Abstract PS10-39: Risk factors for all-cause death and breast cancer-specific death in patients with HER2-positive and lymph node negative breast cancer : A retrospective analysis based on SEER database (2010 to 2017)
Authors: Wang Ju , Zhang Yi , Jiang Jun , Qi Xiaowei 
Published: February 2021

Abstract
Purpose: Trastuzumab combined with pertuzumab (HP) is currently the standard treatment for HER2-positive (HER2+) and lymph node-positive (LN+) breast cancer, but it is not clear which subgroup of patients with HER2+ and LN- breast cancer are suitable for HP dual-targeted therapy. By collecting the clinicopathological and prognostic information of HER2+ and LN- breast cancer patients in the SEER database from 2010 to 2017, we explored the risk factors of recurrence in these populations, aiming to identify subgroup who may need HP dual-targeted therapy among HER2+ and LN- breast cancer patients. Methods: From the SEER database, the clinicopathological and prognostic information of pathologically confirmed HER2+ and LN- breast cancer from 2010 to 2017 were extracted, and the risk factors of breast cancer-specific survival and overall survival were analyzed by multivariate Cox risk proportional model and competitive risk model.Results: After data cleaning, a total of 5163 patients were included in the current analysis. The median survival time was 49 months (IQR: 34 to 70 months). A total of 209 patients had breast cancer-specific deaths, and 325 patients died due to all causes. Multivariate Cox analysis showed that compared with patients of 20-34 years old, the 70-74 age group (HR=2.683, 95%CI=[1.221,5.895], P=0.014), 75-79 age group (HR=5.303, 95% CI=[2.437,11.543], P&lt;0.001), 80-84 age group (HR=7.971, 95%CI=[3.655,17.386], P&lt;0.001) and 85+ age group (HR=13.591, 95%CI =[6.327,29.192], P&lt;0.001) had significantly higher risk of all-cause death, respectively; compared with T1 patients, the T2 patients (HR=1.784, 95%CI=[1.481,2.148], P&lt;0.001), Patients with T3 (HR=2.413, 95%CI=[1.649,3.532], P&lt;0.001), patients with T4 (HR=2.943, 95%CI=[1.968,4.401], P&lt;0.001) are at significantly higher risk of total cause of death, respectively. Compared with patients of 20-34 years old, the 85+ age group (HR=2.923, 95%CI=[1.299,6.583], P=0.010) had significantly higher risk of breast cancer-specific death; compared with T1 patients, the T2 patients (HR=2.316, 95%CI=[1.709,3.139], P&lt;0.001), T3 patients (HR=2.421, 95%CI=[1.298,4.514], P=0.005), and T4 patients (HR=8.906, 95%CI=[5.394,14.713], P&lt;0.001) are at significantly higher risk of breast cancer-specific death, respectively; compared with patients with histological Grade I, the risk of breast cancer-specific death is significantly increased in patients with Grade III (HR=2.424, 95%CI=[1.021,5.751], P=0.045); compared with PR-positive patients, the risk of breast cancer specific death was significantly increased for PR-negative patients (HR=1.665, 95%CI=[1.141 , 2.431], P=0.008).Conclusion: Tumor size, histological grade, and hormone receptor status are independent prognostic factors for breast cancer-specific death in patients with HER2+ and LN- breast cancer. In clinical practice, patients can be recommended for single-targeted (H) or double-targeted (HP) therapy according to the individualized factor.
Citation Format: Ju Wang, Yi Zhang, Jun Jiang, Xiaowei Qi. Risk factors for all-cause death and breast cancer-specific death in patients with HER2-positive and lymph node negative breast cancer : A retrospective analysis based on SEER database (2010 to 2017) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-39.