Top Line: What were the patterns of locoregional recurrence after breast conservation and mastectomy with or without regional nodal irradiation in EORTC 22922?
The Study: EORTC 22922, along with MA.20, was one of key randomized trials to describe the benefits of regional nodal irradiation (RNI) for breast cancer. It randomized over 4000 patients with either a central or medial tumor location or lymph node involvement to receive RNI or not. At 15 years, RNI reduced breast cancer recurrence 27.1 → 24.5% and breast cancer mortality 19.8 → 16%, but there were no differences in OS, DFS, or DMFS. In this study, the locations of local and regional recurrences were mapped for over 3000 participants to determine how the extent of surgery and radiation impacted patterns of recurrence. Of those, 76% had breast conservation surgery and 24% had mastectomy. Among the former, 99.7% had whole breast RT and 85.2% had a boost. Among the latter, 73.4% had chest wall RT. At 15 years, the rate of local recurrence was higher after BCS than after mastectomy (7.3% v 3.1%). In each surgery group, the rate of LR did not appear to be influenced by RNI. A higher proportion of BCS recurrences were in-field (72% v 57%), but only about a third of BCS recurrences were near the tumor bed. The rate of regional recurrence was actually higher in patients who had mastectomy (5.8% without RNI, 4.8% with RNI) compared to BCS (4.8% without RNI, 2.8% with RNI). Overall the rate of RR was lower after RNI (3.2% v 5%). After RNI, the rate of recurrences involving the axilla was 1.7%, the supraclavicular fossa 1.6%, and the IMN 0.2%. Without RNI, those rates were 2.4% in the axilla, 2.5% in the supraclavicular fossa, and 0.8% in the IMN. The absolute benefit of RT in reducing locoregional recurrence increased with stage and with less extensive surgery (i.e. breast conservation and limited axillary surgery.
TBL: As might be expected, the recurrence patterns in EORTC 22922 were influenced by the extent of surgery and radiation with a higher rate of LR after BCS and a higher risk of regional recurrence without RNI. The absolute benefit of radiation was greater following less extensive surgery. | Kaidar-Person, Radiother Oncol 2023
The Study: EORTC 22922, along with MA.20, was one of key randomized trials to describe the benefits of regional nodal irradiation (RNI) for breast cancer. It randomized over 4000 patients with either a central or medial tumor location or lymph node involvement to receive RNI or not. At 15 years, RNI reduced breast cancer recurrence 27.1 → 24.5% and breast cancer mortality 19.8 → 16%, but there were no differences in OS, DFS, or DMFS. In this study, the locations of local and regional recurrences were mapped for over 3000 participants to determine how the extent of surgery and radiation impacted patterns of recurrence. Of those, 76% had breast conservation surgery and 24% had mastectomy. Among the former, 99.7% had whole breast RT and 85.2% had a boost. Among the latter, 73.4% had chest wall RT. At 15 years, the rate of local recurrence was higher after BCS than after mastectomy (7.3% v 3.1%). In each surgery group, the rate of LR did not appear to be influenced by RNI. A higher proportion of BCS recurrences were in-field (72% v 57%), but only about a third of BCS recurrences were near the tumor bed. The rate of regional recurrence was actually higher in patients who had mastectomy (5.8% without RNI, 4.8% with RNI) compared to BCS (4.8% without RNI, 2.8% with RNI). Overall the rate of RR was lower after RNI (3.2% v 5%). After RNI, the rate of recurrences involving the axilla was 1.7%, the supraclavicular fossa 1.6%, and the IMN 0.2%. Without RNI, those rates were 2.4% in the axilla, 2.5% in the supraclavicular fossa, and 0.8% in the IMN. The absolute benefit of RT in reducing locoregional recurrence increased with stage and with less extensive surgery (i.e. breast conservation and limited axillary surgery.
TBL: As might be expected, the recurrence patterns in EORTC 22922 were influenced by the extent of surgery and radiation with a higher rate of LR after BCS and a higher risk of regional recurrence without RNI. The absolute benefit of radiation was greater following less extensive surgery. | Kaidar-Person, Radiother Oncol 2023