Tumor-infiltrating Lymphocytes Infiltration Research Articles

Association of stromal tumor-infiltrating lymphocytes with clinicopathological parameters in endometrial cancer.

Endometrial cancer (EC) ranks as one of the most prevalent gynecological malignancies globally. The presence and role of stromal tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment have garnered interest due to their prognostic and therapeutic potential. This study aimed to evaluate the association between stromal TILs and various clinicopathological parameters in EC. A prospective study was conducted which included 30 histologically confirmed cases of endometrial carcinoma. Specimens collected from January 2023 to June 2024 were processed for routine histopathological examination and immunohistochemistry for CD3 and CD20 markers. TILs were quantified as per the International Immuno-Oncology Biomarker Working Group guidelines and categorized into low (<20%) and high (≥20%) TILs. The study comprised 30 female patients, predominantly aged 51 to 60 years. Most tumors were of the endometrioid subtype (93.3%). High TILs were significantly associated with early tumor stage, lower grade, lesser myometrial invasion, and absence of nodal involvement on univariate analysis and with lower tumor stage and grade on multivariate analysis. No significant association was found between TILs and age, lymphovascular, or perineural invasion. The findings suggest that high TIL infiltration correlates with favorable tumor characteristics, potentially serving as a prognostic marker for early and less aggressive EC. High TILs were associated with better tumor stage, grade, and reduced nodal involvement, indicating their protective role in tumor progression. However, the lack of association with certain parameters calls for further investigation into the functional state of TILs and their interactions within the tumor microenvironment.

Response Gene to Complement 32 is associated with poor patient survival and an inflamed tumor-immune microenvironment in clear cell renal cell carcinoma.

It has been well established that tumor-infiltrating lymphocytes (TILs) play a critical role in the pathogenesis and progression of clear cell renal cell carcinoma (ccRCC). However, the mechanism on the interactions between TILs and tumor cells in the tumor-immune microenvironment remains unclear. In the present study, the expression of Response Gene to Complement 32 (RGC-32) was evaluated using immunohistochemistry. We analyzed the associations of RGC-32 expression with patient characteristics and survival. We also assessed TILs and their subsets (CD3+, CD4+, CD8+ and PD-1+) in the tumor nest. The level of RGC-32 expression was positively correlated with ISUP grade and Ki67 expression and was an independent poor prognosis factor of patients with ccRCC. RGC-32 expression was negatively correlated with the infiltration of TIL and CD3+T cells, but positively correlated with infiltration of PD-1+cells. In vitro studies showed that RGC-32 expression in renal cancer cells was downregulated by activated immune cells. Further investigation revealed that RGC-32 expression in renal cancer cells was inhibited by TNF-α and IL-1β secreted by activated immune cells. Collectively, these data indicate that RGC-32 could be a novel prognostic and druggable target related to the tumor-immune microenvironment in renal cancer.

Tumor-Infiltrating Lymphocytes as Mediators of the Obesity and Papillary Thyroid Carcinoma Lymph Node Metastasis Association: An Observational Retrospective Cohort Study.

Obesity increases the risk of papillary thyroid carcinoma (PTC) and lymph node metastasis (LNM), possibly via modulation of the tumor immunological microenvironment. The STROCSS guideline was followed to conduct a retrospective cohort study. Binary logistic regression analysis with odds ratios (OR) was performed to assess the association between tumor-infiltrating lymphocytes (TILs), obesity, and LNM. Using The Cancer Genome Atlas (TCGA) data, we examined the relationship between immune cell subsets and obesity-regulating molecules in thyroid cancer tissues. The Cox regression risk model was used to analyze the prognosis of thyroid cancer. After adjusting for confounding factors, our findings revealed that overweight and obesity were associated with a decrease in TIL infiltration (OR 0.876, p = 0.005 and OR 0.795, p = 0.001, respectively). Furthermore, these conditions were observed to be correlated with increased likelihood of LNM (OR 1.134, p = 0.005 and OR 1.307, p < 0.001, respectively). On the contrary, TIL infiltration was inversely associated with LNM (OR 0.868, p < 0.001). When controlling for TIL infiltration as the sole variable, the combination of obesity and TIL infiltration did not independently predict LNM (adjusted OR 1.442, p = 0.113). However, obesity alone was found to elevate the likelihood of LNM (adjusted OR 1.539, p = 0.02). Additionally, adiponectin (a crucial adipokine) was reduced in obesity and demonstrated a negative correlation with the abundance of infiltrated dendritic cells and regulatory T cells, as evidenced by TCGA data analysis. Furthermore, ADIPOR2 expression negatively correlated with LNM and positively associated with unfavorable prognosis in PTC, with a hazard ratio of 0.480 (p = 0.007). TIL infiltration may affect obesity-associated PTC LNM. Obesity may affect LNM and result in poor prognosis through ADIPOR2 regulation of antitumor immune cells.

Characterization of tumor-infiltrating lymphocytes and their spatial distribution in triple-negative breast cancer

BackgroundThe tumor immune microenvironment, particularly tumor-infiltrating lymphocytes (TILs), plays a critical role in disease progression and treatment response in triple-negative breast cancers (TNBCs). This study was aimed to characterize the composition of TILs and investigate their clinicopathological and prognostic significance with a special focus on the spatial distribution of TILs in TNBCs.MethodsWe analyzed TNBC samples through PanCancer Immune Profiling using NanoString nCounter assays to identify immune-related genes that are expressed differentially in relation to TIL levels and evaluated protein expression of selected markers through immunohistochemical staining on tissue microarrays. For a comprehensive assessment of the expression of cytotoxic T lymphocyte (CTL) and natural killer (NK) cell markers, a CTL-NK score was devised based on CD8+, CD56+, CD57+, GNLY+, and GZMB+ TIL levels.ResultsGene expression analysis revealed significant upregulation of CTL and NK cell-associated genes including GNLY, KLRC2, and GZMB in TIL-high TNBCs. Immunohistochemical validation confirmed that TNBCs with higher TILs had a greater amount of CD56+, CD57+, GNLY+, and GZMB+ TILs not only in absolute number but also in proportion relative to CD4+ or CD8+ TILs. High TIL and its subset (CD4+, CD8+, CD56+, CD57+, GNLY+, and GZMB+ TIL) infiltration correlated with favorable clinicopathological features of tumor. In survival analysis, high CTL-NK score was found to be an independent prognostic factor for better disease-free survival (DFS) of the patients. Furthermore, uniformly high TIL infiltration was linked to better DFS, whereas cases with heterogeneous TIL infiltration showed no difference in survival compared to those with uniformly low TIL infiltration.ConclusionOur study showed that CTL and NK cell-associated gene expression and protein levels differ significantly according to TIL levels and that CTL-NK score and distribution of TILs within tumors have a prognostic value. These findings emphasize the importance of CTLs and NK cells as well as the spatial uniformity of TIL infiltration in clinical outcome of TNBC patients, providing valuable insights for refining prognostic assessments and guiding immunotherapeutic strategies.

Prognostic value of tumor-infiltrating lymphocyte subtypes and microorganisms in triple-negative breast cancer.

Tumor-infiltrating lymphocytes (TILs) are key components of the tumor microenvironment (TME) and serve as prognostic markers for breast cancer. Patients with high TIL infiltration generally experience better clinical outcomes and extended survival compared to those with low TIL infiltration. However, as the TME is highly complex and TIL subtypes perform distinct biological functions, TILs may only provide an approximate indication of tumor immune status, potentially leading to biased prognostic results. Therefore, we reviewed the interactions between immune-infiltrating subtypes and tumor cells throughout the entire TME. By examining the antitumor or protumor effects of each TIL subtype, we aimed to better characterize the tumor immune landscape, offering more accurate and comprehensive insights for guiding triple-negative breast cancer (TNBC) treatment. In addition, this approach could lead to the development of new therapeutic targets, enabling tailored treatment strategies and precision medicine. Accumulating evidence suggests that the intestinal microbiome and its metabolites influence antitumor responses by modulating innate and adaptive immunity, with specific bacteria potentially serving as biomarkers for predicting clinical responses. Various studies have identified microorganisms in breast tissue, previously considered sterile, revealing differences in breast microbial composition between patients with breast cancer and controls, as well as associations between specific breast microorganisms and clinicopathologic features, including immune correlations. The aim of this review was to provide a more comprehensive set of prognostic markers for TNBC and to tap into potential-specific therapeutic targets.

Anti-CTLA-4 antibody self-presented dendritic cell nanovesicles boost the immunotherapy of hepatocellular carcinoma after microwave ablation

Microwave ablation (MWA) is a frequently adopted regional therapy for treating hepatocellular carcinoma (HCC) in clinic. However, incomplete microwave ablation (IMWA) is often inevitable due to the restraint of ablating large tumors or tumors in special locations, resulting in a high recurrence rate of HCC. Moreover, the most promising immune checkpoint blockade (ICB)-based immunotherapy is raising hindered by the toxicity and insufficient immune response. To overcome these barriers, we conjugate small nanovesicle (smDV)-derived from matured dendritic cells (mDCs) with anti-CTLA-4 antibody (smDV-aCTLA-4) using a metabolic tagging technology, which could trigger the infiltration of cytotoxic T cells (CTLs) and adopted tumor-infiltrating lymphocytes (TILs) in residual HCC after IMWA. In HCC microenvironment, the administration of smDV-aCTLA-4 could promote antigen presentation and immune checkpoint suppression to activate CTLs and improve the safety of anti-CTLA-4 antibody. Moreover, the anti-tumor efficacy of CTLs elicited by smDV-aCTLA-4 could also be further enhanced by anti-programmed death 1 (aPD-1) antibody. In addition, compared to the adoptive TILs therapy, the treatment using smDV-aCTLA-4-bonded TILs (smDV-aCTLA-4@TILs) could promote the proliferation and infiltration of cytotoxic TILs in residual HCC after IMWA. Our results clearly evidences the potency of a new type of engineered DC nanovesicles in reducing HCC recurrence after IMWA.

Stroma-and Tumor-Associated Predictive Features inSalivary Gland Adenoid Cystic Carcinoma of the Headand Neck.

There is lack of knowledge on the utility of prognostic histopathologic characteristics in adenoid cystic carcinoma (ACC) of the head and neck. We evaluated the prognostic value of tumor and stroma-related histopathologic features in ACC. A total of 65 cases of ACC from minor and major salivary glands were included in this study. We evaluated tumor budding, tumor-infiltrating lymphocytes (TILs), and tumor-stroma ratio (TSR) in hematoxylin and eosin (HE) stained sections. Stroma-rich ACCs recurred more frequently (p = 0.029) during follow-up and associated with distant metastasis (p = 0.038). In multivariable analysis, stroma-rich tumors associated with poorer disease-specific survival with a hazard ratio of 3.76 (95% CI 1.10-12.83, p = 0.034). ACCs commonly showed a low infiltration of TILs as 89% of the tumors was characterized by an immune desert pattern. Low infiltration of TILs associated significantly with increased tumor budding (p = 0.039). Adverse features of TSR and tumor budding are widely expressed in ACC, and stroma-rich tumors are associated with poor prognosis. Low number of TILs in ACC tissue indicates a weak immune response by the host and illustrates the nature of ACC as a relentless malignancy.

WNT/β-catenin Signaling and CD8+ Tumor-infiltrating Lymphocytes in Tremelimumab Plus Durvalumab for Advanced Hepatocellular Carcinoma.

Tremelimumab plus durvalumab is an approved first-line therapy for advanced hepatocellular carcinoma (HCC). Previous studies identified WNT/β-catenin mutations or CD8+ tumor-infiltrating lymphocytes (TILs) as biomarkers that can predict responsiveness to immune checkpoint inhibitor therapy in HCC. However, biomarkers for effectiveness of tremelimumab plus durvalumab in HCC have not been reported. This study investigated whether evaluation of WNT/β-catenin signaling and CD8+ TILs by immunohistochemical staining of tumor biopsy tissues can predict the response to tremelimumab plus durvalumab in patients with HCC. Fifteen HCC patients who underwent tumor biopsies were classified into three groups based on WNT/β-catenin signal activation and CD8+ TIL infiltration. The clinical responses to treatment in the groups were evaluated. Four patients had HCC with WNT/β-catenin signal inactivation and high-level CD8+ TIL infiltration, four patients had HCC with WNT/β-catenin signal activation and low-level CD8+ TIL infiltration, and seven patients had WNT/β-catenin signal activation and high-level CD8+ TIL infiltration or WNT/β-catenin signal inactivation and low-level CD8+ TIL infiltration. A better response rate was observed in the WNT/β-catenin signal inactivation and high-level CD8+ TIL infiltration group, and a worse response rate was observed in the WNT/β-catenin signal activation and low-level CD8+ TIL infiltration group. Although the present study involved a small number of patients, the findings suggest that the efficacy of tremelimumab plus durvalumab may be affected by WNT/β-catenin signaling and CD8+ TIL infiltration.

CD8+ Tumor-Infiltrating Lymphocytes in Head and Neck Cancer: A Review.

CD8+ tumor-infiltrating lymphocytes (TILs) are increasingly used in oncology as a prognostic and predictive tool to guide patient management. This review summarizes current literature on CD8+ TILs in head and neck squamous cell carcinoma (SCC). Published meta-analyses and clinical trials evaluating CD8+ TILs were analyzed. Consistent positive associations between elevated CD8+ TILs and overall survival have been observed across head and neck sites. CD8+ TILs have been found to predict response to treatment, most commonly immunotherapy, but also chemoradiation. Numerous trials have shown that increased CD8+ TIL frequencies in pretreatment biopsies could identify patients likely to respond to neoadjuvant therapies. CD8+ TIL infiltration has also been elevated in responders both during and after treatment. However, wider adoption of CD8+ TIL quantification as a biomarker has been limited by the need for clinical validation and universal measurement guidelines for head and neck SCC, as there are for other malignancies. Measurement variability includes which tumor compartment is sampled, how TILs are quantified, and which cutoffs are clinically relevant. For several head and neck SCC, measurement of CD8+ TILs in the central or intratumoral compartment, followed by the stromal compartment, has been most consistently associated with survival. Future studies are needed to evaluate subpopulations of CD8+ TILs and biomarker-based treatment selection.

The relationship between the tertiary lymphoid structure and immune-infiltrating cells in gastrointestinal cancers: A systematic review and meta-analysis.

This study systematically evaluated the relationship between tertiary lymphoid structures (TLS) and clinical pathological features as well as immune infiltrating cells in gastrointestinal cancers. We searched Web of science, Pubmed, Embase, and Cochrane Library for studies that met the requirements as of July 1, 2023, and the odds ratio, the corresponding 95% confidence interval or mean and standard deviation, were included in the analysis. We eventually included 20 studies, involving a total of 4856 patients. TLS were found to be significantly associated with T stage, N stage, TNM stage, and tumor size. Moreover, patients with positive TLS showed significantly elevated expression of T-cell related markers, including CD3, CD4, CD8, CD45RO; B-cell related markers, such as CD11c and CD20; and dendritic cell-related marker CD103. On the other hand, positive TLS correlated significantly with low expression of FOXP3 and CD68. Additionally, there was a significant positive association between TLS and overall infiltration of tumor-infiltrating lymphocytes. The presence of TLS is significantly correlated with the infiltration of various immune cells in gastrointestinal cancers. To determine the ideal balance between the presence of mature TLS and appropriate immune cell infiltration, further high-quality and multicenter clinical studies need to be conducted.

Stromal CD4 (+) T Cell Subsets Mediate Antitumor Cytotoxic Immune Responses in Human Colorectal Carcinoma.

The local immune response in colorectal cancer is closely related to prognosis and therapeutic efficacy. In this study, histological analyses were performed to determine the phenotype of tumor-infiltrating lymphocytes (TILs) and their infiltration in the stromal and intratumoral regions, aiming to elucidate their interactions and prognostic effects. Multiplex fluorescent labeling was performed using surgically resected colorectal cancer specimens to investigate the infiltration of CD45RO (+) TILs, which exhibit cytotoxicity, and subsets of CD4 (+) TILs, identified by their characteristic transcription factor expression. The degree of CD45RO (+) TIL infiltration in the entire observation field or stromal area was not associated with prognosis. However, a high degree of infiltration in the tumor nest (intratumoral area) was significantly associated with a favorable prognosis. CD4 (+) TILs and their subsets were not associated with prognosis. However, stratified analyses revealed that a high degree of infiltration of stromal CD4 (+) TILs and the subsets T helper (Th)1, Th2, Th17, and regulatory T cells is necessary for the association between high intratumoral CD45RO (+) TIL infiltration and favorable prognosis. A sufficient degree of infiltration of stromal CD4 (+) TIL subsets is required for intratumoral CD45RO (+) TILs to exert toxicity against cancer cells. This highlights the significance of stromal immune reactions in achieving effective cytotoxic immune responses in the intratumoral area and demonstrates the critical role of the spatial distribution pattern of TILs in exerting their functions.

Spatial heterogeneity and prognostic significance of TAMs and TILs infiltrates in different staging esophageal squamous carcinoma

BackgroundThe prognostic value and clinical relevance of tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) in esophageal squamous cell carcinoma (ESCC) remain unclear. AimsTo investigate the prognostic value and functional involvement of TILs in ESCC. MethodsWe included 40 patients across different stages of ESCC from Xinjiang. Multiplex fluorescent immunohistochemistry characterized TILs and TAMs. TILs in different tumor regions were quantified and correlated with overall survival (OS) using log-rank test and Cox regression analyses. ResultsInvasive ESCC exhibited increased CD4 T cells and Tregs compared to carcinoma in situ, with a higher Tregs/CD4 T cells ratio (p < 0.05). TAMs, primarily in stromal regions, were significantly associated with Foxp3+ cells (p < 0.05). Higher infiltration of stromal TAMs and a higher CD4/CD8 T cells ratio correlated with poorer OS, while a higher CD8 T/Foxp3+ cells ratio indicated better survival. Multivariate Cox analysis revealed TNM stage, tumor length, and stromal CD4/CD8 T cells ratio as independent prognostic factors (p < 0.05). An immune prognostic risk score-based nomogram was constructed to predict patient outcomes. ConclusionsThe spatial distribution and abundance of TILs significantly correlated with prognosis, providing a useful immune classification for ESCC.

The aminophospholipid transporter, ATP8B3, as a potential biomarker and target for enhancing the therapeutic effect of PD-L1 blockade in colon adenocarcinoma

BackgroundColon adenocarcinoma (COAD) is a prevalent malignant tumor globally, contributing significantly to cancer-related mortality. COAD guidelines label MSI (Microsatellite instability) and MSS (Microsatellite stability) subtypes as global classification criteria and treatment strategy selection criteria for COAD. Various combination therapies involving PD-L1 inhibitors and adjuvant therapy to enhance anti-tumor efficacy. MethodsDatasets from single-cell RNA sequencing and bulk RNA sequencing in the TCGA and GEO databases were utilized to identify differentially expressed genes (DEGs). Furthermore, the correlation between ATP8B3 and PD-L1 was validated using siRNA, shRNA, and western blot analysis. Additionally, the association between ATP8B3 and immune checkpoint blockade (ICB) therapy was investigated through immune infiltration analysis and flow cytometry in both in vivo and in vitro assays. ResultsIn the COAD patient group, ATP8B3 significantly contributed to the establishment of an immunosuppressive microenvironment. Inhibiting ATP8B3 led to a reduction in PD-L1 expression in colon cancer cell lines. Additionally, ATP8B3 expression levels could serve as a potential guide for PD-L1 treatment in MSI-H COAD patients, with higher ATP8B3 expression associated with increased sensitivity to PD-L1 therapy. However, due to the lack of immuno-killer cells in the microenvironment of MSS subtypes, elevated ATP8B3 expression couldn't increase the sensitivity of MSS COAD patients to PD-L1 inhibitors. ConclusionOur research results support that Inhibiting ATP8B3 could enhance TIL (tumor-infiltrating lymphocyte) infiltration by reducing PD-L1 expression in MSI-H COAD, thereby serving as an effective strategy to improve PD-L1 blocker efficacy. The treatment strategy of combining ATP8B3 inhibitors and immunotherapy for MSI/MSS COAD patients will be the best choice.

Association of tumor budding and tumor infiltrating lymphocytes with clinicopathological parameters in gallbladder carcinoma.

Gallbladder carcinoma (GBC) poses significant challenges in oncology due to its aggressive nature and limited treatment options. The lack of effective biomarkers for early detection and prognosis exacerbates the prognosis for GBC patients. Tumor budding (TB) and tumor infiltrating lymphocytes (TILs) have emerged as potential prognostic indicators in various cancers, reflecting tumor-host immune interactions and tumor aggressiveness. The study of TB and TILs in GBC is particularly important due to the limited literature available. This retrospective observational study aimed to evaluate the association of TB and TILs with clinicopathological parameters in GBC patients. Clinicopathological data were collected from patients with histologically confirmed GBC who underwent surgical resection. The sections were evaluated for TB and TILs using standardized methods. Statistical analysis was performed to assess associations between these parameters and clinicopathological variables. Tumor stage and grade showed significant associations with TB and TILs, indicating their potential as prognostic markers. High TB correlated with advanced tumor stage and higher grade, while high TIL infiltration was associated with early tumor stage and lower grade. Additionally, TILs exhibited a significant association with lymphovascular invasion. Interestingly, an inverse association was observed between TB and TILs, highlighting the dynamic interplay between tumor aggressiveness and host immune response. TB and TILs hold prognostic significance in GBC, offering insights into its pathogenesis and potential therapeutic targets. Future research exploring the mechanistic underpinnings of tumor-host immune interactions in GBC is crucial for translating these findings into clinical applications and improving outcomes for patients.

Prognostic biomarker tumor-infiltrating lymphocytes failed to serve as a predictive biomarker for postoperative radiotherapy in completely resected pN2 non-small cell lung cancer: a retrospective analysis

BackgroundEvidence suggests that radiotherapy is a potent immunomodulator in non-small cell lung cancer (NSCLC). Conversely, it has rarely been demonstrated if immune infiltration can influence radiotherapy efficacy. Herein, we explored the effect of tumor-infiltrating lymphocytes (TILs) on the response to postoperative radiotherapy (PORT) in completely resected stage III-pN2 NSCLC.MethodsThis retrospective study included 244 patients with pathologically confirmed stage III-N2 NSCLC who underwent complete resection at our institution between 2014 and 2020. TILs were assessed with permanent full-face hematoxylin and eosin (H&E) sections and the evaluation of TILs was based on a published guideline. Patients were stratified into the TILlow or TILhigh group with a cutoff value of 50%. Kaplan-Meier method and Log‐rank test were utilized to assess disease-free survival (DFS) and overall survival (OS). Univariate and multivariate Cox regression analysis were conducted to determine prognostic indicators.ResultsAmong 244 patients, a total of 121 patients received PORT whereas 123 did not. TILs level in patients with PORT was significantly higher than that in patients without PORT (p < 0.001). High TILs level was significantly associated with an improved DFS and OS in all the entire chort (DFS, p < 0.001; OS, p = 0.001), PORT chort (DFS, p = 0.003; OS, p = 0.011) and non-PORT chort (DFS, p < 0.001; OS, p = 0.034). There were no significant survival differences between different treatment modalities in the low TILs infiltration (DFS, p = 0.244; OS, p = 0.404) and high TILs infiltration (DFS, p = 0.167; OS, p = 0.958) groups.ConclusionsTILs evaluated with H&E sections could represent a prognostic biomarker in patients with completely resected pN2 NSCLC, and high TILs infiltration was associated with favorable survival outcomes.The predictive value of TILs for PORT still need to be further explored in the future.

Predictive and prognostic value of aurora kinase A combined with tumor-infiltrating lymphocytes in medullary thyroid carcinoma.

Aurora kinase A (AURKA) and tumor-infiltrating lymphocytes (TILs) are both known to play an essential role in tumorigenesis. However, the expression and prognostic value of the AURKA and TILs in medullary thyroid carcinoma (MTC) have not yet been investigated. Surgical specimens and clinical data of 137 patients diagnosed with MTC were collected. AURKA expression and TILs infiltration were quantified by immunohistochemistry and hematoxylin-eosin staining. Subsequently, the prognostic value of AURKA expression and TIL infiltration in MTC was evaluated. AURKA was highly expressed in patients with multifocal tumor, cervical lymph node metastasis, and an advanced TNM stage, indicating a high probability of recurrence. AURKA further exhibited a positive correlation with TILs (R = 0.44, P < 0.001). High expression of AURKA combined with a low numbers of TILs (AURKAhigh/TILslow) was identified as an independent prognostic factor for biochemical recurrence (odds ratio: 4.57, 95% confidence interval: 1.54-14.66, P < 0.01) and recurrence-free survival (hazard ratio: 3.64, 95% confidence interval: 1.52-8.71, P < 0.001). The combination of AURKA and TILs apparently improves the prognostic value for biochemical recurrence (area under the curve: 0.751) and structural recurrence (area under the curve: 0.836) of MTC. Notably, AURKAhigh/TILslow demonstrated a high value for prediction of distant or unresectable locoregional recurrence, with an overall accuracy of 86.9%. AURKAhigh is associated with the MTC malignancy. The combination of AURKAhigh/TILslow was identified as novel independent prognostic marker in MTC, predicting incurable disease recurrence with high accuracy.

The tumor immune microenvironment features and their prognostic value in rectal and sigmoid colon signet-ring cell carcinoma.

3544 Background: Signet-ring cell carcinoma (SRCC) of the rectum and sigmoid colon is a rare and highly malignant challenge in clinical practice. Although high PD-1+CD8+ tumor-infiltrating lymphocyte (TIL) infiltration has been reported as a positive prognostic factor in gastric cancer, pancreatic cancer, etc., its role in colorectal SRCC remains unclear. This study aims to explore the immune landscape of colorectal SRCC and its prognostic implications. Methods: The study included 34 patients with stage II-IV SRCC of the rectum and sigmoid colon. The immune contextures of tumor tissues were characterized using multiplex immunofluorescence assays and compared with a cohort of 57 cases of stage II-IV AC. The ratio density and spatial distribution of CD3+, CD8+, PD-1+, PD-L1+ cells, M1/M2 macrophages, and NK cells were quantitively analyzed in both parenchymal (p) and interstitial (i) regions. Characteristics of immune cell infiltration and their prognostic value for long-term survival were investigated in SRCC cases. Results: Compared to AC, SRCC exhibited significantly higher infiltration of CD8+ and CD3+ iTILs in the interstitial region (P=0.00024; P=0.00321, respectively) and elevated CD8+ pTILs infiltration in tumor parenchyma (P=0.041). Conversely, parenchymal infiltration of TILs co-expressing PD-1 was significantly lower in SRCC than AC (PD-1+CD8+ pTILs: P=0.00035; PD-1+CD3+ pTILs: P=5.0e-05). SRCC showed significantly lower infiltration of M1 macrophages in both parenchyma and interstitium (P=0.0035; P=5.4e-09, respectively), lower interstitial infiltration of M2 macrophages (P=1.5e-05), and a borderline lower parenchymal infiltration of M2 macrophages (P=0.0522), compared to AC. Additionally, patients with high parenchymal or interstitial infiltration of PD-1+CD8+ TILs exhibited significantly longer DFS (P=0.00024; P=0.0041, respectively) and OS (P=0.011; P=0.0044, respectively) than those with low infiltration. Multivariate analysis indicated that the level of PD-1+CD8+ pTILs infiltration is an independent prognostic factor for DFS, being independent of CEA levels and TNM stage (P = 0.018; P = 0.02, respectively). Among patients with normal CEA level or of stage II-III, high level of PD-1+CD8+ pTILs infiltration was still associated with significantly improved DFS (P&lt;0.0001; P=0.00018, respectively) and OS (P=0.00021; P&lt;0.0001, respectively). Conclusions: SRCC of rectum and sigmoid colon exhibits distinct immune profiles compared to conventional AC, characterized by higher infiltration of CD8+ and CD3+ TILs, but lower infiltration of PD-1+CD8+ TILs. The unique immune landscape in SRCC, particularly the level of PD-1+CD8+ TILs infiltration and its positive predictive value for DFS and OS, provides new perspectives for immune-based stratification and therapeutic strategies for this clinically significant cancer subtype.

PROGNOSTIC VALUE OF THE DENSITY OF TUMOR-INFILTRATING LYMPHOCYTES AND ITS ASSOCIATION WITH CLINICAL-MORPHOLOGICAL FEATURES OF COLON ADENOCARCINOMAS

Aim. To study the prognostic value of the density of tumor-infiltrating lymphocytes (TILs) and its association with other clinical-morphological parameters in colon adenocarcinomas (CAC). Materials and Methods. 236 CAC samples were examined. TILs density was estimated as the percentage of tumor stromal area occupied by TILs. By the index of TILs density, the patients were divided into 3 groups: TILs 0—9% (n = 88); TILs 10—39% (n = 106); TILs &gt; 40% (n = 42). Dependent on this index, their overall survival (OS) was analyzed. Results. Kaplan — Meier curves revealed a significant (p &lt; 0.001) difference in the OS for patients with different TILs infiltration intensities. Multivariate Cox’s proportional hazard regression model analysis has confirmed that patients with moderate TILs density (HR 0.57, 95% CI 0.34—0.96, p = 0.035) had better OS rates compared to low TILs density. TILs were associated with the stage (p &lt; 0.001), lymph node metastasis pN (p &lt; 0.001), distant metastasis M (p &lt; 0.001), and the patient’s outcome (p &lt; 0.001). Conclusion. TILs can be considered an additional prognostic tool during regular histological examination and are strongly associated with the most significant clinical-morphological features of CAC.

IMMUNOREACT 7: Regular aspirin use is associated with immune surveillance activation in colorectal cancer.

Long-term daily use of aspirin reduces incidence and mortality due to colorectal cancer (CRC). This study aimed to analyze the effect of aspirin on the tumor microenvironment, systemic immunity, and on the healthy mucosa surrounding cancer. Patients with a diagnosis of CRC operated on from 2015 to 2019 were retrospectively analyzed (METACCRE cohort). Expression of mRNA of immune surveillance-related genes (PD-L1, CD80, CD86, HLA I, and HLA II) in CRC primary cells treated with aspirin were extracted from Gene Expression Omnibus-deposited public database (GSE76583). The experiment was replicated in cell lines. The mucosal immune microenvironment of a subgroup of patients participating in the IMMUNOREACT1 (ClinicalTrials.gov NCT04915326) project was analyzed with immunohistochemistry and flow cytometry. In the METACCRE Cohort, 12% of 238 patients analyzed were aspirin users. Nodal metastasis was significantly less frequent (p=.008) and tumor-infiltrating lymphocyte infiltration was higher (p=.02) among aspirin users. In the CRC primary cells and selected cell lines, CD80 mRNA expression was increased following aspirin treatment (p=.001). In the healthy mucosa surrounding rectal cancer, the ratio of CD8/CD3 and epithelial cells expressing CD80 was higher in aspirin users (p=.027 and p=.034, respectively). These data suggested that regular aspirin use may have an active role in enhancing immunosurveillance against CRC.

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.