Abstract：
Breast cancer with low human epidermal growth factor receptor (HER2) expression is increasingly considered as a distinct subtype which consists of types of HER2 immunohistochemistry (IHC) 1+ and HER2 IHC 2+/in-situ hybridization (ISH)-negative. We aim to assess the survival difference between HER2 IHC 1+ and HER2 IHC 2+/ISH-negative breast cancer patients with metastasis at presentation and construct a prognostic nomogram for HER2-low patients.
Patients diagnosed with de novo metastatic HER2-low breast cancer from 2010 to 2015 were included and analyzed using the National Cancer Database (NCDB). Cox proportional hazards regression model and Kaplan-Meier (KM) method were used for survival analysis. Nomograms were built to predict survival.
A total of 7897 patients were included in the final analysis, among which 5458 (69.1%) patients were HER2 IHC 1+ and 2439 (30.9%) were HER2 IHC 2+/ISH-negative. Although the Kaplan-Meier survival analysis showed difference in survival, this survival difference was lost in the multivariate Cox analysis (multivariate: HR (hazard ratio) = 0.97; 95% CI (confidence interval) [0.92-1.03]). A prognostic nomogram was successfully constructed for individually predicting the long-term survival rate of HER2-low patients, which exhibited an acceptable predictive capability in training (C index: 0.719) and validation cohort (C index: 0.706). This nomogram could easily divide patients into high and low-risk subgroups with distinct prognoses.
Our data suggest no statistical survival differences between HER2 1+ and HER2 2+ breast cancer. Additionally, a nomogram was constructed with an acceptable capacity to individually predict the long-term outcome of HER2-low metastatic breast cancer patients.
Patients diagnosed with de novo metastatic HER2-low breast cancer from 2010 to 2015 were included and analyzed using the National Cancer Database (NCDB). Cox proportional hazards regression model and Kaplan-Meier (KM) method were used for survival analysis. Nomograms were built to predict survival.
A total of 7897 patients were included in the final analysis, among which 5458 (69.1%) patients were HER2 IHC 1+ and 2439 (30.9%) were HER2 IHC 2+/ISH-negative. Although the Kaplan-Meier survival analysis showed difference in survival, this survival difference was lost in the multivariate Cox analysis (multivariate: HR (hazard ratio) = 0.97; 95% CI (confidence interval) [0.92-1.03]). A prognostic nomogram was successfully constructed for individually predicting the long-term survival rate of HER2-low patients, which exhibited an acceptable predictive capability in training (C index: 0.719) and validation cohort (C index: 0.706). This nomogram could easily divide patients into high and low-risk subgroups with distinct prognoses.
Our data suggest no statistical survival differences between HER2 1+ and HER2 2+ breast cancer. Additionally, a nomogram was constructed with an acceptable capacity to individually predict the long-term outcome of HER2-low metastatic breast cancer patients.
摘要：
背景：人表皮生长因子受体（HER2）低表达的乳腺癌越来越被认为是一种独特的亚型，由HER2免疫组织化学（IHC）1+和HER2IHC2+/原位杂交（ISH）阴性的类型组成。我们的目标是评估HER2IHC1+和HER2IHC2+/ISH阴性乳腺癌患者之间的生存差异，并构建HER2低患者的预后列线图。
方法：纳入2010年至2015年诊断为低HER2-novo转移性乳腺癌的患者，并使用国家癌症数据库（NCDB）进行分析。采用Cox比例风险回归模型和Kaplan-Meier(KM)法进行生存分析。建立列线图来预测生存。
结果：共7897例患者纳入最终分析，其中5458例(69.1%)为HER2IHC1+,2439例(30.9%)为HER2IHC2+/ISH阴性.尽管Kaplan-Meier生存分析显示生存率存在差异，这种生存差异在多变量Cox分析中消失(多变量:HR(风险比)=0.97;95%CI(置信区间)[0.92-1.03]).成功构建了预后列线图，用于单独预测低HER2患者的长期生存率。在训练（C指数：0.719）和验证队列（C指数：0.706）中表现出可接受的预测能力。此列线图可以轻松地将患者分为具有不同预后的高风险和低风险亚组。
结论：我们的数据表明HER21+和HER2+乳腺癌之间没有统计学差异。此外,我们构建的列线图具有可接受的能力,可以单独预测低HER2转移性乳腺癌患者的长期结局.
方法：纳入2010年至2015年诊断为低HER2-novo转移性乳腺癌的患者，并使用国家癌症数据库（NCDB）进行分析。采用Cox比例风险回归模型和Kaplan-Meier(KM)法进行生存分析。建立列线图来预测生存。
结果：共7897例患者纳入最终分析，其中5458例(69.1%)为HER2IHC1+,2439例(30.9%)为HER2IHC2+/ISH阴性.尽管Kaplan-Meier生存分析显示生存率存在差异，这种生存差异在多变量Cox分析中消失(多变量:HR(风险比)=0.97;95%CI(置信区间)[0.92-1.03]).成功构建了预后列线图，用于单独预测低HER2患者的长期生存率。在训练（C指数：0.719）和验证队列（C指数：0.706）中表现出可接受的预测能力。此列线图可以轻松地将患者分为具有不同预后的高风险和低风险亚组。
结论：我们的数据表明HER21+和HER2+乳腺癌之间没有统计学差异。此外,我们构建的列线图具有可接受的能力,可以单独预测低HER2转移性乳腺癌患者的长期结局.
