Tumor-associated macrophages and tumor-infiltrating lymphocytes in canine cutaneous and subcutaneous mast cell tumors

Cutaneous and subcutaneous mast cell tumors (MCTs) are common canine neoplasms characterized by variable biological behavior. Tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) can be effective prognostic markers in numerous human neoplasms and are increasingly investigated in dogs. The aim of this study was to characterize immune cells in canine MCTs and their relationship with histological location (cutaneous, subcutaneous) and histologic nodal metastatic status (HN0-3). Thirty-eight MCTs (26 cutaneous, 12 subcutaneous) from 33 dogs with known sentinel lymph node (SLN) metastatic status were immunolabeled for Iba1 (macrophages), CD20 (B cells), CD3 (T cells), and Foxp3 (regulatory T cells). Semiquantitative scoring of interstitial and perivascular CD3+, CD20+, and Foxp3+ cells and morphological evaluation of Iba1+ cells were performed. For each marker, the percent immunopositive area was evaluated by image analysis. All MCTs were diffusely infiltrated by Iba1+ cells and variably infiltrated by CD20+, CD3+, and rare Foxp3+ cells. Stellate/spindle Iba1+ cells were associated with HN2 and HN3 SLNs. Perivascular Foxp3+ cells, CD3+ cells, and percent CD3+ areas were increased in subcutaneous MCTs. Interstitial CD3+ cells were increased in cutaneous MCTs with HN0 SLNs. No differences in CD20+ cells were identified between cutaneous and subcutaneous MCTs and among SLN classes. MCTs were markedly infiltrated by TAMs and variably infiltrated by TILs. Stellate/spindle morphology of TAMs associated with HN2 and HN3 SLNs is suggestive of a pro-tumoral (M2) phenotype. Cutaneous and subcutaneous MCTs have different tumor-immune microenvironments, and T-cell infiltration might contribute to prevention of nodal metastatic spread of cutaneous MCTs.

Effect of Neoadjuvant Chemotherapy on Tumor-Infiltrating Lymphocytes in Resectable Gastric Cancer: Analysis from a Western Academic Center

Tumor-infiltrating lymphocytes (TILs) are an emerging biomarker predictive of response to immunotherapy across a spectrum of solid organ malignancies. The characterization of TILs in gastric cancer (GC) treated with contemporary, multiagent neoadjuvant chemotherapy (NAC) is understudied. In this retrospective investigation, we analyzed the degree of infiltration, phenotype, and spatial distribution of TILs via immunohistochemistry within resected GC specimens treated with or without NAC at a Western center. We hypothesized that NAC executes immunostimulatory roles, as evidenced by an increased number of anti-tumor TILs in the tumor microenvironment. We found significantly elevated levels of conventional and memory CD8+ T cells, as well as total TILs (CD4+, CD8+, Treg, B cells), within chemotherapy-treated tumors compared with chemotherapy-naïve specimens. We also revealed important associations between survival and pathologic responses with enhanced TIL infiltration. Taken together, our findings advocate for an immunostimulatory role of chemotherapy and underscore the potential synergistic effect of combining chemotherapy with immunotherapy in resectable gastric cancer.

High PD-L1 expression on immune cells along with increased density of tumor-infiltrating lymphocytes predicts a favorable survival outcome for patients with loco-regionally advanced head and neck cancer: early results from a prospective study

Introduction

In the era of personalized medicine and treatment optimization, use of immune biomarkers holds promise for estimating the prognosis of patients with head and neck squamous cell carcinoma (HNSCC) undergoing definitive treatment.

Methods

To evaluate the prognostic potential of immune biomarkers, we conducted a prospective monocentric cohort study with loco-regionally advanced HNSCC patients indicated for definitive radiotherapy/radiochemotherapy at the Department of Oncology, Ostrava University Hospital, Czech Republic, between June 2020 and August 2023. We focused on the expression of programmed death ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) relative to overall survival (OS) and specific survival rates. Associations between biomarkers and survival rates were assessed by crude and adjusted hazard ratios (cHR, aHR, respectively) obtained from Cox proportional hazards regression.

Results

Among a total of 55 patients within a median follow-up of 19.7 months, there were 21 (38.2%) all-cause deaths and 15 (27.3%) cancer-related deaths. An overall survival (OS) rate of 61.8% and a disease-specific survival (DSS) rate of 72.7% were recorded. A significant association between survival rates and a ≥10% difference in PD-L1 expression on immune versus tumor cells (high PD-L1IC expression) was documented regardless of the type of analysis (univariate or multivariate). In addition, a stronger association was confirmed for OS and the composite biomarker high PD-L1IC expression along with either median-higher CD8+ TIL count or increased TIL density ≥30%, as indicated by an aHR of 0.08 (95% CI, 0.01 to 0.52) and 0.07 (95% CI, 0.01 to 0.46), respectively. Similar results were demonstrated for other specific survival rates.

Discussion

The early outcomes of the present study suggest the utility of a strong prognostic factor involving a composite biomarker high PD-L1IC expression along with increased TIL density in HNSCC patients undergoing definitive radiotherapy and radiochemotherapy.

Trial registration

The study is registered with Clinicaltrials.gov. - NCT05941676.

Tumor-infiltrating lymphocytes as a prognostic and predictive factor for Melanoma

INTRODUCTION

Tumor-infiltrating lymphocytes (TILs) have been investigated as prognostic factors in melanoma. Recent advancements in assessing the tumor microenvironment in the setting of more widespread use of immune checkpoint blockade have reignited interest in identifying predictive biomarkers. This review examines the function and significance of TILs in cutaneous melanoma, evaluating their potential as prognostic and predictive markers.

AREAS COVERED

A literature search was conducted on papers covering tumor infiltrating lymphocytes in cutaneous melanoma available online in PubMed and Web of Science from inception to 1 December 2023, supplemented by citation searching. This article encompasses the assessment of TILs, the role of TILs in the immune microenvironment, TILs as a prognostic factor, TILs as a predictive factor for immunotherapy response, and clinical applications of TILs in the treatment of cutaneous melanoma.

EXPERT OPINION

Tumor-infiltrating lymphocytes play a heterogeneous role in cutaneous melanoma. While they have historically been associated with improved survival, their status as independent prognostic or predictive factors remains uncertain. Novel methods of TIL assessment, such as determination of TIL subtypes and molecular signaling, demonstrate potential for predicting therapeutic response. Further, while their clinical utility in risk-stratification in melanoma treatment shows promise, a lack of consensus data hinders standardized application.

Immune Cytolytic Activity and Strategies for Therapeutic Treatment

Intratumoral immune cytolytic activity (CYT), calculated as the geometric mean of granzyme-A (GZMA) and perforin-1 (PRF1) expression, has emerged as a critical factor in cancer immunotherapy, with significant implications for patient prognosis and treatment outcomes. Immune checkpoint pathways, the composition of the tumor microenvironment (TME), antigen presentation, and metabolic pathways regulate CYT. Here, we describe the various methods with which we can assess CYT. The detection and analysis of tumor-infiltrating lymphocytes (TILs) using flow cytometry or immunohistochemistry provide important information about immune cell populations within the TME. Gene expression profiling and spatial analysis techniques, such as multiplex immunofluorescence and imaging mass cytometry allow the study of CYT in the context of the TME. We discuss the significant clinical implications that CYT has, as its increased levels are associated with positive clinical outcomes and a favorable prognosis. Moreover, CYT can be used as a prognostic biomarker and aid in patient stratification. Altering CYT through the different methods targeting it, offers promising paths for improving treatment responses. Overall, understanding and modulating CYT is critical for improving cancer immunotherapy. Research into CYT and the factors that influence it has the potential to transform cancer treatment and improve patient outcomes.

Spatial Distribution and Densities of CD103+ and FoxP3+ Tumor Infiltrating Lymphocytes by Digital Analysis for Outcome Prediction in Breast Cancer

BACKGROUND

The evaluation of tumor-infiltrating lymphocytes (TILs) for breast cancer prognosis is now established. However, the clinical value for their spatial distributions of specific immune subsets, namely CD103+ tissue-resident memory T cells FoxP3+ regulatory T ells, have not been thoroughly examined.

METHOD

Representative whole sections of breast cancers were subjected to CD103 and FoxP3 double staining. Their density, ratio, and spatial features were analyzed in tumor area and tumor-stromal interface. Their associations with clinicopathological parameters and patient's prognosis were analyzed.

RESULTS

CD103 TILs were closer to tumor nests than FoxP3 TILs in the tumor-stromal interface. Their densities were associated with high-grade disease, TNBC, and stromal TILs. High stromal FoxP3 (sFoxP3) TILs and close proximity of sCD103 TILs to tumor were independently associated with better survival at multivariate analysis. Subgroup analysis showed the high FoxP3 TILs density associated better survival was seen in HER2-OE and TNBC subtypes while the proximity of CD103 TILs to tumor nests associated better survival was seen in luminal cancers.

CONCLUSION

The prognostic impact of CD103 and FoxP3 TILs in breast cancer depends on their spatial localization. High sFoxP3 TIL density and the lower distance of CD103 TILs from the tumor nests had independent favorable prognostic values.

Cytokine Plasma Levels in Breast Cancer Patients, Before and After Surgery

Studying the levels of cytokines in the plasma of patients could be valuable in guiding immunotherapy policies. We assessed the plasma levels of 4 major cytokines [interferon (IFN)-β, interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β)] collected from 19 patients with ductal breast cancer (BCa), before surgery (BS) and 5 days after surgery (AS). The ratio AS/BS was also calculated and correlated with histopathological variables and tumor-infiltrating lymphocyte (TIL) density. The IFN-β and TNF-α levels were significantly higher in BCa patients, BS and AS, than healthy controls (P < 0.02). High IL-2 levels BS were linked with node involvement (P = 0.02), and marginally with HER2 expression (P = 0.08), while high TNF-α levels were linked with high PgR expression (P = 0.02). Increasing IFN-β, IL-2, and TNF-α levels were noted AS, which was more evident in patients with larger tumors. The TGF-β levels were significantly lower in BCa patients (P < 0.007). Linear regression analysis showed a direct association of IFN-β levels AS (P = 0.02, r = 0.52) and of TNF-α AS/BS-ratio (P = 0.001, r = 0.72) with TIL-density. It is suggested that although effector immune response is evident in the majority of early stage BCa patients, removal of the primary tumor further unblocks such responses.

Immunosurveillance in clinical cancer management

The progression of cancer involves a critical step in which malignant cells escape from control by the immune system. Antineoplastic agents are particularly efficient when they succeed in restoring such control (immunosurveillance) or at least establish an equilibrium state that slows down disease progression. This is true not only for immunotherapies, such as immune checkpoint inhibitors (ICIs), but also for conventional chemotherapy, targeted anticancer agents, and radiation therapy. Thus, therapeutics that stress and kill cancer cells while provoking a tumor-targeting immune response, referred to as immunogenic cell death, are particularly useful in combination with ICIs. Modern oncology regimens are increasingly using such combinations, which are referred to as chemoimmunotherapy, as well as combinations of multiple ICIs. However, the latter are generally associated with severe side effects compared with single-agent ICIs. Of note, the success of these combinatorial strategies against locally advanced or metastatic cancers is now spurring successful attempts to move them past the postoperative (adjuvant) setting to the preoperative (neoadjuvant) setting, even for patients with operable cancers. Here, the authors critically discuss the importance of immunosurveillance in modern clinical cancer management.

Tumor-infiltrating lymphocytes in patients undergoing esophagectomy following neoadjuvant DCF therapy

BACKGROUND

Accumulating evidence suggests that expression levels of tumor-infiltrating (TI) cells may play a prognostic role in patients with esophageal cancer who have undergone esophagectomy. However, its effect on patients undergoing neoadjuvant docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy followed by esophagectomy for esophageal squamous cell carcinoma (ESCC) remains unclear. Therefore, this study aimed to elucidate the prognostic impact of TI cells in patients who underwent esophagectomy following neoadjuvant DCF therapy.

METHODS

Overall, 81 patients with ESCC who underwent curative esophagectomy following neoadjuvant DCF therapy were included. The number of TI CD8+ cells was determined using light microscopy at ×400 in tumor invasive margins. Receiver operative characteristic curve was used to determine the cutoff values for mortality for continuous variables; the patients were separated into high and low TI CD8+ cell groups and their backgrounds and clinical outcomes were compared.

RESULTS

Overall and relapse-free survival were significantly worse in the TI CD8+-low group than that in the TI CD8+-high group (p < 0.01). Multivariate analysis revealed that positive ypN (hazard ratio [HR], 3.12; 95% confidence interval [CI], 1.08-9.02) and low TI CD8+ cell levels (HR, 2.77; 95% CI, 1.31-5.85) were independent prognostic factors for overall survival. Furthermore, positive venous invasion (HR, 2.63; 95% CI, 1.29-5.35) and low TI CD8+ cell levels (HR, 2.77; 95% CI, 1.70-5.46) were significant prognostic factors for relapse-free survival.

CONCLUSIONS

Low TI CD8+ cell level was a prominent prognostic factor for patients with ESCC undergoing neoadjuvant DCF therapy followed by esophagectomy.

Tumor Characteristics and Treatment Responsiveness in Pembrolizumab-Treated Non-Small Cell Lung Carcinoma

Pembrolizumab, a widely used immune checkpoint inhibitor (ICI), has revolutionized the treatment of non-small cell lung cancer (NSCLC). Identifying unique tumor characteristics in patients likely to respond to pembrolizumab could help the clinical adjudication and development of a personalized therapeutic strategy. In this retrospective study, we reviewed the clinical data and pathological features of 84 NSCLC patients treated with pembrolizumab. We examined the correlation between the clinical and demographic characteristics and the tumor histopathologic features obtained before immunotherapy. The response to pembrolizumab therapy was evaluated via the Response Evaluation Criteria in Solid Tumors (RECIST). The clinical data and cancer tissue characteristics were assessed and compared among three groups according to the following RECIST: the responsive group (RG), the stable disease group (SD), and the progressive disease group (PD), where the RG comprised patients with either a complete response (CR) or a partial response (PR). The overall survival rate of the RG group was significantly higher than the SD and PD groups. In addition, the percentage of pre-treatment viable tumor cell content in the RG and SD groups was significantly higher. At the same time, the extracellular stroma proportion was significantly lower than that of the PD group. The number of tumor-infiltrating lymphocytes (TILs) in the RG group was significantly higher than in the PD group. There were no significant differences in tumor necrosis, the stroma composition, PD-L1 expression level (TPS 1-49% vs. ≥50%), and treatment response. In conclusion, our population of NSCLC patients who experienced positive treatment responses to pembrolizumab therapy had a better prognosis compared to patients with either SD or PD. Moreover, the relative proportions of viable tumor cells to tumor-associated lymphocytes were associated with responsiveness to treatment. It is expected that larger prospective clinical studies will further validate these findings.

Predictive value of stromal tumor-infiltrating lymphocytes in patients with breast cancer treated with neoadjuvant chemotherapy: A meta-analysis

BACKGROUND

The predictive value of tumor-infiltrating lymphocytes (TILs) in response to neoadjuvant chemotherapy (NAC) for breast cancer (BC) has received increasing attention. Here, a meta-analysis was conducted to evaluate the correlation between the expression of stromal TILs and pathological complete response (pCR) after NAC in BC patients.

METHODS

The PubMed, Embase, Cochrane Library, and Web of Science databases were searched online by using a combination of keywords and free words to screen literature on the expression of stromal TILs and pCR after NAC in patients with BC. The data were extracted and evaluated for quality. Relative risk (RR) was used to evaluate the relationship between the expression of stromal TILs before NAC and pCR in BC patients. Meta-analysis was performed with Review Manager 5.3 and STATA 14.0 software.

RESULTS

Eleven studies involving 6039 BC patients were included in the meta-analysis. The results showed a generally high expression of stromal TILs in BC patients, and the pCR rate after NAC in BC patients with a high expression of stromal TILs was significantly higher than that in BC patients with a low expression of stromal TILs [RR = 1.83, 95% confidence interval (CI): 1.69-1.97]. Subgroup analysis based on the molecular subtypes of BC showed that the pCR rate was significantly higher in patients with a high expression of stromal TILs in hormone receptor (HR)-positive BC [RR = 3.23, 95% CI: 2.43-4.30], human epidermal growth factor receptor 2 (HER-2)-positive BC [RR = 1.41, 95% CI: 1.25-1.60], and triple-negative BC [RR = 1.70, 95% CI: 1.53-1.90] than in those with a low expression of stromal TILs. Subgroup analysis based on expression threshold showed that the pCR rate was higher in patients with a high expression of stromal TILs than in patients with a low expression of stromal TILs at different expression thresholds (10% [RR = 1.99, 95% CI: 1.55-2.55], 20%/30% [RR = 1.57, 95% CI: 1.37-1.81], 50%/60% [RR = 1.91, 95% CI: 1.73-2.11].

CONCLUSION

TILs can be used as a predictor of pCR after NAC in patients with BC, and the appropriate high expression threshold of stromal TILs should be selected as the predictive value according to the molecular subtype of BC.

Clinical and biomarker analyses of hepatic arterial infusion chemotherapy plus lenvatinib and PD-1 inhibitor for patients with advanced intrahepatic cholangiocarcinoma

Background

Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive cancer with a dismal prognosis and few effective therapeutic approaches. This study aimed to investigate the efficacy, safety, and predictive biomarkers of hepatic arterial infusion chemotherapy (FOLFOX-HAIC) in combination with lenvatinib and PD-1 inhibitor for patients with advanced iCCA.

Methods

Locally advanced or metastatic iCCA patients receiving the triple combination therapy of lenvatinib, PD-1 inhibitor, and FOLFOX-HAIC were included in this retrospective study. Primary endpoint was the progression-free survival, evaluated using the RECIST criterion. The secondary endpoints included overall survival, objective response rate, and safety. Whole exome and RNA sequencing of tumor biopsy tissues were performed for biomarker exploration.

Results

Between May, 2019 and December 2022, a total of 46 patients were included in this study. The primary endpoint showed a median progression-free survival of 9.40 months (95% CI: 5.28-13.52), with a 6-month progression-free survival rate of 76.1%. The median overall survival was 16.77 months (95% CI, 14.20-19.33), with an objective response rate of 47.8% and disease control rate of 91.3% per RECIST. In addition, 4.3% and 8.7% of patients achieved complete response of all lesions and intrahepatic target lesions per mRECIST, respectively. The most common treatment-related adverse events were neutropenia, thrombocytopenia, elevated aspartate aminotransferase and alanine aminotransferase level. Furthermore, integrated analysis of genetic, transcriptomic, and immunohistochemistry data revealed that pre-existing immunity (high expression level of immune-related signatures and intra-tumoral CD8+ T cell density) in baseline tumor tissues was associated with superior clinical benefits. However, the evaluation of tumor mutation burden did not show potential predictive value in this triple combination.

Conclusion

FOLFOX-HAIC in combination with lenvatinib and PD-1 inhibitor demonstrated a promising antitumor activity with manageable safety profiles in patients with advanced iCCA. Moreover, our study also revealed new perspectives on potential biomarkers for clinical efficacy.

Presence, Subtypes, and Prognostic Significance of Tertiary Lymphoid Structures in Urothelial Carcinoma of the Bladder

OBJECTIVE

To evaluate the presence and subtypes of tertiary lymphatic structures (TLSs) in urothelial carcinoma of the bladder (UCB) and to analyze their associated clinicopathological characteristics and prognostic significance.

METHODS

The study enrolled 580 patients with surgically treated UCB, including 313 non-muscle invasive bladder cancer (NMIBC) and 267 muscle-invasive bladder cancer (MIBC). The presence and subtypes of TLSs were identified by immunohistochemistry (CD20, CD3, Bcl-6, and CD21). TLSs were classified into non-GC (nGC) TLS and GC TLS subtypes based on germinal center (GC) formation. Disease-free survival (DFS) was used as an endpoint outcome to evaluate the prognostic significance of TLS and its subtypes in UCB.

RESULTS

TLSs were more common in MIBC than in NMIBC (67.8% vs 48.2%, P < .001), and the tumor-infiltrating lymphocyte (TIL) mean density was significantly higher in MIBC than in NMIBC (24.0% vs 17.5%, P < .001). Moreover, a positive correlation was found between TLS presence and GC structure formation and TIL infiltration in UCB. Endpoint events occurred in 191 patients. Compared to patients with endpoint events, patients without disease progression exhibited higher TIL density and more TLSs (P < .05). Kaplan-Meier curves showed that TLS was associated with better DFS in NMIBC (P = .041) and MIBC (P = .049). However, the Cox multivariate analysis did not demonstrate the prognostic significance of TLS.

CONCLUSIONS

TLS is heterogeneous in UCB, and that TLS and GC structures are related to TIL density and prognostic events. However, TLS as a prognostic indicator remains unclear, warranting further investigation.

Prognostic Value of Immunoscore in Colorectal Carcinomas

Aims. Immunoscore, based on the evaluation of CD3+ and CD8+ densities in the center of the tumor and its invasive margin, is currently considered as a potential prognostic factor, particularly in colorectal carcinomas. In the current study, we aimed to assess the prognostic value of immunoscore in colorectal cancer stage I to IV, through a survival study. Methods and Results. It was a descriptive and retrospective study involving 104 cases of colorectal cancer. Data were collected over 3 years (2014-2016). An immunohistochemical study (anti-CD3, anti-CD8) by the tissue microarray technique was carried out in the areas of "hot spot" in the tumor center and invasive margin. A percentage was assigned to each marker and within each region. Then, the density was classified as "low" or "high," according to a cutoff fixed at the median of percentages. immunoscore was calculated by the method described by Galon et al. The prognostic value of the immunoscore was assessed through a survival study. The mean age of patients was 61.6 years. immunoscore was low in 60.6% (n = 63). Our study had shown that low immunoscore significantly deteriorates survival and a high immunoscore enhances survival significantly (P < .001). We found a correlation between immunoscore and T stage (P = .026). A multivariate showed that the predictive factors for survival were immunoscore (P = .001) and age (P = .035). Conclusions. Our study highlights the potential role of immunoscore as a prognostic factor in colorectal cancer. Its reproducibility and reliability allow its introduction into daily practice for better therapeutic management.

Direct visualization of immune status for tumor-infiltrating lymphocytes by rolling circle amplification

The immune status of tumor-infiltrating lymphocytes (TILs) is essential for the effectiveness of cancer immunotherapies. However, due to the diversity of immune status in TILs, cellular heterogeneity, and the applicability to the clinic, it is still lacking effective strategies to meet clinical needs. We developed a novel immuno-recognition-induced method based on rolling circle amplification (RCA), namely immunoRCA, to in situ visualize the immune status of TILs in actual clinical samples. This developed immunoRCA method, in which, feature mRNAs were used as the biomarkers for the immune status of TILs, has a low fluorescence background, high sensitivity, and specificity. The immunoRCA was able to efficiently evaluate the immune status of CD8+ T cells regulated by activating or inhibiting factors, track the T cell type and immune status during in vitro expansion, and in situ visualize the number, location, and immune status of TILs in clinical specimens.

The levels of immunosuppressive checkpoint protein PD-L1 and tumor-infiltrating lymphocytes were integrated to reveal the glioma tumor microenvironment

In spite of significant strides in the realm of cancer biology and therapeutic interventions, the clinical prognosis for patients afflicted with glioblastoma (GBM) remains distressingly dismal. The tumor immune microenvironment (TIME), a crucial player in the progression, treatment response, and prognostic trajectory of glioma, warrants thorough exploration. Within this intricate microcosm, the immunosuppressive checkpoint protein PD-L1 and tumor-infiltrating lymphocytes (TILs) emerge as pivotal constituents, underscoring their potential role in deciphering glioma biology and informing treatment strategies. However, prognostic models based on the association between PD-L1 expression and TIL infiltration in the tumor immune microenvironment have not been established. The aim of this study was to explore TIME genes associated with PD-L1 expression and TIL invasion and to construct a risk score for predicting the overall survival (OS) of GBM patients based on these genes. The samples were separately classified according to the PD-L1 expression level and TIL score and TIME-related genes were identified using differential expression and weighted gene co-expression network analysis. The DEGs were subjected to least absolute contraction and selection operator (LASSO) -Cox regression to construct TIME associated risk score (TIMErisk). A TIMErisk was developed based on STEAP3 and CXCL13 genes. The STLEAP3 was demonstrated to be involved in glioma progression. The results showed that the patients in the high TIMErisk group had poor OS compared with subjects in the low TIMErisk group. The biological phenotypes associated with TIMErisk were analyzed in terms of functional enrichment, tumor immune profile, and tumor mutation profile. The results on tumor immune dysfunction and exclusion dysfunction (TIDE) score and immune surface score (IPS) showed that GBM patients with different TIME risks had different responses to immunotherapy. Tumor purity analysis indicated that PD-L1 and TIL scores were positively correlated with TIMErisk score and negatively correlated with tumor purity. These results show that the TIMErisk-based prognostic model had high predictive value for the prognosis and immune characteristics of GBM patients. Immunohistochemical staining images of patients in the high and low TIMErisk groups were analyzed, showing that the degree of immune cell infiltration was higher in the high TIMErisk group relative to the low TIMErisk group. The present study provides a basis for understanding glioma tumor microenvironment and a foundation for conducting comprehensive immunogenomic analysis.

Insight into the significance of CD8+ tumor-infiltrating lymphocytes in squamous cell lung cancer

BACKGROUND

Although there are great expectations regarding the use of tumor-infiltrating lymphocytes (TILs) to predict effects of immunotherapies and prognosis, knowledge about TILs remains insufficient for clinical application.

METHODS

We objectively investigated the prognostic significance of tumor-infiltrating CD8 + lymphocytes (CD8 + TILs) in squamous cell lung cancer (SQ-LC). Among patients who underwent surgical resection of SQ-LC in 2011-2017, 100 patients with pathological stage IA3-III were immunohistochemically studied to evaluate CD8 + TILs in the tumor stroma and parenchyma. The impact of CD8 + TILs on relapse-free survival was analyzed using a Kaplan-Meier survival analysis and multivariate analyses using Fine-Gray and Cox proportional hazards models.

RESULTS

The multivariate analysis showed that large and small numbers, but not intermediate numbers, of CD8 + TILs in the tumor stroma may be related to a more favorable prognosis (small vs. intermediate: HR, 0.64; 95% CI: 0.29-1.41, p = 0.27; large vs. intermediate: HR, 0.48; 95% CI: 0.21-1.09, p = 0.08). In contrast, a large number of CD8 + TILs in the tumor parenchyma was associated with a poor prognosis (HR, 2.60; 95% CI: 0.91-7.42, p = 0.075). An exploratory analysis showed a potentially strong association between an extremely large number of CD8 + TILs in the tumor parenchyma and a poor prognosis, even with a large number of CD8 + TILs in the tumor stroma.

CONCLUSION

Our study provided partial but important information on the significance of CD8 + TILs in SQ-LC. To use CD8 + TILs as biomarkers, a better understanding of CD8 + TILs as well as other important components in the tumor microenvironment and the inflammatory phenotypes they form may be needed.

Clinical presentation of cardiac symptoms following treatment with tumor-infiltrating lymphocytes: diagnostic challenges and lessons learned

BACKGROUND

Treatment with tumor-infiltrating lymphocytes (TILs) is rapidly evolving for patients with solid tumors. Following metastasectomy, TILs (autologous, intratumoral CD4+ and CD8+ T cells with the potential to recognize tumor-associated antigens) are isolated and non-specifically expanded ex vivo in the presence of interleukin-2 (IL-2). Subsequently, the TILs are adoptively transferred to the patients after a preconditioning non-myeloablative, lymphodepleting chemotherapy regimen, followed by administration of high-dose (HD) IL-2. Here, we provide an overview of known cardiac risks associated with TIL treatment and report on seven patients presenting with cardiac symptoms, all with different clinical course and diagnostic findings during treatment with lymphodepleting chemotherapy, TIL, and HD IL-2, and propose a set of clinical recommendations for diagnosis and management of these symptoms.

PATIENTS AND METHODS

This single-center, retrospective study included selected patients who experienced TIL treatment-related cardiac symptoms at the Netherlands Cancer Institute. In addition, 12 patients were included who received TIL in the clinical trial setting without experiencing cardiac symptoms, from whom complete cardiac biomarker follow-up during treatment was available [creatine kinase (CK), CK-myocardial band, troponin T and N-terminal pro-B-type natriuretic peptide].

RESULTS

Within our TIL patient population, seven illustrative cases were chosen from the patients who developed symptoms suspected of severe cardiotoxicity: myocarditis, myocardial infarction, peri-myocarditis, atrial fibrillation, acute dyspnea, and two cases of heart failure. An overview of their clinical course, diagnostics carried out, and management of the symptoms is provided.

CONCLUSIONS

In the absence of evidence-based guidelines for the treatment of TIL therapy-associated cardiotoxicity, we provided an overview of literature, case descriptions, and recommendations for diagnosis and management to help physicians in daily practice, as the number of patients qualifying for TIL treatment is rapidly increasing.

Defining Melanoma Immune Biomarkers-Desert, Excluded, and Inflamed Subtypes-Using a Gene Expression Classifier Reflecting Intratumoral Immune Response and Stromal Patterns

The spatial distribution of tumor infiltrating lymphocytes (TILs) defines several histologically and clinically distinct immune subtypes-desert (no TILs), excluded (TILs in stroma), and inflamed (TILs in tumor parenchyma). To date, robust classification of immune subtypes still requires deeper experimental evidence across various cancer types. Here, we aimed to investigate, define, and validate the immune subtypes in melanoma by coupling transcriptional and histological assessments of the lymphocyte distribution in tumor parenchyma and stroma. We used the transcriptomic data from The Cancer Genome Atlas melanoma dataset to screen for the desert, excluded, and inflamed immune subtypes. We defined subtype-specific genes and used them to construct a subtype assignment algorithm. We validated the two-step algorithm in the qPCR data of real-world melanoma tumors with histologically defined immune subtypes. The accuracy of a classifier encompassing expression data of seven genes (immune response-related: CD2, CD53, IRF1, and CD8B; and stroma-related: COL5A2, TNFAIP6, and INHBA) in a validation cohort reached 79%. Our findings suggest that melanoma tumors can be classified into transcriptionally and histologically distinct desert, excluded, and inflamed subtypes. Gene expression-based algorithms can assist physicians and pathologists as biomarkers in the rapid assessment of a tumor immune microenvironment while serving as a tool for clinical decision making.

High ANO1 expression is a prognostic factor and correlated with an immunosuppressive tumor microenvironment in pancreatic cancer

Background

Aminooctylamine (ANO1) plays an oncogenic role in various cancers. However. its role in pancreatic cancer (PC) has rarely been studied. This study investigated the prognostic value of ANO1 and its correlation with the tumor microenvironment (TME) in PC.

Methods

Consecutive patients with PC (n = 119) were enrolled. The expression of ANO1 in cancer cells, the expression of fibroblast activation protein (FAP) and alpha smooth muscle actin in cancer-associated fibroblasts (CAFs), and the numbers of CD8- and FOXP3-positive tumor-infiltrating lymphocytes (TILs) were evaluated using immunohistochemistry. The prognostic value of ANO1 and its correlation with CAF subgroups and TILs were analyzed. The possible mechanism of ANO1 in the TME of PC was predicted using the the Cancer Genome Atlas (TCGA) dataset.

Results

The expression of AN01 was correlated with overall survival (OS) and disease-free survival. Multi-factor analysis showed that high ANO1 expression was an independent adverse prognostic factor for OS (hazard ratio, 4.137; P = 0.001). ANO1 expression was positively correlated with the expression of FAP in CAFs (P < 0.001) and negatively correlated with the number of CD8-positive TILs (P = 0.005), which was also validated by bioinformatics analysis in the TCGA dataset. Moreover, bioinformatic analysis of the TCGA dataset revealed that ANO1 may induce an immunosuppressive tumor microenvironment in pancreatic cancer in a paracrine manner.

Conclusion

ANO1 is a prognostic factor in patients with PC after radical resection. ANO1 may induce an immunosuppressive tumor microenvironment in PC in a paracrine manner, suggesting that ANO1 may be a novel therapeutic target.

Flow cytometry quantification of tumor-infiltrating lymphocytes to predict the survival of patients with diffuse large B-cell lymphoma

Introduction

Our previous studies have demonstrated that tumor-infiltrating lymphocytes (TILs), including normal B cells, T cells, and natural killer (NK) cells, in diffuse large B-cell lymphoma (DLBCL) have a significantly favorable impact on the clinical outcomes of patients treated with standard chemoimmunotherapy. In this study, to gain a full overview of the tumor immune microenvironment (TIME), we assembled a flow cytometry cohort of 102 patients diagnosed with DLBCL at the Duke University Medical Center.

Methods

We collected diagnostic flow cytometry data, including the proportion of T cells, abnormal B cells, normal B cells, plasma cells, NK cells, monocytes, and granulocytes in fresh biopsy tissues at clinical presentation, and analyzed the correlations with patient survival and between different cell populations.

Results

We found that low T cell percentages in all viable cells and low ratios of T cells to abnormal B cells correlated with significantly poorer survival, whereas higher percentages of normal B cells among total B cells (or high ratios of normal B cells to abnormal B cells) and high percentages of NK cells among all viable cells correlated with significantly better survival in patients with DLBCL. After excluding a small number of patients with low T cell percentages, the normal B cell percentage among all B cells, but not T cell percentage among all cells, continued to show a remarkable prognostic effect. Data showed significant positive correlations between T cells and normal B cells, and between granulocytes and monocytes. Furthermore, we constructed a prognostic model based on clinical and flow cytometry factors, which divided the DLBCL cohort into two equal groups with remarkable differences in patient survival and treatment response.

Summary

TILs, including normal B cells, T cells, and NK cells, are associated with favorable clinical outcomes in DLBCL, and flow cytometry capable of quantifying the TIME may have additional clinical utility for prognostication.

An Investigation of the Immune Microenvironment and Genome during Lung Adenocarcinoma Development

Background: Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are two consecutive pathological processes that occur before invasive lung adenocarcinoma (LUAD). However, our understanding of the immune editing patterns during the progression of LUAD remains limited. Furthermore, we know very little about whether alterations in driver genes are involved in forming the tumor microenvironment (TME). Therefore, it is necessary to elucidate the regulatory role of TME in LUAD development from multiple dimensions, including immune cell infiltration, molecular mutation events, and oncogenic signaling pathways. Methods: We collected 145 surgically resected pulmonary nodule specimens, including 28 cases of AIS, 52 cases of MIA, and 65 cases of LUAD. Immunohistochemistry (IHC) was used to detect the expression of immune markers CD3, CD4, CD8, CD68 and programmed death ligand 1 (PD-L1). Genomic data and TMB generated by targeted next-generation sequencing (NGS). Results: LUAD exhibited higher levels of immune cell infiltration, tumor mutation burden (TMB), and activation of oncogenic pathways compared to AIS and MIA. In LUAD, compared to epidermal growth factor receptor (EGFR) single mutation and wild-type (WT) samples, cases with EGFR co-mutations showed a more pronounced rise in the CD4/CD8 ratio and CD68 infiltration. Patients with low-density lipoprotein (LDL) receptor-related protein 1B (LRP1B) mutation have higher TMB and PD-L1 expression. The transition from AIS to LUAD tends to shift the TME towards the PD-L1+CD8+ subtype (adaptive resistance). Progression-associated mutations (PAMs) were enriched in the lymphocyte differentiation pathway and related to exhausted cells' phenotype. Conclusion: Tumor-infiltrating immune cells tend to accumulate as the depth of LUAD invasion increases, but subsequently develop into an immune exhaustion and immune escape state. Mutations in EGFR and LRP1B could potentially establish an immune niche that fosters tumor growth. PAMs in LUAD may accelerate disease progression by promoting T cell differentiation into an exhausted state.

Platelet-derived microparticles adoptively transfer integrin β3 to promote antitumor effect of tumor-infiltrating T cells

Approximately two-thirds of hepatocellular carcinoma (HCC) is considered a "cold tumor" characterized by few tumor-infiltrating T cells and an abundance of immunosuppressive cells. Cilengitide, an integrin αvβ3 inhibitor, has failed in clinical trials as a potential anticancer drug. This failure implies that integrin αvβ3 may play an important role in immune cells. However, the expression and potential role of integrin αvβ3 in T cells of HCC patients remain unknown. Here, we established two HCC models and found that cilengitide had a dual effect on the HCC microenvironment by exerting both antitumor effect and immunosuppressive effect on T cells. This may partly explain the failure of cilengitide in clinical trials. In clinical specimens, HCC-infiltrating T cells exhibited deficient expression and activation of integrin β3, which was associated with poor T-cell infiltration into tumors. Additionally, integrin β3 functioned as a positive immunomodulatory molecule to facilitate T-cell infiltration and T helper 1-type immune response in vitro. Furthermore, T cells and platelet-derived microparticles (PMPs) co-culture assay revealed that PMPs adoptively transferred integrin β3 to T cells and positively regulated T cell immune response. This process was mediated by clathrin-dependent endocytosis and macropinocytosis. Our data demonstrate that integrin β3 deficiency on HCC-infiltrating T cells may be involved in shaping the immunosuppressive tumor microenvironment. PMPs transfer integrin β3 to T cells and positively regulate T cell immune response, which may provide a new insight into immune therapy of HCC.

Autologous Tumor-Infiltrating Lymphocyte Mono-Therapy Can Rapidly Shrank Tumor in Asian Patient with Stage III/IV Cervical Cancer: Two Cases Report

Introduction

Tumor-infiltrating lymphocytes (TILs) therapy is one of the most promising adoptive T cell therapies, which has shown great clinical efficacy against several solid malignancies. Nevertheless, clinical response to TILs mono-therapy in Asian patients with recurrent cervical cancer has not been well reported.

Case Presentation

Here, we report two patients who were diagnosed with metastatic cervical cancer and tumor progression following multiple conventional treatments. In particular, one of the patients has a history of severe myelosuppression after chemotherapy. The patients received lymphodepletion therapy, which consisted of cyclophosphamide (30mg/kg) for 2 days, followed by Fludarabine (25mg/m2) for 5 days, approximately 24 hr before receiving intravenous autologous TILs infusion. These two patients then received high doses of IL-2 for 10 days with the purpose of maintaining T cell survival and proliferation. Patient 1 experienced clinical partial response (PR) at 6 weeks post TILs infusion and a 33% tumor shrinkage at 12 weeks follow-up, and patient 2 was evaluated as stable disease (SD) at 6 weeks post treatment. Mild and manageable adverse events were observed and soon subsided after the TILs treatment. A time-course study examining the peripheral blood cell count and cytokine secretion demonstrated the persistence of infused TILs and long-term immune response.

Conclusion

These results suggest that TILs mono-therapy can be a promising treatment strategy for Asian patients with late-stage metastatic cervical cancer even with severe myelosuppression. TILs infusion can induce persistence and a long-term systematic immune response that reversed peripheral CD4+T and CD8+T percentages implying that TILs infusion increased cytotic T cell responses, which is consistent with clinical responses in these patients. Trial registration number: NCT05366478.

Improving Tumor-Infiltrating Lymphocytes Score Prediction in Breast Cancer with Self-Supervised Learning

Tumor microenvironment (TME) plays a pivotal role in immuno-oncology, which investigates the intricate interactions between tumors and the human immune system. Specifically, tumor-infiltrating lymphocytes (TILs) are crucial biomarkers for evaluating the prognosis of breast cancer patients and have the potential to refine immunotherapy precision and accurately identify tumor cells in specific cancer types. In this study, we conducted tissue segmentation and lymphocyte detection tasks to predict TIL scores by employing self-supervised learning (SSL) model-based approaches capable of addressing limited labeling data issues. Our experiments showed a 1.9% improvement in tissue segmentation and a 2% improvement in lymphocyte detection over the ImageNet pre-training model. Using these SSL-based models, we achieved a TIL score of 0.718 with a 4.4% improvement. In particular, when trained with only 10% of the entire dataset, the SwAV pre-trained model exhibited a superior performance over other models. Our work highlights improved tissue segmentation and lymphocyte detection using the SSL model with less labeled data for TIL score prediction.

Single-cell analysis of T lymphocytes infiltrating colorectal carcinoma: the dilemma of specificity

Advances in single-cell RNA and T cell receptor (TCR) sequencing allow to study the specificity and functionality of tumor-infiltrating T lymphocytes. A recent study unravels fundamental differences between microsatellite-instable (MSI) colorectal cancers, in which T cells tend to be tumor-specific, and microsatellite-stable (MSS) cancers, in which T cells exhibit bystander features.

A comparative analysis of clinicopathological features of HPV-associated and HPV-independent cervical carcinomas based on P16 INK4a immunohistochemistry: A one-year retrospective study

The recent WHO classification of female genital tracts recommends cervical carcinomas to be further subtyped as HPV-associated and HPV-independent and accepted p16 immunoreactivity as a surrogate biomarker for HPV testing. This paper presents the clinicopathological spectrum of cervical carcinomas in correlation with p16 immunoreactivity.

Aims and Objectives

This study aims to evaluate the immunoreactivity of p16 in cervical carcinoma, subtype them into HPV-associated and HPV-independent based on p16 immunoreactivity, and correlate them with clinicopathological features.

Design

A hospital-based retrospective study of one-year duration was done after ethics approval. A total of 124 cases were identified, and various parameters like the presence of mitosis, lymphovascular invasion, tumor budding, tumor-infiltrating lymphocytes, the pattern of stromal invasion, and the pattern of necrosis were recorded and graded. Immunohistochemistry (IHC) with p16 marker was done in 40 cases, and immunoreactivity was correlated with clinical and histopathological parameters.

Statistical Analysis

Multivariate analysis was done with Fisher's exact test, and a P value of <0.05 was considered significant.

Results

P16 was positive in 36 out of 40 cases which included 35 cases of squamous cell carcinoma (SCC) (keratinizing-14 out of 35 SCC, 11 positive out of these 14, non-keratinizing-21 out of 35 SCC, 20 positive, out of these 21), two cases of adenocarcinoma (both positive), two cases of adenosquamous carcinoma (both positive), and one case of small cell neuroendocrine carcinoma (positive). p16 negative in four cases (10%) (keratinizing type-3, non-keratinizing-1). P value was significant for HPV-independent carcinoma and keratinizing SCC morphology. The P value was not significant when p16 positivity with other parameters.

Conclusion

HPV-associated were 90%, HPV-independent were 10%.

Impact of Mutations in Subunit Genes of the Mammalian SWI/SNF Complex on Immunological Tumor Microenvironment

BACKGROUND/AIM

Recently, inactivating somatic mutations of SWI/SNF chromatin-remodeling genes in cancers have been reported. However, few studies have been performed regarding the immunological analysis of the tumor microenvironment (TME) in chromatin remodeling complex gene-mutated tumors. In the present study, we identified cancer patients harboring various mammalian SWI/SNF complex mutations and investigated the immunological features in those mutated cancers.

PATIENTS AND METHODS

Cancer patients harboring any type of chromatin remodeling complex gene mutation were selected and clinicopathological features were compared between chromatin remodeling complex gene expression-low and expression-high groups. Specifically, expression levels of immune response-associated genes and cancer-associated genes were compared between the SMARCA4 expression-low and expression-high groups using volcano plot analysis.

RESULTS

Among cancers harboring PBRM1, SAMRACA4 and ARID2 gene mutations, T-cell marker and mature B-cell marker genes were up-regulated in the tumor. Specifically, T-cell effector genes (CD8B, CD40LG), central memory marker genes (CD27, CCR7) and mature B-cell marker genes (CD20, CD38, CD79 and IRF4) were up-regulated, and cancer-associated genes including MYB, MYC and AURKB genes were down-regulated in the SMARCA4 expression-low group. Remarkably, heatmap of gene expression and immunohistochemistry (IHC) data demonstrated that the tertiary lymphoid structure (TLS) gene signature of mature B cells was up-regulated in SMACA4 gene-mutated stomach cancers.

CONCLUSION

These results suggest that immune tumor microenvironment status, such as mature B cell recruitment featuring the TLS gene signature and immune activation mediated by cancer signal down-regulation, might contribute to the classification of SMARCA4 gene-mutated tumors as immune checkpoint blockade therapy-sensitive target tumors.

Limited Effects of Class II Transactivator-Based Immunotherapy in Murine and Human Glioblastoma

BACKGROUND

The major histocompatibility complex type II is downregulated in glioblastoma (GB) due to the silencing of the major transcriptional regulator class II transactivator (CIITA). We investigated the pro-immunogenic potential of CIITA overexpression in mouse and human GB.

METHODS

The intracerebral growth of wildtype GL261-WT cells was assessed following contralateral injection of GL261-CIITA cells or flank injections with GL261-WT or GL261-CIITA cells. Splenocytes obtained from mice implanted intracerebrally with GL261-WT, GL261-CIITA cells or phosphate buffered saline (PBS) were transferred to other mice and subsequently implanted intracerebrally with GL261-WT. Human GB cells and (syngeneic) GB-infiltrating immune cells were isolated from surgical samples and co-cultured with GB cells expressing CIITA or not, followed by RT-qPCR assessment of the expression of key immune regulators.

RESULTS

Intracerebral vaccination of GL261-CIITA significantly reduced the subsequent growth of GL261-WT cells implanted contralaterally. Vaccination with GL261-WT or -CIITA subcutaneously, however, equivalently retarded the intracerebral growth of GL261 cells. Adoptive cell transfer experiments showed a similar antitumor potential of lymphocytes harvested from mice implanted intracerebrally with GL261-WT or -CIITA. Human GB-infiltrating myeloid cells and lymphocytes were not activated when cultured with CIITA-expressing GB cells. Tumor-infiltrating NK cells remained mostly inactivated when in co-culture with GB cells, regardless of CIITA.

CONCLUSION

these results question the therapeutic potential of CIITA-mediated immunotherapy in glioblastoma.

Targeting the immune microenvironment for ovarian cancer therapy

Ovarian cancer (OC) is an aggressive malignancy characterized by a complex immunosuppressive tumor microenvironment (TME). Immune checkpoint inhibitors have emerged as a breakthrough in cancer therapy by reactivating the antitumor immune response suppressed by tumor cells. However, in the case of OC, these inhibitors have failed to demonstrate significant improvements in patient outcomes, and existing biomarkers have not yet identified promising subgroups. Consequently, there remains a pressing need to understand the interplay between OC tumor cells and their surrounding microenvironment to develop effective immunotherapeutic approaches. This review aims to provide an overview of the OC TME and explore its potential as a therapeutic strategy. Tumor-infiltrating lymphocytes (TILs) are major actors in OC TME. Evidence has been accumulating regarding the spontaneous TILS response against OC antigens. Activated T-helpers secrete a wide range of inflammatory cytokines with a supportive action on cytotoxic T-cells. Simultaneously, mature B-cells are recruited and play a significant antitumor role through opsonization of target antigens and T-cell recruitment. Macrophages also form an important subset of innate immunity (M1-macrophages) while participating in the immune-stimulation context. Finally, OC has shown to engage a significant natural-killer-cells immune response, exerting direct cytotoxicity without prior sensitization. Despite this initial cytotoxicity, OC cells develop various strategies to induce an immune-tolerant state. To this end, multiple immunosuppressive molecules are secreted to impair cytotoxic cells, recruit regulatory cells, alter antigen presentation, and effectively evade immune response. Consequently, OC TME is predominantly infiltrated by immunosuppressive cells such as FOXP3+ regulatory T-cells, M2-polarized macrophages and myeloid-derived suppressor cells. Despite this strong immunosuppressive state, PD-1/PD-L1 inhibitors have failed to improve outcomes. Beyond PD-1/PD-L1, OC expresses multiple other immune checkpoints that contribute to immune evasion, and each representing potential immune targets. Novel immunotherapies are attempting to overcome the immunosuppressive state and induce specific immune responses using antibodies adoptive cell therapy or vaccines. Overall, the OC TME presents both opportunities and obstacles. Immunotherapeutic approaches continue to show promise, and next-generation inhibitors offer exciting opportunities. However, tailoring therapies to individual immune characteristics will be critical for the success of these treatments.

Correlation between stromal Th and Tc lymphocytes and PD-L1 expression in early breast cancer tumors

INTRODUCTION

Prognostic and predictive value of PD-L1 as a biomarker in breast cancer remains controversial. While some studies suggest its association with negative prognostic parameters, others reported a highly significant association between PD-L1 expression and tumor-infiltrating lymphocytes, which are known to be an independent favorable prognostic factor. The aim of present study is to examine the relationship between immune response markers and PD-L1 expression in early breast cancer.

MATERIAL AND METHODS

Immunohistochemical expression of PD-L1, along with density and composition of stromal lymphocytic infiltrate and peritumoral lymphoid aggregates was analyzed in 95 samples of invasive breast cancer.

RESULTS

A strong positive correlation between PD-L1 expression and the density of stromal lymphocytic infiltrate and peritumoral lymphoid aggregates was identified and a cut-off value of 53% coverage of tumor stroma by lymphocytes, with which PD-L1 positivity can be predicted with excellent diagnostic accuracy, was determined for the first time using statistical methods. Additionally, PD-L1 positivity was observed significantly more often in tumors with higher absolute number of both CD4 and CD8 T-lymphocytes in the stromal infiltrate. No significant correlation with molecular subtype of breast cancer was found.

CONCLUSIONS

Our results indicate that the density of stromal lymphocytic infiltrate might be a better predictor of PD-L1 positivity in early breast cancer than the molecular subtype and that the key to the optimization of PD-L1 as a biomarker in breast cancer lies in its interpretation in the context of other immune response markers.

Immune Cells in the Tumor Microenvironment of Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) are a rare heterogeneous group of malignant neoplasms characterized by their aggressive course and poor response to treatment. This determines the relevance of research aimed at studying the pathogenesis of STSs. By now, it is known that STSs is characterized by complex relationships between the tumor cells and immune cells of the microenvironment. Dynamic interactions between tumor cells and components of the microenvironment enhance adaptation to changing environmental conditions, which provides the high aggressive potential of STSs and resistance to antitumor therapy. Today, active research is being conducted to find effective antitumor drugs and to evaluate the possibility of using therapy with immune cells of STS. The difficulty in assessing the efficacy of new antitumor options is primarily due to the high heterogeneity of this group of malignant neoplasms. Studying the role of immune cells in the microenvironment in the progression STSs and resistance to antitumor therapies will provide the discovery of new biomarkers of the disease and the prediction of response to immunotherapy. In addition, it will help to initially divide patients into subgroups of good and poor response to immunotherapy, thus avoiding wasting precious time in selecting the appropriate antitumor agent.

Evaluation of tumor-infiltrating lymphocytes, PD-L1, and PIK3CA mutations and association with prognosis in HER2-positive early stage breast cancer

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have predictive and prognostic potential in HER2-positive breast cancer (HER2+ BC). Programmed death-ligand 1 (PD-L1) is an immune checkpoint protein, with important roles in the tumor microenvironment, possibly in both tumor and immune cells (ICs), providing rationale for targeting with immune-checkpoint therapy. PIK3CA mutations are oncogenic, activating mutations, which are also of relevance in breast cancer. Herein, we investigate the frequency of TILs, PD-L1 and PIK3CA mutations, and whether these factors influence outcome, in early HER2+ BC.

MATERIALS AND METHODS

Stromal TILs (sTILs) and PD-L1 expressions were assessed using full tumor-sections and TMA, respectively, from 236 patients with HER2+ BC. TILs were assessed, according to a standardized method, as continuous measurement and according to three predefined categories: low (0-10%), intermediate (11-59%), and high (60-100%). PD-L1 immunohistochemistry (Ventana SP263) was evaluated and positivity defined as ≥1% expression in tumor and ICs. PIK3CA mutations (exons 9 and 20) were determined by pyrosequencing.

RESULTS

Fourteen percent of patients had high sTILs and 25% had a PIK3CA mutation. PD-L1 expression was more frequent in ICs (68%) than tumor cells (24%). Patients with low sTILs had a significantly worse overall survival (multivariate: HR 2.80; 95% CI 1.36-5.78; p = .02).

DISCUSSION

Patients with low sTILs had a significantly poorer survival, despite adequate treatment with adjuvant therapy.

Initial interactions with the FDA on developing a validation dataset as a medical device development tool

Quantifying tumor-infiltrating lymphocytes (TILs) in breast cancer tumors is a challenging task for pathologists. With the advent of whole slide imaging that digitizes glass slides, it is possible to apply computational models to quantify TILs for pathologists. Development of computational models requires significant time, expertise, consensus, and investment. To reduce this burden, we are preparing a dataset for developers to validate their models and a proposal to the Medical Device Development Tool (MDDT) program in the Center for Devices and Radiological Health of the U.S. Food and Drug Administration (FDA). If the FDA qualifies the dataset for its submitted context of use, model developers can use it in a regulatory submission within the qualified context of use without additional documentation. Our dataset aims at reducing the regulatory burden placed on developers of models that estimate the density of TILs and will allow head-to-head comparison of multiple computational models on the same data. In this paper, we discuss the MDDT preparation and submission process, including the feedback we received from our initial interactions with the FDA and propose how a qualified MDDT validation dataset could be a mechanism for open, fair, and consistent measures of computational model performance. Our experiences will help the community understand what the FDA considers relevant and appropriate (from the perspective of the submitter), at the early stages of the MDDT submission process, for validating stromal TIL density estimation models and other potential computational models. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Evaluation of tumor-infiltrating lymphocytes and mammographic density as predictors of response to neoadjuvant systemic therapy in breast cancer

BACKGROUND

Response rates vary among breast cancer patients treated with neoadjuvant systemic therapy (NAST). Thus, there is a need for reliable treatment predictors. Evidence suggests tumor-infiltrating lymphocytes (TILs) predict NAST response. Still, TILs are seldom used clinically as a treatment determinant. Mammographic density (MD) is another potential marker for NAST benefit and its relationship with TILs is unknown. Our aims were to investigate TILs and MD as predictors of NAST response and to study the unexplored relationship between TILs and MD.

MATERIAL AND METHODS

We studied 315 invasive breast carcinomas treated with NAST between 2013 and 2020. Clinicopathological data were retrieved from medical records. The endpoint was defined as pathological complete response (pCR) in the breast. TILs were evaluated in pre-treatment core biopsies and categorized as high (≥10%) or low (<10%). MD was scored (a-d) according to the breast imaging reporting and data system (BI-RADS) fifth edition. Binary logistic regression and Spearman's test of correlation were performed using SPSS.

RESULTS

Out of 315 carcinomas, 136 achieved pCR. 94 carcinomas had high TILs and 215 had low TILs. Six carcinomas had no available TIL data. The number of carcinomas in each BI-RADS category were 37, 122, 112, and 44 for a, b, c, and d, respectively. High TILs were independently associated with pCR (OR: 2.95; 95% CI: 1.59-5.46) compared to low TILs. In the univariable analysis, MD (BI-RADS d vs. a) showed a tendency of higher likelihood for pCR (OR: 2.43; 95% CI: 0.99-5.98). However, the association was non-significant, which is consistent with the result of the multivariable analysis (OR: 2.51; 95% CI: 0.78-8.04). We found no correlation between TILs and MD (0.02; p = .80).

CONCLUSION

TILs significantly predicted NAST response. We could not define MD as a significant predictor of NAST response. These findings should be further replicated.

Spatial Proximity and Relative Distribution of Tumor-Infiltrating Lymphocytes and Macrophages Predict Survival in Melanoma

Tumor microenvironment plays a crucial role in primary cutaneous melanoma (CM) progression. Although the role of tumor-infiltrating lymphocyte (TIL) density has been known for a long time, its spatial distribution and impact with or without tumor-associated macrophages (TAMs) remain controversial. Herein, we investigated spatial proximity between tumor cells and immune cells in 113 primary CM and its correlation with disease-free (DFS) and overall survival (OS). The study cohort included clinical stage II (n = 79) and stage III (n = 34) primary CM with a Breslow thickness of >2 mm (with a median age of 64 years, including 72 men and 41 women). In univariate models, patients with SOX10+ melanoma cells with high proximity to CD8+ TILs in a 20 μm radius showed longer DFS (hazard ratio [HR], 0.58; 95% CI, 0.36-0.93; P = .025) and OS (HR, 0.55; 95% CI, 0.32-0.92; P = .023). Furthermore, at multivariate combined analysis, patients with SOX10+ melanoma cells with high proximity to CD8+ TILs or low proximity to CD163+ TAMs in a 20 μm radius showed an increased OS (aHR, 0.37; 95% CI, 0.14-0.96; P = .04) compared with melanoma patients with low proximity to CD8+ TILs or high proximity to CD163+ TAMs. In a subgroup analysis including 92 patients, a significant negative impact on DFS (aHR, 4.49; 95% CI, 1.73-11.64; P = .002) and OS (aHR, 3.97; 95% CI, 1.37-11.49; P = .01) was observed in sentinel lymph node (SLN)-negative patients with a high proximity of CD163+ TAMs to CD8+ TILs. These findings could help identify high-risk patients in the context of thick melanoma and a negative SLN. Our study suggests the importance of quantifying not only the density of immune cells but also the individual and combined relative spatial distributions of tumor cells and immune cells for clinical outcomes in SLN-negative primary CM patients.

Artificial intelligence-assisted analysis for tumor-immune interaction within the invasive margin of colorectal cancer

BACKGROUND

In colorectal cancer (CRC), both tumor invasion and immunological analysis at the tumor invasive margin (IM) are significantly associated with patient prognosis, but have traditionally been reported independently. We propose a new scoring system, the TGP-I score, to assess the association and interactions between tumor growth pattern (TGP) and tumor infiltrating lymphocytes at the IM and to predict its prognostic validity for CRC patient stratification.

MATERIALS AND METHODS

The types of TGP were assessed in hematoxylin and eosin-stained whole-slide images. The CD3⁺ T-cells density at the IM was automatically quantified on immunohistochemical-stained slides using a deep learning method. A discovery (N = 347) and a validation (N = 132) cohorts were used to evaluate the prognostic value of the TGP-I score for overall survival.

RESULTS

The TGP-I score₃ (trichotomy) was an independent prognostic factor, with higher TGP-I score₃ associated with worse prognosis in the discovery (unadjusted hazard ratio [HR] for high vs. low 3.62, 95% confidence interval [CI] 2.22-5.90; p < 0.001) and validation cohort (unadjusted HR for high vs. low 5.79, 95% CI 1.84-18.20; p = 0.003). The relative contribution of each parameter to predicting survival was analyzed. The TGP-I score₃ had similar importance compared to tumor-node-metastasis staging (31.2% vs. 32.9%) and was stronger than other clinical parameters.

CONCLUSIONS

This automated workflow and the proposed TGP-I score could further provide accurate prognostic stratification and have potential value for supporting the clinical decision-making of stage I-III CRC patients.Key messagesA new scoring system, the TGP-I score, was proposed to assess the association and interactions of TGP and TILs at the tumor invasive margin.TGP-I score could be an independent predictor of prognosis for CRC patients, with higher scores being associated with worse survival.TGP-I score had similar importance compared to tumor-node-metastasis staging and was stronger than other clinical parameters.

Magnetic Resonance Imaging Features Associated with a High and Low Expression of Tumor-Infiltrating Lymphocytes: A Stratified Analysis According to Molecular Subtypes

A total of 457 patients, including 241 HR+/HER2- patients, 134 HER2+ patients, and 82 TN patients, were studied. The percentage of TILs in the stroma adjacent to the tumor cells was assessed using a 10% cutoff. The low TIL percentages were 82% in the HR+ patients, 63% in the HER2+ patients, and 56% in the TN patients (p < 0.001). MRI features such as morphology as mass or non-mass enhancement (NME), shape, margin, internal enhancement, presence of peritumoral edema, and the DCE kinetic pattern were assessed. Tumor sizes were smaller in the HR+/HER2- group (p < 0.001); HER2+ was more likely to present as NME (p = 0.031); homogeneous enhancement was mostly seen in HR+ (p < 0.001); and the peritumoral edema was present in 45% HR+, 71% HER2+, and 80% TN (p < 0.001). In each subtype, the MR features between the high- vs. low-TIL groups were compared. In HR+/HER2-, peritumoral edema was more likely to be present in those with high TILs (70%) than in those with low TILs (40%, p < 0.001). In TN, those with high TILs were more likely to present a regular shape (33%) than those with low TILs (13%, p = 0.029) and more likely to present the circumscribed margin (19%) than those with low TILs (2%, p = 0.009).

The molecular mechanism of actions and clinical utilities of tumor infiltrating lymphocytes in gastrointestinal cancers: a comprehensive review and future prospects toward personalized medicine

Gastrointestinal (GI) cancers remain a significant global health burden, accounting for a substantial number of cases and deaths. Regrettably, the inadequacy of dependable biomarkers hinders the precise forecasting of patient prognosis and the selection of appropriate therapeutic sequencing for individuals with GI cancers, leading to suboptimal outcomes for numerous patients. The intricate interplay between tumor-infiltrating lymphocytes (TILs) and the tumor immune microenvironment (TIME) has been shown to be a pivotal determinant of response to anti-cancer therapy and consequential clinical outcomes across a multitude of cancer types. Therefore, the assessment of TILs has garnered global interest as a promising prognostic biomarker in oncology, with the potential to improve clinical decision-making substantially. Moreover, recent discoveries in immunotherapy have progressively changed the landscape of cancer treatment and significantly prolonged the survival of patients with advanced cancers. Nonetheless, the response rate remains constrained within solid tumor sufferers, even when TIL landscapes appear comparable, which calls for the development of our understanding of cellular and molecular cross-talk between TIME and tumor. Hence, this comprehensive review encapsulates the extant literature elucidating the TILs' underlying molecular pathogenesis, prognostic significance, and their relevance in the realm of immunotherapy for patients afflicted by GI tract cancers. Within this review, we demonstrate that the type, density, and spatial distribution of distinct TIL subpopulations carries pivotal implications for the prediction of anti-cancer treatment responses and patient survival. Furthermore, this review underscores the indispensable role of TILs in modulating therapeutic responses within distinct molecular subtypes, such as those characterized by microsatellite stability or programmed cell death ligand-1 expression in GI tract cancers. The review concludes by outlining future directions in TIL-based personalized medicine, including integrating TIL-based approaches into existing treatment regimens and developing novel therapeutic strategies that exploit the unique properties of TILs and their potential as a promising avenue for personalized cancer treatment.

Corrigendum: Exploring the dual role of B cells in solid tumors: implications for head and neck squamous cell carcinoma

[This corrects the article DOI: 10.3389/fimmu.2023.1233085.].

Current Knowledge about the Peritumoral Microenvironment in Glioblastoma

Glioblastoma is a deadly disease, with a mean overall survival of less than 2 years from diagnosis. Recurrence after gross total surgical resection and adjuvant chemo-radiotherapy almost invariably occurs within the so-called peritumoral brain zone (PBZ). The aim of this narrative review is to summarize the most relevant findings about the biological characteristics of the PBZ currently available in the medical literature. The PBZ presents several peculiar biological characteristics. The cellular landscape of this area is different from that of healthy brain tissue and is characterized by a mixture of cell types, including tumor cells (seen in about 30% of cases), angiogenesis-related endothelial cells, reactive astrocytes, glioma-associated microglia/macrophages (GAMs) with anti-inflammatory polarization, tumor-infiltrating lymphocytes (TILs) with an "exhausted" phenotype, and glioma-associated stromal cells (GASCs). From a genomic and transcriptomic point of view, compared with the tumor core and healthy brain tissue, the PBZ presents a "half-way" pattern with upregulation of genes related to angiogenesis, the extracellular matrix, and cellular senescence and with stemness features and downregulation in tumor suppressor genes. This review illustrates that the PBZ is a transition zone with a pre-malignant microenvironment that constitutes the base for GBM progression/recurrence. Understanding of the PBZ could be relevant to developing more effective treatments to prevent GBM development and recurrence.

Machine Learning Quantification of Intraepithelial Tumor-Infiltrating Lymphocytes as a Significant Prognostic Factor in High-Grade Serous Ovarian Carcinomas

The prognostic and predictive role of tumor-infiltrating lymphocytes (TILs) has been demonstrated in various neoplasms. The few publications that have addressed this topic in high-grade serous ovarian carcinoma (HGSOC) have approached TIL quantification from a semiquantitative standpoint. Clinical correlation studies, therefore, need to be conducted based on more accurate TIL quantification. We created a machine learning system based on H&E-stained sections using 76 molecularly and clinically well-characterized advanced HGSOC. This system enabled immune cell classification. These immune parameters were subsequently correlated with overall survival (OS) and progression-free survival (PFI). An intense colonization of the tumor cords by TILs was associated with a better prognosis. Moreover, the multivariate analysis showed that the intraephitelial (ie) TILs concentration was an independent and favorable prognostic factor both for OS (p = 0.02) and PFI (p = 0.001). A synergistic effect between complete surgical cytoreduction and high levels of ieTILs was evidenced, both in terms of OS (p = 0.0005) and PFI (p = 0.0008). We consider that digital analysis with machine learning provided a more accurate TIL quantification in HGSOC. It has been demonstrated that ieTILs quantification in H&E-stained slides is an independent prognostic parameter. It is possible that intraepithelial TIL quantification could help identify candidate patients for immunotherapy.

Advances in Tumour-Infiltrating Lymphocytes for Triple-Negative Breast Cancer Management

Triple negative breast cancer (TNBC) is a subtype of breast cancer which does not express or expresses a minimum amount of estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor 2 (HER2) protein. TNBCs include a heterogenic group of cancers that are aggressive, grow rapidly and are associated with poor prognosis and overall survival, mainly attributed to a lack of effective therapeutic targets. For a long time, a major issue with predicting the outcome and prognosis of TNBCs was the lack of an accurate biomarker, a molecule that helps us objectively assess a patient's health status. In recent times, defining the presence of tumor-infiltrating lymphocytes (TIL) is becoming an indispensable method of determining a patient's prognosis. TILs are found in tumor tissue and the surrounding stroma and carry a prognostic value. Furthermore, they are known to improve the effect of systemic therapy. With the rise of immunotherapy, the role of TIL in this newer therapeutic option is a topic of increased importance. The goal behind this research article is a comprehensive review of the current literature on the importance of tumor-infiltrating lymphocytes in the prognosis of TNBC.

Cost-effectiveness analysis of tumor-infiltrating lymphocytes biomarkers guiding chemotherapy de-escalation in early triple-negative breast cancer

BACKGROUND

To accelerate the clinical translation of tumor-infiltrating lymphocytes (TILs) biomarkers for guiding chemotherapy de-escalation in early-stage triple-negative breast cancer (TNBC), cost-effectiveness evidence is essential but has not been investigated. We intend to evaluate the cost-effectiveness of using TILs to guiding chemotherapy de-escalation in patients with early-stage TNBC from the perspective of the Chinese health service system.

METHODS

The hybrid decision-tree-Markov model was designed to compare the cost-effectiveness of cytotoxic chemotherapy guided by whether TILs assay was performed in 50-year-old female patients with early-stage TNBC over a lifetime horizon. In Strategy (1), if TILs testing was performed, patients with TILs values exceeding 30% could be spared from chemotherapy. In Strategy (2), where no TILs testing was performed, all patients were administered chemotherapy following China's clinical practices. Based on the algorithm built by Guyot, the individual patient data were reconstructed from the published Kaplan-Meier curves, and the survival functions were calculated by parametric methods. Cost estimates were valued in Chinese yuan (as per rates in 2022).

RESULTS

In 50-year-old female patients with early-stage TNBC, Strategy (1), which employs TILs testing to guide cytotoxic chemotherapy yielded an additional 0.47 quality-adjusted life years (QALYs) and saved 40,976 yuan, with an incremental cost-effectiveness ratio (ICER) of -87,182.98 yuan per QALY gained compared with Strategy (2). This indicates that compared with Strategy (2), Strategy (1) is the dominant scheme. The results were sensitive to utility parameters, discount rates, and treatment costs after relapse. At a willingness-to-pay threshold of 85,700 yuan (based on GDP per capita) per QALY, the probability of TILs being cost-effective was almost 100%.

CONCLUSIONS

The application of biomarkers (TILs) to guide decisions for chemotherapy de-escalation is a cost-effective strategy for early-stage TNBC patients and deserves to be widely promoted in clinical practice.

Tumor-Infiltrating Lymphocytes and Adoptive Cell Therapy: State of the Art in Colorectal, Breast and Lung Cancer

Our knowledge of tumor-infiltrating lymphocytes (TILs) is dramatically expanding. These cells have proven prognostic and therapeutic value for many cancer outcomes and potential to treat also disseminated breast, colorectal, or lung cancer. However, the therapeutical outcome of TILs is negatively affected by tumor mutational burden and neoantigens. On the other hand, it can be improved in combination with checkpoint blockade therapy. This knowledge and rapid detection techniques alongside gene editing allow us to classify and modify T cells in many ways. Hence, to tailor them precisely to the patient´s needs as to program T cell receptors to recognize specific tumor-associated neoantigens and to insert them into lymphocytes or to select tumor neoantigen-specific T cells, for the development of vaccines that recognize tumor-specific antigens in tumors or metastases. Further studies and clinical trials in the field are needed for an even better-detailed understanding of TILs interactions and aiming in the fight against multiple cancers.

Delineating spatial cell-cell interactions in the solid tumour microenvironment through the lens of highly multiplexed imaging

The growth and metastasis of solid tumours is known to be facilitated by the tumour microenvironment (TME), which is composed of a highly diverse collection of cell types that interact and communicate with one another extensively. Many of these interactions involve the immune cell population within the TME, referred to as the tumour immune microenvironment (TIME). These non-cell autonomous interactions exert substantial influence over cell behaviour and contribute to the reprogramming of immune and stromal cells into numerous pro-tumourigenic phenotypes. The study of some of these interactions, such as the PD-1/PD-L1 axis that induces CD8+ T cell exhaustion, has led to the development of breakthrough therapeutic advances. Yet many common analyses of the TME either do not retain the spatial data necessary to assess cell-cell interactions, or interrogate few (<10) markers, limiting the capacity for cell phenotyping. Recently developed digital pathology technologies, together with sophisticated bioimage analysis programs, now enable the high-resolution, highly-multiplexed analysis of diverse immune and stromal cell markers within the TME of clinical specimens. In this article, we review the tumour-promoting non-cell autonomous interactions in the TME and their impact on tumour behaviour. We additionally survey commonly used image analysis programs and highly-multiplexed spatial imaging technologies, and we discuss their relative advantages and limitations. The spatial organization of the TME varies enormously between patients, and so leveraging these technologies in future studies to further characterize how non-cell autonomous interactions impact tumour behaviour may inform the personalization of cancer treatment.​.

Unveiling the Immune Microenvironment's Role in Breast Cancer: A Glimpse into Promising Frontiers

Breast cancer (BC), one of the most widespread and devastating diseases affecting women worldwide, presents a significant public health challenge. This review explores the emerging frontiers of research focused on deciphering the intricate interplay between BC cells and the immune microenvironment. Understanding the role of the immune system in BC is critical as it holds promise for novel therapeutic approaches and precision medicine strategies. This review delves into the current literature regarding the immune microenvironment's contribution to BC initiation, progression, and metastasis. It examines the complex mechanisms by which BC cells interact with various immune cell populations, including tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs). Furthermore, this review highlights the impact of immune-related factors, such as cytokines and immune checkpoint molecules. Additionally, this comprehensive analysis sheds light on the potential biomarkers associated with the immune response in BC, enabling early diagnosis and prognostic assessment. The therapeutic implications of targeting the immune microenvironment are also explored, encompassing immunotherapeutic strategies and combination therapies to enhance treatment efficacy. The significance of this review lies in its potential to pave the way for novel therapeutic interventions, providing clinicians and researchers with essential knowledge to design targeted and personalized treatment regimens for BC patients.

Intra-tumoral microbial community profiling and associated metabolites alterations of TNBC

Triple-negative breast cancer (TNBC) presents significant challenges to female health owing to the lack of therapeutic targets and its poor prognosis. In recent years, in the field of molecular pathology, there has been a growing focus on the role of intra-tumoral microbial communities and metabolic alterations in tumor cells. However, the precise mechanism through which microbiota and their metabolites influence TNBC remains unclear and warrants further investigation. In this study, we analyzed the microbial community composition in various subtypes of breast cancer through 16S rRNA MiSeq sequencing of formalin-fixed, paraffin-embedded (FFPE) tissue samples. Notably, Turicibacter, a microbe associated with cancer response, exhibited a significantly higher abundance in TNBC. Similarly, mass spectrometry-based metabolomic analysis revealed substantial differences in specific metabolites, such as nutriacholic, pregnanetriol, and cortol. Furthermore, we observed significant correlations between the intra-tumoral microbiome, clinicopathological characteristics, and human epidermal growth factor receptor-2 expression(HER2). Three microbial taxa (Cytophagaceae, Conexibacteraceae, and Flavobacteriaceae) were associated with tumor-infiltrating lymphocytes(TILs), which are indicative of antitumor immunity. This study creatively utilized FFPE tissue samples to assess intra-tumoral microbial communities and their related metabolic correlations, presenting avenues for the identification of novel diagnostic biomarkers, the development of therapeutic strategies, and the early clinical diagnosis of TNBC.

Exploring the dual role of B cells in solid tumors: implications for head and neck squamous cell carcinoma

In the tumor milieu of head and neck squamous cell carcinoma (HNSCC), distinct B cell subpopulations are present, which exert either pro- or anti-tumor activities. Multiple factors, including hypoxia, cytokines, interactions with tumor cells, and other immune infiltrating lymphocytes (TILs), alter the equilibrium between the dual roles of B cells leading to cancerogenesis. Certain B cell subsets in the tumor microenvironment (TME) exhibit immunosuppressive function. These cells are known as regulatory B (Breg) cells. Breg cells suppress immune responses by secreting a series of immunosuppressive cytokines, including IL-10, IL-35, TGF-β, granzyme B, and adenosine or dampen effector TILs by intercellular contacts. Multiple Breg phenotypes have been discovered in human and mouse cancer models. However, when compartmentalized within a tertiary lymphoid structure (TLS), B cells predominantly play anti-tumor effects. A mature TLS contains a CD20+ B cell zone with several important types of B cells, including germinal-center like B cells, antibody-secreting plasma cells, and memory B cells. They kill tumor cells via antibody-dependent cytotoxicity and phagocytosis, and local complement activation effects. TLSs are also privileged sites for local T and B cell coordination and activation. Nonetheless, in some cases, TLSs may serve as a niche for hidden tumor cells and indicate a bad prognosis. Thus, TIL-B cells exhibit bidirectional immune-modulatory activity and are responsive to a variety of immunotherapies. In this review, we discuss the functional distinctions between immunosuppressive Breg cells and immunogenic effector B cells that mature within TLSs with the focus on tumors of HNSCC patients. Additionally, we review contemporary immunotherapies that aim to target TIL-B cells. For the development of innovative therapeutic approaches to complement T-cell-based immunotherapy, a full understanding of either effector B cells or Breg cells is necessary.