Top Line: What are the long term outcomes of hypofractionated regional nodal irradiation?
The Study: Moderate hypofractionation is now commonplace in the treatment of breast cancer, and it’s increasingly utilized when treating regional lymph nodes. DBCG Skagen 1 is one of the largest randomized trials that directly compared moderate hypofractionation and conventional fractionation. It included 2908 patients with high risk, node positive breast cancer who were planned to receive adjuvant RT with regional nodal irradiation. Just over half (52%) had undergone breast conservation surgery. In both arms, the target volume included the breast or chest wall, axilla, supraclavicular fossa, and internal mammary nodes. They were randomized to 40 Gy in 15 fractions or 50 Gy in 25 fractions. The trial was designed to see if lymphedema was noninferior at 3 years after hypofractionation. At 3 years, the rate of lymphedema was deemed noninferior (8% v 9.4%). What was associated with a higher risk of lymphedema? Axillary lymph node dissection. There were no other differences in late adverse effects between arm. There were also no differences in locoregional recurrence (2.5% v 2.9% at 5 years), distant metastasis (12% v 11% at 5 years), or breast cancer mortality (7.2% v 5% at 5 years).
TBL: In Skagen 1, hypofractionated locoregional radiation did not increase late effects, specifically lymphedema, and had similar treatment outcomes to conventional fractionation. | Offerson, J Clin Oncol 2026
The Study: Moderate hypofractionation is now commonplace in the treatment of breast cancer, and it’s increasingly utilized when treating regional lymph nodes. DBCG Skagen 1 is one of the largest randomized trials that directly compared moderate hypofractionation and conventional fractionation. It included 2908 patients with high risk, node positive breast cancer who were planned to receive adjuvant RT with regional nodal irradiation. Just over half (52%) had undergone breast conservation surgery. In both arms, the target volume included the breast or chest wall, axilla, supraclavicular fossa, and internal mammary nodes. They were randomized to 40 Gy in 15 fractions or 50 Gy in 25 fractions. The trial was designed to see if lymphedema was noninferior at 3 years after hypofractionation. At 3 years, the rate of lymphedema was deemed noninferior (8% v 9.4%). What was associated with a higher risk of lymphedema? Axillary lymph node dissection. There were no other differences in late adverse effects between arm. There were also no differences in locoregional recurrence (2.5% v 2.9% at 5 years), distant metastasis (12% v 11% at 5 years), or breast cancer mortality (7.2% v 5% at 5 years).
TBL: In Skagen 1, hypofractionated locoregional radiation did not increase late effects, specifically lymphedema, and had similar treatment outcomes to conventional fractionation. | Offerson, J Clin Oncol 2026