Atezolizumab therapy for advanced or metastatic triple-negative breast cancer (TNBC) was found to have a similar safety profile to those of previous trials and was associated with changes to the immune system in a recent retrospective study.
Triple-negative breast cancer (TNBC) refers to breast tumors that lack hormone receptors (HR) and human epidermal growth factor receptor 2 (HER2). Immune checkpoint inhibitors (ICI) in combination with chemotherapy is the recommended first-line treatment for triple-negative breast cancer (TNBC).
The absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) predict ICI effectiveness in certain malignancies. This study, published in the journal Clinical and Experimental Medicine, examined the clinical efficacy and safety of atezolizumab in routine clinical practice and the potential of systemic immune markers to predict clinical outcomes in advanced or metastatic TNBC patients.
Study Population
The study retrospectively included 36 TNBC patients who received atezolizumab. It examined systemic immune indicators, including dynamic changes, as predictors of atezolizumab-induced survival benefits. Patients averaged 52 years of age (range: 29–83). Eleven (30.6%) had advanced TNBC, 23 (63.9%) had previously received chemotherapy, 20 (55.6%) had ≥3 metastatic sites, and 23 (63.9%) had visceral metastases.
Longer Overall Survival Rate With a Low NLR Reported
Cut-off values for ALC (high: >1300/μL; low: ≤1300/μL) and NLR (high: >5; low: < 5) were used to compare median time to treatment failure (TTF) and overall survival (OS) based on baseline values. The median TTF was 116 days, while the median OS was not reached. Compared to patients with a high NLR at baseline and a subsequent increase at the beginning of the second cycle (SO2nd), those with a low NLR at baseline and a subsequent drop at the beginning of the second cycle (SO2nd) had a considerably longer OS.
Independent Predictors in Multivariate Analyses
The median TTF and OS were compared based on dynamic changes in ALC at the start of the second cycle and after treatment. The results were better for patients with high ALC and low NLR, but TTF was not significantly different. Low NLR and high ALC at baseline were independent predictors of longer OS and longer TTF, respectively, in multivariate analyses.
Metastases and Safety Profile in Patients
Patients with longer TTF had fewer visceral metastases and metastatic locations (≤3) than those with shorter TTF. All 36 patients experienced adverse events of varying severity. No new adverse events were observed. However, neutropenia (77.8%) and fatigue (63.9%) were prevalent. In 16 (37.2%) cases, grade 3 or 4 adverse events occurred. Hypo/hyperthyroidism in seven cases was potentially immune-related.
Source
Nakamoto, S., Shien, T., Itoh, M., Yamamoto, Y., Ohsumi, S., Yoshitomi, S., Hikino, H., Miyoshi, K., Notsu, A., Taira, N., Doihara, H., & Ikeda, M. (2023b). Systemic immunity markers are associated with clinical outcomes of atezolizumab treatment in patients with triple-negative advanced breast cancer: a retrospective multicenter observational study. Clinical and Experimental Medicine. https://doi.org/10.1007/s10238-023-01230-x
