta-analysis of randomized trials comparing RNI and no RNI for breast cancer. It included data from over 14,000 patients treated on 16 randomized trials that started enrolling between 1961 and 2008. Such a time span allowed for comparisons across decades. Among patients treated on 8 randomized trials after 1989, the addition of RNI significantly reduced recurrence risk, distant recurrence, breast cancer mortality, and all-cause mortality. In particular, there were no negative effects on non-breast cancer mortality including no increase in cardiac mortality or second malignancies. The same wasn’t true for the older trials where RNI didn’t improve breast cancer mortality and increased non-breast cancer mortality. These findings suggest that newer techniques (at least early 2000’s new) have both improved treatment outcomes and reduced adverse outcomes. The mortality benefit of RNI increased with increasing nodal disease burden. At 15 years, RNI provided a 1.6% absolute reduction for node-negative patients compared to 2.7% for those with 1-3 positive nodes and 4.5% for those with 4 or more nodes.
TBL: Regional nodal irradiation using modern techniques significantly reduces breast cancer mortality without affecting non-breast cancer mortality. For those with 4 or more positive nodes, this translates to a 4.5% absolute reduction in breast cancer mortality at 15 years. | EBCTCG, Lancet 2023