稲村 健太郎

BACKGROUND/AIM: The Hippo signaling pathway comprises mammalian sterile 20-like kinase 1/2, large tumor suppressor 1/2, and Yes-associated protein 1 (YAP1). This study investigated phosphorylated YAP (pYAP, Ser 127) protein expression in oral squamous cell carcinoma (OSCC). PATIENTS AND METHODS: Tissues from patients with oral epithelial dysplasia (OED, n=7), carcinoma in situ (CIS, n=14), and OSCC (n=109) were analyzed. RESULTS: Cytoplasmic expression of pYAP was low in OED, CIS, and OSCC tissues. The expression of pYAP was correlated with differentiation, and the expression of low levels of YAP was significantly more common in well-differentiated to moderately differentiated OSCC than in poorly differentiated OSCC. High pYAP expression correlates with characteristics of epithelial-to-mesenchymal transition (EMT), e.g., loss of E-cadherin and increased expression of vimentin and laminin 5 (p<0.0001). Additionally, the protein arginine methyltransferase 1, a positive modulatory factor of YAP activity, was found to be correlated with elevated levels of pYAP expression (p<0.0007). CONCLUSION: The presence of elevated pYAP expression may serve as a prognostic indicator of an aggressive OSCC with EMT during the invasive stage.

Renal tumors that develop in congenitally malformed kidneys often fall outside standard histologic classifications. We present an unusual renal neoplasm in a 19-year-old boy with a hypoplastic right kidney. Computed tomography revealed a 70-mm sized unilocular cyst containing a 25-mm sized mural nodule, and laparoscopic nephroureterectomy was performed. Histologic examination showed low-grade papillary structures with reverse polarity. Immunohistochemistry demonstrated cytoplasmic (but not membranous) CA9 positivity, and RNA sequencing identified a pathogenic von Hippel-Lindau (VHL) splicing-site mutation (c.341-2A > G). Despite the VHL alteration, the tumor did not fulfill the morphologic and immunohistochemical criteria for clear cell renal cell carcinoma and was diagnosed as unclassified renal cell carcinoma. This report illustrates the diagnostic complexity of renal tumors arising in congenital renal anomalies and underscores the importance of integrating molecular, morphologic, and immunophenotypic data when standard criteria are inconclusive.

Background: Enterotoxigenic Bacteroides fragilis (ETBF) carries the bft toxin gene, which influences the host immune response and inflammatory pathways and promotes colorectal cancer (CRC). This study investigated the potential role of ETBF in CRC liver metastasis. Methods: We reviewed the records of 226 consecutive patients who underwent curative-intent (R0) resection of CRC liver metastases. ETBF DNA in fresh-frozen metastasis specimens was quantified using droplet digital PCR (ddPCR). Patients were grouped into very-low (≤80%; N = 178), low (80-90%; N = 24), and high (>90%; N = 24) ETBF-DNA groups. Three tissue cores per specimen were stained for CD8, CD4, CD20, FOXP3, CD68, and CD163, and immune-cell densities were measured digitally (cells/mm2). Results: ETBF DNA was detected in 219 of 226 lesions (96.9%). The densities of cytotoxic CD8+ T-cells, effector CD4+ T-cells, CD20+ B-cells, and CD163+ macrophages did not differ significantly by ETBF-DNA group (Ptrend all > 0.12). FOXP3+ regulatory T-cells (Tregs) decreased (Ptrend = 0.010), and CD68+ macrophages increased (Ptrend = 0.020) as ETBF-DNA levels increased. ETBF-DNA levels in CRC liver metastases were not associated with disease-free survival or overall survival or serum C-reactive protein levels. Conclusions: ETBF was present in almost all CRC liver metastases. Higher ETBF levels were associated with a tumor-immune microenvironment enriched in CD68+ macrophages and deficient in FOXP3+ Tregs, suggesting that ETBF facilitates immune evasion without loss of effector lymphocytes. Although ETBF-DNA levels did not predict survival in this single-center cohort, the potential role of ETBF in immune remodeling and as a candidate biomarker and therapeutic target in metastatic CRC warrants further study.

In hepatocellular carcinoma (HCC), CD147 expression contributes to tumor malignancy; however, its relationship with the tumor-immune microenvironment (TIME) remains unclear. This study aimed to elucidate the clinicopathological characteristics associated with CD147 expression in HCC and investigate its association with the TIME, specifically its association with tumor-infiltrating lymphocytes (TILs) and oncostatin M (OSM). Using 397 HCC specimens from patients undergoing curative-intent resection, we assessed CD147 expression in tumor cells and quantified OSM-positive cells and various TILs (CD8+, CD4+, FOXP3+, and CD20+ cells) in the TIME. Using tissue microarrays, these assessments were performed through immunohistochemical analysis. We investigated the associations between CD147 expression status, the density of OSM-positive cells, and the densities of various TILs. High CD147 expression, found in 332 specimens (83.6%), was associated with advanced clinical stage (P = 0.029), fibrosis (P = 0.036), and higher densities of FOXP3+ cells (P = 0.0039), CD4+ cells (P = 0.0012), and OSM-positive cells (P = 0.0017). In CD147-high tumors, OSM-positive cell density was associated with all assessed TIL subsets (CD8+, CD4+, FOXP3+, and CD20+ cells; all Ps < 0.001), whereas in CD147-low tumors, OSM-positive cell density was associated only with FOXP3+ cells (P = 0.0004). In HCC, CD147 expression is associated with an immunosuppressive TIME, characterized by increased FOXP3+ regulatory T cells and a correlation with OSM-positive cells. These results elucidate the potential mechanisms through which CD147 facilitates tumor-immune evasion, suggesting the CD147 - OSM axis as a promising target for therapeutic intervention in HCC.

BACKGROUND: An elevated peripheral blood neutrophil-to-lymphocyte ratio (NLR) has been reported to be a negative prognostic marker in many types of cancer, including pancreatic ductal adenocarcinoma (PDAC). However, whether NLR is associated with the tumor-immune microenvironment (TIME) in PDAC is unclear. Understanding the interplay between systemic inflammation as reflected by NLR and TIME in PDAC is crucial for identifying prognostic biomarkers and potential therapeutic targets. The aim of this study was to examine the relationship between the NLR and clinical outcomes in patients with early-stage PDAC and the impact of the TIME in PDAC. METHODS: We conducted a retrospective analysis including two cohorts: PDAC patients versus healthy controls and untreated stage I-II PDAC cases. We collected clinical data, including NLR values and followed PDAC patients for overall survival (OS) and relapse-free survival (RFS), and the TIME was evaluated through immunohistochemical staining for CD8+ T cells and CD33+ myeloid-derived suppressor cells (MDSCs). Statistical analyses were performed to assess the relationship between NLR, clinical outcomes, and TIME components to further determine the value of NLR in reflecting the status of the TIME and predicting outcomes of patients with PDAC. RESULTS: NLR was negatively associated with OS and RFS in patients with PDAC. Moreover, NLR was found to be a prognostic factor for PDAC and early-stage PDAC. The NLR was inversely correlated with the abundance of tumoral CD8+ T cells (r=-0.345, P=0.004) and positively correlated with that of CD33+ MDSCs (r=0.407, P=0.001). CONCLUSIONS: Our findings indicate that a high NLR value is closely correlated with poor outcomes in patients with PDAC. In addition, it was significantly associated with the presence of tumoral CD8+ tumor-infiltrating lymphocytes and CD33+ cells in the TIME of patients with PDAC. NLR may be a biomarker that can inform treat-related decision-making.

BACKGROUND: Small cell carcinoma (SmCC) of the bladder is a rare and aggressive malignancy. Characterizing transcription factor (TF)-defined subtypes may provide insights into its biology and inform targeted therapies. This study investigates lineage-specific TF expression in bladder SmCC, its association with clinicopathological features, and comparisons with prostate SmCC. METHODS: A retrospective analysis was conducted on 9 cases of bladder SmCC and 6 cases of prostate SmCC diagnosed at a single cancer hospital in Japan. Immunohistochemistry was performed for lineage-specific TFs (ASCL1, NEUROD1, POU2F3, and YAP1) and neuroendocrine and other markers. Statistical comparisons were made using Fisher's exact test and independent samples t-tests. RESULTS: Combined SmCC morphology, including urothelial carcinoma (UC) (5 cases) and adenocarcinoma (2 cases), was more frequent in bladder SmCC than in prostate SmCC (78% [7 of 9 cases] vs. 17% [1 of 6 cases], p = 0.041). NEUROD1 was more frequently expressed in bladder SmCC than in prostate SmCC (67% [6 of 9 cases] vs. 0% [0 of 6 cases]; p = 0.028). NEUROD1 expression was more frequent in combined SmCC and UC bladder tumors than in other bladder SmCC tumors (100% [5 of 5 cases] vs. 25% [1 of 4 cases], p = 0.048). Conversely, HNF4A expression was absent in all combined SmCC and UC bladder tumors (0 of 5) but present in 75% (3 of 4) of other bladder SmCC tumors (p = 0.048). In 2 cases of bladder SmCC, NEUROD1 and POU2F3 were expressed in a mutually exclusive manner, with neuroendocrine markers expressed only in the NEUROD1-expressing component. CONCLUSIONS: NEUROD1 is characteristically expressed in bladder SmCC, especially in SmCC combined with UC, suggesting a distinct phenotype from prostate SmCC. These findings highlight the potential for TF-based classification to improve diagnostic accuracy and inform therapeutic strategies.

The tumor microenvironment is highly heterogeneous and consists of neoplastic cells and diverse stromal components, including fibroblasts, endothelial cells, pericytes, immune cells, local and bone marrow-derived stromal stem and progenitor cells, and the surrounding extracellular matrix. Although the significance of p16 and p53 has been reported in various tumor types, their involvement in the stromal cells of oral squamous cell carcinoma (OSCC) remains unclear. We performed immunohistochemical analyses of p16 and p53 expression in OSCC samples, Of the 116 samples, 74 showed p16-positive stromal cells, and 33 showed p53-positive stromal cells. Both p16 and p53 positivity were associated with an increased histological grade, lymphovascular invasion, an immature stromal pattern with abundant amorphous extracellular matrix material, infiltrative invasion patterns (Yamamoto Kohama classification-4C and 4D), and poor prognosis. Multivariate analyses identified p16 and p53 positivity in the stroma as independent prognostic factors for overall survival (P = 0.032 and P = 0.020, respectively); moreover, stromal p16 positivity correlated with stromal p53 positivity. These findings indicated that p16 and p53 stroma positivity may regulate OSCC tumor aggressiveness.

BACKGROUND: Neoadjuvant therapy followed by surgery is the recommended treatment for patients with locally advanced lung cancer. No studies have examined the risk factors of postoperative pulmonary complications (PPCs) in this group of patients. The addition of immune checkpoint inhibitors (ICIs) can improve the efficacy of neoadjuvant therapy; however, it is unknown whether ICIs will also increase the PPC incidence. Thus, we conducted this study to identify the predictors of PPCs. METHODS: We reviewed the database of Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University. Patients with non-adenocarcinoma non-small cell lung cancer (non-ADC NSCLC) who underwent surgery after neoadjuvant therapy were included. The clinical information was collected, the PPCs and mortality were evaluated. RESULTS: The cohort in this study consisted of 108 patients. Among them, 36 had PPCs, and the incidence of PPCs was 33.3% (36/108). The majority of PPCs were prolonged time to chest tube removal and pneumonia. One patient died within 30 days due to serious postoperative complications. The mortality within 30 days was 0.9%. The addition of ICIs to neoadjuvant therapy did not increase the incidence of PPCs, but the operation time was longer in the ICI group. Multivariate analysis indicated that age, blood urea nitrogen (BUN) level and N2 stage may be superior predictors of PPCs. CONCLUSIONS: The addition of ICIs did not increase the incidence of PPCs but did prolong the operation time. Age, BUN level, and N2 stage were excellent predictors of PPCs in non-ADC NSCLC patients treated with surgery after neoadjuvant therapy.

Neuroendocrine carcinoma (NEC) is a rare and aggressive malignancy derived from multiple body parts, with the urogenital organs being the second-largest extrapulmonary sites. The detailed mechanism of bladder NEC pathogenesis remains unknown. We reviewed data from 23 patients diagnosed with NEC from urogenital organs (bladder and prostate) and conducted targeted sequencing of 523 cancer-related genes, focusing on bladder NEC. While 14 cases featured a pure NEC histology, the remaining nine cases included NEC histology mixed with other tumors, such as urothelial carcinoma (UC) or adenocarcinoma. Median overall survival in the entire cohort was 11.1 months, and survival curves were comparable between pure NEC and NEC of mixed appearance. Major mutations detected in the NEC component were in TP53 (38%), TERT promoter (31%), PIK3CA (25%), histone-modification genes (19%), and RB1 (19%). The BARD1 frameshift variant related to homologous recombination was also detected in one patient. More than half of the patients had a high total mutational burden (TMB; ≥10), including two with a TMB ≥45. Intriguingly, at least one identical gene variant in driver genes was detected between NEC and non-NEC (UC) components in the four bladder specimens analyzed. These results highlight the possibility of shared genetic background between bladder NEC and UC. Additionally, several cases harbored druggable gene alterations as presented by TMB-high. Our presentation of the histopathological and molecular features of NEC may help clarify the underlying mechanisms and contribute to efficient treatment of the disease.

Pheochromocytoma and paraganglioma (PPGL) are rare tumors that occur in the adrenal medulla and extra-adrenal tissues, respectively. The prognosis and tumor microenvironment (TME) of pseudohypoxic PPGL as a major entity have not been fully described. Based on the clinical database of 65 patients with PPGL, we assessed the morphological features as well as the immunohistochemistry of pseudohypoxia-related proteins (SDHB and CAIX) and TME-related immune cell markers. Furthermore, we compared the relapse-free survival (RFS) rates in localized patients between the pathological subgroups. Among 50 available specimens, 84% and 30% of the cases exhibited at least one morphological adverse feature including vascular/capsular invasion and a Ki-67 index > 3%, respectively. The SDHB and CAIX positivity rates were 81% and 51%. Concerning the immune cell markers, the CD163-positive cell numbers were higher in hypoxia-associated PPGL composed of SDHB-negative or CAIX-positive cases than in non-hypoxia PPGL (median 66 vs. 23/mm2). Concerning prognosis, RFS rates were significantly lower in cases with Ki-67 indices > 3% and SDHB-negativity than in those with Ki-67 indices ≤ 3% and SDHB-positivity (3-year rate: 64% vs. 100%, P < 0.001; 57% vs. 100%, P = 0.03). In contrast, RFS was comparable between CAIX-positive and CAIX-negative PPGL cases. Our analyses suggested that SDHB-deficient PPGL exhibited a higher incidence of relapse. Furthermore, M2 macrophage infiltration in TME might be crucial in pseudohypoxic PPGL pathogenesis.

BACKGROUND: Neoadjuvant chemo-immunotherapy has increased the number of patients with advanced lung cancer eligible for surgery. However, only a small number of such patients respond to this approach. Intensive research is being conducted to identify biomarkers to predict the efficacy of neoadjuvant chemo-immunotherapy. Among these, blood predictive biomarkers are particularly promising, and have the advantages of being both non-invasive and cost effective. This study aims to evaluate the predictive value of blood biomarkers in determining the efficacy of neoadjuvant chemo-immunotherapy for patients with non-small cell lung cancer (NSCLC), addressing a critical need for more personalized treatment strategies in clinical practice. METHODS: We retrospectively collected the data of 199 NSCLC patients who received neoadjuvant chemo-immunotherapy from January 1, 2021 to December 31, 2023, at Zhejiang Cancer Hospital. We then analyzed the performance of blood biomarkers in predicting the efficacy of neoadjuvant chemo-immunotherapy. RESULTS: The patients in the major pathological response (MPR) group had significantly higher pre-treatment squamous cell carcinoma antigen (SCCA) levels, and a significantly lower post-treatment platelet-lymphocyte ratio (PLR) than those in the non-MPR group. For patients with higher pre-treatment SCCA levels, the 1- and 2-year event-free survival (EFS) rates were 97.87% [95% confidence interval (CI): 94.99-100.00%] and 93.21% (95% CI: 84.32-100.00%), respectively. In those with lower pre-treatment SCCA levels, the 1- and 2-year EFS rates were 91.39% (95% CI: 84.93-98.35%) and 82.24% (95% CI: 72.42-93.39%), respectively. The survival analysis showed that higher pre-treatment SCCA levels were correlated with improved EFS (P=0.02) in patients receiving neoadjuvant chemo-immunotherapy. Conversely, for patients undergoing surgery alone, high pre-treatment SCCA levels were correlated with a poorer prognosis [disease-free survival (DFS), P=0.001]. These findings confirm the value of SCCA levels in predicting which patients will have a more favorable response to neoadjuvant chemo-immunotherapy. In patients receiving neoadjuvant chemo-immunotherapy, a high post-treatment PLR indicated a poorer prognosis (P=0.02). The Cox regression analysis indicated that the pre-treatment SCCA level (P=0.04) and post-treatment PLR (P=0.04) were independent predictive factors of EFS. CONCLUSIONS: In patients receiving neoadjuvant chemo-immunotherapy, high pre-treatment SCCA levels and low post-treatment PLRs were significantly associated with better efficacy and survival. Thus, these biomarkers could be used to guide the choice of treatment modalities.

Colibactin, a genotoxin produced by Escherichia coli strains harboring the polyketide synthetase (pks) gene cluster, causes DNA damage and somatic mutations. pks+E. coli is enriched in primary colorectal cancer (CRC) and is associated with clonal driver mutations, but its role in CRC liver metastasis is unclear. We assessed the association of pks+ E. coli in CRC liver metastasis tissues with systemic and local immune responses and the number of organs involved in recurrence using specimens and clinicopathological data from 239 patients with CRC liver metastasis who underwent metastasectomy. The levels of pks+E. coli in fresh-frozen specimens were quantified as "very low" (<50th percentile), "low" (50th to 75th percentiles), and "high" (>75th percentile) using a digital PCR. Immunohistochemical analysis of tumor-infiltrating immune cells was performed using tissue microarrays. Systemic inflammation was evaluated using serum C-reactive protein (CRP) levels. pks+E. coli was detected in 66.7% (157 of 239) liver metastasis tissues. Higher levels of pks+E. coli were associated with decreased serum CRP levels and reduced densities of CD4+ cells and CD163+ cells in the tumor-immune microenvironment. The "high" pks+ E. coli group had fewer metastatic organs involved than the "very low" pks+ E. coli group (mean number of organs: 1.00 vs. 1.23). These findings suggest that pks+E. coli play a modulating role in CRC metastasis.

The presence of Fusobacterium nucleatum is associated with an immunosuppressive tumor immune microenvironment (TIM) in primary colorectal cancer (CRC), contributing to tumor progression. Its persistence in CRC liver metastasis tissues raises questions about its role in modulating local and systemic immune responses and influencing recurrence patterns. This retrospective cohort study of 218 patients with CRC liver metastasis investigated the association of F. nucleatum in CRC liver metastasis tissues with systemic inflammation, TIM alterations, and the number of metastatic organs involved in recurrence. Two-step polymerase chain reaction (PCR), including digital PCR, detected F. nucleatum in 42% (92/218) of fresh-frozen specimens of CRC liver metastases. Compared with the F. nucleatum-none group, the F. nucleatum-high group showed higher C-reactive protein levels (0.82 vs. 0.22 mg/dL; Ptrend = 0.02), lower numbers of CD8+ cells (33.2 vs. 65.3 cells/mm2; Ptrend = 0.04) and FOXP3+ cells (11.3 vs. 21.7 cells/mm2; Ptrend = 0.01) in the TIM, and a greater number of metastatic organs involved in recurrence (1.6 vs. 1.1; p < 0.001). The presence of F. nucleatum in CRC liver metastasis tissues was associated with increased systemic inflammation, TIM alterations, and a greater number of metastatic organs involved in recurrence. These findings suggest a potential contribution of F. nucleatum to the metastatic propensity of CRC cells and could inform future research to enhance understanding of the interaction between tumor, host, and microbes in the metastatic process.

BACKGROUND AND OBJECTIVE: Lactic acid is a metabolite of glycolysis produced in the body, and its production is thought to be a mechanism by which cancer cells evade immune surveillance. Immune evasion and metabolic changes are well established as basic hallmarks of cancer. Although lactate has long been considered a waste product, it is now generally recognized to be a versatile small-molecule chemical that plays an important part in the tumor microenvironment (TME), with increased lactate production linked to the development of human malignancies. Metabolism in liver cancer is redirected toward glycolysis, which enhances the production of metabolic compounds used by tumor cells to produce proteins, lipids, and nucleotides, enabling them to maintain high proliferation rates and to establish the TME. Dysregulation of metabolic activity in liver cancer may impair antitumor responses owing to the immunosuppressive activity of the lactate produced by anaerobic glycolytic rates in tumor cells. This review primarily explores the link connection between lactic acid and the TME; evaluates the role of lactic acid in the occurrence, metastasis, prognosis, and treatment of liver cancer. Additionally, it investigates the associated pathways as potential targets for liver cancer treatment. METHODS: Literature searches were conducted in PubMed, Web of Science, and Google Scholar, with the publication date of the most recent article included being January 2024. After eliminating duplicate articles and less relevant articles through titles and abstracts, we selected 113 articles for this review. We categorized references into two categories. One is to classify the content into lactate-related, liver cancer-related and tumor metabolism-related. The other is to classify the article types, which are divided into reviews, research articles and clinical trials. Additionally, we consulted the reference lists of the relevant articles to ensure coverage was comprehensive and unbiased. KEY CONTENT AND FINDINGS: The connection between lactic acid and the TME has recently become an area of intense research interest, and many related articles have been published in this field. The main finding of this review is to summarize the proven link between lactate and the TME and its possible impact on the TME of liver cancer. And analyzed the potential of lactate in liver cancer treatment and prognosis prediction. CONCLUSIONS: Lactate may be key to developing novel approaches in the future treatment of liver cancer. Related research on the combination of classic therapies and molecular targeted drugs may provide innovative medicines that more selectively regulate immune cell activity.

INTRODUCTION: NUT carcinoma is a rare cancer associated with a poor prognosis. Because of its rarity, its diagnosis is challenging and is usually made by excluding other diagnoses. Immunohistochemical analysis is a reliable technique that contributes to a correct diagnosis, but overestimating the expression of neuroendocrine (NE) markers may result in an incorrect diagnosis. In this study, we established the immunohistochemical phenotypes of NUT carcinoma compared with tumors that mimic its phenotype to identify potential diagnostic pitfalls. METHODS: Eight cases of NUT carcinoma were examined along with eight basaloid squamous cell carcinomas and thirteen cases of small cell carcinoma using an immunohistochemical panel consisting of various antibodies. RESULTS: Of the eight NUT carcinomas, three patients had a smoking history. All the cases examined for INSM1 were positive (6/6, 100%), although the staining was somewhat weak. Among the NE markers, synaptophysin was variably positive in two NUT carcinomas (2/6, 33%); however, all cases were negative for ASCL1, chromogranin A, and CD56. Moreover, the squamous cell markers, p40 and CK5/6, were weakly expressed in 4/6 (67%) and 3/6 (50%) of the NUT carcinomas, respectively. CONCLUSIONS: For tumors with an ambiguous morphology, applying the neuroendocrine phenotype of NUT carcinoma may be misleading; particularly, when distinguishing it from small-cell carcinoma. Similarly, null or weak expression of squamous cell markers may be observed in NUT carcinoma, but this differs from squamous cell carcinoma, which consistently demonstrates strong positivity for squamous cell markers.

Inverted urothelial papilloma (IUP) is a benign neoplasm characterized by a downgrowth of the urothelium beneath the surface of morphologically normal urothelial cells; however, the molecular features of IUP and their association with clinicopathological characteristics are unclear. In this study, we aimed to investigate the mutational landscape, clinicopathological features, genotype-phenotype associations, and spread patterns of IUP. We performed targeted next-generation sequencing of 39 consecutive IUP cases, the largest series investigated to date, and identified oncogenic driver mutations in RAS family genes in 34 cases (87%). HRAS mutations were the most prevalent (28 cases), which included Q61R (15 cases), followed by KRAS (5 cases) and NRAS (1 case) mutations. Characteristic mutations observed in urothelial carcinoma, including those in FGFR3, TP53, or the TERT promoter, were absent. HRAS-mutated IUPs were associated with a history of smoking (P = 0.017) and streaming morphology (P < 0.001), corresponding to the trabecular subtype. In contrast, all KRAS-mutated IUPs occurred in never-smoking patients (P = 0.001) and showed cystic changes in morphology (P = 0.005), corresponding to the glandular subtype. RAS Q61R immunohistochemistry visually revealed the neoplastic nature of the overlying cells and distinct spread patterns of IUP cells within the surface, including pseudoinfiltrative spread. No recurrence or carcinoma development was observed in any of the IUP cases during the follow-up period. Thus, we confirmed the importance of RAS pathway activation in IUP pathogenesis, an association between RAS family gene mutations and IUP subtypes, and the spread patterns of IUP cells within the surface.

AIM: Vessels encapsulating tumor clusters (VETC) represents an adverse prognostic morphological feature of hepatocellular carcinoma (HCC), which is associated with an immunosuppressive tumor immune microenvironment (TIM). However, the underlying factors characterizing the TIM in HCC with a VETC pattern (VETC-positive HCC) remain uncertain. Oncostatin M (OSM), a pleiotropic cytokine of the interleukin-6 family, regulates various biological processes, including inflammation, proliferation, and invasiveness of tumor cells. We aimed to test a hypothesis that OSM is associated with the immunosuppressive TIM of VETC-positive HCC. METHODS: A total of 397 consecutive HCC patients with curative-intent hepatectomy were included. OSM-positive cells and inflammatory cells including CD4-, CD8-, CD163-, and FOXP3-positive cells were immunohistochemically evaluated. We compared VETC-positive and VETC-negative HCCs in terms of the number of these cells. RESULTS: We found the VETC pattern in 62 patients (15.6%). Our analysis revealed a significant decrease in the expression of arginase-1, a marker associated with mature hepatocyte differentiation, in VETC-positive HCC (p = 0.046). The number of tumor-infiltrating OSM-positive cells was significantly low in VETC-positive HCC (p = 0.0057). Notably, in VETC-positive HCC, the number of OSM-positive cells was not associated with vascular invasion, whereas in VETC-negative HCC, an increase in the number of OSM-positive cells was associated with vascular invasion (p = 0.042). CONCLUSIONS: We identified an association between a decrease in OSM-positive cells and the VETC pattern. Additionally, our findings indicate that VETC-positive HCC is characterized by low hepatocyte differentiation and OSM-independent vascular invasion. These findings highlight the potential interaction between VETC-positive HCC cells and their TIM through the reduction of OSM-expressing cells.

INTRODUCTION: Recently, perioperative use of immune checkpoint inhibitors has improved the prognosis of muscle-invasive bladder cancer. It is unclear whether radical cystectomy or systemic pembrolizumab is the optimal next treatment in patients with muscle-invasive bladder cancer and progressive disease in the pelvic lymph node following neoadjuvant chemotherapy (NAC). CASE PRESENTATION: A 62-year-old woman with cT3N0M0 bladder cancer and high programmed death-ligand 1 expression developed solitary obturator lymph node metastasis following 5 cycles of neoadjuvant chemotherapy. Six subsequent cycles of pembrolizumab shrank the lymph node significantly, and conversion radical cystectomy was planned. Pathologically, only carcinoma in situ around the scar of transurethral resection of bladder tumor remained in the primary tumor, and the accumulation of foamy macrophages and fibrosis without viable tumor cells was observed in the dissected lymph node. Eighteen months passed without a recurrence following radical cystectomy. CONCLUSION: Pembrolizumab administration before radical cystectomy achieved a good response in a patient with obturator lymph node metastasis following neoadjuvant chemotherapy.

Female urethral adenocarcinoma has attracted attention as a rare tumor type based on its differential pathogenesis from its male counterpart. However, to date, our knowledge concerning its immunohistochemical and morphological characteristics remains limited due to the small number of cases studied. In this study, nine consecutive cases of female urethral adenocarcinoma were used for immunohistochemical and morphological characterization of the tumor based on semi-comprehensive immunohistochemical analysis and detailed morphological evaluations. Our immunohistochemical assay revealed two subtypes of female urethral adenocarcinoma with distinctive staining patterns: the CDX2- and PAX8-expressing subtypes. The former stained positive for other intestinal markers (e.g., HNF4α and TFF1) as well (7 of 7 cases); the latter stained negative for these intestinal markers (0 of 2 cases) but stained positive for clear cell carcinoma markers (e.g., Napsin A and HNF1β) (2 of 2 cases). Regarding cytokeratins, the former displayed a CK7- and CK20-positive immunoprofile (7 of 7 cases); the latter exhibited a CK7-positive and CK20-negative immunoprofile (2 of 2 cases). Morphologically, CDX2- and PAX8-expressing subtypes resembled intestinal-type adenocarcinoma and clear cell carcinoma (occurring in gynecological organs), respectively. The semi-comprehensive immunoprofiling data presented in this study can potentially contribute to the correct diagnosis of this rare tumor type. Finally, our study represents an important basis for future investigations aiming to further elucidate the details and origin of female urethral adenocarcinoma, and it can potentially contribute to developing diagnostic and therapeutic strategies for treating this malignancy.

Hepatocellular carcinomas (HCCs) with biliary/progenitor cell features frequently show increased programmed death-ligand 1 (PD-L1) expression, but their response to immunotherapy is not high. One possible explanation for this phenomenon could be the loss of major histocompatibility complex (MHC) class I expression on tumor cells, which impairs the presentation of tumor antigens to cytotoxic T cells. However, the potential correlation between MHC class I loss, biliary/progenitor cell features, and the tumor-immune microenvironment remains largely unexplored. Herein, we hypothesized that MHC class I loss could be associated with biliary/progenitor cell features and potentially impact the tumor-immune microenvironment. To evaluate this hypothesis and gain insight into the characteristics of tumor cells and the tumor-immune microenvironment in HCCs with MHC class I loss, we examined a consecutive series of 397 HCC cases. MHC class I loss was observed in 32 HCCs (8.1%). Lipid-less cytologic morphology was significantly associated with MHC class I loss (P = 0.02). CK19 expression and decreased ARG1 expression, both known as biliary/progenitor cell features, were significantly associated with MHC class I loss (P < 0.05). PD-L1 expression was irrelevant to the MHC class I status. HCCs with MHC class I loss exhibited significantly lower infiltration of CD8+, CD4+, CD20+, and FOXP3+ cells than those with intact MHC class I (all Ps < 0.01). Our study reveals an association between MHC class I loss, biliary/progenitor cell features, and a "cold" tumor-immune microenvironment in HCCs. These insights highlight the potential impact of MHC class I loss on tumor cells and the tumor-immune microenvironment.

The microbiota is widely recognized to influence diverse biological processes, including metabolism, neurological and cardiovascular functions, the inflammatory response and immunity [...].

INTRODUCTION: In Lynch syndrome, urothelial cancer is the third most common cancer, following colorectal and endometrial cancers. Little is known, however, about the efficacy of immune checkpoint inhibitors in the treatment of metastatic urothelial cancer in Lynch syndrome. CASE PRESENTATION: A 49-year-old patient with metastatic urothelial cancer underwent pembrolizumab therapy after platinum-containing chemotherapy. The efficacy of the pembrolizumab therapy was good. Her lung and bone metastatic lesions disappeared in imaging studies and her back pain decreased dramatically. Pathogenic mutations of MSH2 and BRCA2 were found in the DNA extracted from her tumor, and subsequent genetic analysis confirmed the germline pathogenic variant of MSH2. As such, this case was genetically diagnosed as Lynch syndrome. CONCLUSION: We report metastatic urothelial cancer in a patient with Lynch syndrome who demonstrated a radiological complete response to pembrolizumab therapy. Accurate genetic diagnosis can provide useful information to both the patient and their relatives.

INTRODUCTION: Prostatic large-cell neuroendocrine carcinoma is poorly studied. Although several case reports are available, information on the clinicopathological characteristics of this disease is limited, particularly for the de novo (hormone-naive) type. Herein, we report an extremely rare de novo case of this disease with a good prognosis despite a multi-metastatic status. CASE PRESENTATION: An 83-year-old male patient presented with a high serum prostate-specific antigen level and was found to have de novo prostatic large-cell neuroendocrine carcinoma with an adenocarcinoma component upon pathological examination. Diagnosed with stage pT4cN1cM1c, he underwent chemo-hormonal therapy using a luteinizing hormone-releasing hormone antagonist and combined etoposide and cisplatin, which achieved a partial response. The patient has survived for 20 months without progression. CONCLUSION: Although prostatic large-cell neuroendocrine carcinoma is known for its aggressive clinical behavior, the de novo type with an adenocarcinoma component may be sensitive to hormonal therapy and achieve a good prognosis.

The incidence of non-alcoholic non-virus-related hepatocellular carcinoma (NANV-HCC) is increasing along with the growing prevalence of metabolic disorders. In this subset, few useful biomarkers are available to narrow down the high-risk group for recurrence. This study aimed to evaluate the prognostic impact of decreased ARG1 (arginase-1), which is pathologically known as a marker reflecting hepatocyte differentiation, in NANV-HCC. Besides, its relationship with biliary/progenitor cell markers, whose expressions are associated with poor prognosis, was also assessed. To reveal the clinicopathological association of decreased ARG1 expression in NANV-HCC, we investigated 99 patients who underwent curative-intent hepatectomy for NANV-HCC. Tissue microarrays were employed for immunohistochemical analysis. A total of 21 NANV-HCC cases (21%; 21/99) showed decreased ARG1 expression. Decreased ARG1 expression was an independent prognostic factor for both poor DFS (hazard ratio 2.17; 95% confidence interval 1.15-4.09; p = 0.02) and OS (hazard ratio 4.09; 95% confidence interval 1.71-9.80; p = 0.002). In addition, decreased ARG1 expression was significantly associated with expressions of biliary/progenitor cell markers, CK19 and CD56 (p < 0.01). As cytologic features of tumor cells, decreased ARG1 expression was significantly associated with lipid-less cytologic morphology (p = 0.045). These findings indicate that decreased ARG1 expression is a predictive phenotype of postoperative recurrence with poor prognosis in patients with NANV-HCC. Decreased ARG1 expression may be a precursor or overlapping feature with biliary/progenitor cell marker expressions in NANV-HCC.

Cancer is generally regarded as a localised disease, with the well-established role of the tumour microenvironment. However, the realm of cancer goes beyond the tumour microenvironment, and cancer should also be regarded as a systemic and environmental disease. The exposome (ie, the totality of exposures), which encompasses diets, supplements, smoking, alcohol, other lifestyle factors, medications, etc, likely alters the microbiome (inclusive of bacteria, viruses, archaea, fungi, parasites, etc) and immune system in various body sites and influences tumour phenotypes. The systemic metabolic/inflammatory status, which is likely influenced by exposures and intestinal physiological changes, may affect tissue microenvironment of colorectum and any other organs. Germline genomic factors can modify disease phenotypes via gene-by-environment interactions. Although challenges exist, it is crucial to advance not only basic experimental research that can analyse the effects of exposures, microorganisms and microenvironmental components on tumour evolution but also interdisciplinary human population research that can dissect the complex pathogenic roles of the exposome, microbiome and immunome. Metagenomic, metatranscriptomic and metabolomic analyses should be integrated into well-designed population research combined with advanced methodologies of artificial intelligence and molecular pathological epidemiology. Ideally, a prospective cohort study design that enables biospecimen (such as stool) collection before disease detection should be considered to address reverse causation and recall biases. Robust experimental and observational research together can provide insights into dynamic interactions between environmental exposures, microbiota, tumour and immunity during carcinogenesis processes, thereby helping us develop precision prevention and therapeutic strategies to ultimately reduce the cancer burden.

BACKGROUND: Understanding the gene alteration status of primary lung cancers is important for determining treatment strategies, but gene testing is both time-consuming and costly, limiting its application in clinical practice. Here, potential therapeutic targets were selected by predicting gene alterations in cytologic specimens before conventional gene testing. METHODS: This was a retrospective study to develop a cytologic image-based gene alteration prediction model for primary lung cancer. Photomicroscopic images of cytology samples were collected and image patches were generated for analyses. Cancer-positive (n = 106) and cancer-negative (n = 32) samples were used to develop a neural network model for selecting cancer-positive images. Cancer-positive cases were randomly assigned to training (n = 77) and validation (n = 26) data sets. Another neural network model was developed to classify cancer images of the training data set into 4 groups: anaplastic lymphoma kinase (ALK)-fusion, epidermal growth factor receptor (EGFR), or Kirsten rat sarcoma viral oncogene homologue (KRAS) mutated groups, and other (None group), and images of the validation data set were classified. A decision algorithm to predict gene alteration for cases with 3 probability ranks was developed. RESULTS: The accuracy and precision for selecting cancer-positive patches were 0.945 and 0.991, respectively. Predictive accuracy for the EGFR and KRAS groups in the validation data set was ~0.95, whereas that for the ALK and None groups was ~0.75 and ~ 0.80, respectively. Gene status was correctly predicted in the probability rank A cases. The model extracted characteristic conventional cytologic findings in images and a novel specific feature was discovered for the EGFR group. CONCLUSIONS: A gene alteration prediction model for lung cancers by machine learning based on cytologic images was successfully developed.

BACKGROUND&AIMS: Immunotherapy has become the standard-of-care treatment for hepatocellular carcinoma (HCC), but its efficacy remains limited. To identify immunotherapy-susceptible HCC, we profiled the molecular abnormalities and tumor immune microenvironment (TIME) of rapidly increasing nonviral HCC. APPROACHES&RESULTS: We performed RNA-seq of tumor tissues in 113 nonviral HCC patients and cancer genome sequencing of 69 genes with recurrent genetic alterations reported in HCC. Unsupervised hierarchical clustering classified nonviral HCCs into 3 molecular classes (Class I, II, III), which stratified patient prognosis. Class I, with the poorest prognosis, was associated with TP53 mutations, whereas class III, with the best prognosis, was associated with CTNNB1 mutations. Thirty-eight percent of nonviral HCC was defined as an immune class characterized by a high frequency of intratumoral steatosis and a low frequency of CTNNB1 mutations. Steatotic HCC, which accounts for 23% of nonviral HCC cases, presented an immune-enriched but immune-exhausted TIME characterized by T-cell exhaustion, M2 macrophage and cancer-associated fibroblast (CAF) infiltration, high PD-L1 expression, and TGF-β signaling activation. Spatial transcriptome analysis suggested that M2 macrophages and CAFs may be in close proximity to exhausted CD8+ T cells in steatotic HCC. An in vitro study showed that palmitic acid-induced lipid accumulation in HCC cells upregulated PD-L1 expression and promoted immunosuppressive phenotypes of cocultured macrophages and fibroblasts. Steatotic HCC patients, confirmed by chemical-shift MR imaging, had significantly longer PFS with combined immunotherapy using anti-PD-L1 and anti-VEGF antibodies. CONCLUSIONS: Multiomics stratified nonviral HCCs according to prognosis or TIME. We identified the link between intratumoral steatosis and immune-exhausted immunotherapy-susceptible TIME.