Prognostic Influence of Residual Tumor-Infiltrating Lymphocyte Subtype After Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

Association of tumor-infiltrating lymphocytes with clinical outcomes in patients with triple-negative breast cancer receiving neoadjuvant chemotherapy: a systematic review and meta-analysis

OBJECTIVE

Triple-negative breast cancer (TNBC) presents a clinical challenge as an aggressive tumor, correlated with unfavorable prognosis. Tumor-infiltrating lymphocytes (TILs) have garnered interest as a potential prognostic biomarker. However, the disparity in outcomes between varying TILs rates remains inadequately explored.

METHODS

PubMed, Scopus, Web of Science, and Cochrane databases were searched for studies about the prognostic value of TILs in patients with TNBC receiving neoadjuvant chemotherapy. The hazard ratios (HRs) or odds ratios (ORs) were computed for binary endpoints, with 95% confidence intervals (CIs).

RESULTS

Twenty-nine studies were included, involving a population of six thousand one hundred sixty-one (80.41%) with TNBC. The cut-off TILs value ranged from 10 to 60%, with 50% being the most related value. Compared with the low-TIL expression group, the disease-free survival (DFS) (HR 0.71; 95% CI 0.61-0.82; p < 0.00001) and overall survival (OS) (HR 0.76; 95% CI 0.63-0.90; p = 0.002) rates showed significant improvement with higher TIL infiltrations. In the subgroup analyses of the lymphocyte subtypes CD4 + and CD8 + , there was statistical significance favoring higher TILs rates in both subtypes, each associated with improved DFS (HR 0.48; 95% CI 0.33-0.71; p = 0.0002) and OS (HR 0.53; 95% CI 0.36-0.78; p = 0.001), regardless of which cell subtype was predominantly infiltrated. The complete pathological response analysis showed better rates for the higher TIL group than the control for both the TIL (OR 1.29; 95% CI 1.13-1.48; p = 0.0003) and Ki-67 (OR 2.74; 95% CI 2.01-3.73; p < 0.00001) analyses.

CONCLUSION

Higher expressions of TILs in patients with TNBC were associated with improved significantly DFS, OS, and pCR outcomes.

Single-cell resolution characterization of myeloid-derived cell states with implication in cancer outcome

Tumor-associated myeloid-derived cells (MDCs) significantly impact cancer prognosis and treatment responses due to their remarkable plasticity and tumorigenic behaviors. Here, we integrate single-cell RNA-sequencing data from different cancer types, identifying 29 MDC subpopulations within the tumor microenvironment. Our analysis reveals abnormally expanded MDC subpopulations across various tumors and distinguishes cell states that have often been grouped together, such as TREM2+ and FOLR2+ subpopulations. Using deconvolution approaches, we identify five subpopulations as independent prognostic markers, including states co-expressing TREM2 and PD-1, and FOLR2 and PDL-2. Additionally, TREM2 alone does not reliably predict cancer prognosis, as other TREM2+ macrophages show varied associations with prognosis depending on local cues. Validation in independent cohorts confirms that FOLR2-expressing macrophages correlate with poor clinical outcomes in ovarian and triple-negative breast cancers. This comprehensive MDC atlas offers valuable insights and a foundation for futher analyses, advancing strategies for treating solid cancers.

Prognostic relevance of tumor‑infiltrating lymphocytes in residual tumor tissue from patients with triple‑negative breast cancer following neoadjuvant chemotherapy: A systematic review and meta‑analysis

Further adjuvant chemotherapy treatment can provide benefits to certain patients with triple-negative breast cancer (TNBC) that fail to achieve pathological complete response (pCR) after the administration of a neoadjuvant chemotherapy (NAC) regimen. However, biomarkers suitable for identifying patients likely to experience poor prognostic outcomes after undergoing additional adjuvant chemotherapy are currently lacking. Accordingly, the present meta-analysis was conducted to explore the relationship between tumor-infiltrating lymphocytes (TILs) or TIL subtypes (CD4+ or CD8+) in residual tumor (RT) tissue following NAC and TNBC patient prognosis. Relevant studies published through March 2023 were identified in Pubmed, The Cochrane Library, Embase and Web of Science databases. After excluding irrelevant studies, data were extracted from the remaining reports, while study quality was analyzed with the Newcastle-Ottawa Scale. Subsequent analyses were performed with Stata 14.0 and Review Manager 5.3. In total, seven relevant studies incorporating 1,202 patients were identified, all of which were retrospective cohort studies. Pooled analyses demonstrated that those patients exhibiting higher levels of RT TIL infiltration following NAC exhibited significantly improved recurrence-free, metastasis-free and event-free survival (RFS/MFS/EFS) compared with patients with lower RT TIL infiltration levels, together with an improved distant recurrence-free interval (DRFI) [hazard ratio (HR)=0.52; 95% confidence interval (CI)=0.39-0.69; P<0.00001]. In addition, patients exhibiting high RT TIL infiltration exhibited improved overall survival (OS) and breast cancer-specific survival (BCSS; HR=0.49; 95% CI=0.38-0.65; P<0.00001). Additional subgroup analyses revealed that patients with higher TIL infiltration levels or TIL subtype (CD4+ or CD8+) infiltration exhibited improved RFS/MFS/EFS/DRFI as compared with patients with lower levels of overall TIL or TIL subtype (CD4+ or CD8+) infiltration in RT tissue (HR=0.35, 95% CI=0.20-0.59, P<0.0001; HR=0.49, 95% CI=0.33-0.71, P=0.0002). Consistently, the OS/BCSS of patients exhibiting high levels of overall TIL or TIL subtype (CD4+ or CD8+) infiltration was increased compared with patients with lower levels of such infiltration (HR=0.33, 95% CI=0.19-0.59, P=0.0002; HR=0.55, 95% CI=0.41-0.76, P=0.0002). These data thus demonstrate that levels of overall TIL infiltration or infiltration by CD4+ or CD8+ TILs in RT following NAC can be used as a biomarker to reliably predict prognostic outcomes in patients with TNBC, in addition to highlighting possible targets that may guide the further immunotherapeutic management of these patients.

Programmed death receptor ligand-2 (PD-L2) bearing extracellular vesicles as a new biomarker to identify early triple-negative breast cancer patients at high risk for relapse

PURPOSE

Based on the tumor-promoting features of extracellular vesicles (EV) and PD-L1/2-bearing EV subpopulations (PD-L1/2_EV), we evaluated their potential as surrogate markers for disease progression or eligibility criteria for PD-1 immune checkpoint inhibition (ICI) approaches in early triple-negative breast cancer (TNBC).

METHODS

After enrichment of EV from plasma samples of 56 patients before and 50 after chemotherapy (CT), we determined levels of EV particle number and PD-L1/2_EV by nanoparticle tracking analysis or ELISA and associated the results with clinical status/outcome and the presence of distinct circulating tumor cells (CTC) subpopulations.

RESULTS

Compared to healthy controls, patients had a tenfold higher EV concentration and significantly elevated PD L2_EV but not PD L1_EV levels. The most important clinical implications were found for PD-L2_EV. High PD-L2_EV levels were associated with a significantly reduced 3-year progression-free and overall survival (PFS and OS). A loss of PD-L2_EV after CT was significantly more prominent in patients achieving pathological complete response (pCR). Increased pre-CT PD-L2_EV levels were found in patients having NOTCH1-positive or ERBB3-positive CTC. The presence of ERBB3-positive CTC combined with high pre-CT PD-L2_EV resulted in a shorter PFS.

CONCLUSION

This study highlights PD L2_EV as a promising biomarker for risk assessment of TNBC patients and represents the basic for additional studies introducing PD-L2_EV as an eligibility criterion for PD-1 ICI approaches.

The prognostic values of FOXP3+ tumor-infiltrating T cells in breast cancer: a systematic review and meta-analysis

BACKGROUND

Tumor microenvironment is infiltrated by many immune cells, of which Regulatory T (Treg) cells are usually considered as negative regulators of the immune responses. However, the effect of FOXP3⁺ (forkhead box transcription factor 3) Treg cells infiltrated into the tumor areas on the prognosis of breast cancer is controversial. This meta-analysis aimed to dissect the potential values of FOXP3⁺ tumor-infiltrating lymphocytes (TILs) as a prognosis predictor of breast cancer.

METHODS

After systematic retrieval of all relevant studies, 28 eligible articles were identified for meta-analysis. Odd ratio (OR), hazard ratio (HR), and 95% confidence interval (CI) were obtained for pooled analyses of pathological complete response (pCR), overall survival (OS), and corresponding forest plots and funnel plots were plotted, respectively.

RESULTS

Pooled results revealed that patients with higher levels of FOXP3⁺ TILs experienced better pCR (OR: 1.24, 95% CI 1.09-1.41) and OS (HR: 0.79, 95% CI 0.64-0.97). Subgroup analysis revealed that elevated FOXP3⁺ TILs were significantly associated with improved pCR (OR: 1.20, 95% CI 1.02-1.40) and OS (HR: 0.22, 95% CI 0.06-0.88) in human epidermal growth factor receptor 2 positive (HER2⁺) breast cancer patients. Furthermore, FOXP3⁺ TILs in the stromal area were statistically correlated with the favorable pCR (OR: 1.22, 95% CI 1.08-1.38) and OS (HR: 0.68, 95% CI 0.49-0.96).

CONCLUSIONS

The predictive role of FOXP3⁺ TILs in the prognosis of breast cancer is influenced by various factors such as molecular subtype of breast cancer and the location of Treg. In HER2⁺ breast cancer and triple-negative breast cancer, FOXP3⁺ TILs are associated with better pCR and OS. Additionally, FOXP3⁺ TILs in stromal represent a favourable prognosis.

Prognostic Implications of the Residual Tumor Microenvironment after Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer Patients without Pathological Complete Response

With a high risk of relapse and death, and a poor or absent response to therapeutics, the triple-negative breast cancer (TNBC) subtype is particularly challenging, especially in patients who cannot achieve a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). Although the tumor microenvironment (TME) is known to influence disease progression and the effectiveness of therapeutics, its predictive and prognostic potential remains uncertain. This work aimed to define the residual TME profile after NAC of a retrospective cohort with 96 TNBC patients by immunohistochemical staining (cell markers) and chromogenic in situ hybridization (genetic markers). Kaplan-Meier curves were used to estimate the influence of the selected TME markers on five-year overall survival (OS) and relapse-free survival (RFS) probabilities. The risks of each variable being associated with relapse and death were determined through univariate and multivariate Cox analyses. We describe a unique tumor-infiltrating immune profile with high levels of lymphocytes (CD4, FOXP3) and dendritic cells (CD21, CD1a and CD83) that are valuable prognostic factors in post-NAC TNBC patients. Our study also demonstrates the value of considering not only cellular but also genetic TME markers such as MUC-1 and CXCL13 in routine clinical diagnosis to refine prognosis modelling.