Immune checkpoint inhibitors in first-line therapies of metastatic or early triple-negative breast cancer: a systematic review and network meta-analysis

Different Chemotherapy Regimens and Pathologic Complete Response in Triple-Negative Breast Cancer: An Updated Network Meta-Analysis of Phase 3 Trials

Background and Objectives: Currently, the standard treatment for non-metastatic triple-negative breast cancer (TNBC) consists of a systemic neoadjuvant (or perioperative) anthracycline plus taxane-based chemotherapy, delivered either sequentially or concomitantly. We performed a network meta-analysis (NMA) to compare the relative efficacy of different neoadjuvant treatments for TNBC in terms of pathologic complete response (pCR). Materials and Methods: The MEDLINE, Embase, and Cochrane databases were searched from database inception to 1 November 2023. Randomized clinical trials were used that enrolled adults with stage I-III TNBC and provided data on pCR defined as residual ypT0/TisN0M0. Between-group comparisons were estimated using risk ratios (RRs) with 95% credible intervals (95% CrIs). The primary outcome was the pCR rate. Results: 1129 citations were screened, and 12 randomized clinical trials were included. In Bayesian comparisons, all regimens, except anthracycline/taxanes plus gemcitabine or capecitabine, resulted in a higher pCR than the standard regimen in both direct and indirect comparisons. In particular, immunotherapy-based regimens resulted in more than double the pCR compared to historical regimens (RR = 2.3, 95% CI 1.9-2.9) and ranked as being the optimal regimen with a probability of 97%. Disease-free survival was better for immune checkpoint inhibitor-based chemotherapy (HR = 0.36, 95% 1.21-2.09) than for historical regimens. Conclusion: This meta-analysis confirmed that incorporating immunotherapy with neoadjuvant platinum-based chemotherapy is the best option to guarantee remarkable pathologic downstaging and improve clinical outcomes.

Addition of PD-1/PD-L1 inhibitors to chemotherapy for triple-negative breast cancer: a meta-analysis

Background

In recent years, the addition of immune checkpoint inhibitors (ICI) to chemotherapy (CT) has become a research hotspot in the therapy of metastatic triple-negative breast cancer. Nevertheless, controversial results have been revealed among the published randomized controlled trials. Hence, a meta-analysis was performed to assess the therapeutic effect of this treatment regimen.

Methods

Five English databases (PubMed, WOS, CENTRAL, Scopus, and Embase), and four Chinese databases (CBM, CNKI, VIP, and Wanfang), as well as oncological meetings, were systematically searched to identify eligible studies that assessed the addition of ICI to CT versus CT alone in metastatic triple-negative breast cancer. The pooled hazard ratios (HR) of progression-free survival (PFS) and overall survival (OS) were estimated using fixed- or random-effect model. Subgroup analyses were also performed in the intention-to-treat (ITT) and PD-L1-positive individuals.

Results

All told there are five eligible randomized controlled trials involving 3,000 patients were enrolled in this meta-analysis. Compared with CT alone, the ICI plus CT regimen significantly increased PFS in the ITT (HR = 0.80, 95% CI: 0.73-0.88) and PD-L1-positive (HR = 0.70, 95% CI: 0.62-0.79) populations, as well as OS in the ITT (HR = 0.89, 95% CI: 0.81-0.97) and PD-L1-positive populations (HR = 0.80, 95% CI: 0.71-0.91). Moreover, the PFS of sufferers treated with the combination strategy of ICI with CT increased alongside PD-L1 enrichment. A clinical benefit in terms of objective response rate was also distinctly observed in both populations treated with ICI plus CT. In the subgroup analysis, patients in the no prior CT subgroup experienced a striking increase in PFS in both populations; however, a difference was not observed in other subgroups.

Conclusions

The combination strategy striking improves PFS and OS in both ITT and PD-L1-positive populations, and PFS is prolonged with PD-L1 enrichment. Patients who do not receive CT prior to this treatment are associated with longer PFS in both populations.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42021289817.

From Reductionistic Approach to Systems Immunology Approach for the Understanding of Tumor Microenvironment

The tumor microenvironment (TME) is a complex and dynamic ecosystem that includes a variety of immune cells mutually interacting with tumor cells, structural/stromal cells, and each other. The immune cells in the TME can have dual functions as pro-tumorigenic and anti-tumorigenic. To understand such paradoxical functions, the reductionistic approach classifies the immune cells into pro- and anti-tumor cells and suggests the therapeutic blockade of the pro-tumor and induction of the anti-tumor immune cells. This strategy has proven to be partially effective in prolonging patients' survival only in a fraction of patients without offering a cancer cure. Recent advances in multi-omics allow taking systems immunology approach. This essay discusses how a systems immunology approach could revolutionize our understanding of the TME by suggesting that internetwork interactions of the immune cell types create distinct collective functions independent of the function of each cellular constituent. Such collective function can be understood by the discovery of the immunological patterns in the TME and may be modulated as a therapeutic means for immunotherapy of cancer.