Strong CD8+ lymphocyte infiltration in combination with expression of HLA class I is associated with better tumor control in breast cancer patients treated with neoadjuvant chemotherapy

HLA-class-I expression loss, tumor microenvironment and breast cancer prognosis

Loss of HLA-class-I molecule expression by cancer cells is a frequent event in human tumors that may lead to immune evasion from cytotoxic T-cells. We examined the expression patterns of HLA-class-I molecules in a series of 175 patients with operable breast cancer (BCa). Extensive loss of BCa cell HLA-class-I expression was noted 76.6 % of patients (27.5 % complete loss). A significant association of HLA-preservation with high TIL-density (p = 0.001) was documented. Preservation of HLA was evident only in BCa carcinomas with low HIF1α expression and high TIL-density. Cell line experiments (MCF7 and T47D) showed that induction of HLAs in cancer cells following incubation with lymphocytes or IFNγ, was abrogated under hypoxic conditions. HLA-preservation was linked with better distant metastasis-free survival (p = 0.01), which was confirmed also in multivariate analysis (p = 0.02, HR 3.17). Studying the expression of HLA-class-I molecules in parallel with TIL-density and HIF1α expression may identify subgroups of BCa patients who would benefit from immunotherapy.

Assessment of cancer cell-expressed HLA class I molecules and their immunopathological implications

Immunotherapy using immune checkpoint inhibitors (ICIs) has shown superior efficacy compared with conventional chemotherapy in certain cancer types, establishing immunotherapy as the fourth standard treatment alongside surgical intervention, chemotherapy, and radiotherapy. In cancer immunotherapy employing ICIs, CD8-positive cytotoxic T lymphocytes are recognized as the primary effector cells. For effective clinical outcomes, it is essential that the targeted cancer cells express HLA class I molecules to present antigenic peptides derived from the tumor. However, cancer cells utilize various mechanisms to downregulate or lose HLA class I molecules from their surface, resulting in evasion from immune surveillance. Correlations between prognosis and the integrity of HLA class I molecules expressed by cancer cells have been consistently found across different types of cancer. This paper provides an overview of the regulatory mechanisms of HLA class I molecules and their role in cancer immunotherapy, with a particular emphasis on the significance of utilizing pathological tissues to evaluate HLA class I molecules expressed in cancer cells.

Metabolic targeting of cancer associated fibroblasts overcomes T-cell exclusion and chemoresistance in soft-tissue sarcomas

T cell-based immunotherapies have exhibited promising outcomes in tumor control; however, their efficacy is limited in immune-excluded tumors. Cancer-associated fibroblasts (CAFs) play a pivotal role in shaping the tumor microenvironment and modulating immune infiltration. Despite the identification of distinct CAF subtypes using single-cell RNA-sequencing (scRNA-seq), their functional impact on hindering T-cell infiltration remains unclear, particularly in soft-tissue sarcomas (STS) characterized by low response rates to T cell-based therapies. In this study, we characterize the STS microenvironment using murine models (in female mice) with distinct immune composition by scRNA-seq, and identify a subset of CAFs we termed glycolytic cancer-associated fibroblasts (glyCAF). GlyCAF rely on GLUT1-dependent expression of CXCL16 to impede cytotoxic T-cell infiltration into the tumor parenchyma. Targeting glycolysis decreases T-cell restrictive glyCAF accumulation at the tumor margin, thereby enhancing T-cell infiltration and augmenting the efficacy of chemotherapy. These findings highlight avenues for combinatorial therapeutic interventions in sarcomas and possibly other solid tumors. Further investigations and clinical trials are needed to validate these potential strategies and translate them into clinical practice.

Prognostic and Clinical Significance of Human Leukocyte Antigen Class I Expression in Breast Cancer: A Meta-Analysis

BACKGROUND

The value of human leukocyte antigen (HLA; also known as major histocompatibility complex) class I expression for the prediction of breast cancer survival outcomes remains unclear. We conducted a meta-analysis to explore the prognostic significance of this expression.

MATERIALS AND METHODS

We searched electronic databases to identify reports on associations of HLA class I protein or mRNA expression with survival outcomes and clinicopathological factors in the breast cancer context. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were used to conduct a quantitative meta-analysis.

RESULTS

The sample comprised eight studies involving 3590 patients. Only the classical HLA class Ia (HLA-ABC) molecules studies were included in this meta-analysis. Elevated HLA class I protein expression was found to be significantly related to better disease-free survival (DFS) (HR 0.58, 95% CI 0.35-0.95, P = 0.03), particularly among patients with triple-negative breast cancer (TNBC) (HR 0.31, 95% CI 0.18-0.52, P < 0.001), but not to overall survival. It was also associated with estrogen receptor (ER) negativity (OR 1.71, 95% CI 1.24-2.35, P = 0.001), progesterone receptor (PR) negativity (OR 1.49, 95% CI 1.22-1.81, P < 0.001), human epidermal growth factor receptor 2 (HER2) positivity (OR 1.51, 95% CI 1.18-1.94, P = 0.001), TNBC (OR 1.68, 95% CI 1.15-2.45, P < 0.01), high Ki-67 indices (OR 2.06, 95% CI 1.62-2.61, P < 0.001), and high nuclear grades (OR 2.67, 95% CI 2.17-3.29, P < 0.001).

CONCLUSION

This meta-analysis demonstrated that enhanced HLA class I protein expression is significantly associated with the better DFS of patients with breast cancer, especially TNBC, as well as with ER and PR negativity, HER2 positivity, TNBC, and high Ki-67 indices and nuclear grades. The immune target HLA class I may serve as a prognostic indicator for breast cancer.

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 value of CD8+ tumor-infiltrating T cells in patients with breast cancer: A systematic review and meta-analysis

CD8⁺ tumor-infiltrating lymphocytes have been regarded as potential biomarkers for cancer prognosis, while the prognostic effect of CD8⁺ tumor-infiltrating T cells remains controversial in breast cancer. In the present study, a meta-analysis was performed to evaluate the prognostic value of CD8⁺ T cells in breast cancer and the associations between CD8⁺ T cells and the pathological characteristics. The PubMed, Embase and the Cochrane Library were systematically searched entries added from the establishment of the database to November 2021 and prospective or retrospective studies of patients with breast cancer were included. The Newcastle-Ottawa Scale was used to assess the quality of evidence for each study. STATA 15.1 was used for the data analysis. A total of 14 studies comprising 22,222 patients were included in the final analysis and the pooled results suggested that a high CD8⁺ T-cell infiltration level was significantly related to better overall survival [hazard ratio (HR)=0.70, 95% confidence interval (CI): 0.60-0.82, P<0.001] and disease-free survival (HR=0.63, 95% CI: 0.49-0.81, P<0.001) for patients with breast cancer. In addition, a high CD8⁺ T-cell infiltration level was significantly associated with decreased expression of estrogen receptor [odds ratio (OR)=1.92, 95% CI: 1.30-2.85, P=0.001] and progesterone receptor (OR=1.66, 95% CI: 1.14-2.42, P=0.008), and increased human epidermal growth factor receptor 2 expression (OR=0.79, 95% CI: 0.66-0.94, P=0.010) in patients with breast cancer, while there was no significant association between CD8+ T-cell infiltration and age, tumor size or lymph node status of patients with breast cancer (P>0.05). In conclusion, CD8⁺ T-cell infiltration is of prognostic value in patients with breast cancer. High levels of CD8⁺ T-cell infiltration were related to improved prognosis, including OS and DFS, in patients with breast cancer.

Predictive and prognostic values of tumor infiltrating lymphocytes in breast cancers treated with neoadjuvant chemotherapy: A meta-analysis

BACKGROUND

This meta-analysis assessed the predictive and prognostic value of tumor infiltrating lymphocytes (TILs) in neoadjuvant chemotherapy (NACT) treated breast cancer and an optimal threshold for predicting pathologic complete response (pCR).

METHODS

A systematic search of PubMed, EMBASE and Web of Science electronic databases was conducted to identify eligible studies published before April 2022. Either a fixed or random effects model was applied to estimate the pooled hazard ratio (HR) and odds ratio (OR) for prognosis and predictive values of TILs in breast cancer patients treated with NACT. The study is registered with PROSPERO (CRD42020221521).

RESULTS

A total of 29 published studies were eligible. Increased levels of TILs predicted response to NACT in HER2 positive breast cancer (OR = 2.54 95%CI, 1.50-4.29) and triple negative breast cancer (TNBC) (OR = 3.67, 95%CI, 1.93-6.97), but not for hormone receptor (HR) positive breast cancer (OR = 1.68, 95 %CI, 0.67-4.25). A threshold of 20% of H & E-stained TILs was associated with prediction of pCR in both HER2 positive breast cancer (P = 0.035) and TNBC (P = 0.001). Moreover, increased levels of TILs (either iTILs or sTILs) were associated with survival benefit in HER2-positive breast cancer and TNBC. However, an increased level of TILs was not a prognostic factor for survival in HR positive breast cancer (pooled HR = 0.64, 95%CI: 0.03-14.1, P = 0.78).

CONCLUSIONS

Increased levels of TILs were associated with increased rates of response to NACT and improved prognosis for the molecular subtypes of TNBC and HER2-positive breast cancer, but not for patients with HR positive breast cancer. A threshold of 20% TILs was the most powerful outcome prognosticator of pCR.

Immunostimulatory Properties of Chemotherapy in Breast Cancer: From Immunogenic Modulation Mechanisms to Clinical Practice

Breast cancer (BC) is the most common malignancy among females. Chemotherapy drugs remain the cornerstone of treatment of BC and undergo significant shifts over the past 100 years. The advent of immunotherapy presents promising opportunities and constitutes a significant complementary to existing therapeutic strategies for BC. Chemotherapy as a cytotoxic treatment that targets proliferation malignant cells has recently been shown as an effective immune-stimulus in multiple ways. Chemotherapeutic drugs can cause the release of damage-associated molecular patterns (DAMPs) from dying tumor cells, which result in long-lasting antitumor immunity by the key process of immunogenic cell death (ICD). Furthermore, Off-target effects of chemotherapy on immune cell subsets mainly involve activation of immune effector cells including natural killer (NK) cells, dendritic cells (DCs), and cytotoxic T cells, and depletion of immunosuppressive cells including Treg cells, M2 macrophages and myeloid-derived suppressor cells (MDSCs). Current mini-review summarized recent large clinical trials regarding the combination of chemotherapy and immunotherapy in BC and addressed the molecular mechanisms of immunostimulatory properties of chemotherapy in BC. The purpose of our work was to explore the immune-stimulating effects of chemotherapy at the molecular level based on the evidence from clinical trials, which might be a rationale for combinations of chemotherapy and immunotherapy in BC.

Flow Cytometry Analysis to Detect Lapatinib-Induced Modulation of Constitutive and IFN-γ-Induced HLA Class I Expression in HER2-Positive Breast Cancer Cells

Drug-induced modulation of HLA molecules on cancer cell lines can easily be detected using flow cytometry and HLA-specific antibodies to ascertain the number of positive cells and their expression levels. Loss or downregulation of HLA-I molecules on cancer cells, a well-documented immune escape mechanism, may occur via activation and integration of numerous signalling pathways that are operative in cancer. Whereas IFN-γ, produced during an adaptive anti-tumor immune response upregulates HLA expression, activation of the human epidermal growth factor receptor 2 (HER2) pathway and its downstream signalling pathways are reported to decrease HLA-I. Here we describe the flow cytometry procedure used to determine whether lapatinib, known to negate HER2 signalling, increased HLA-I expression on HER2+ cell lines, in the presence and absence of IFN-γ. Contrary to our prediction, the flow cytometry data clearly show lapatinib-mediated downregulation of both constitutive and IFN-γ-induced HLA class I expression. These results, for which we do not yet have an explanation, may have important implications for our understanding of lapatinib resistance in metastatic HER2+ cancer.

Oncotype DX 21-gene test has a low recurrence score in both pure and mixed mucinous breast carcinoma

The Oncotype DX 21-gene test can be used to predict chemotherapy efficacy in patients with estrogen receptor (ER)-positive and HER2-negative breast cancer; however, the data on the 21-gene recurrence score (RS) for mucinous breast carcinoma (MBC) are limited. The present study aimed to evaluate the distribution pattern and clinical value of the 21-gene RS in patients with MBC. A total of 38 pure MBC (PMBC) and 11 mixed MBC (MMBC) cases were retrospectively analyzed, and a total of 29 ER-positive and HER2-negative MBCs underwent the Oncotype DX 21-gene test. There were no statistically significant differences between the PMBCs and MMBCs in age, tumor size and molecular subtype; however, patients with MMBC showed a significantly higher incidence rate of nodal metastases compared with that in patients with PMBC (72.7 vs. 16.2%, respectively). Following surgery, 87.8 and 59.2% of the enrolled patients received endocrine therapy and chemotherapy, respectively. With a median follow-up of 65.6 months, the 5-year disease-free survival and overall survival rates were 97.0 and 100.0%, respectively. The 21-gene test revealed that the proportions of patients with MBC categorized into low (RS <18), intermediate (RS ≥18-30) and high (RS ≥30) risk groups were 51.7, 44.8 and 3.5%, respectively, and there was no statistically significant difference between the PMBC and MMBC cases. Notably, among the genes in the 21-gene RS testing, the expression levels of cathepsin V, progesterone receptor (PR) and CD68 were significantly higher in the PMBC group compared with that in the MMBC group. In conclusion, the current study demonstrated that patients with MBC had a favorable prognosis, and both PMBC and MMBC cases had a low- and intermediate-risk RS, which suggests that a considerable proportion of patients may be able to avoid chemotherapy. In addition, the high expression level of PR, based on the 21-gene test in PMBCs, indicated that they may have a more favorable response to endocrine therapy than MMBCs.

Comprehensive analysis of the 21-gene recurrence score in invasive ductal breast carcinoma with or without ductal carcinoma in situ component

Background

Invasive ductal carcinoma (IDC) is often accompanied by ductal carcinoma in situ (DCIS). Whether the DCIS component affects the 21-gene recurrence score (RS) is unclear.

Methods

Consecutive ER-positive, HER2-negative, N0–1 patients with RS results were included. Patients were divided into pure IDC and IDC with DCIS (IDC/DCIS) groups. The RS, the expression of its 16 cancer genes and prognosis were compared between IDC and IDC/DCIS patients.

Results

A total of 1458 patients were enrolled, 320 of whom had concomitant DCIS. DCIS component was independently associated with lower RS (P = 0.038). IDC/DCIS patients more often had a low-risk RS (P = 0.018) or intermediate-risk RS (P = 0.024). Regarding individual genes in the RS panel, Ki67, CCNB1 and MYBL2 in the proliferation group and MMP11 and CTSL2 in the invasion group were significantly lower among IDC/DCIS patients than pure IDC patients. Among IDC/DCIS patients, lower RS was independently correlated with a higher DCIS proportion and lower DCIS grade. Within a median follow-up of 31 months, the DCIS component in IDC did not significantly influence prognosis.

Conclusions

IDC with DCIS component is associated with a lower 21-gene RS, possibly due to lower expression of proliferation and invasion genes. DCIS proportion and grade independently influenced the 21-gene RS in IDC/DCIS patients. Due to the relatively short follow-up period and low recurrence rate, the impact of the DCIS component in IDC on prognosis needs further evaluation.