Background: The interaction between HER2-low expression, oncotype recurrence score (RS), and their influence on the prognosis of HR+/HER2- breast cancer (BC) is not very well studied. Methods: We conducted a retrospective cohort study of patients diagnosed with resectable HER2-low and HER2-zero BC from the National Cancer Database. The primary outcome was overall survival (OS), and the association of RS with the clinical outcomes in HR+/HER2- BC was analyzed as an exploratory endpoint. Results: The distribution of RS was comparable between HER2-low and HER2-zero groups; however, the RSs of HER2-low tumors were more likely to be 16–25. Women with HER2-low tumors had longer 5-year OS than women with HER2-zero tumors in the HR-negative (84.3% vs. 83.9%;p< 0.001, HR: 0.87 (0.84–0.90),p< 0.001) but not in the HR-positive group (94.0% vs. 94.0%;p= 0.38, HR: 0.97 (0.95–0.99),p= 0.01). The survival advantage was observed in patients who received adjuvant/neoadjuvant chemotherapy (p-interaction (chemo vs. no chemo) < 0.001). Among those who received adjuvant chemotherapy in the group with higher RSs (26–100), those with HER2-low BC had higher 5-year OS than HER2-zero BC. Conclusions: Resectable HER2-low BC had a better prognosis than HER2-zero BC. Among those who received adjuvant chemotherapy in the higher oncotype RS group, those with HER2-low tumors had better survival.
背景：HER2低表达与癌基因复发评分（RS）之间的相互作用及其对HR+/HER2-乳腺癌（BC）预后的影响尚未得到充分研究。方法：我们利用国家癌症数据库对诊断为可切除HER2低表达与HER2零表达乳腺癌患者开展了一项回顾性队列研究。主要结局指标为总生存期（OS），并将RS与HR+/HER2-乳腺癌临床结局的关联性分析作为探索性终点。结果：HER2低表达组与HER2零表达组的RS分布具有可比性，但HER2低表达肿瘤的RS更倾向于16-25分。在HR阴性组中，HER2低表达肿瘤女性的5年OS长于HER2零表达女性（84.3% vs. 83.9%；p<0.001，HR：0.87（0.84-0.90），p<0.001），但在HR阳性组中未观察到差异（94.0% vs. 94.0%；p=0.38，HR：0.97（0.95-0.99），p=0.01）。在接受辅助/新辅助化疗的患者中观察到生存优势（化疗与未化疗的交互作用p值<0.001）。在较高RS组（26-100分）接受辅助化疗的患者中，HER2低表达乳腺癌患者的5年OS高于HER2零表达患者。结论：可切除HER2低表达乳腺癌的预后优于HER2零表达乳腺癌。在癌基因RS较高组接受辅助化疗的患者中，HER2低表达肿瘤患者生存结局更佳。
肿瘤(癌症)患者之家