METHODS: This retrospective analysis of all consecutive HR + patients who underwent OncotypeDX from January 2004 to December 2020 was conducted in a single medical center (n = 1429). We divided HER2-negative cases into HER2-low (IHC = 1 + or 2 + and non-amplified fluorescent situ hybridization) and HER2-0 (IHC = 0). HER2 RT-PCR was evaluated from the OncotypeDX results.
RESULTS: HER2-low cases exhibited significantly higher HER2 RT-PCR scores (p = 2.1e-9), elevated estrogen receptor (ER) levels (p = 0.0114), and larger tumor sizes compared to HER2-0 cases (> 2 cm; 36.6% vs. 22.1%, respectively, p < 0.00001). Primary tumors > 2 cm were more likely to be HER2-low (OR = 2.07, 95% CI: 1.6317 to 2.6475, p < 0.0001). Metastatic BCs expressed higher HER2 IHC scores compared with primary BCs (Wilcoxon signed-rank, p = 0.046). HER2 IHC scores were higher for low-risk vs. medium-risk OncotypeDX (p = 0.0067). No other clinical or pathological parameters were associated with the increase in HER2 levels in the metastatic samples.
CONCLUSIONS: It might be beneficial to use clinical data from the primary tumor, including the HER2 RT-PCR score, to determine a HER2-low status.
方法:这项对2004年1月至2020年12月接受OncotypeDX的所有连续HR+患者的回顾性分析是在一个医疗中心进行的(n=1429)。我们将HER2阴性病例分为低HER2(IHC=1+或2+和非扩增荧光原位杂交)和HER2-0(IHC=0)。从OncotypeDX结果评估HER2RT-PCR。
结果:HER2低的病例表现出明显更高的HER2RT-PCR评分(p=2.1e-9),雌激素受体(ER)水平升高(p=0.0114),与HER2-0病例相比,肿瘤大小更大(>2cm;36.6%vs.22.1%,分别,p<0.00001)。>2cm的原发肿瘤更可能是HER2低(OR=2.07,95%CI:1.6317至2.6475,p<0.0001)。与原发性BCs相比,转移性BCs表达更高的HER2IHC评分(Wilcoxonsigned-rank,p=0.046)。低风险与低风险的HER2IHC评分较高中等风险OncotypeDX(p=0.0067)。没有其他临床或病理参数与转移样品中HER2水平的增加相关。
结论:使用原发肿瘤的临床数据可能是有益的,包括HER2RT-PCR评分,以确定HER2低状态。