Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
Department of Breast Oncology, Miyagi Cancer Center Hospital, 47-1 Nodayama, Medeshima-Shiode, Natori, Miyagi, 981-1293, Japan.
Breast Cancer Res Treat. 2019 Dec;178(3):647-656. doi: 10.1007/s10549-019-05413-7. Epub 2019 Aug 26.
Recurrence risk management of patients with small (≤ 2 cm), node-negative, human epidermal growth factor receptor 2 (HER2)-positive breast cancer remains challenging. We studied the effects of adjuvant chemotherapy and/or trastuzumab and survival outcomes among these patients, using data from the population-based Japanese National Clinical Database (NCD).
We identified a cohort of 2736 breast cancer patients with HER2+ pT1N0 disease: 489 pT1a, 642 pT1b, and 1623 pT1c. The median observation period was 76 months, and the 5-year follow-up rate was 48.2%. The number of events was 212 for disease-free survival (DFS), 40 for breast cancer-specific survival, and 84 for overall survival (OS).
There were 24.5% of pT1a, 51.9% of pT1b, and 63.3% of pT1c patients who were treated systemically after surgery. OS in pT1b (logrank test; p = 0.03) and DFS in pT1c (logrank test; p < 0.001) were significantly improved in treated compared with untreated patients. In the Cox proportional hazards model, treated patients had significantly longer OS than untreated patients in pT1b (hazard ratio (HR) 0.20) and pT1c (HR 0.54) groups. Estrogen receptor-negative tumors was also a significant predictor of survival in pT1c (HR 2.01) but not pT1ab patients. Furthermore, HR was greater in patients aged ≤ 35 years (3.18) compared to that in patients aged 50-69 years in the pT1b group.
NCD data revealed that systemic treatment improved OS in pT1bc but not in pT1a node-negative HER2+ breast cancer patients. Future observational research using big-sized data is expected to play an important role in optimizing treatment for patients with early-stage breast cancer.
对于小（≤2cm）且淋巴结阴性、人表皮生长因子受体 2（HER2）阳性的乳腺癌患者，复发风险的管理仍然具有挑战性。我们利用基于人群的日本国家临床数据库（NCD）的数据，研究了辅助化疗和/或曲妥珠单抗对这些患者的生存结果的影响。
我们从 NCD 数据库中确定了一个 HER2+ pT1N0 疾病的队列，包含 2736 例乳腺癌患者：489 例 pT1a，642 例 pT1b，1623 例 pT1c。中位观察期为 76 个月，5 年随访率为 48.2%。无病生存期（DFS）的事件数为 212，乳腺癌特异性生存期（BCSS）为 40，总生存期（OS）为 84。
489 例 pT1a 中有 24.5%，642 例 pT1b 中有 51.9%，1623 例 pT1c 中有 63.3%的患者在手术后接受了系统治疗。与未接受治疗的患者相比，pT1b（对数秩检验；p=0.03）和 pT1c（对数秩检验；p<0.001）的 OS 显著改善。在 Cox 比例风险模型中，与未接受治疗的患者相比，接受治疗的患者在 pT1b（危险比（HR）0.20）和 pT1c（HR 0.54）组的 OS 明显更长。在 pT1c 患者中，雌激素受体阴性肿瘤也是生存的显著预测因子（HR 2.01），但在 pT1ab 患者中并非如此。此外，pT1b 组中年龄≤35 岁的患者 HR 为 3.18，而年龄 50-69 岁的患者 HR 为 0.54。
NCD 数据显示，系统治疗改善了 pT1bc 但未改善 pT1a 淋巴结阴性 HER2+乳腺癌患者的 OS。未来使用大数据的观察性研究有望在优化早期乳腺癌患者的治疗方面发挥重要作用。
