HER2‐low heterogeneity between primary and paired recurrent/metastatic breast cancer: Implications in treatment and prognosis

作者：Mingxi Lin, Ting Luo, Yizi Jin, Xiaorong Zhong, Dan Zheng, Cheng Zeng, Qing Guo, Jiong Wu, Zhi‐Ming Shao, Xichun Hu, Wentao Yang, Jian Zhang · 发表于：Cancer · 年份：2023 · DOI：10.1002/cncr.35101 · 被引用次数：24 · 研究领域：HER2/EGFR in Cancer Research、Breast Cancer Treatment Studies、Advanced Breast Cancer Therapies

BACKGROUND: With the largest sample size to date, the authors' objective was to investigate the incidence of primary-to-metastatic human epidermal growth factor 2 (HER2) conversion and the predictors for such conversion. Moreover, no previous studies have evaluated the prognosis of patients who have negative HER2 expression (HER2-0) versus low HER2 expression (HER2-low) when HER2 status was assessed based on all recurrent/metastatic lesions. METHODS: The authors included 1299 patients who had available HER2 status of primary breast tumors and paired recurrent/metastatic lesions at Fudan University Shanghai Cancer Center and West China Hospital. RESULTS: In total, 370 patients (28.5%) experienced primary-to-metastatic HER2 conversion. Intrapatient intermetastasis spatial heterogeneity and temporal heterogeneity of HER2 were detected. When assessing HER2 based on recurrent/metastatic tumors, patients who had HER2-0 tumors had significantly shorter overall survival than those who had HER2-low tumors in the overall population and in the estrogen receptor (ER)-negative subgroup. However, when assessing HER2 based on primary tumors, there was no difference in overall survival between patients who had HER2-0 versus HER2-low tumors. Moreover, patients who had tumors that converted from HER2-0 to HER2-low had longer overall survival than those who had consistent HER2-0 status in the ER-negative subgroup. By combining four predictors (ER status, Ki67 index, biopsy site, and disease-fre...