Programmed Death Ligand 1 (PD-L1) Tumor Expression Is Associated with a Better Prognosis and Diabetic Disease in Triple Negative Breast Cancer Patients

Mass Spectrometry-Based Proteomics for Classification and Treatment Optimisation of Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) presents a significant medical challenge due to its highly invasive nature, high rate of metastasis, and lack of drug-targetable receptors, which together lead to poor prognosis and limited treatment options. The traditional treatment guidelines for early TNBC are based on a multimodal approach integrating chemotherapy, surgery, and radiation and are associated with low overall survival and high relapse rates. Therefore, the approach to treating early TNBC has shifted towards neoadjuvant treatment (NAC), given to the patient before surgery and which aims to reduce tumour size, reduce the risk of recurrence, and improve the pathological complete response (pCR) rate. However, recent studies have shown that NAC is associated with only 30% of patients achieving pCR. Thus, novel predictive biomarkers are essential if treatment decisions are to be optimised and chemotherapy toxicities minimised. Given the heterogeneity of TNBC, mass spectrometry-based proteomics technologies offer valuable tools for the discovery of targetable biomarkers for prognosis and prediction of toxicity. These biomarkers can serve as critical targets for therapeutic intervention. This review aims to provide a comprehensive overview of TNBC diagnosis and treatment, highlighting the need for a new approach. Specifically, it highlights how mass spectrometry-based can address key unmet clinical needs by identifying novel protein biomarkers to distinguish and early prognostication between TNBC patient groups who are being treated with NAC. By integrating proteomic insights, we anticipate enhanced treatment personalisation, improved clinical outcomes, and ultimately, increased survival rates for TNBC patients.

Evaluating the Prognostic Role of the PAM50 Signature and Selected Immune-Related Signatures for Recurrence in Patients With T1abN0 Breast Cancer

BACKGROUND

De-escalation of adjuvant treatment in patients with T1abN0 breast cancer is discussed internationally. Identification of new prognostic factors in these patients may assist this de-escalation. The PAM50 signature and tumor inflammation signature (TIS), Programmed Cell Death Protein 1 (PD-1) and Programmed Cell Death Ligand 1 (PD-L1) signatures are possible prognostic factors for recurrence.

MATERIALS AND METHODS

Danish patients with T1abN0 breast cancer diagnosed between 2007-2016 were identified, the NanoString Breast Cancer 360 Panel was performed on tissue samples from cases with recurrence matched 1:1 with controls without recurrence (n = 234). The association between gene signatures and recurrence was analyzed with conditional logistic regression.

RESULTS

Patients with the basal-like subtype had higher values of TIS, PD-1 and PD-L1 scores compared with other subtypes. Patients with higher PD-L1 score had significantly lower odds of recurrence (odds ratio [OR] 0.61, P = .01). Likewise, an increased TIS score was associated to lower, but nonsignificant odds of recurrence (OR 0.76, P = .07). Patients with human epidermal growth factor receptor 2 (HER2)-enriched subtype had significantly higher odds of recurrence compared with patients with luminal A subtype (OR 4.8, P = .03).

DISCUSSION

PAM50 and immune-related signatures provide important prognostic information in patients with T1abN0 breast cancer, which may refine the risk assessment in these patients.

PD-L1 intrinsically promotes the proliferation of breast cancer cells through the SKP2-p27/p21 axis

BACKGROUND

PD-L1 intrinsically promotes tumor progression through multiple mechanisms, which potentially leads to resistance to anti-PD-1/PD-L1 therapies. The intrinsic effect of PD-L1 on breast cancer (BC) cell proliferation has not been fully elucidated.

METHODS

we used proteomics, gene expression knockdown (KD), quantitative immunofluorescence (qIF), western blots, functional assays including colony-forming assay (CFA) and real-time cell analyzer (RTCA), and in vivo data using immunohistochemistry in breast cancer patients.

RESULTS

PD-L1 promoted BC cell proliferation by accelerating cell cycle entry at the G1-to-S phase transition. Global proteomic analysis of the differentially expressed nuclear proteins indicated the involvement of several proliferation-related molecules, including p21CIP1/WAF1. Western blotting and qIF demonstrated the higher expression of SKP2 and the lower expression of p21CIP1/WAF1 and p27Kip1 in PD-L1 expressing (PD-L1pos) cells as compared to PD-L1 KD (PD-L1KD) cells. Xenograft-derived cells and the TCGA BC dataset confirmed this relationship in vivo. Functionally, CFA and RTCA demonstrated the central role of SKP2 in promoting PD-L1-mediated proliferation. Finally, immunohistochemistry in 74 breast cancer patients confirmed PD-L1 and SKP-p21/p27 axis relationship, as it showed a highly statistically significant correlation between SKP2 and PD-L1 expression (p < 0.001), and both correlated significantly with the proliferation marker Ki-67 (p < 0.001). On the other hand, there was a statistically significant inverse relationship between PD-L1 and p21CIP1/WAF1 expression (p = 0.005). Importantly, double negativity for p21CIP1/WAF1 and p27Kip1 correlated significantly with PD-L1 (p < 0.001), SKP2 (p = 0.002), and Ki-67 (p = 0.002).

CONCLUSIONS

we have demonstrated the role of the SKP2-p27/p21 axis in intrinsic PD-L1-enhanced cell cycle progression. Inhibitors of SKP2 expression can alleviate resistance to ICPIs.

Contribution of tumour and immune cells to PD-L1 expression as a predictive biomarker in metastatic triple-negative breast cancer: exploratory analysis from KEYNOTE-119

The efficacy of pembrolizumab monotherapy versus chemotherapy increased with increasing programmed death ligand 1 (PD-L1) expression, as quantified by combined positive score (CPS; PD-L1 expression on both tumour cells and immune cells) in patients with previously treated metastatic triple-negative breast cancer (mTNBC) in the phase 3 KEYNOTE-119 study. This exploratory analysis was conducted to determine whether the expression of PD-L1 on tumour cells contributes to the predictive value of PD-L1 CPS in mTNBC. PD-L1 expression in tumour samples was assessed using PD-L1 IHC 22C3 pharmDx and quantified using both CPS and tumour proportion score (TPS; PD-L1 expression on tumour cells alone). Calculated immune cell density (CID) was defined as CPS minus TPS. The ability of each scoring method (CPS, TPS, and CID) to predict clinical outcomes with pembrolizumab was evaluated. With pembrolizumab, the area under the receiver operating characteristic curve was 0.69 (95% CI = 0.58-0.80) for CPS, 0.55 (95% CI = 0.46-0.64) for TPS, and 0.67 (95% CI = 0.56-0.77) for CID. After correction for cutoff prevalence, CPS performed as well as, if not better than, CID with respect to predicting objective response rate, progression-free survival, and overall survival. Data from this exploratory analysis suggest that, although PD-L1 expression on immune cells alone is predictive of response to programmed death 1 blockade in mTNBC, adding tumour PD-L1 expression assessment (i.e. CPS, which combines immune cell and tumour cell PD-L1 expression) may improve prediction. PD-L1 CPS thus remains an effective and broadly applicable uniform scoring system for enriching response to programmed death 1 blockade with pembrolizumab in mTNBC as well as other tumour types.

Frequency of Programmed Death Receptor Ligand 1 Expression and Clinicopathological Factors Associated With Metastatic Triple-Negative Breast Cancer at a Tertiary Cancer Care Centre in South India

Purpose Triple-negative breast cancer (TNBC) has a poor outcome compared to other subtypes. Immune checkpoint inhibitors (ICIs) have changed the treatment paradigm in metastatic diseases as well as in neoadjuvant setting. The response to these agents is affected by programmed death ligand 1 (PDL1) receptor expression which are reported objectively as a score. PDL1 is a prognostic marker also. Here, we present clinicopathological characteristics of metastatic TNBCs, report the proportion of PDL1 expression and its association with clinicopathological factors as well as survival. Methods This is a prospective study carried out at a tertiary cancer care centre in South India. Case records of all breast cancer patients treated in two years between August 2021 and July 2023 were reviewed, patients with metastatic TNBC were selected. Patient's characteristics, histological features, molecular profile, and treatment were analyzed. PDL1 testing was carried out on pretreatment tumor tissue sections with immunohistochemistry (IHC) (Dako 22C3). PDL1 staining was interpreted as negative or positive based on combined positive score (CPS), with an expression less than 10 considered negative. Results A total of 118 patients were analyzed. With a median age of 46 years (36-65 years), 52.5% (62/118) were premenopausal. Family history of Ca Breast was seen in 22% (26/118) patients. A majority of patients had left-sided tumor 55.9% (66/118). Visceral metastasis was more common 96.6% (82/118) than skeletal. Radical intent of treatment was adopted in 10% as patients had oligometastatic disease at presentation. As front-line treatment, anthracycline-based chemotherapy was administered to the majority 54.2% (64/118). The PDL1 expression with CPS more or equal to 10 was seen in 32.2% (38/118) patients. Survival was associated with menopausal status (p value=0.000) and family history (p value=0.028) but not with PDL1 nor sidedness in our study. Estimated survival at 12 months in PDL1 negative case is 10 ± 0.29 months, while in PDL1 positive case it is slightly more at 10 ± 0.75 months, but difference was not found to be statistically significant (p value=0.15). Conclusion TNBCs are highly aggressive subtype with limited treatment options and poorer outcomes. Our study shows PDL1 expression in 31.66% of the cases similar to other literature from India. Survival is associated with menopausal status and family history. No association was found between survival and PDL1 as well sidedness in our study.

Revolutionizing the battle against locally advanced breast cancer: A comprehensive insight into neoadjuvant radiotherapy

Breast cancer (BC) constitutes one of the most pervasive malignancies affecting the female population. Despite progressive improvements in diagnostic and therapeutic technologies, leading to an increased detection of early stage BCs, locally advanced breast cancer (LABC) persists as a significant clinical challenge. Owing to its poor overall survival (OS) rate, elevated recurrence rate, and high potential for distant metastasis, LABC prominently impacts the comprehensive efficacy of BC treatments. Radiotherapy, encompassing preoperative, intraoperative, and postoperative modalities, is acknowledged as an effective strategy for mitigating BC metastasis and enhancing survival rates among patients. Nevertheless, the domain of preoperative neoadjuvant radiotherapy (NART) remains conspicuously underexplored in clinical studies. Available research suggests that NART can induce tumor volume reduction, provoke fibrotic changes in tumor and adjacent normal tissues, thereby mitigating intraoperative cancer propagation and enhancing the quality of life for LABC patients. This manuscript seeks to provide a review of contemporary research pertaining to LABC and its preoperative radiotherapy.

The Programmed Cell Death Ligand 1 and Lipocalin 2 Expressions in Primary Breast Cancer and Their Associations with Molecular Subtypes and Prognostic Factors

Purpose

Breast cancers exhibit molecular heterogeneity, leading to diverse clinical outcomes and therapeutic responses. Immune checkpoint inhibitors targeting PD-L1 have shown promise in various malignancies, including breast cancer. Lipocalin 2 (LCN2) has also been associated with tumor aggressiveness and prognostic potential in breast cancers. However, the expression of PD-L1 and LCN2 in breast cancer subtypes and their prognostic implications remains poorly investigated.

Methods

A retrospective analysis of 89 primary breast cancer cases was conducted to assess PD-L1 and LCN2 expressions using immunohistochemistry. Cases were classified into four different molecular subtypes based on ER, PR, HER2, and Ki-67 status. Associations between PD-L1 and LCN2 expressions and various prognostic factors were examined.

Results

Although low expression of LCN2 (Allred score of <3) was observed even in normal breast tissue, LCN2 expression with increasing Allred score (≥3) positively correlated with the histological grade, high Ki-67 proliferation index, and ER/PR negativity. Significant elevations of LCN2 and PD-L1 expressions were observed in triple-negative and HER2-positive breast cancers.

Conclusion

The results of the study highlight the association of LCN2 with known prognostic factors and molecular subtypes. To identify potential immunotherapy recipients, it would be useful to evaluate LCN2 as well as PD-L1 immune targets in different subgroups of breast cancer patients. Further studies with larger patient numbers are warranted to validate these observations and establish standardized scoring criteria for LCN2 expression assessment.

Novel Dual-Mode NIR-II/MRI Nanoprobe Targeting PD-L1 Accurately Evaluates the Efficacy of Immunotherapy for Triple-Negative Breast Cancer

Background

Durable responses to immune-checkpoint blocking therapy (ICT) targeting programmed cell death protein-1/ligand-1 (PD-1/PD-L1) have improved outcomes for patients with triple negative breast cancer (TNBC). Unfortunately, only 19-23% of patients benefit from ICT. Hence, non-invasive strategies evaluating responses to therapy and selecting patients who will benefit from ICT are critical issues for TNBC immunotherapy.

Methods

We developed a novel nanoparticle-Atezolizumab (NPs-Ate) consisting of indocyanine green (ICG), gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA), human serum albumin (HSA), and Atezolizumab. The efficiency of Gd-DTPA linking was verified using mass spectrometry, and the size of NPs-Ate was characterized using Nano-flow cytometry. The synthesized NPs-Ate were evaluated for fluorescence stability, penetration depth, and target specificity. TNBC cell lines and tumor-bearing mice models were used to identify the feasibility of this dual-modal second near-infrared/magnetic resonance imaging (NIR-II/MRI) system. Additionally, ICT combination with chemotherapy or radiotherapy in TNBC tumor-bearing mice models were used to assess dynamic changes of PD-L1 and predicted therapeutic responses with NPs-Ate.

Results

Atezolizumab, a monoclonal antibody, was successfully labeled with ICG and Gd-DTPA to generate NPs-Ate. This demonstrated strong fluorescence signals in our NIR-II imaging system, and relaxivity (γ1) of 9.77 mM-1 s-1. In tumor-bearing mice, the NIR-II imaging signal background ratio (SBR) reached its peak of 11.51 at 36 hours, while the MRI imaging SBR reached its highest as 1.95 after 12 hours of tracer injection. NPs-Ate specifically targets cells and tumors expressing PD-L1, enabling monitoring of PD-L1 status during immunotherapy. Combining therapies led to inhibited tumor growth, prolonged survival, and increased PD-L1 expression, effectively monitored using the non-invasive NPs-Ate imaging system.

Conclusion

The NIR-II/MRI NPs-Ate effectively reflected PD-L1 status during immunotherapy. Real-time and non-invasive immunotherapy and response/prognosis monitoring under NIR-II/MRI imaging guidance in TNBC is a promising and innovative technology with potential for extensive clinical applications in the future.

The PD-1 single-nucleotide polymorphism rs11568821 and rs2227981 as a novel prognosis model in a triple-negative breast cancer patient

INTRODUCTION

The aim of the study is to determine the relationship between polymorphisms rs11568821 C/T and at rs2227981 G/A in the programmed cell death 1 gene (PDCD1) and the clinicopathologic characteristics of triple negative breast cancer patient (TNBC).

MATERIAL AND METHODS

The study included 30 TNBC patients and 30 healthy controls. Genotyping was performed with allelic discrimination using PCR with TaqMan SNP Genotyping Assays.

RESULTS

The presence of CC/CT in rs11568821and GG/AG in rs2227981 were not associated with the risk of progression of TNBC. The correlation between rs11568821 minor allele distribution and risk of TNBC has borderline significance (p = 0.0619). The rs2227981 polymorphism has a significant association with grade G (G3, p = 0.0229). There was a trend toward significance (p = 0.063448) in the minor allele presentation and Ki67 > 20% for rs2227981. Other clinical features (e.g. age, TNM stage) did not significantly correlate with the rs11568821 or the rs2227981 polymorphism.

CONCLUSION

rs2227981 is associated with grading; hence PDCD1 can be used as a prognostic marker in TNBC.

Narrative review on the role of immunotherapy in early triple negative breast cancer: unveiling opportunities and overcoming challenges

Background and Objective

Triple negative breast cancer (TNBC) represents a highly aggressive breast cancer subtype, historically managed with chemotherapy regimens predominantly involving anthracyclines and taxanes, yielding unfavorable prognoses. This review endeavors to offer a thorough examination of the present state of treatment strategies for early stage triple negative breast cancer (eTNBC), with a particular emphasis on immunotherapy modalities, combination therapies, predictive biomarkers, and ongoing clinical trials. The principal aim of this review is to meticulously assess the available literature, ascertain significant discoveries, and engage in discussions regarding their potential implications for future research endeavors, clinical applications, and policy formulation.

Methods

This review was conducted using PubMed and Google Scholar databases, with the latest update performed in March 2023. The search strategy was designed to ensure a comprehensive analysis of the literature, with a focus on recent advancements.

Key Content and Findings

We critically assess the current eTNBC treatment landscape, covering efficacy and limitations of monotherapy, combination therapies, and predictive biomarkers. We highlight promising results from recent trials, address controversies surrounding chemotherapy, and explore optimal approaches for adjuvant and neoadjuvant therapy (NAT). Insights into personalized treatment strategies, ongoing trials, and future perspectives are provided, advancing our understanding of therapeutic options for eTNBC.

Conclusions

Through a comprehensive analysis of the literature, this review highlights the potential of immunotherapy, particularly in combination with chemotherapy, as a promising approach for treating eTNBC. However, further research is warranted to optimize treatment strategies, refine patient selection criteria, and identify reliable biomarkers for predicting response to immune checkpoint inhibitors (ICIs). The findings of this review hold significant implications for future research, clinical practice, and policy-making, offering valuable insights into the current challenges and advancements in eTNBC treatment. Ultimately, this knowledge can contribute to improved patient outcomes, enhanced quality of life, and the development of more effective therapeutic approaches for eTNBC.

HUVECs affect HuT-78 cell apoptosis and cytokine production via the HIF-1α-PD-L1/PD-1 pathway under hypoxia

We investigated whether human umbilical vein endothelial cells (HUVECs) under hypoxic conditions can suppress the production of cytokines in Hut-78 cells via the HIF-1α/PD-L1/PD-1 pathway, and the intervention effect of Nivolumab. HUVECs and HuT-78 cells were monocultured or cocultured in a tri-gas incubator with or without Nivolumab pretreatment. Real-time PCR, western blotting, and protein chips were used. Transcriptional regulation of PD-L1 and PD-1 by HIF-1α was analyzed by ChIP-qPCR and luciferase reporter gene assays. Apoptosis was assessed by flow cytometry. In HuT-78 cells, hypoxic monoculture significantly increased the expression of HIF-1α, PD-1, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, IFN-α, and Bax, decreased the expression of Bcl-2, and resulted in increased apoptosis. In comparison to hypoxic monoculture, hypoxic coculture significantly reduced the expression of IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, and IFN-α, as well as Bcl-2, in HuT-78 cells. Meanwhile, Bax expression was significantly increased with elevated apoptosis in HuT-78 cells. However, pretreatment with Nivolumab significantly antagonized the reduction in cytokines and the elevation in apoptosis in HuT-78 cells. Chip-qPCR and luciferase reporter gene assays demonstrated that hypoxia significantly increased the binding of HIF-1α to the upstream regulatory regions of PD-1 at -63 and -66 bp and PD-L1 at -571 bp, promoting their transcription. Therefore, HUVECs under hypoxia can reduce cytokine production and inhibit their own apoptosis in co-culture with HuT-78 cells via the HIF-1α/PD-L1/PD-1 pathway. These findings provide new clues for exploring the combined use of immune checkpoint inhibitors and anti-angiogenic drugs in clinical settings.

Association of PD-L1 and p16 expression with clinicopathological parameters in oral cavity and oropharyngeal squamous cell carcinoma

BACKGROUND

High expression of PD-L1 in tumour cells is associated with a higher response rate to immune checkpoint inhibitors, which target T regulatory pathways. p16 is a surrogate marker for human papilloma virus associated cancers. The present study was conducted to evaluate PD-L1 and p16 expression in head and neck squamous cell carcinomas and its correlation with clinicopathological parameters.

MATERIALS AND METHODS

Histologically confirmed cases of head and neck squamous cell carcinomas were evaluated for PD-L1 and p16 expression along with its correlation with grade and site of the tumour.

RESULTS

Out of 40 cases, 21 (52.5 %) showed positive immunoreactivity for PD-L1 while 13 (32.5 %) were positive for p16. A significant association was observed between PD-L1 and p16 expression in the oropharynx (p value= 0.035). No significant association could be established between clinicopathological parameters and PD-L1/ p16 expression or between PD-L1 and p16 in the oral cavity.

CONCLUSION

PD-L1 expression shows a positive association with p16 in oropharyngeal squamous cell carcinomas. Immune checkpoint inhibitors against PD-L1 can be used in carcinomas with positive expression for PD-L1.

Study of PD-L1 Expression with Association of Pathological Factors and Molecular Subtypes in Breast Carcinoma

Background Programmed death ligand 1 (PD-L1), expressed on cancer cells, shows varied results in the prognosis of breast cancer. This study was conducted to study the expression of PD-L1 in breast carcinoma and to correlate it with pathological, molecular classification and prognostic factors.

Materials and Methods PD-L1 expression was correlated with tumor size, histopathological grade, necrosis, lymphovascular, perineurial invasion, lymph node metastasis, molecular classification, and survival in breast carcinoma cases.

Results Fifty cases were included which showed statistically significant difference of PD-L1 with mean age, tumor size, histopathological grade, lymphovascular emboli, and lymph node metastasis (p < 0.05). Estrogen receptor was strongly positive in 46%, progesterone receptor in 42%, and PD-L1 in 6% of cases. No statistically significant difference between pathological tumor–node–metastasis (TNM) staging and PD-L1 expression (p = 0.354) was observed. Receptor operating characteristic curve analysis showed that at the cutoff of PD-L1 greater than 120, specificity was 56.1%, sensitivity 66.7%, negative predictive value 88.5%, and positive predictive value 25% for predicting living status.

Conclusion PD-L1 is associated with poor prognostic factors including tumor size, histopathological grade, lymphovascular emboli, and lymph node metastasis in breast carcinoma. However, no significant association was observed between PD-L1 and pathological TNM stage or molecular subtypes of breast carcinoma. It is suggested that immunohistochemical reporting of PD-L1 should be standardized so that it is reproducible and reliable for the evaluation of breast carcinoma. Further, larger studies with extended follow-ups are recommended so that the exact role of PD-L1 as a prognostic marker in breast carcinoma could be ascertained.

PD-L1-Positive High-Grade Triple-Negative Breast Cancer Patients Respond Better to Standard Neoadjuvant Treatment-A Retrospective Study of PD-L1 Expression in Relation to Different Clinicopathological Parameters

Triple negative breast cancer (TNBC) is typically a high-grade breast cancer with poorest clinical outcome despite available treatment modalities with chemo-, immuno- and radiotherapy. The status of tumor-infiltrating lymphocytes (TILs) is a prognostic factor closely related to programmed death ligand 1 (PD-L1) expressed on T lymphocytes modulating antitumor immunity. Immune-checkpoint inhibitors (ICI) are showing promising results in a subset of breast cancer patients in both neo- and adjuvant settings. Pathologic complete response (pCR) after neoadjuvant treatment was found to be associated with better prognosis. We analyzed the prognostic and predictive significance of PD-L1 (SP142 assay) immunohistochemical expression on TNBC patients' samples as illustrated by pCR with regard to its relation to treatment regimen, stage, BRCA mutational status and outcome. Furthermore, we analyzed a few other clinicopathological parameters such as age, TILs and proliferation index. The study highlighted a positive role of PD-L1 evaluation for personalized pCR probability assessment. Although considerable research was made on comparison of PD-L1 level in TNBC with different patient parameters, to our best knowledge, the relation of PD-L1 status to pCR while taking treatment regimen and stage into consideration was so far not investigated.

Programmed death-ligand 1 (PD-L1) expression predicts response to neoadjuvant chemotherapy in triple-negative breast cancer: A systematic review and meta-analysis

Background: In patients with metastatic triple-negative breast cancer (TNBC), PD-L1 expression has been demonstrated to predict response to immunotherapy. It is unclear whether PD-L1 expression measured with currently available validated assays can predict chemotherapy response in patients with non-metastatic TNBC.Methods: We conducted a systematic review and meta-analysis of clinical studies to assess the PD-L1 expression as a predictor of response to chemotherapy in non-metastatic TNBC using validated assays. The primary endpoint was pathological complete response (pCR) rate to neoadjuvant chemotherapy. Secondary endpoints included the prevalence of PD-L1 expression in non-metastatic TNBC and its impact on disease-free survival (DFS) and overall survival (OS). Moreover, RNA sequence data from the TCGA breast cancer cohort was used to define the relationship between PDCD1 and response to chemotherapy and prognosis.Results: Nineteen studies were eligible for the meta-analysis with a total of 2403 patients with non-metastatic TNBC disease. The PD-L1-positive cohort had a significantly higher likelihood of achieving pCR with neoadjuvant chemotherapy (pooled odds ratio =1.95; 95% CI= 1.39-2.73, p <0.0001). In studies which reported long-term outcomes, PD-L1 positivity was associated with significantly better DFS and OS compared to PD-L1 negative patients (pooled hazard ratio= 0.51; 95% CI= 0.35-0.74, p< 0.0001 and 0.51; 95% CI= 0.27-0.94, p = 0.031, respectively). Transcriptomic data suggested that PD-L1 expression is a surrogate marker for the upregulation of key immune-related genes that mediate response to chemotherapy in TNBC.Conclusion: This analysis clearly shows that patients with PD-L1 positive TNBC respond better to neoadjuvant chemotherapy and are associated with better survival outcomes compared to patients with PD-L1 negative tumors. The newly distinct quadruple negative breast cancer (QNBC) subtype should be defined as the BC subtype with the poorest outcome in the non-metastatic setting, highlighting the need for more aggressive therapy approaches.

Prognostic significance of programmed death-1 and programmed death ligand-1 proteins in breast cancer

In numerous studies related to tumor prognosis, programmed death-ligand 1 (PD-L1) has been identified as a biomarker. This work aimed to determine the prognostic importance of PD-L1 in breast cancer. We searched electronic databases such as PubMed, Google scholar, home pages of publishing groups, medical, clinical, and pharmaceutical sciences journals, as well as other relevant sources to discover the importance of PD-1 and PD-L1 expression in breast cancer therapies and also recurrence. The keywords used in this search were autoimmunity, programmed cell death, PD-L1 or PD-1, and breast cancer. Our inclusion criteria included studies showing the synergy between the expression of PD-L1 and PD-1 in primary breast cancers as prognostic markers and this research was limited to humans only. We included review articles, original research, letters to the editor, case reports, and short communications in our study, published in English. We focused our work on PD-L1 mRNA expression in breast cancer cell lines. PD-L1 expression has been decisively demonstrated to be a high-risk factor for breast cancer with a bad prognosis.

PD-L1 Protein Expression Is Associated With Good Clinical Outcomes and Nomogram for Prediction of Disease Free Survival and Overall Survival in Breast Cancer Patients Received Neoadjuvant Chemotherapy

Objective

This study aims to investigate the potential prognostic significance of programmed death ligand-1 (PD-L1) protein expression in tumor cells of breast cancer patients received neoadjuvant chemotherapy (NACT).

Methods

Using semiquantitative immunohistochemistry, the PD-L1 protein expression in breast cancer tissues was analyzed. The correlations between PD-L1 protein expression and clinicopathologic characteristics were analyzed using Chi-square test or Fisher’s exact test. The survival curve was stemmed from Kaplan-Meier assay, and the log-rank test was used to compare survival distributions against individual index levels. Univariate and multivariate Cox proportional hazards regression models were accessed to analyze the associations between PD-L1 protein expression and survival outcomes. A predictive nomogram model was constructed in accordance with the results of multivariate Cox model. Calibration analyses and decision curve analyses (DCA) were performed for the calibration of the nomogram model, and subsequently adopted to assess the accuracy and benefits of the nomogram model.

Results

A total of 104 breast cancer patients received NACT were enrolled into this study. According to semiquantitative scoring for IHC, patients were divided into: low PD-L1 group (61 cases) and high PD-L1 group (43 cases). Patients with high PD-L1 protein expression were associated with longer disease free survival (DFS) (mean: 48.21 months vs. 31.16 months; P=0.011) and overall survival (OS) (mean: 83.18 months vs. 63.31 months; P=0.019) than those with low PD-L1 protein expression. Univariate and multivariate analyses indicated that PD-L1, duration of neoadjuvant therapy, E-Cadherin, targeted therapy were the independent prognostic factors for patients’ DFS and OS. Nomogram based on these independent prognostic factors was used to evaluate the DFS and OS time. The calibration plots shown PD-L1 based nomogram predictions were basically consistent with actual observations for assessments of 1-, 3-, and 5-year DFS and OS time. The DCA curves indicated the PD-L1 based nomogram had better predictive clinical applications regarding prognostic assessments of 3- and 5-year DFS and OS, respectively.

Conclusion

High PD-L1 protein expression was associated with significantly better prognoses and longer DFS and OS in breast cancer patients. Furthermore, PD-L1 protein expression was found to be a significant prognostic factor for patients who received NACT.

Effector memory cytotoxic CD3+/CD8+/CD45RO+ T cells are predictive of good survival and a lower risk of recurrence in triple-negative breast cancer

Triple-negative breast cancer (TNBC) with high tumour-infiltrating lymphocytes (TILs) has been associated with a promising prognosis. To better understand the prognostic value of immune cell subtypes in TNBC, we characterised TILs and the interaction between tumour cells and immune cell subtypes. A total of 145 breast cancer tissues were stained by multiplex immunofluorescence (mIF), including panel 1 (PD-L1, PD-1, CD3, CD8, CD68 and CK) and panel 2 (Foxp3, Granzyme B, CD45RO, CD3, CD8 and CK). Phenotypes were analysed and quantified by pathologists using InForm software. We found that in the ER-negative (ER <1% and HER2-negative) group and the ER/PR-low positive (ER 1-9% and HER2-negative) group, 11.2% and 7.1% of patients were PD-L1⁺ by the tumour cell score, 29.0% and 28.6% were PD-L1⁺ by the modified immune cell score and 30.8% and 32.1% were PD-L1⁺ by the combined positive score. We combined ER-negative and ER/PR-low positive cases for the survival analysis since a 10% cut-off is often used in clinical practice for therapeutic purposes. The densities of PD-L1⁺ tumour cells (HR: 0.366, 95% CI: 0.138-0.970; p = 0.043) within the tumour compartment and CD3⁺ immune cells in the total area (tumour and stromal compartments combined) (HR: 0.213, 95% CI: 0.070-0.642; p = 0.006) were favourable prognostic biomarkers for overall survival (OS) in TNBC. The density of effector/memory cytotoxic T cells (CD3⁺CD8⁺CD45RO⁺) in the tumour compartment was an independent prognostic biomarker for OS (HR: 0.232, 95% CI: 0.086-0.628; p = 0.004) and DFS (HR: 0.183, 95% CI: 0.1301-0.744; p = 0.009) in TNBC. Interestingly, spatial data suggested that patients with a higher density of PD-L1⁺ tumour cells had shorter cell-cell distances from tumour cells to cytotoxic T cells (p < 0.01). In conclusion, we found that phenotyping tumour immune cells by mIF is highly informative in understanding the immune microenvironment in TNBC. PD-L1⁺ tumour cells, total T cells and effector/memory cytotoxic T cells are promising prognostic biomarkers in TNBC.

Potential Predictive and Prognostic Value of Biomarkers Related to Immune Checkpoint Inhibitor Therapy of Triple-Negative Breast Cancer

As an aggressive subtype of breast cancer, triple-negative breast cancer (TNBC) is associated with poor prognosis and lack of effective therapy, except chemotherapy. In recent years, immunotherapy based on immune checkpoint (IC) inhibition has emerged as a promising therapeutic strategy in TNBC. TNBC has more tumor-infiltrating lymphocytes (TILs) and higher rate of mutation and programmed cell death ligand-1 (PD-L1) expression than other subtypes of breast cancer have. However, previous studies have shown that monotherapy has little efficacy and only some TNBC patients can benefit from immunotherapy. Therefore, it is important to identify biomarkers that can predict the efficacy of IC inhibitors (ICIs) in TNBC. Recently, various biomarkers have been extensively explored, such as PD-L1, TILs and tumor mutational burden (TMB). Clinical trials have shown that PD-L1-positive patients with advanced TNBC benefit from ICIs plus chemotherapy. However, in patients with early TNBC receiving neoadjuvant therapy, PD-L1 cannot predict the efficacy of ICIs. These inconsistent conclusions suggest that PD-L1 is the best to date but an imperfect predictive biomarker for efficacy of ICIs. Other studies have shown that advanced TNBC patients with TMB ≥10 mutations/Mb can achieve clinical benefits from pembrolizumab. TILs also have potential predictive value in TNBC. Here, we select some biomarkers related to ICIs and discuss their potential predictive and prognostic value in TNBC. We hope these biomarkers could help to identify suitable patients and realize precision immunotherapy.

Expression of PD-L1 and BRCA1 in Triple-Negative Breast Cancer Patients and Relationship with Clinicopathological Characteristics

Objective

To study the expression of programmed cell death ligand-1 (PD-L1) and breast cancer susceptibility gene 1 (BRCA1) in triple-negative breast cancer (TNBC) patients and analyze their relationship with clinicopathological characteristics.

Methods

76 TNBC tissues were collected as the research object, while 60 adjacent tissues were used as controls. All patients underwent surgical treatment, and the expression of PD-L1 and BRCA1 in cancer tissues and adjacent tissues was detected by immunohistochemistry. At the same time, the relationship between PD-L1, BRCA1, and clinicopathological characteristics of patients with TNBC (including patient age, menopausal status, tumor size, lymph node metastasis, histological grade, Ki-67 expression, and p53 expression) were analyzed by univariate and logistic multivariate analysis.

Results

The positive expression rate of PD-L1 in the TNBC group was 64.47%, which was higher than the control group by 41.67%. The positive expression rate of BRCA1 was 27.63%, which was lower than the control group by 48.33%. PD-L1 expression has no significant relationship with age, menopausal status, and p53 expression in TNBC patients. TNBC patients with tumors ≥2 cm, histological grade III, lymph node metastasis, and Ki-67 expression ≥20% had higher PD-L1 positive expression rates. The tumor size, Ki-67 expression, and PD-L1 expression of TNBC patients have independent effects. The expression of BRCA1 has no significant relationship with menopausal status, tumor size, Ki-67 expression, etc. TNBC patients with age <45 years, histological grade I or II, no lymph node metastasis, and high p53 expression positive rate had higher BRCA1 positive expression rate. The age of TNBC patients, p53 expression, and BRCA1 expression have independent effects.

Conclusion

In TNBC cancer tissues, there is a high expression of PD-L1 and low expression of BRAC1. The tumor size, Ki-67 expression, and PD-L1 expression of TNBC patients have independent effects. The age of TNBC patients, p53 expression, and BRCA1 expression have independent effects.

Molecular Biomarkers Predict Pathological Complete Response of Neoadjuvant Chemotherapy in Breast Cancer Patients: Review

Simple Summary

Breast cancer is the most common cancer in women worldwide. Although many studies have aimed to understand the genetic basis of breast cancer, leading to increasingly accurate diagnoses, only a few molecular biomarkers are used in clinical practice to predict response to therapy. Current studies aim to develop more personalized therapies to decrease the adverse effects of chemotherapy. Personalized medicine not only requires clinical, but also molecular characterization of tumors, which allows the use of more effective drugs for each patient. The aim of this study was to identify potential molecular biomarkers that can predict the response to therapy after neoadjuvant chemotherapy in patients with breast cancer. In this review, we summarize genomic, transcriptomic, and proteomic biomarkers that can help predict the response to therapy.

Abstract

Neoadjuvant chemotherapy (NAC) is often used to treat locally advanced disease for tumor downstaging, thus improving the chances of breast-conserving surgery. From the NAC response, it is possible to obtain prognostic information as patients may reach a pathological complete response (pCR). Those who do might have significant advantages in terms of survival rates. Breast cancer (BC) is a heterogeneous disease that requires personalized treatment strategies. The development of targeted therapies depends on identifying biomarkers that can be used to assess treatment efficacy as well as the discovery of new and more accurate therapeutic agents. With the development of new “OMICS” technologies, i.e., genomics, transcriptomics, and proteomics, among others, the discovery of new biomarkers is increasingly being used in the context of clinical practice, bringing us closer to personalized management of BC treatment. The aim of this review is to compile the main biomarkers that predict pCR in BC after NAC.

Inhibitors of PD-1/PD-L1 and ERK1/2 impede the proliferation of receptor positive and triple-negative breast cancer cell lines

PURPOSE

Triple-negative breast cancer (TNBC) is characterized by an unfavorable prognosis and missing systemic therapeutic approaches beside chemotherapy. Targeting the immune checkpoint PD-1/PD-L1 showed promising results in breast cancer and especially in TNBC. The extracellular signal-regulated kinase 1/2 (ERK1/2) is an important driver of carcinogenesis. Here, the effect of combined PD-1/PD-L1 and ERK1/2 inhibitor treatment is investigated of cell growth and intracellular impact of breast cancer cell lines.

METHODS

The IC50 values of each inhibitor and the effect of combined treatment were determined in three TNBC cell lines of different subtypes and one non-TNBC cell line. Phospho-specific antibodies were used in western blot analyses to investigate an effect on ERK1/2 activation. Expressions of immune modulatory and cell cycle-associated genes were examined by quantitative reverse transcription PCR.

RESULTS

Both inhibitors PD-1/PD-L1 and ERK1/2 impeded the proliferation of TNBC to a higher extent than of non-TNBC. By combined treatment, cell lines were inhibited either synergistically or additively. ERK1/2 and S6 phosphorylation were reduced and expressions of c-Fos and FosL were diminished after ERK1/2 inhibitor as single and combined treatment. Between genes involved in immune modulation, IL-8 was upregulated in TNBC cells after combined treatment.

CONCLUSION

In conclusion, combination of PD-1/PD-L1 and ERK1/2 inhibitors showed favorable effects for a new therapy strategy, with better results in TNBC cell lines than in non-TNBC cells. The effects have to be validated in models that can reflect the interaction between immune and tumor cells like the situation in the tumor micro-environment.

SP142 PD-L1 Scoring Shows High Interobserver and Intraobserver Agreement in Triple-negative Breast Carcinoma But Overall Low Percentage Agreement With Other PD-L1 Clones SP263 and 22C3

SP142 programmed cell death ligand 1 (PD-L1) status predicts response to atezolizumab in triple-negative breast carcinoma (TNBC). Prevalence of VENTANA PD-L1 (SP142) Assay positivity, concordance with the VENTANA PD-L1 (SP263) Assay and Dako PD-L1 IHC 22C3 pharmDx assay, and association with clinicopathologic features were assessed in 447 TNBCs. SP142 PD-L1 intraobserver and interobserver agreement was investigated in a subset of 60 TNBCs, with scores enriched around the 1% cutoff. The effect of a 1-hour training video on pretraining and posttraining scores was ascertained. At a 1% cutoff, 34.2% of tumors were SP142 PD-L1 positive. SP142 PD-L1 positivity was significantly associated with tumor-infiltrating lymphocytes (P <0.01), and node negativity (P=0.02), but not with tumor grade (P=0.35), tumor size (P=0.58), or BRCA mutation (P=0.53). Overall percentage agreement (OPA) for intraobserver and interobserver agreement was 95.0% and 93.7%, respectively, among 5 pathologists trained in TNBC SP142 PD-L1 scoring. In 5 TNBC SP142 PD-L1-naive pathologists, significantly higher OPA to the reference score was achieved after video training (posttraining OPA 85.7%, pretraining OPA 81.5%, P<0.05). PD-L1 status at a 1% cutoff was assessed by SP142 and SP263 in 420 cases, and by SP142 and 22C3 in 423 cases, with OPA of 88.1% and 85.8%, respectively. The VENTANA PD-L1 (SP142) Assay is reproducible for classifying TNBC PD-L1 status by trained observers; however, it is not analytically equivalent to the VENTANA PD-L1 (SP263) Assay and Dako PD-L1 IHC 22C3 pharmDx assay.

Tumor Microenvironment: Key Players in Triple Negative Breast Cancer Immunomodulation

Simple Summary

The tumor microenvironment (TME) is a complicated network composed of various cells, signaling molecules, and extra cellular matrix. TME plays a crucial role in triple negative breast cancer (TNBC) immunomodulation and tumor progression, paradoxically, acting as an immunosuppressive as well as immunoreactive factor. Research regarding tumor immune microenvironment has contributed to a better understanding of TNBC subtype classification. Shall we treat patients precisely according to specific subtype classification? Moving beyond traditional chemotherapy, multiple clinical trials have recently implied the potential benefits of immunotherapy combined with chemotherapy. In this review, we aimed to elucidate the paradoxical role of TME in TNBC immunomodulation, summarize the subtype classification methods for TNBC, and explore the synergistic mechanism of chemotherapy plus immunotherapy. Our study may provide a new direction for the development of combined treatment strategies for TNBC.

Abstract

Triple negative breast cancer (TNBC) is a heterogeneous disease and is highly related to immunomodulation. As we know, the most effective approach to treat TNBC so far is still chemotherapy. Chemotherapy can induce immunogenic cell death, release of damage-associated molecular patterns (DAMPs), and tumor microenvironment (TME) remodeling; therefore, it will be interesting to investigate the relationship between chemotherapy-induced TME changes and TNBC immunomodulation. In this review, we focus on the immunosuppressive and immunoreactive role of TME in TNBC immunomodulation and the contribution of TME constituents to TNBC subtype classification. Further, we also discuss the role of chemotherapy-induced TME remodeling in modulating TNBC immune response and tumor progression with emphasis on DAMPs-associated molecules including high mobility group box1 (HMGB1), exosomes, and sphingosine-1-phosphate receptor 1 (S1PR1), which may provide us with new clues to explore effective combined treatment options for TNBC.

Clinicopathological and prognostic significance of programmed cell death ligand 1 expression in patients diagnosed with breast cancer: meta-analysis

BACKGROUND

Uncertainty exists regarding the clinical relevance of programmed cell death ligand 1 (PD-L1) expression in breast cancer.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. Observational studies that compared high versus low expression of PD-L1 on breast cancer cells were identified. Log hazard ratios (HRs) for disease-free and overall survival and their standard errors were calculated from Kaplan-Meier curves or Cox regression analyses, and pooled using the inverse-variance method. Dichotomous variables were pooled as odds ratios (ORs) using the Mantel-Haenszel method.

RESULTS

Sixty-five studies with 19 870 patients were included; 14 404 patients were classified as having low and 4975 high PD-L1 expression. High PD-L1 was associated with achieving a pathological complete response following neoadjuvant chemotherapy (OR 3.30, 95 per cent confidence interval 1.19 to 9.16; P < 0.01; I2 = 85 per cent). Low PD-L1 expression was associated with human epidermal growth factor receptor 2 (OR 3.98, 1.81 to 8.75; P < 0.001; I2 = 96 per cent) and luminal (OR 14.93, 6.46 to 34.51; P < 0.001; I2 = 99 per cent) breast cancer subtypes. Those with low PD-L1 had favourable overall survival rates (HR 1.30, 1.05 to 1.61; P = 0.02; I2 = 85 per cent).

CONCLUSION

Breast cancers with high PD-L1 expression are associated with aggressive clinicopathological and immunohistochemical characteristics and are more likely to achieve a pathological complete response following neoadjuvant chemotherapy. These breast cancers are, however, associated with worse overall survival outcomes.

Pathogenesis and Potential Therapeutic Targets for Triple-Negative Breast Cancer

Triple negative breast cancer (TNBC) is a heterogeneous tumor characterized by early recurrence, high invasion, and poor prognosis. Currently, its treatment includes chemotherapy, which shows a suboptimal efficacy. However, with the increasing studies on TNBC subtypes and tumor molecular biology, great progress has been made in targeted therapy for TNBC. The new developments in the treatment of breast cancer include targeted therapy, which has the advantages of accurate positioning, high efficiency, and low toxicity, as compared to surgery, radiotherapy, and chemotherapy. Given its importance as cancer treatment, we review the latest research on the subtypes of TNBC and relevant targeted therapies.

Prognostic and Clinicopathologic Associations of LAG-3 Expression in Triple-negative Breast Cancer

The immune checkpoint molecule lymphocyte activation gene 3 (LAG-3) is currently being investigated as a possible target for immunotherapy in triple-negative breast cancer (TNBC), frequently as an addition to treatment with programmed cell death protein 1/programmed death ligand 1 (PD-L1) inhibition. However, expression of LAG-3, the frequency of coexpression with PD-L1, and the prognostic significance of this marker have not been studied extensively in TNBC. For this study, tissue microarrays (TMAs) were constructed from surgical specimens of 514 patients with TNBC. TMAs were stained immunohistochemically for LAG-3 and PD-L1 expression. Tumor-infiltrating lymphocytes (TILs) were evaluated on full glass slides. LAG-3 expression was significantly associated with improved overall survival and relapse-free survival. When adjusted for clinicopathologic factors, each increment of 10 LAG-3-positive intratumoral lymphocytes per TMA core was associated with improved overall survival (hazard ratio=0.93, 95% confidence interval: 0.89-0.97, P=0.002), and recurrence-free survival (hazard ratio=0.91, 95% confidence interval: 0.85-0.97, P=0.002). PD-L1 expression on immune cells and PD-L1 expression evaluated with the combined positive score and TILs were also associated with improved survival in both univariate and multivariate analyses. PD-L1 expression on tumor cells was only associated with improved survival in univariate analysis. LAG-3 expression was associated with both TILs and PD-L1 expression. Coexpression of LAG-3 and PD-L1 did not confer additional survival benefits. In conclusion, LAG-3 expression is associated with improved survival in TNBC. LAG-3 is often coexpressed with PD-L1, confirming that TNBC is likely a suitable candidate for cotreatment with LAG-3 and programmed cell death protein 1/PD-L1 inhibitors. However, coexpression does not confer additional survival benefits.

Delineating the breast cancer immune microenvironment in the era of multiplex immunohistochemistry/immunofluorescence

Breast cancer is the most common malignancy and the leading cause of cancer death in females worldwide. Treatment is challenging, especially for those who are triple-negative. Increasing evidence suggests that diverse immune populations are present in the breast tumour microenvironment, which opens up avenues for personalised drug targets. Historically, our investigations into the immune constitution of breast tumours have been restricted to analyses of one or two markers at a given time. Recent technological advances have allowed simultaneous labelling of more than 35 markers and detailed profiling of tumour-immune infiltrates at the single-cell level, as well as determining the cellular composition and spatial analysis of the entire tumour architecture. In this review, we describe emerging technologies that have contributed to the field of breast cancer diagnosis, and discuss how to interpret the vast data sets obtained in order to effectively translate them for clinically relevant use.

Programmed cell death 1 (PD-1) receptor and programmed death ligand 1 (PD-L1) gene expression in primary breast cancer

PURPOSE

The interaction of the programmed cell death 1 (PD-1) receptor on tumor-infiltrating lymphocytes with programmed death ligand 1 (PD-L1) on tumor cells downregulates anti-tumor immunity. This study evaluated associations between PD-1 and PD-L1 expression in primary breast cancer, clinical characteristics, and patient outcomes.

METHODS

Microarray data from the Investigation of Serial Studies to predict your therapeutic response with imaging and molecular analysis (I-SPY 1) study (n = 149) was used to evaluate PD-1 and PD-L1 expression. Associations with clinical features and chemotherapy response were determined using Kruskal-Wallis and Wilcoxon rank sum tests, respectively. Recurrence-free survival (RFS) associations were determined with the Cox proportional hazard model. Associations of PD-1 and PD-L1 and selected genes associated with breast cancer, as well as a predictor of olaparib response (PARPi-7), were determined in I-SPY 1 and 2 other datasets: METABRIC (n = 1992) and TCGA (n = 817), using Pearson correlations.

RESULTS

In I-SPY 1, PD-1 expression was higher in triple-negative breast cancer (TNBC) and HER2 + breast cancer (p = 0.003), and grade 2/3 tumors (p = 0.043), and was associated with pathologic complete response (p = 0.006). PD-L1 expression in the lowest quintile was associated with worse RFS, even after subtype adjustment (HR 2.33, p = 0.01). PD-1 and PD-L1 gene expression correlated with the expression of immune-related genes and PARPi-7.

CONCLUSIONS

PD-1 expression is higher in breast cancers with aggressive features such as TNBC. Low PD-L1 expression may be an adverse prognostic factor. PD-1 and PD-L1 gene expression correlates with the expression of immune-related and DNA damage repair genes.

Prevalence Study of PD-L1 SP142 Assay in Metastatic Triple-negative Breast Cancer

Metastatic triple-negative breast cancer (mTNBC) is the most aggressive breast cancer subtype. Programmed death ligand 1 (PD-L1) on immune cells (IC) using the VENTANA SP142 assay is linked to improved clinical outcome in atezolizumab plus nab-paclitaxel-treated patients with mTNBC in the IMpassion130 study. The goal of the current study was to evaluate prevalence of VENTANA SP142 PD-L1 assay by anatomic location in 670 histologically confirmed TNBC cases from subjects with metastatic disease screened for the phase 1 study PCD4989g (NCT01375842). PD-L1 immunohistochemistry was centrally tested on tumor cells (TC) and on tumor infiltrating IC, following manufacturer's instructions. At a 1% cutoff, tumor PD-L1 was more prevalent in IC than TC: 46% were PD-L1 IC+/TC-, 3% were PD-L1 IC-/TC+, and 10% were PD-L1 IC+/TC+. PD-L1 IC and TC immunostaining correlated with CD274 RNA expression, as assessed by fluidigm. Analyses of anatomic locations suggest that prevalence of PD-L1 IC+ was highest in lymph nodes (65.0%), lowest in liver metastases (26.9%), while breast tissue was intermediate (57.1%). Matched paired samples from the same subject collected synchronously or asynchronously showed a PD-L1 IC status agreement of 80% (8/10) and 75% (15/20), respectively. Our results suggest that the anatomic location of metastases and time of collection may influence the detection of PD-L1.

PD-L1 Protein Expression in Middle Eastern Breast Cancer Predicts Favorable Outcome in Triple-Negative Breast Cancer

Programmed cell-death ligand 1 (PD-L1) has been shown to induce potent T-cell mediated anti-tumoral immunity. The significance of PD-L1 expression in the prognosis of breast cancer (BC) remains controversial and its prevalence and prognostic value in breast cancer from Middle Eastern ethnicity is lacking. A total of 1003 unselected Middle Eastern breast cancers were analyzed for PD-L1 expression using immunohistochemistry. PD-L1 expression, seen in 32.8% (329/1003) of cases, was significantly associated with poor prognostic indicators such as younger patients, high-grade tumors, estrogen-receptor (ER)-negative, progesterone-receptor (PR)-negative, and triple-negative breast cancers (TNBC) as well as high Ki-67 index. We also found a significant association between PD-L1 expression and deficient mismatch repair protein expression. No association was found between PD-L1 expression and clinical outcome. However, on further subgroup analysis, PD-L1 expression was found to be an independent marker for favorable overall survival and recurrence-free survival in TNBC. In conclusion, we demonstrated strong association between PD-L1 and mismatch repair deficiency in Middle Eastern BC patients and that PD-L1 overexpression in tumor cells was an independent prognostic marker in TNBCs from Middle Eastern ethnicity. Overall, these findings might help in the development of more appropriate treatment strategies for BC in Middle Eastern population.

PD-L1 Expression and Tumor-infiltrating Lymphocytes in Breast Cancer: Clinicopathological Analysis in Women Younger than 40 Years Old

BACKGROUND/AIM

To evaluate the association between programmed cell death ligand 1 (PD-L1) expression on both tumor cells (TC) and inflammatory cells (IC), tumor infiltrating lymphocytes (TILs), CD3⁺ and CD8⁺ lymphocytes and other clinicopathological parameters in primary infiltrative breast cancer (IBC) of young women, a population shown to have a worse prognosis.

MATERIALS AND METHODS

A retrospective study was performed collecting data from patients younger than 40 years old. Forty-five young women with IBC were included. Whole tissue sections were used to evaluate all parameters.

RESULTS

Twenty percent (20%) of cases showed PD-L1 expression by tumor cells (PDL1TC) and 44.4% showed PD-L1 expression by immune cells (PDL1IC). Furthermore, 28.88% revealed high stromal TILs. PDL1TC and PDL1IC expression were significantly associated with tumor diameter and expression of estrogen (ER) and progesterone (PR) receptors and Ki67. PDL1TC expression was also associated with grade. High TILs were associated with tumor diameter, ER and Ki67 expression. PDL1TC, PDL1IC expression and TILs were associated with the density of CD3⁺ and CD8⁺ lymphocytes.

CONCLUSION

Our results are similar to those of other age groups, as reported in the literature.

Novel PD-L1 mAb HC16 reveals upregulation of PD-L1 in BAC subtype

Programmed death-ligand 1 (PD-L1) is an inhibitory transmembrane protein that can prevent autoimmune response. Upregulated PD-L1 serves as a predictive biomarker for patients who may respond well to immune checkpoint therapies. However, variable associations of PD-L1 level with prognoses have been reported. In this study, a short peptide sequence corresponding to PD-L1 amino acids 172-187 (from the extracellular Ig-like C-type domain, and with high predicted antigenicity and hydrophilicity) was used to generate a monoclonal antibody (mAb). The resultant PD-L1 mAb, clone HC16, was examined for binding specificity and reactivity in cancer cell-lines, as assessed by immunocytochemical, immunoblotting, and co-immunoprecipitation. The potential diagnostic and clinical applicability of clone HC16 was further tested using malignant tissue arrays derived from various cancer types analyzed with an automated immunohistochemical (IHC) staining platform. Additionally, tumor samples from patients diagnosed with non-small cell lung cancer (NSCLC) were analyzed by western blotting. Clone HC16 showed obvious staining activity in lung and breast cancer tissues. Interestingly, we observed that PD-L1 level was negatively associated with clinical stage in NSCLC. Strong PD-L1 expression tended to be found in patients diagnosed with bronchioloalveolar carcinoma (BAC). These results demonstrate that clone HC16 harbors good target specificity and is suitable for further development in diagnostic tools to assess PD-L1 expression in human tissues. In addition, our findings also suggest a role for PD-L1 in a non-invasive subtype of lung cancer.

Prognostication of a 13-immune-related-gene signature in patients with early triple-negative breast cancer

PURPOSE

We investigated the expression profiles of immune genes in patients with triple-negative breast cancer (TNBC) to identify the prognostic value of immune genes and their clinical implications.

METHODS

NanoString nCounter Analysis of 770 immune-related genes was used to measure immune gene expression in patients with TNBC who underwent curative surgery followed by adjuvant chemotherapy at Samsung Medical Center between 2000 and 2004. Statistical analyses were conducted to identify the associations between gene expression and distant recurrence-free survival (DRFS).

RESULTS

Of 1189 patients who underwent curative BC surgery, 200 TNBC patients were included and stage was the only clinical factor predictive of DRFS. In terms of immune genes, 155 of 770 genes were associated with DRFS (p < 0.01). Further multivariate analysis revealed that 13 genes, CD1B, CD53, CT45A1, GTF3C1, IL11RA, IL1RN, LRRN3, MAPK1, NEFL, PRKCE, PTPRC, SPACA3 and TNFSF11, were associated with patient prognosis (p < 0.05). The prognostic value of stage and expression levels of 13 immune genes was analyzed and the area under the receiver operating characteristic curve (AUC) was 0.923. Based on the AUC, we divided patients into three genetic risk groups and DRFS rate was significantly different according to genetic risk groups, even in the same stage (p < 0.001).

CONCLUSIONS

In this study, a 13-gene expression profile in combination with stage precisely predicted distant recurrence of early TNBC. Therefore, this 13-immune-gene signature could help predict TNBC prognosis and provide guidance for treatment as well as the opportunity to develop new targets for immunotherapy in TNBC patients.

Prognostic Role of Immune Markers in Triple Negative Breast Carcinoma

Tumor immune microenvironment (TIME) is a significant prognostic parameter for triple negative breast carcinomas (TNBC) due to being a target for immunotherapeutic agents and its essential role during the cancer immunoediting process. In this study, CD8, FOXP3, CD163, PD-L1/SP142 and PD-L1/SP263 antibodies were examined in a sample of 51 TNBC cases. Patients who received neoadjuvant therapy were excluded. CD8, FOXP3 and CD163 antibodies were evaluated separately in intratumoral area (ITA) and tumor stroma (TS). PD-L1 status was also examined in tumor cells (TC) and immune cells (IC) using both SP142 and SP263 antibodies. In multivariate Cox regressions, the only antibody that was found to be significantly associated with survival was SP142. SP142-positivity in TC and IC was related to increased overall survival. Higher CD163 expression in ITA and SP263-positivity in IC were associated with younger age. Lymphatic/angioinvasion was more frequent in cases with negative/low CD8 and FOXP3 expressions. Moreover, metastatic axillary lymph node(s) was associated with negative/low FOXP3 expression in TS. CD8, FOXP3, CD163, SP142 and SP263 expressions were positively correlated with each other, except a mild discordance caused by CD163 in ITA. Although PD-L1 status with both SP142 and SP263 antibodies were concordant in the majority of cases, 33.3% and 13.7% of the cases showed SP142-negative/SP263-positive pattern in TC and IC respectively. In conclusion, we suggest that composition, density and localization of the immune cells and the check point molecules are important prognostic parameters in TNBC. Immunohistochemistry can be used as an accessible and less expensive tool to demonstrate TIME.

Pathology of triple negative breast cancer

Triple negative breast cancer (TNBC) is a subtype of breast tumor lacking hormone receptors expression and HER2 gene amplification and represents 24 % of newly diagnosed breast neoplasms. In this review, pathological aspects of triple-negative breast cancer are illustrated, with particular attention to the seminal studies that defined this subtype of breast cancer by a molecular point of view. This paper also focuses on practical issues raised in clinical routine by the introduction of genetic expression breast cancer profiling and the innovative prognostic and predictive impact on triple-negative breast cancer pathology. Moreover, histopathological aspects of triple-negative neoplasms are also mentioned, underlying the importance of histologic diagnosis of particular cancer subtypes with decisive impact on clinical outcome. Importantly, focus on new therapeutic frontier represented by immunotherapy is illustrated, with particular mention of immune checkpoint inhibitors introduction in TNBC therapy and their impact on future treatments.

Breast cancer immunology and immunotherapy: targeting the programmed cell death protein-1/programmed cell death protein ligand-1

Historically, breast cancer has been regarded as an immunogenic "cold" tumor. However, the discovery of immune checkpoint inhibitors has made immunotherapy becoming an emerging new treatment modality for breast cancer. This review discusses the immune system, immune features of breast cancer, and the programmed cell death protein-1/programmed cell death protein ligand-1 (PD-1/PD-L1) inhibitors used in the treatment of breast cancer. High T lymphocyte infiltration and mutation burden were observed in triple-negative breast cancer and human epidermal growth factor receptor 2 positive breast cancer. Increasing breast cancer immunogenicity and modulating the tumor microenvironment has been reported to improve the therapeutic efficacy of immunotherapy. Recent clinical trials involving PD-1/PD-L1 inhibitors monotherapy in breast cancer has revealed little efficacy, which highlights the need to develop combinations of PD-1/PD-L1 inhibitors with chemotherapy, molecularly targeted therapies, and other immunotherapies to maximize the clinical efficacy. Collectively, the immunotherapy might be a promising therapeutic strategy for breast cancer and several clinical trials are still on-going.

Mastitis in Autoimmune Diseases: Review of the Literature, Diagnostic Pathway, and Pathophysiological Key Players

Mastitis frequently affects women of childbearing age. Of all the pathological breast conditions requiring specific management, autoimmune mastitis is in the third position after infection and breast cancer. The aim of this literature review was to make a comprehensive description of autoimmune diseases targeting the mammary gland. Four main histological patterns of autoimmune mastitis are described: (i) lymphocytic infiltrates; (ii) ductal ectasia; (iii) granulomatous mastitis; and (iv) vasculitis. Our literature search found that all types of autoimmune disease may target the mammary gland: organ-specific diseases (diabetes, thyroiditis); connective tissue diseases (such as systemic erythematosus lupus or Sjögren’s syndrome); vasculitides (granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, giant cell arteritis, polyarteritis nodosa, Behçet’s disease); granulomatous diseases (sarcoidosis, Crohn’s disease); and IgG4-related disease. Cases of breast-specific autoimmune diseases have also been reported, including idiopathic granulomatous mastitis. These breast-limited inflammatory diseases are sometimes the first symptom of a systemic autoimmune disease. Although autoimmune mastitis is rare, it is probably underdiagnosed or misdiagnosed. Early diagnosis may allow us to detect systemic diseases at an earlier stage, which could help to initiate a prompt, appropriate therapeutic strategy. In case of suspected autoimmune mastitis, we hereby propose a diagnostic pathway and discuss the potential pathophysiological pathways leading to autoimmune breast damage.

PD-L1/PD-1 axis as a potent therapeutic target in breast cancer

Although both the incidence and the mortality rate of breast cancer is rising, there is no potent and practical option for the treatment of these patients, particularly in advanced stages. One of the most critical challenges for treatment is the presence of complicated and extensive tumor escape mechanisms in the tumor microenvironment. Immune checkpoint molecules are of the main immunosuppressive mechanisms used by cancerous cells to block anti-cancer immune responses. Among these molecules, PD-1 (Programmed cell death) and PD-L1 (programmed cell death-ligand 1) have been considered as worthy therapeutic targets for breast cancer therapy. In this review, we intend to discuss the immunobiology and signaling of the PD-1/PD-L1 axis and highlight its importance as a worthy therapeutic target in breast cancer. We believe that the prognostic value of PD-L1 depends on the breast cancer subtype. Moreover, the combination of PD-1/PD-L1 targeting with immune-stimulating vaccines can be considered as an effective therapeutic strategy in breast cancer.

Multiplex immunohistochemistry/immunofluorescence (mIHC/IF) for PD-L1 testing in triple-negative breast cancer: a translational assay compared with conventional IHC

BACKGROUND

Programmed death-ligand 1 (PD-L1) monoclonal antibody therapy has recently gained approval for treating metastatic triple-negative breast cancer (TNBC) -, in particular in the PD-L1⁺ patient subgroup of the recent IMpassion130 trial. The SP142 PD-L1 antibody clone was used as a predictive assay in this trial, but this clone was found to be an outlier in previous harmonisation studies in lung cancer.

AIMS

To address the comparability of PD-L1 clones in TNBC, we evaluated the concordance between conventional immunohistochemistry (IHC) and multiplex immunohistochemistry/immunofluorescence (mIHC/IF) that allowed simultaneous quantification of three different PD-L1 antibodies (22C3, SP142 and SP263).

METHODS

Our cohort comprised 25 TNBC cases, 12 non-small-cell lung carcinomas and 8 other cancers. EpCAM labelling was used to distinguish tumour cells from immune cells.

RESULTS

Moderate-to-strong correlations in PD-L1 positivity were found between results obtained through mIHC/IF and IHC. Individual concordance rates in the study ranged from 67% to 100%, with Spearman's rank correlation coefficient values up to 0.88.

CONCLUSIONS

mIHC/IF represents a promising tool in the era of cancer immunotherapy, as it can simultaneously detect and quantify PD-L1 labelling with multiple antibody clones, and allow accurate evaluation of tumour and immune cells. Clinicians and pathologists require this information to predict patient response to anti-PD-1/PD-L1 therapy. The adoption of this assay may represent a significant advance in the management of therapeutically challenging cancers. Further analysis and assay harmonisation are essential for translation to a routine diagnostic setting.

Immunotherapy in HER2-positive breast cancer: state of the art and future perspectives

Breast cancer (BC) is a complex disease with primary or acquired incurability characteristics in a significant part of patients. Immunotherapeutical agents represent an emerging option for breast cancer treatment, including the human epidermal growth factor 2 positive (HER2+) subtype. The immune system holds the ability to spontaneously implement a defensive response against HER2+ BC cells through complex mechanisms which can be exploited to modulate this response for obtaining a clinical benefit. Initial immune system modulating strategies consisted mostly in vaccine therapies, which are still being investigated and improved. However, the entrance of trastuzumab into the scenery of HER2+ BC treatment was the real game changing event, which embodied a dominant immune-mediated mechanism. More recently, the advent of the immune checkpoint inhibitors has caused a new paradigm shift for immuno-oncology, with promising initial results also for HER2+ BC. Breast cancer has been traditionally considered poorly immunogenic, being characterized by relatively low tumor mutation burden (TMB). Nevertheless, recent evidence has revealed high tumor infiltrating lymphocytes (TILs) and programmed cell death-ligand 1 (PD-L1) expression in a considerable proportion of HER2+ BC patients. This may translate into a higher potential to elicit anti-cancer response and, therefore, wider possibilities for the use and implementation of immunotherapy in this subset of BC patients. We are herein presenting and critically discussing the most representative evidence concerning immunotherapy in HER2+ BC cancer, both singularly and in combination with therapeutic agents acting throughout HER2-block, immune checkpoint inhibition and anti-cancer vaccines. The reader will be also provided with hints concerning potential future projection of the most promising immutherapeutic agents and approaches for the disease of interest.

Association between PD-1 and PD-L1 Polymorphisms and the Risk of Cancer: A Meta-Analysis of Case-Control Studies

A number of case-control studies regarding the association of the polymorphisms in the programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) genes with the risk of cancer have yielded inconsistent findings. Therefore, we have conducted a comprehensive, updated meta-analysis study to identify the impact of PD-1 and PD-L1 polymorphisms on overall cancer susceptibility. The findings revealed that PD-1 rs2227981 and rs11568821 polymorphisms significantly decreased the overall cancer risk (Odds Ratio (OR) = 0.82, 95% CI = 0.68–0.99, p = 0.04, TT vs. CT+CC; OR = 0.79, 95% CI = 0.67–0.94, p = 0.006, AG vs. GG, and OR = 0.82, 95% CI = 0.70–0.96, p = 0.020, AG+AA vs. GG, respectively), while PD-1 rs7421861 polymorphism significantly increased the risk of developing cancer (OR = 1.16, 95% CI = 1.02–1.33, p = 0.03, CT vs. TT). The PD-L1 rs4143815 variant significantly decreased the risk of cancer in homozygous (OR = 0.62, 95% CI = 0.41–0.94, p = 0.02), dominant (OR = 0.70, 95% CI = 0.50–0.97, p = 0.03), recessive (OR = 0.76, 95% CI = 0.60–0.96, p = 0.02), and allele (OR = 0.78, 95% CI = 0.63–0.96, p = 0.02) genetic models. No significant association between rs2227982, rs36084323, rs10204525, and rs2890658 polymorphisms and overall cancer risk has been found. In conclusions, the results of this meta-analysis have revealed an association between PD-1 rs2227981, rs11568821, rs7421861, as well as PD-L1 rs4143815 polymorphisms and overall cancer susceptibility.

Prognostic and clinicopathological value of PD-L1 expression in primary breast cancer: a meta-analysis

PURPOSE

To evaluate the association between PD-L1 expression (PD-L1+) and clinicopathological characteristics and effect on prognosis in primary breast cancer (PBC).

METHODS

A systematic search of the PubMed, Web of Science, and Embase databases was conducted in November 2018. Studies detecting PD-L1 using immunohistochemistry, and concerning its prognostic or clinicopathological significance in PBC were included. The HR with 95% CI for survival, and the events for clinicopathological features were pooled.

RESULTS

Forty-seven studies were included, with a total of 14,367 PBC patients. PD-L1+ tumor cells (TCs) were associated with ductal carcinomas, large tumor size, histological Grade 3 tumors, high Ki-67, ER and PR negative, and triple-negative breast cancer; and also, related to high tumor-infiltrating lymphocytes (TILs) and PD-1 expression. PD-L1+ TCs were significantly associated with shorter disease-free survival (DFS, HR = 1.43, 95% CI 1.21-1.70, P < 0.0001) and overall survival (OS, HR = 1.58, 95% CI 1.14-2.20, P = 0.006). And the HRs of PD-L1+ TCs on DFS and OS were higher (1.48 and 1.70, respectively) and homogeneous when using whole tissue section, compared with tumor microarrays. However, PD-L1+ TILs related to better DFS (HR = 0.45, 95% CI 0.28-0.73, P = 0.001) and OS (HR = 0.41, 95% CI 0.27-0.63, P < 0.0001).

CONCLUSION

PD-L1 expression on TCs associates with high-risk clinicopathological parameters and poor prognosis in PBC patients, while PD-L1+ TILs may relate to a better survival. Comprehensive assessment of TCs and TILs is required when evaluating the clinical relevance of PD-L1 expression in future studies.

Prognostic Implications of PD-L1 Expression in Breast Cancer: Systematic Review and Meta-analysis of Immunohistochemistry and Pooled Analysis of Transcriptomic Data

PURPOSE

Conflicting data have been reported on the prognostic value of PD-L1 protein and gene expression in breast cancer.Experimental Design: Medline, Embase, Cochrane Library, and Web of Science Core Collection were searched, and data were extracted independently by two researchers. Outcomes included pooled PD-L1 protein positivity in tumor cells, immune cells, or both, per subtype and per antibody used, and its prognostic value for disease-free and overall survival. A pooled gene expression analysis of 39 publicly available transcriptomic datasets was also performed.

RESULTS

Of the initial 4,184 entries, 38 retrospective studies fulfilled the predefined inclusion criteria. The overall pooled PD-L1 protein positivity rate was 24% (95% CI, 15%-33%) in tumor cells and 33% (95% CI, 14%- 56%) in immune cells. PD-L1 protein expression in tumor cells was prognostic for shorter overall survival (HR, 1.63; 95% CI, 1.07-2.46; P = 0.02); there was significant heterogeneity (I² = 80%, P _{heterogeneity} < 0.001). In addition, higher PD-L1 gene expression predicted better survival in multivariate analysis in the entire population (HR, 0.82; 95% CI, 0.74-0.90; P < 0.001 for OS) and in basal-like tumors (HR, 0.64; 95% CI, 0.52-0.80; P < 0.001 for OS; P _interaction 0.005).

CONCLUSIONS

The largest to our knowledge meta-analysis on the subject informs on PD-L1 protein positivity rates and its prognostic value in breast cancer. Standardization is needed prior to routine implementation. PD-L1 gene expression is a promising prognostic factor, especially in basal-like breast cancer. Discrepant prognostic information might be related to PD-L1 gene expression in the stroma.

Immunotherapy in breast cancer: Current status and future directions

Breast cancer, one of the leading causes of death in women in the United States, challenges therapeutic success in patients due to tumor heterogeneity, treatment resistance, metastasis and disease recurrence. Knowledge of immune system involvement in normal breast development and breast cancer has led to extensive research into the immune landscape of breast cancer and multiple immunotherapy clinical trials in breast cancer patients. However, poor immunogenicity and T-cell infiltration along with heightened immunosuppression in the tumor microenvironment have been identified as potential challenges to the success of immunotherapy in breast cancer. Oncodrivers, owing to their enhanced expression and stimulation of tumor cell proliferation and survival, present an excellent choice for targeted immunotherapy development in breast cancer. Loss of anti-tumor immune response specific to oncodrivers has been reported in breast cancer patients as well. Dendritic cell vaccines have been tested for their efficacy in generating anti-tumor T-cell response against specific tumor-associated antigens and oncodrivers and have shown improved survival outcome in patients. Here, we review the current status of immunotherapy in breast cancer, focusing on dendritic cell vaccines and their therapeutic application in breast cancer. We further discuss future directions of breast cancer immunotherapy and potential combination strategies involving dendritic cell vaccines and existing chemotherapeutics for improved efficacy and better survival outcome in breast cancer.

Role of programmed cell death ligand-1 expression on prognostic and overall survival of breast cancer: A systematic review and meta-analysis

BACKGROUND

Recently, the correlation of immunological checkpoint marker programmed cell death ligand-1 (PD-L1) and the prognosis of various cancers has been a research hotspot. The aim of this study is to examine the prognostic effect of PD-L1 in breast cancer.

METHODS

PubMed, EMBASE, Web of Science, the Cochrane Library database were searched for eligible studies and additional hand-searching were reviewed as an augmentation. Pooled hazard ratios (HR) and 95% confidence interval (CI) for overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS)/recurrence-free survival (RFS), and metastasis-free survival (MFS) were estimated using fixed- or random-effect models.

RESULTS

Data from 19 studies involving 12,505 patients were collected. Study quality was assessed according to guidelines for assessing quality in prognostic studies. PD-L1 expression was significantly associated with lymph node metastasis (P < .001), high tumor grade (P < .001), negative hormone receptor (P < .001), human epidermal growth factor receptor 2 (HER2) positivity (P < .001), high Ki67 (P < .001), and high tumor-infiltrating lymphocytes (TILs) (P < .001). PD-L1 expression had no significant impact on CSS (pooled HR 0.83, 95% CI = 0.64-1.09, P = .19) or MFS (pooled HR 1.11, 95% CI = 0.62-1.97, P = .72), but significantly correlated with shortened OS (pooled HR 1.52, 95% CI = 1.14-2.03, P = .004) and DFS (pooled HR 1.31, 95% CI = 1.14-1.51, P < .000). Subgroup analysis showed that not PD-L1 RNA expression, but protein expression was associated with shorter survival, in addition, the adverse prognostic effect of PD-L1 expression remained in luminal A, luminal B, and HER2 subtype, not in basal-like or triple-negative subtype.

CONCLUSIONS

An elevated PD-L1 expression significantly correlates with high-risk prognostic indicators and decreased survival in patients with breast cancer.

Prognostic value of CD8 + PD-1+ immune infiltrates and PDCD1 gene expression in triple negative breast cancer

The role of programmed cell death protein-1 (PD-1)/programmed cell death ligand 1 (PD-L1) in triple negative breast cancer (TNBC) remains to be fully understood. In this study, we investigated the role of PD-1 as a prognostic marker for TNBC in an Asian cohort (n = 269). Samples from patients with TNBC were labeled with antibodies against PD-L1 and PD-1, and subjected to NanoString assays to measure the expression of immune-related genes. Associations between disease-free survival (DFS), overall survival (OS) and biomarker expression were investigated. Multivariate analysis showed that tumors with high PD-1⁺ immune infiltrates harbored significantly increased DFS, and this increase was significant even after controlling for clinicopathological parameters (HR 0.95; P = 0.030). In addition, the density of cells expressing both CD8 and PD-1, but not the density of CD8⁻PD-1⁺ immune infiltrates, was associated with improved DFS. Notably, this prognostic significance was independent of clinicopathological parameters and the densities of total CD8⁺ cell (HR 0.43, P = 0.011). At the transcriptional level, high expression of PDCD1 within the tumor was significantly associated with improved DFS (HR 0.38; P = 0.027). In line with these findings, high expression of IFNG (HR 0.38; P = 0.001) and IFN signaling genes (HR 0.46; p = 0.027) was also associated with favorable DFS. Inclusion of PD-1 immune infiltrates and PDCD1 gene expression added significant prognostic value for DFS (ΔLRχ² = 6.35; P = 0.041) and OS (ΔLRχ² = 9.53; P = 0.008), beyond that provided by classical clinicopathological variables. Thus, PD-1 mRNA and protein expression status represent a promising, independent indicator of prognosis in TNBC.

Associations in tumor infiltrating lymphocytes between clinicopathological factors and clinical outcomes in estrogen receptor-positive/human epidermal growth factor receptor type 2 negative breast cancer

The value of assessing tumor infiltrating lymphocytes (TILs) in estrogen receptor (ER) positive/human epidermal growth factor receptor type 2 (HER2) negative breast cancer has yet to be determined. In the present study, a total of 184 cases with early distant recurrence detected within 5 years following the primary operation, 134 with late distant recurrence diagnosed following 5 years or longer and 321 controls without recurrence for >10 years following starting the initial treatment for ER-positive/HER2 negative breast cancer, registered in 9 institutions, were analyzed. The distributions of TILs and their clinical relevance were investigated. TIL distributions did not differ significantly among the early, late and no recurrence groups, employing a 30% cut-off point as a dichotomous variable. In those who had received adjuvant chemotherapy as well as endocrine therapy, a trend toward higher TIL proportions was detected when the early recurrence group was compared with the no recurrence group employing the 30% cut-off point (P=0.064). The TIL distributions were significantly associated with nodal metastasis (P=0.004), ER status (P=0.045), progesterone receptor (PgR) status (P=0.002), tumor grade (P=0.021), and the Ki67 labeling index (LI) (P=0.002) in the no recurrence group and with the Ki67 LI in the recurrence groups (P=0.002 in early recurrence group, P=0.023 in late recurrence group). High TIL distributions also predicted shorter survival time following the detection of recurrence (P=0.026). However, these prognostic interactions were not significant in multivariate analysis (P=0.200). The present retrospective study demonstrated no significant interaction between TIL proportions and the timing of recurrence. However, higher TIL proportions were observed in breast cancer patients with aggressive biological phenotypes, which tended to be more responsive to chemotherapy. The clinical relevance of stromal TILs for identifying patients who would likely benefit from additional therapies merits further investigation in a larger patient population.