Incidence of antibody–drug conjugate-related fatigue in patients with breast cancer: A systematic review and meta-analysis

Numerous studies have reported the efficacy of antibody–drug conjugates (ADCs) for treating breast cancer. However, during cytotoxic drug treatment, long-term disabling fatigue is common. Moreover, studies in the relevant literature have indicated that fatigue can significantly increase the incidence of depression and sleep disorders. Therefore, this meta-analysis aims to evaluate the incidence of fatigue in breast cancer survivors treated with ADCs. PubMed, EMBASE, Web of Science, and Cochrane Library databases were systematically searched for articles and conference abstracts published before March 16, 2023. Further, two authors independently extracted data from the included studies. The primary outcome of this study was the incidence of all-grade fatigue caused by the use of ADCs in patients with breast cancer. Finally, a random-effects model was used to calculate the incidence and 95% confidence intervals (CIs) of the outcome. Overall, 7963 patients from 31 studies were included in this meta-analysis to assess the incidence of fatigue caused by the use of approved and marketed ADCs in patients with breast cancer. Notably, the incidence of all-grade fatigue during ADC monotherapy was 39.84% (95% CI, 35.09%–44.69%). In subgroup analyses, among ADCs, the incidence of trastuzumab deruxtecan-induced fatigue was the highest, with an all-grade fatigue incidence of 47.05% (95% CI, 42.38%–51.75%). Meanwhile, the incidence of trastuzumab emtansine (T-DM1)-induced all-grade fatigue was 35.17% (95% CI, 28.87%–41.74%), which was the lowest among ADCs. Further, the incidence of all-grade fatigue due to sacituzumab govitecan was 42.82% (95% CI, 34.54%–51.32%), which was higher than that due to T-DM1. Moreover, the incidence of fatigue was higher with T-DM1 combination therapy than with monotherapy. Clinicians have highlighted the high incidence of ADC-related fatigue and its negative impact on patients' physical and mental health, making fatigue an important research variable. The results of this study will further contribute to a comprehensive understanding of ADCs, which have some clinical importance and are of great benefit to patients with breast cancer.