Clinicopathological characteristics and long-term prognosis of triple-negative breast cancer patients with HER2-Low expression: a retrospective propensity score-matched cohort study.

Purpose: The objective of the current research was to assess the clinicopathological characteristics and long-term prognosis of triple-negative breast cancer (TNBC) patients with human epidermal growth factor receptor 2 (HER2)-low status following breast surgery.
Methods: A total of 202 TNBC patients treated at Qingdao Central Hospital from January 2010 to December 2019 were included, comprising 71 HER2-low and 131 HER2-zero patients. Propensity score matching (PSM) was applied to minimize differences between the cohorts.
Results: HER2-low TNBC patients had lower histological grade, lower Ki-67 expression levels, and a higher prevalence of hypertension compared to HER2-zero TNBC patients. Before and after PSM, the HER2-low group consistently exhibited a lower recurrence rate and longer RFS compared to HER2-zero TNBC patients. HER2-low status was validated as an independent low-risk factor for RFS both pre-PSM (HR 0.354, 95% CI 0.178-0.706, p = 0.003) and post-PSM (HR 0.405, 95% CI 0.185-0.886, p = 0.024). No statistically significant differences in mortality rate and OS were observed, both before and after PSM.
Conclusions: HER2-low and HER2-zero TNBC patients show significant clinicopathological differences. Compared to HER2-zero, HER2-low status is linked to better long-term prognosis and serves as an independent low-risk factor for RFS in TNBC patients.
Competing Interests: Declarations. Ethical approval: The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Qingdao Central Hospital. Written informed consent requirement was waived by the Ethics Committee. Consent to publish: Not applicable. Competing interests: The authors declare no competing interests.
(© 2024. The Author(s).)