Pretreatment tumour immune microenvironment predicts clinical response and prognosis of muscle-invasive bladder cancer in the neoadjuvant chemotherapy setting

Different characteristics of the tumor immune microenvironment among subtypes of salivary gland cancer

AIM

Although immune checkpoint inhibitors (ICPi) for salivary gland cancer (SGC) have been investigated in clinical trials, details of the tumor immune microenvironment (TIME) remain unclear. This research aimed to elucidate the TIME of SGC and its relationship with tumor mutation burden (TMB) and to explore the rationale for the applicability of ICPi.

MATERIALS AND METHODS

We selected five pathological types, namely adenoid cystic carcinoma (ACC); adenocarcinoma, not otherwise specified (ANOS); salivary duct carcinoma (SDC); and low/high-grade mucoepidermoid carcinoma (MEClow/high). We investigated the TIME and TMB of each pathological type. TIME was evaluated by multiplexed fluorescent immunohistochemistry. TMB was measured by next-generation sequencing.

RESULTS

ACC and MEChigh showed the lowest and highest infiltration of immune effector and suppressor cells in both tumor and stroma. ANOS, SDC, and MEClow showed modest infiltration of immune effector cells in tumors. Correlation analysis showed a positive correlation between CD3+CD8+ T cells in tumor and TMB (r = 0.647). CD3+CD8+ T cells in tumors showed a positive correlation with programmed cell death-ligand 1 expression in tumor cells (r = 0.513) and a weak positive correlation with CD3+CD4+Foxp3+ cells in tumors (r = 0.399). However, no correlation was observed between CD3+CD8+ T cells and CD204+ cells in tumors (r = -0.049).

CONCLUSION

The TIME of ACC was the so-called immune desert type, which may explain the mechanisms of the poor response to ICPi in previous clinical trials. On the other hand, MEChigh was the immune-inflamed type, and this may support the rationale of ICPi for this pathological subtype.

Surface Markers and Chemokines/Cytokines of Tumor-Associated Macrophages in Osteosarcoma and Other Carcinoma Microenviornments-Contradictions and Comparisons

Osteosarcoma (OS) is the most common primary bone tumor in children and adolescents. Prognosis is improving with advances in multidisciplinary treatment strategies, but the development of new anticancer agents has not, and improvement in prognosis for patients with pulmonary metastases has stalled. In recent years, the tumor microenvironment (TME) has gained attention as a therapeutic target for cancer. The immune component of OS TME consists mainly of tumor-associated macrophages (TAMs). They exhibit remarkable plasticity, and their phenotype is influenced by the TME. In general, surface markers such as CD68 and CD80 show anti-tumor effects, while CD163 and CD204 show tumor-promoting effects. Surface markers have potential value as diagnostic and prognostic biomarkers. The cytokines and chemokines produced by TAMs promote tumor growth and metastasis. However, the role of TAMs in OS remains unclear to date. In this review, we describe the role of TAMs in OS by focusing on TAM surface markers and the TAM-produced cytokines and chemokines in the TME, and by comparing their behaviors in other carcinomas. We found contrary results from different studies. These findings highlight the urgency for further research in this field to improve the stalled OS prognosis percentages.

Impact of intra-tumoral immunity on predicting response and survival after neoadjuvant cisplatin-based chemotherapy in patients with muscle invasive bladder cancer

BACKGROUND

Neoadjuvant cisplatin-based chemotherapy (NAC) followed by cystectomy is the standard of care for patients with muscle-invasive bladder cancer (MIBC). Pathologic complete response (pCR) is associated with favorable outcomes, but only 30%-40% of patients achieve that response. The aim of this study is to investigate the role played by the Tumor and Immune Microenvironment (TIME) in association with the clinical outcome of patients with MIBC undergoing NAC.

METHODS

Nineteen patients received NAC and were classified as pCR (n = 10) or non-pCR (n = 9). Bulk RNA-seq and immune protein evaluations using Digital Spatial Profiling (DSP) were performed on formalin-fixed paraffin-embedded (FFPE) tumor biopsies collected before NAC (baseline). Immunohistochemistry (IHC) evaluation focused on CD3 and CD20 expression was performed on baseline and end-of-treatment (EOT) FFPEs. Baseline peripheral blood was assessed for lymphocyte and neutrophil counts. Kaplan-Meier analyses and Cox PH regression models were used for survival analyses (OS).

RESULTS

In the periphery, pCR patients showed lower neutrophil counts, and neutrophil/ lymphocyte ratio (NLR) when compared to non-pCR patients. In the tumor microenvironment (TME), gene expression analysis and protein evaluations highlighted an abundance of B cells and CD3+ T cells in pCR versus non-pCR patients. On the contrary, increased protein expression of ARG1+ cells, and cells expressing immune checkpoints such as LAG3, ICOS, and STING were observed in the TME of patients with non-pCR.

CONCLUSIONS

In the current study, we demonstrated that lower NLR levels and increased CD3+ T cells and B cell infiltration are associated with improved response and long-term outcomes in patients with MIBC receiving NAC. These findings suggest that the impact of immune environment should be considered in determining the clinical outcome of MIBC patients treated with NAC.

Impact of LAG-3/FGL1 pathway on immune evasive contexture and clinical outcomes in advanced urothelial carcinoma

BACKGROUND

Anti-programmed death-1 (PD-1)/anti-PD-ligand-1 (PD-L1) pathway inhibition is a standard regimen for advanced urothelial carcinoma (UC); however, its limited efficacy has been reflected in reported medium response rates. This study explored the role of next-generation coinhibitory receptors (IRs; lymphocyte activation gene 3 (LAG-3), T-cell immunoglobulin and mucin domain 3 (TIM-3), and T-cell immunoreceptor with Ig and ITIM domains (TIGIT)) and their ligands (LGs) in the response to PD-(L)1 blockade therapy and the oncological outcomes in patients with UC.

METHODS

We investigated metastatic UC cases who underwent PD-(L)1 therapy (cohort 1: n=348, cohort 2: n=89, and cohort 4: n=29) or advanced UC cases involving surgery (cohort 3: n=293 and cohort 5: n=90). We assessed the mRNA expression profiles and corresponding clinical information regarding IRs and LGs using cohorts 1, 2, and 3. Additionally, we elucidated the spatial features of these targeted markers using multiplex immunohistochemistry (mIHC) on formalin-fixed paraffin-embedded samples from cohorts 4 and 5. Survival, differential expressed gene, and Gene Set Enrichment analyses were performed. For mIHC, quantitative analyses were also performed to correlate immune and tumor cell densities with patient survival.

RESULTS

LAG-3 expression was strongly associated with the responsiveness of PD-(L)1 blockade compared with the expression of TIM-3 and TIGIT. In tumors with high LAG-3 levels, the increased expression of fibrinogen-like protein 1 (FGL1) had a significantly negative effect on the response to PD-(L)1 blockade and overall survival. Moreover, high FGL1 levels were associated with elevated CD4+ regulatory T-cell gene signatures and the upregulation of CD39 and neuropilin-1, with both indicating CD8+ T-cell exhaustion. mIHC analyses revealed that patients with stromal CD8+LAG-3+cellshigh-tumor FGL1+cellshigh exhibited a significant negative correlation with survival rates compared with those with stromal CD8+LAG-3+cellshigh-tumor FGL1+cellslow.

CONCLUSIONS

LAG-3 expression and high FGL1 coexpression are important predictive factors of adverse oncological outcomes related to the presence of immunosuppressive contextures. These findings are hypothesis-generating, warranting further mechanistic and clinical studies aimed to evaluate LAG-3/FGL1 blockade in UC.

Characterization of double-negative T cells in colorectal cancers and their corresponding lymph nodes

TCRαβ+ CD4- CD8- double-negative T (DNT) cells are minor populations in peripheral blood, and their roles have mostly been discussed in inflammation and autoimmunity. However, the functions of DNT cells in tumor microenvironment remain to be elucidated. We investigated their characteristics, possible origins and functions in colorectal cancer tissues as well as their corresponding tumor-draining lymph nodes. We found a significant enrichment of DNT cells in tumor tissues compared with their corresponding lymph nodes, especially in tumors with lower T cell infiltration. T cell receptor (TCR) sequence analysis of CD4+ T, CD8+ T and DNT cells indicated that TCR sequences detected in DNT cells were found in CD8+ T cells, but rarely in CD4+ T cells, suggesting that a part of DNT cells was likely to be originated from CD8+ T cells. Through a single-cell transcriptomic analysis of DNT cells, we found that a DNT cell cluster, which showed similar phenotypes to central memory CD8+ T cells with low expression of effector and exhaustion markers, revealed some specific gene expression patterns, including higher GZMK expression. Moreover, in flow cytometry analysis, we found that DNT cells lost production of cytotoxic mediators. These findings imply that DNT cells might function as negative regulators of anti-tumor immune responses in tumor microenvironment.

In Silico Transcriptomic Expression of MSR1 in Solid Tumors Is Associated with Responses to Anti-PD1 and Anti-CTLA4 Therapies

Immuno-oncology has gained momentum with the approval of antibodies with clinical activities in different indications. Unfortunately, for anti-PD (L)1 agents in monotherapy, only half of the treated population achieves a clinical response. For other agents, such as anti-CTLA4 antibodies, no biomarkers exist, and tolerability can limit administration. In this study, using publicly available genomic datasets, we evaluated the expression of the macrophage scavenger receptor-A (SR-A) (MSR1) and its association with a response to check-point inhibitors (CPI). MSR1 was associated with the presence of macrophages, dendritic cells (DCs) and neutrophils in most of the studied indications. The presence of MSR1 was associated with macrophages with a pro-tumoral phenotype and correlated with TIM3 expression. MSR1 predicted favorable overall survival in patients treated with anti-PD1 (HR: 0.56, FDR: 1%, p = 2.6 × 10-5), anti PD-L1 (HR: 0.66, FDR: 20%, p = 0.00098) and anti-CTLA4 (HR: 0.37, FDR: 1%, p = 4.8 × 10-5). When specifically studying skin cutaneous melanoma (SKCM), we observed similar effects for anti-PD1 (HR: 0.65, FDR: 50%, p = 0.0072) and anti-CTLA4 (HR: 0.35, FDR: 1%, p = 4.1 × 10-5). In a different dataset of SKCM patients, the expression of MSR1 predicted a clinical response to anti-CTLA4 (AUC: 0.61, p = 2.9 × 10-2). Here, we describe the expression of MSR1 in some solid tumors and its association with innate cells and M2 phenotype macrophages. Of note, the presence of MSR1 predicted a response to CPI and, particularly, anti-CTLA4 therapies in different cohorts of patients. Future studies should prospectively explore the association of MSR1 expression and the response to anti-CTLA4 strategies in solid tumors.

High CD204+ tumor-associated macrophage density predicts a poor prognosis in patients with clear cell renal cell carcinoma

Purpose: Tumor-associated macrophages (TAMs) play a crucial role in solid tumors and display varying characteristics depending on the specific tumor microenvironment (TME). The study investigated the presence and characteristics of TAMs in renal clear cell carcinoma (ccRCC) and assessed their influence on patient prognosis. Methods: Immunohistochemistry (IHC) was used to identify CD204+ TAMs in a cohort of 72 patients with ccRCC. Kaplan-Meier survival analysis and log-rank test were used to evaluate the prognostic significance of CD204+ TAMs in each group. The TCGA-KIRC cohort was used to analyze the relationship between CD204 and immunity. The functions of CD204+ TAMs in the TCGA-KIRC cohort were analyzed through GO enrichment analysis. Immunofluorescence (IF) was conducted to confirm the positive effects of CD204 on regulatory T (Treg) cells and exhausted T (Tex) cells. Results: There was a negative relation between high infiltration of CD204+ TAMs and both overall survival (OS) and progression-free survival (PFS) in ccRCC. A positive correlation was found between high-infiltrating CD204+ TAMs and distant organ metastasis, as well as lymph node metastasis. In the TCGA-KIRC cohort, the group with high expression of CD204 exhibited significant up-regulation of 120 genes as well as enrichment in the negative regulation of immunity. CD204 high-expression group showed up-regulation of Treg cells and Tex cells. Conclusion: The presence of CD204+ TAMs in ccRCC is associated with a negative prognosis in patients. The high infiltration of CD204 promotes distant organ metastasis by aggerating Treg cells and Tex cells.

Pathological complete response to neoadjuvant chemotherapy may improve antitumor immune response via reduction of regulatory T cells in muscle-invasive bladder cancer

The prognosis for patients who achieve a pathologic complete response in bladder cancer is excellent, but the association between their prognosis and the tumor microenvironment is unclear. We investigated the tumor immune microenvironment of those with pathological complete response after platinum-based neoadjuvant chemotherapy for cT2-4aN0M0 bladder cancer using multiplex fluorescence immunohistochemistry. Our retrospective study included 12 patients with pathological complete response who underwent radical cystectomy following neoadjuvant chemotherapy for cT2-4aN0M0 muscle-invasive bladder cancer. We assessed the density of several immune cell types in pretreatment and posttreatment tissues via multiplex fluorescence immunohistochemical analysis. The median age was 67 years; 10 patients were male. Nine (75%) and 3 (25%) patients were cT2 and cT3, respectively. The 5-year progression-free and overall survivals were 90% and 100%, respectively. The densities of regulatory T cells (Treg; CD3+CD4+FoxP3+ cell) were significantly decreased and almost disappeared in the tumor microenvironment of posttreatment tissue compared with pretreatment tissue. Other immune cells, such as effector T cells or M2 macrophages, were not significantly changed between posttreatment and pretreatment tissues. In pathological complete response, Tregs in the tumor immune microenvironment were significantly decreased after platinum-based chemotherapy for muscle-invasive bladder cancer. The temporary arresting of immune response in the tumor microenvironment may reflect a favorable prognosis due to the decrease of Tregs with tumor shrinkage and improve the host tumor immune response.

Three versus four cycles of neoadjuvant chemotherapy for muscle-invasive bladder cancer: a systematic review and meta-analysis

OBJECTIVE

The optimal cycle of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) remains controversial. This study aimed to compare the efficacy of three and four cycles of NAC in the treatment of MIBC through a systematic review and meta-analysis of the literature.

MATERIALS AND METHODS

Relevant studies were systematically collected and reviewed in PubMed, Medline, Embase, Web of Science Databases, and the Cochrane Library. Relative ratios (RRs), Hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to estimate outcome measures. Studies comparing the pathological response and prognosis of three versus four cycles of NAC for MIBC were included.

RESULTS

Five studies were included in this meta-analysis, including 2190 patients, of whom 1016 underwent three cycles of NAC and 1174 underwent four cycles of NAC. All studies were retrospective cohort studies. We found that 4 cycles of NAC had significantly better cancer-specific survival than 3 cycles (HR = 1.31, 95%CI,1.03-1.67, p = 0.029). There was no significant difference in overall survival between patients who received 3 and 4 cycles of chemotherapy (HR = 1.18, 95%CI = 0.83-1.69, p = 0.345). Similarly, no significant difference was observed in pathological objective response (RR = 0.95, 95%CI= 0.81-1.11, p = 0.515) and complete response rates (RR = 0.87, 95%CI = 0.69-1.11, p = 0.256) in MIBC after 3 or 4 cycles of NAC.

CONCLUSIONS

Three and four cycles of NAC had similar pathological responses and prognosis for MIBC, although the cancer-specific survival rate of four cycles was better than that of three cycles.

Low level of ARID1A contributes to adaptive immune resistance and sensitizes triple-negative breast cancer to immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) shed new light on triple-negative breast cancer (TNBC), but only a minority of patients demonstrate response. Therefore, adaptive immune resistance (AIR) needs to be further defined to guide the development of ICI regimens.

METHODS

Databases, including The Cancer Genome Atlas, Gene Ontology Resource, University of California Santa Cruz Genome Browser, and Pubmed, were used to screen epigenetic modulators, regulators for CD8+ T cells, and transcriptional regulators of programmed cell death-ligand 1 (PD-L1). Human peripheral blood mononuclear cell (Hu-PBMC) reconstruction mice were adopted for xenograft transplantation. Tumor specimens from a TNBC cohort and the clinical trial CTR20191353 were retrospectively analyzed. RNA-sequencing, Western blotting, qPCR and immunohistochemistry were used to assess gene expression. Coculture assays were performed to evaluate the regulation of TNBC cells on T cells. Chromatin immunoprecipitation and transposase-accessible chromatin sequencing were used to determine chromatin-binding and accessibility.

RESULTS

The epigenetic modulator AT-rich interaction domain 1A (ARID1A) gene demonstrated the highest expression association with AIR relative to other epigenetic modulators in TNBC patients. Low ARID1A expression in TNBC, causing an immunosuppressive microenvironment, promoted AIR and inhibited CD8+ T cell infiltration and activity through upregulating PD-L1. However, ARID1A did not directly regulate PD-L1 expression. We found that ARID1A directly bound the promoter of nucleophosmin 1 (NPM1) and that low ARID1A expression increased NPM1 chromatin accessibility as well as gene expression, further activating PD-L1 transcription. In Hu-PBMC mice, atezolizumab demonstrated the potential to reverse ARID1A deficiency-induced AIR in TNBC by reducing tumor malignancy and activating anti-tumor immunity. In CTR20191353, ARID1A-low patients derived more benefit from pucotenlimab compared to ARID1A-high patients.

CONCLUSIONS

In AIR epigenetics, low ARID1A expression in TNBC contributed to AIR via the ARID1A/NPM1/PD-L1 axis, leading to poor outcome but sensitivity to ICI treatment.

Molecular classification of urothelial bladder carcinoma

Urothelial bladder carcinoma (UC) ranks among the top ten most commonly diagnosed cancers worldwide on an annual basis. The standardized classification system for urothelial bladder tumors is the Tumor, Node, Metastasis classification, which reflects differences between non-muscle-invasive bladder carcinoma (NMIBC) and muscle-invasive bladder carcinoma (MIBC) and it depends on the extent to which tumor has infiltrated the bladder wall and other tissues and organs. NMIBC and MIBC exhibit great intrinsic heterogeneity regarding different prognoses, survival, progression, and treatment outcomes. In recent years, studies based on mRNA expression profiling revealed the existence of biologically relevant molecular subtypes of UC, which show variant molecular features that can provide more precise stratification of UC patients. Here, we present a complex classification of UC based on mRNA expression studies and molecular subtypes of NMIBC and MIBC in detail with regard to different mRNA expression profiles, mutational signatures, and infiltration by non-tumor cells. The possible impact of molecular subtyping on treatment decisions and patients' outcomes is outlined, too.

Dynamic alteration and prognostic significance of tumor-associated CD68+ and CD68+ PD-L1- macrophages in muscle-invasive bladder cancer treated with neoadjuvant chemotherapy

BACKGROUND

The current study aimed to investigate the dynamic alteration and prognostic significance of tumor-infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs), and PD-L1 status of immune cells in muscle-invasive bladder cancer (MIBC) treated with neoadjuvant chemotherapy (NAC).

METHODS

Multiplex immunofluorescence staining was performed to examine CD68⁺ TAM, CD4⁺ T cell, CD8⁺ T cell, FOXP3⁺ Treg cell, and PD-L1 expression in paired MIBC tissues (n = 54) before and after NAC. Patients were then divided into definite responders (DR), (≤pT1) and incomplete responders (IR).

RESULTS

There was no significant difference between DR and IR cohorts for the immune cell infiltration levels at the baseline status. Tobacco history was identified to be associated with worse NAC efficacy. CD68⁺ (stroma area: p = 0.025; tumor area: p = 0.028; total area: p = 0.013) and CD68⁺ PD-L1^- (stroma area: p = 0.035; tumor area: p = 0.013 total area: p = 0.014) TAMs infiltration levels decreased significantly after NAC, while there was no significant difference of CD68⁺ PD-L1⁺ and TILs. The infiltration of CD68⁺ (p = 0.033), CD68⁺ PD-L1^- (p = 0.033), and CD68⁺ PD-L1⁺ (p < 0.001) TAMs in stroma area were significantly associated with poorer disease-free survival rate (DFS) of MIBC patients.

CONCLUSION

CD68⁺ and CD68⁺ PD-L1^- TAMs infiltration levels decreased significantly after NAC and pre-treatment TAM infiltration levels were independent prognostic factors for MIBC patients. While there was no sufficient evidence demonstrating that pre-treatment TILs or TAMs could predict response to NAC in MIBC patients.

The role of macrophage scavenger receptor 1 (MSR1) in inflammatory disorders and cancer

Macrophage scavenger receptor 1 (MSR1), also named CD204, holds key inflammatory roles in multiple pathophysiologic processes. Present primarily on the surface of various types of macrophage, this receptor variably affects processes such as atherosclerosis, innate and adaptive immunity, lung and liver disease, and more recently, cancer. As highlighted throughout this review, the role of MSR1 is often dichotomous, being either host protective or detrimental to the pathogenesis of disease. We will discuss the role of MSR1 in health and disease with a focus on the molecular mechanisms influencing MSR1 expression, how altered expression affects disease process and macrophage function, the limited cell signalling pathways discovered thus far, the emerging role of MSR1 in tumour associated macrophages as well as the therapeutic potential of targeting MSR1.

Immune Microenvironment of Muscular-Invasive Urothelial Carcinoma: The Link to Tumor Immune Cycle and Prognosis

In this study, we investigated the relationship between the tumor immune microenvironment (TIME), histological differentiation and hypoxia in patients with muscular-invasive urothelial carcinomas (MIUC) after radical cystectomy. Forty-two cases of pT2-3N0M0 MIUCs underwent clinical, histological and immunohistochemical evaluation by counting CD8+, FOXP3+, CD68+, CD163+ cells and polymorphonuclear leukocytes (PMN) in intra-tumoral and peritumoral areas, assessing PD-L1 and GLUT1 expression for defining the impact of tumor immune contexture on patients’ outcomes. Five-year survival rates and overall survival were calculated. Most of the MIUCs demonstrated the immune-desert or immune-excluded TIME, reflecting altered mechanisms of T-cells’ activation or traffic into tumors. Tumor immune contexture was closely related to histological differentiation. CD8+ cells were scant in MIUCs with papillary and squamous differentiation, while basal-like or mesenchymal-like histological differentiation was associated with increased density of CD8+ cells. A high rate of PD-L1 expression (47.6%) was not related to immune cell infiltration. M2-macrophages predominated under CD8+ lymphocytes. The abundance of PMN and CD163+ macrophages in MIUCs was associated with high GLUT1 expression. CD8+, CD68+, FOXP3+ cells and PD-L1 status did not affect patients’ outcomes, while high CD163+ density and PMN infiltration were associated with the unfavorable outcome of patients with MIUC. These data drive the hypothesis that in MIUC, immune escape mechanisms are shifted towards the role of the innate immunity cells rather than CD8+ lymphocytes’ functioning.

HNRNPA2B1 Demonstrates Diagnostic and Prognostic Values Based on Pan-Cancer Analyses

Some studies have suggested heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) to be a promoter in cancer development. Nonetheless, no detailed pan-cancer investigation has been reported. Thus, this study explored the possible oncogenic role of HNRNPA2B1, such as its expression levels, gene alteration, protein–protein interaction network, immune infiltration, and prognostic value in different cancer types using The Cancer Genome Atlas web platform. Many types of cancer exhibit HNRNPA2B1 overexpression, which is notably associated with poor prognosis. We also found that HNRNPA2B1 with different methylation levels causes a varied prognosis in lung adenocarcinoma (LUAD). It is noteworthy that HNRNPA2B1 levels are connected with cancer-associated fibroblasts in cancers, such as adrenocortical carcinoma, LUAD, and stomach adenocarcinoma. In addition, HNRNPA2B1 participates in the spliceosome- and cell cycle-associated pathways. Finally, HNRNPA2B1 is highly valued in the diagnosis of LUAD, lung squamous cell carcinoma, breast invasive carcinoma, esophageal carcinoma, and liver hepatocellular carcinoma. This systematic study highlighted the role of HNRNPA2B1 in pan-cancer progression.

Immune microenvironment, homologous recombination deficiency, and therapeutic response to neoadjuvant chemotherapy in triple-negative breast cancer: Japan Breast Cancer Research Group (JBCRG)22 TR

BACKGROUND

Triple-negative breast cancer (TNBC) is a biologically diverse disease, with characteristics such as homologous recombination deficiency (HRD), gene mutation, and immune reactions. Japan Breast Cancer Research Group 22 is a multicenter trial examining TNBC's response to neoadjuvant chemotherapy (NAC) according to the HRD status. This translational research investigated the clinical significance of the immune microenvironment of TNBC in association with HRD, tumor BRCA1/2 (tBRCA1/2) mutation, and response to NAC.

METHODS

Patients aged below 65 years with high HRD or germline BRCA1/2 (gBRCA1/2) mutation randomly received paclitaxel + carboplatin (group A1) or eribulin + carboplatin (A2), followed by anthracycline. Patients aged below 65 years with low HRD or those aged 65 years or older without gBRCA1/2 mutation randomly received eribulin + cyclophosphamide (B1) or eribulin + capecitabine (B2); nonresponders to the first four cycles of the therapy received anthracycline. A pathological complete response (pCR) was defined as the absence of residual cancer cells in the tissues. Pretreatment biopsy specimens were stained by multiplexed fluorescent immunohistochemistry using antibodies against CD3, CD4, CD8, Foxp3, CD204, and pan-cytokeratin. Immune cells with specific phenotypes were counted per mm² in cancer cell nests (intratumor) and stromal regions. The immune cell densities were compared with clinicopathological and genetic factors including tumor response.

RESULTS

This study analyzed 66 samples. T1 tumors had a significantly higher density of intratumoral CD8⁺ T cells than T2 or larger tumors. The tBRCA1/2 mutation or HRD status was not associated with the density of any immune cell. The density of intratumoral and stromal CD4⁺ T cells was higher in patients showing pCR than in those without pCR. In a multivariate analysis, intratumoral and stromal CD4⁺ T cell density significantly predicted pCR independent of age, chemotherapy dose, HRD status, and treatment groups (P = 0.009 and 0.0057, respectively). In a subgroup analysis, the predictive value of intratumoral and stromal CD4⁺ T cell density persisted in the platinum-containing chemotherapy group (A1+A2) but not in the non-platinum-containing group (B1+B2).

CONCLUSIONS

Intratumoral and stromal CD4⁺ T cell density was an independent predictor of pCR in patients with TNBC. A larger study is warranted to confirm the results.

TRIAL REGISTRATION

UMIN000023162.

Molecular Subtypes as a Basis for Stratified Use of Neoadjuvant Chemotherapy for Muscle-Invasive Bladder Cancer-A Narrative Review

There are no established biomarkers to guide patient selection for neoadjuvant chemotherapy prior to radical cystectomy for muscle-invasive bladder cancer. Recent studies suggest that molecular subtype classification holds promise for predicting chemotherapy response and/or survival benefit in this setting. Here, we summarize and discuss the scientific literature examining transcriptomic or panel-based molecular subtyping applied to neoadjuvant chemotherapy-treated patient cohorts. We find that there is not sufficient evidence to conclude that the basal subtype of muscle-invasive bladder cancer responds well to chemotherapy, since only a minority of studies support this conclusion. More evidence indicates that luminal-like subtypes may have the most improved outcomes after neoadjuvant chemotherapy. There are also conflicting data concerning the association between biopsy stromal content and response. Subtypes indicative of high stromal infiltration responded well in some studies and poorly in others. Uncertainties when interpreting the current literature include a lack of reporting both response and survival outcomes and the inherent risk of bias in retrospective study designs. Taken together, available studies suggest a role for molecular subtyping in stratifying patients for receiving neoadjuvant chemotherapy. The precise classification system that best captures such a predictive effect, and the exact subtypes for which other treatment options are more beneficial remains to be established, preferably in prospective studies.