Cho Won Kyung, Park Won, Jeong Yuri, Kim Haeyoung, Kim Nalee
Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Department of Radiation Oncology, Wonkwang University Hospital, Iksan, Republic of Korea.
Jpn J Clin Oncol. 2023 Jan 6;53(1):57-62. doi: 10.1093/jjco/hyac161.
There is little evidence regarding the radiotherapy modification based on molecular subtypes in breast cancer. This study aimed to identify the risk and patterns of regional recurrence according to molecular subtype in patients with pN2 breast cancer.
We identified 454 patients who underwent radical surgery for breast cancer with 4-9 axillary lymph node metastases. All patients underwent axillary lymph node dissection, adjuvant chemotherapy and limited-field regional nodal irradiation. The rates and patterns of regional recurrence were compared between the following three subgroups: luminal type (estrogen receptor- and/or progesterone receptor-positive), HER2-type (estrogen receptor- and progesterone receptor-negative and HER2-positive) and triple-negative type (estrogen receptor-, progesterone receptor- and HER2-negative).
Regional recurrence occurred in 18/454 patients (4%). The risk of regional recurrence was higher in the triple-negative (hazard ratio 7.641) and HER2-type (hazard ratio 4.032) subtypes than in the luminal subtype. The predominant pattern of regional recurrence was inside the radiotherapy field in triple-negative breast cancer and outside the radiotherapy field in HER2-type and luminal-type cancers.
In patients with pN2 breast cancer, the risk of regional recurrence was higher in the triple-negative and HER2-type than in the luminal type. In-field recurrence was predominant in triple-negative cancer, while out-field recurrence was frequent in luminal and HER2-type breast cancers.
关于基于分子亚型的乳腺癌放疗调整的证据很少。本研究旨在确定pN2期乳腺癌患者根据分子亚型出现区域复发的风险和模式。
我们纳入了454例接受了乳腺癌根治术且有4 - 9个腋窝淋巴结转移的患者。所有患者均接受了腋窝淋巴结清扫、辅助化疗和局部区域淋巴结照射。比较了以下三个亚组之间区域复发的发生率和模式：腔面型（雌激素受体和/或孕激素受体阳性）、HER2型（雌激素受体和孕激素受体阴性且HER2阳性）和三阴性型（雌激素受体、孕激素受体和HER2阴性）。
454例患者中有18例（4%）出现区域复发。三阴性（风险比7.641）和HER2型（风险比4.032）亚型的区域复发风险高于腔面型亚型。区域复发的主要模式在三阴性乳腺癌中是在放疗野内，而在HER2型和腔面型癌症中是在放疗野外。
在pN2期乳腺癌患者中，三阴性和HER2型的区域复发风险高于腔面型。三阴性癌症中野内复发为主，而腔面型和HER2型乳腺癌中野外复发常见。
