Phase II trial of niraparib for BRCA-mutated biliary tract, pancreatic and other gastrointestinal cancers: NIR-B.

Due to the widespread use of cancer genetic testing in gastrointestinal cancer, the BRCA1/2 genetic mutation has been identified in biliary tract cancer as well as pancreatic cancer. Niraparib is a poly(ADP-ribose) polymerase (PARP) inhibitor, and PARP inhibitors exert their cytotoxicity against cancer cells in the context of homologous recombination deficiency, such as BRCA mutations, via the mechanism of synthetic lethality. The aim of this phase II NIR-B trial is to evaluate the efficacy and safety of niraparib for patients with unresectable advanced or recurrent biliary tract cancer, pancreatic cancer or other gastrointestinal cancers with germline or somatic BRCA1/2 mutations revealed by genetic testing. The primary end point is an investigator-assessed objective response rate in each cohort. Clinical Trial Registration: jRCT2011200023 (ClinicalTrials.gov).

BRCA gene is involved in repairing DNA injury and plays an important role in cancer growth. Cells with a mutation in the BRCA gene cannot repair DNA using a method called homologous recombination repair. Niraparib is part of a class of drugs called 'PARP inhibitors' that inhibit enzymes called 'PARP' involved in repairing DNA injury, and has shown efficacy against cancers with BRCA gene mutations. BRCA gene mutations are infrequent but have been found in a variety of cancers. The NIR-B trial is a clinical trial to evaluate the efficacy and safety of niraparib for people with advanced biliary tract, pancreatic and other abdominal cancers with BRCA gene mutations.

Influence of epicardial adipose tissue inflammation and adipocyte size on postoperative atrial fibrillation in patients after cardiovascular surgery.

Epicardial adipose tissue (EAT) is an active endocrine organ that is closely associated with occurrence of atrial fibrillation (AF). However, the role of EAT in the development of postoperative AF (POAF) remains unclear. We aimed to investigate the association between EAT profile and POAF occurrence in patients who underwent cardiovascular surgery. We obtained EAT samples from 53 patients to evaluate gene expression, histological changes, mitochondrial oxidative phosphorylation (OXPHOS) capacity in the EAT, and protein secretion in EAT-conditioned medium. EAT volume was measured using computed tomography scan. Eighteen patients (34%) experienced POAF within 7 days after surgery. Although no significant difference was observed in EAT profile between patients with and without POAF, logistic regression analysis identified that the mRNA expression levels of tumor necrosis factor-alpha (TNF-α) were positively correlated and adipocyte size in the EAT was inversely correlated with onset of POAF, respectively. Mitochondrial OXPHOS capacity in the EAT was not associated with POAF occurrence; however, it showed an inverse correlation with adipocyte size and a positive correlation with adiponectin secretion. In conclusion, changes in the secretory profile and adipocyte morphology of the EAT, which represent qualitative aspects of the adipose tissue, were present before the onset of AF.

Concurrent targeting of GSK3 and MEK as a therapeutic strategy to treat pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide. However, drug discovery for PDAC treatment has proven complicated, leading to stagnant therapeutic outcomes. Here, we identify Glycogen synthase kinase 3 (GSK3) as a therapeutic target through a whole-body genetic screening utilizing a '4-hit' Drosophila model mimicking the PDAC genotype. Reducing the gene dosage of GSK3 in a whole-body manner or knocking down GSK3 specifically in transformed cells suppressed 4-hit fly lethality, similar to Mitogen-activated protein kinase kinase (MEK), the therapeutic target in PDAC we have recently reported. Consistently, a combination of the GSK3 inhibitor CHIR99021 and the MEK inhibitor trametinib suppressed the phosphorylation of Polo-like kinase 1 (PLK1) as well as the growth of orthotopic human PDAC xenografts in mice. Additionally, reducing PLK1 genetically in 4-hit flies rescued their lethality. Our results reveal a therapeutic vulnerability in PDAC that offers a treatment opportunity for patients by inhibiting multiple targets.

Polymorphisms of the PD-L1 gene 3'-untranslated region are associated with the expression of PD-L1 in non-small cell lung cancer.

Recent results show that polymorphisms of programmed death ligand 1 (PD-L1, also known as CD274 or B7-H1) might be used as a possible marker for effectiveness of chemotherapy and cancer risk. However, the effect of PD-L1 gene variations on PD-L1 expression remain unclear. Given the post-transcriptional machinery in tumor PD-L1 expression, we investigated single nucleotide polymorphisms (SNPs) in the 3'-untranslated region (3'-UTR) of the PD-L1 gene, rs4143815 and rs4742098, using formalin-fixed paraffin-embedded sections of 154 patients with non-small cell lung cancers (NSCLCs). In rs4143815, the GG genotype showed significant association with PD-L1 expression (P = 0.032). In rs4742098, the AA genotype was significantly associated with histology and PD-L1 expression (P = 0.022 and P = 0.008, respectively). In multivariate logistic regression analysis, the AA genotype in rs4742098 was correlated with PD-L1 expression (odds ratio 0.408, P = 0.048). Interestingly, approximately 10% of the NSCLC cases showed somatic mutation when we compared genotypes of these SNPs between NSCLC tissues and non-tumor tissues from the same patients. In addition, cases with somatic mutation showed higher levels of PD-L1 expression than cases with germline mutation in rs4143815 GG. In conclusion, we demonstrated that the rs4143815 and rs4742098 SNPs in the 3'-UTR of PD-L1 were associated with tumor PD-L1 expression in NSCLCs.

Impact of the quality of resected thyroid cancer tissue sample on next-generation sequencing testing.

Activating rearranged during transfection (RET) proto-oncogene alterations can be identified using next-generation sequencing (NGS) of tumor DNA/RNA. We assessed factors associated with NGS (Oncomine Dx Target Test [ODxTT]) success for resected thyroid cancer (TC) specimens, including sample age, processing conditions, and DNA/RNA quality. TC samples were from three Japanese hospitals, with sample age <1-<10 years, fixative 10%/15% neutralized buffered formalin (NBF), and fixation time ≤48 h/>48 h-≤72 h. NGS success rate was defined as the percentage of samples returning validated NGS results (RET fusion-positive/negative [RNA] or RET mutation-positive/negative [DNA], detected using ODxTT). DNA/RNA quality was assessed with indexes based on electrophoresis (DNA/RNA integrity number, DV200 ) and quantitative polymerase chain reaction (DNA/RNA integrity score [ddCq/ΔCq]). NGS success rate (N = 202) was 90%/93% (DNA/RNA) overall, 98%-100% (DNA and RNA) for samples <3 years old, and 91% (DNA and RNA) for samples ≥3-<5 years old fixed in 10% NBF for ≤48 h. Multivariate logistic regression analysis identified ddCq and ΔCq as significant predictors of DNA and RNA NGS success rates, respectively. Quality assessment of nucleic acid extracted from archival tissue samples is important for achieving high NGS success rates in clinical practice, especially for samples ≥3 years old.

Targeted next-generation sequencing of Japanese patients with sinonasal mucosal melanomas identifies frequent NRAS and CTNNB1 mutations.

OBJECTIVE: Mucosal melanoma is a rare malignancy; however, the reported incidence rate of mucosal melanoma is higher in Asians than in Caucasians. Sinonasal mucosal melanoma (SNMM) is an aggressive malignancy with a poor prognosis due to distant metastasis. Systemic therapy with BRAF inhibitor and MEK inhibitor is one of the standards of care for cutaneous melanoma patients with BRAF V600 mutations. However, no molecular targeted therapy for patients with mucosal melanoma has been established. Relatively few studies have described the genetic mutations associated with mucosal melanoma because of its low frequency. Furthermore, to the best of our knowledge, the genetic mutations among Japanese patients have not been reported. Therefore, in the current study, we evaluated the genetic and clinicopathological characteristics of patients with SNMM. METHODS: A total of 18 tissue samples obtained from patients with SNMM were analyzed for genetic mutations based on targeted next-generation sequencing to investigate the driver of tumorigenesis and/or candidate genes for predicting clinical outcomes in SNMM. We also performed immunohistochemistry for patients identified with CTNNB1 mutations. RESULTS: Eight of the 18 (44 %) patients had genetic mutations. The most frequent mutation was NRAS (6/18, 33 %), followed by CTNNB1 (2/18, 11 %) and BRAF (1/18, 5.6 %). One patient had both NRAS and CTNNB1 mutations. Clinical outcomes did not differ significantly between those with and without genetic mutations. NRAS mutations were associated with relatively higher T classification and worse survival rates, although the differences were not significant. The nuclear translocation of ß-catenin was detected in both tumors with CTNNB1 mutations. The amino acid change in the BRAF mutation was K601R in exon 15. In the current study, no BRAF V600 mutations were detected. CONCLUSION: Genetic mutations were not significantly associated with clinical outcomes. However, NRAS mutations may be a prognostic predictor and CTNNB1 mutation may be a treatment effector for immune check inhibitors. A larger prospective study is required to clarify the clinical importance of genetic mutations in patients with SNMM.

Expression Analysis of Early Metastatic Seeding of Colorectal Cancer.

BACKGROUND: Distant metastasis is the leading cause of death in patients with colorectal cancer (CRC). Tumor dissemination for metastasis formation occurs in advanced cancers and also during early stages of tumorigenesis. Here, we investigated the genes involved in early metastatic seeding of CRC using gene expression analysis. PATIENTS AND METHODS: We performed a cDNA microarray using specimens resected from stages I-II CRC with and without metachronous metastatic recurrence. For the candidate genes, we immunohistochemically validated protein expression using a tissue microarray of stages I-III CRC. RESULTS: The expression of TROP2, VWCE, and BMP7 was upregulated in the recurrence group rather than in the non-recurrence group. Protein expression analysis revealed significant association of these genes with distant metastatic recurrence. The specimens with high expression of BMP7 showed worse recurrence-free survival (RFS; p = 0.02). Those with high expression of TROP2 and VWCE showed worse overall survival (OS) and RFS (TROP2: p = 0.01 and p = 0.03; VWCE: p < 0.05 and p < 0.001, respectively). In the multivariate analysis, high expression of VWCE and BMP7 was an independent predictor of recurrence [VWCE: hazard ratio (HR) 3.41, p < 0.001; BMP7: HR 2.93, p = 0.005]. In contrast, TROP2 was an independent prognostic factor for OS (HR 4.58, p = 0.03). CONCLUSIONS: Gene expression analysis revealed that TROP2, VWCE, and BMP7 were involved in early metastatic seeding. The high expression of these genes may warrant careful surveillance or adjuvant therapy, even in stages I-II CRC cases.

Impact of Neutrophil Extracellular Traps Identified by Citrullinated Histone H3 Immunohistochemistry for Postoperative Prognosis in Patients with Extrahepatic Cholangiocarcinomas.

BACKGROUND: Neutrophil extracellular traps (NETs) are extracellular chromatin structures composed of cytoplasmic, granular, and nuclear components of neutrophils. Recently, NETs have received much attention for their role in tumor biology; however, their impact on the postoperative prognosis of patients with extrahepatic cholangiocarcinomas (EHCCs) remains unclear. The purpose of this study was to clarify the impact of NETs identified by immunohistochemical citrullinated histone H3 (Cit-H3) staining on postoperative overall survival (OS) in patients with perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC). METHODS: This study included 318 patients with EHCC (PHCC, n = 192; DCC, n = 126) who underwent surgical resection with curative intent. Neutrophils and NETs were identified by immunohistochemistry using antibodies against CD15 and Cit-H3, respectively. Based on the distribution of CD15 and Cit-H3 expression in the tumor bed, the patients were classified into four groups: one negative group and three subgroups of the positive group (diffuse, intermediate, and focal subgroups). RESULTS: No significant difference was found in the postoperative OS rate depending on the distribution of CD15 expression in patients with PHCC or DCC. However, the three subgroups with positive Cit-H3 expression had significantly poorer OS than the negative group for both PHCC and DCC. Moreover, positive Cit-H3 was an independent OS factor in the multivariable analyses of PHCC (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.11-2.59, P = 0.0115) and DCC (HR 2.03; 95% CI 1.21-3.42, P = 0.0057). CONCLUSIONS: The presence of NETs in the tumor microenvironment may have adverse prognostic effects in patients with EHCCs.

Clinical practice guidelines for molecular tumor markers, 2nd edition review part 1.

With advances in gene and protein analysis technologies, many target molecules that may be useful in cancer diagnosis have been reported. Therefore, the "Tumor Marker Study Group" was established in 1981 with the aim of "discovering clinically" useful molecules. Later, the name was changed to "Japanese Society for Molecular Tumor Marker Research" in 2000 in response to the remarkable progress in gene-related research. Currently, the world of cancer treatment is shifting from the era of representative tumor markers of each cancer type used for tumor diagnosis and treatment evaluation to the study of companion markers for molecular-targeted therapeutics that target cancer cells. Therefore, the first edition of the Molecular Tumor Marker Guidelines, which summarizes tumor markers and companion markers in each cancer type, was published in 2016. After publication of the first edition, the gene panel testing using next-generation sequencing became available in Japan in June 2019 for insured patients. In addition, immune checkpoint inhibitors have been indicated for a wide range of cancer types. Therefore, the 2nd edition of the Molecular Tumor Marker Guidelines was published in September 2021 to address the need to revise the guidelines. Here, we present an English version of the review (Part 1) of the Molecular Tumor Marker Guidelines, Second Edition.

Exhaustion, rather than lack of infiltration and persistence, of CAR-T cells hampers the efficacy of CAR-T therapy in an orthotopic PDAC xenograft model.

Chimeric antigen receptor T-cell (CAR-T) therapy has demonstrated impressive success in the treatment of patients with hematologic tumors yet achieved very limited efficacy for solid tumors due to hurdles unique to solid tumors. It is also noted that the tumor microenvironment composition varies between tumor type, which again imposes unique set of hurdles in each solid tumor. Therefore, elucidation of individual hurdles is key to achieving successful CAR-T therapy for solid tumors. In the present study, we employed an orthotopic human PDAC xenograft model, in which quantitative, spatial and functional dynamics of CAR-T cells in tumor tissues were analyzed to obtain insights into ways of overcoming PDAC related hurdles. Contrary to previous studies that demonstrated a limited persistency and infiltration of CAR-T cells in many solid tumors, they persist and accumulated in PDAC tumor tissues. Ex vivo analysis revealed that CAR-T cells that had been recovered at different time points from mice bearing an orthotopic PDAC tumor exhibited a gradual loss of tumor reactivity. This loss of tumor reactivity of CAR-T cells was associated with the increased expression of AMP-activated protein kinase and Mitofusin 1/ Dynamin-related protein 1 ratio.

Targeted next-generation sequencing for detection of PIK3CA mutations in archival tissues from patients with Klippel-Trenaunay syndrome in an Asian population : List the full names and institutional addresses for all authors.

BACKGROUND: Klippel-Trenaunay syndrome (KTS) is a rare slow-flow combined vascular malformation with limb hypertrophy. KTS is thought to lie on the PIK3CA-related overgrowth spectrum, but reports are limited. PIK3CA encodes p110α, a catalytic subunit of phosphatidylinositol 3-kinase (PI3K) that plays an essential role in the PI3K/AKT/mammalian target of rapamycin (mTOR) signaling pathway. We aimed to demonstrate the clinical utility of targeted next-generation sequencing (NGS) in identifying PIK3CA mosaicism in archival formalin-fixed paraffin-embedded (FFPE) tissues from patients with KTS. RESULTS: Participants were 9 female and 5 male patients with KTS diagnosed as capillaro-venous malformation (CVM) or capillaro-lymphatico-venous malformation (CLVM). Median age at resection was 14 years (range, 5-57 years). Median archival period before DNA extraction from FFPE tissues was 5.4 years (range, 3-7 years). NGS-based sequencing of PIK3CA achieved an amplicon mean coverage of 119,000x. PIK3CA missense mutations were found in 12 of 14 patients (85.7%; 6/8 CVM and 6/6 CLVM), with 8 patients showing the hotspot variants E542K, E545K, H1047R, and H1047L. The non-hotspot PIK3CA variants C420R, Q546K, and Q546R were identified in 4 patients. Overall, the mean variant allele frequency for identified PIK3CA variants was 6.9% (range, 1.6-17.4%). All patients with geographic capillary malformation, histopathological lymphatic malformation or macrodactyly of the foot had PIK3CA variants. No genotype-phenotype association between hotspot and non-hotspot PIK3CA variants was found. Histologically, the vessels and adipose tissues of the lesions showed phosphorylation of the proteins in the PI3K/AKT/mTOR signaling pathway, including p-AKT, p-mTOR, and p-4EBP1. CONCLUSIONS: The PI3K/AKT/mTOR pathway in mesenchymal tissues was activated in patients with KTS. Amplicon-based targeted NGS could identify low-level mosaicism from low-input DNA extracted from FFPE tissues, potentially providing a diagnostic option for personalized medicine with inhibitors of the PI3K/AKT/mTOR signaling pathway.

Postoperative Prognosis According to Pathologic Categorization of Desmoplastic Reaction in Patients with Extrahepatic Cholangiocarcinoma.

BACKGROUND: Recent studies have demonstrated the importance of desmoplastic reaction (DR) in predicting postoperative prognosis for patients with colorectal carcinoma. However, the impact of DR on the prognosis of extrahepatic cholangiocarcinomas (EHCCs) is not established. This study aimed to clarify the associations of pathologic DR categories with clinicopathologic factors and postoperative prognosis of perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC). METHODS: A pathologic review of 174 patients with PHCC and 109 patients with DCC who underwent surgical resection was performed. The patients were classified into three DR categories (immature, intermediate, and mature) based on the histologic features within the fibrotic stroma in the invasive front. The association between DR categories and the distribution of fibroblasts with anti-α-smooth muscle actin (SMA) expression, seeming to be tumor-promoting cancer-associated fibroblasts (CAFs), was evaluated in 191 tissue microarray specimens of EHCCs. RESULTS: Intermediate/immature DR categories were significantly associated with a more invasive nature, including higher pT and pN stages and more tumor buds than the mature category in both PHCC and DCC. The DR categories could stratify overall survival (OS) and relapse-free survival (RFS) in both PHCC and DCC patients. In the multivariate analysis, the DR category was an independent prognostic factor for OS and RFS in both PHCC and DCC (p < 0.001). The mature and immature DR categories were significantly associated respectively with the confined and pervasive distribution of fibroblasts with α-SMA expression. CONCLUSION: In patients with EHCCs, DR categorization was an independent prognostic factor reflecting the distribution of tumor-promoting CAFs in the invasive front.

Drosophila Screening Identifies Dual Inhibition of MEK and AURKB as an Effective Therapy for Pancreatic Ductal Adenocarcinoma.

Significant progress has been made in understanding the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) by generating and using murine models. To accelerate drug discovery by identifying novel therapeutic targets on a systemic level, here we generated a Drosophila model mimicking the genetic signature in PDAC (KRAS, TP53, CDKN2A, and SMAD4 alterations), which is associated with the worst prognosis in patients. The '4-hit' flies displayed epithelial transformation and decreased survival. Comprehensive genetic screening of their entire kinome revealed kinases including MEK and AURKB as therapeutic targets. Consistently, a combination of the MEK inhibitor trametinib and the AURKB inhibitor BI-831266 suppressed the growth of human PDAC xenografts in mice. In patients with PDAC, the activity of AURKB was associated with poor prognosis. This fly-based platform provides an efficient whole-body approach that complements current methods for identifying therapeutic targets in PDAC. SIGNIFICANCE: Development of a Drosophila model mimicking genetic alterations in human pancreatic ductal adenocarcinoma provides a tool for genetic screening that identifies MEK and AURKB inhibition as a potential treatment strategy.

Deep fibrous histiocytoma of the index finger: a case report.

Our patient presented with an elastic soft mass of his left index finger. Hematoxylin and eosin staining showed a high cellular density with spindle-shaped cells in a storiform pattern. Immunohistochemical staining was positive for CD68, factor XIIIa and α-smooth muscle actin, and negative for CD34, STAT6, S100 protein, and desmin.

Assessment for the timing of comprehensive genomic profiling tests in patients with advanced solid cancers.

Comprehensive genomic profiling (CGP) tests have been covered by public insurance in Japan for patients with advanced solid tumors who have completed or are completing standard treatments or do not have them. Therefore, genotype-matched drug candidates are often unapproved or off-label, and improving clinical trial access is critical, involving the appropriate timing of CGP tests. To address this issue, we analyzed the previous treatment data for 441 patients from an observational study on CGP tests discussed by the expert panel at Hokkaido University Hospital between August 2019 and May 2021. The median number of previous treatment lines was two; three or more lines accounted for 49%. Information on genotype-matched therapies was provided to 277 (63%). Genotype-matched clinical trials were ineligible because of an excess number of previous treatment lines or use of specific agents were found in 66 (15%) patients, with the highest proportion in breast and prostate cancers. Many patients met the exclusion criteria of one to two or more treatment lines across cancer types. In addition, previous use of specific agents was a frequent exclusion criterion for breast, prostate, colorectal, and ovarian cancers. The patients with tumor types with a low median number (two or fewer) of previous treatment lines, including most rare cancers, primary unknown cancers, and pancreatic cancers, had significantly fewer ineligible clinical trials. The earlier timing of CGP tests may improve access to genotype-matched clinical trials, with their proportion varying by cancer type. Each relevant society needs to advocate the desirable timing of CGP testing nationwide.

CCR7 Mediates Cell Invasion and Migration in Extrahepatic Cholangiocarcinoma by Inducing Epithelial-Mesenchymal Transition.

The epithelial-mesenchymal transition (EMT) contributes to the metastatic cascade in various tumors. C-C chemokine receptor 7 (CCR7) interacts with its ligand, chemokine (C-C motif) ligand 19 (CCL19), to promote EMT. However, the association between EMT and CCR7 in extrahepatic cholangiocarcinoma (EHCC) remains unknown. This study aimed to elucidate the prognostic impact of CCR7 expression and its association with clinicopathological features and EMT in EHCC. The association between CCR7 expression and clinicopathological features and EMT status was examined via the immunohistochemical staining of tumor sections from 181 patients with perihilar cholangiocarcinoma. This association was then investigated in TFK-1 and EGI-1 EHCC cell lines. High-grade CCR7 expression was significantly associated with a large number of tumor buds, low E-cadherin expression, and poor overall survival. TFK-1 showed CCR7 expression, and Western blotting revealed E-cadherin downregulation and vimentin upregulation in response to CCL19 treatment. The wound healing and Transwell invasion assays revealed that the activation of CCR7 by CCL19 enhanced the migration and invasion of TFK-1 cells, which were abrogated by a CCR7 antagonist. These results suggest that a high CCR7 expression is associated with an adverse postoperative prognosis via EMT induction and that CCR7 may be a potential target for adjuvant therapy in EHCC.

Programmed death ligand 1-positive immune cells in primary tumor or metastatic axillary lymph nodes can predict prognosis of triple-negative breast cancer even when present at < 1% in the tumor region.

BACKGROUND: The efficacy of pre-operative systemic treatment (PST) combined with immune checkpoint inhibition (ICI) for triple-negative breast cancer (TNBC) has been recognized recently as being independent of the degree of programmed death ligand-1 (PD-L1) positivity of infiltrating immune cells, especially for patients with axillary lymph node metastasis (ALNM). METHODS: TNBC patients with ALNM were treated surgically between 2002 and 2016 in our facility (n = 109), of whom 38 received PST before resection. The presence of tumor-infiltrating lymphocytes (TILs) expressing CD3, CD8, CD68, PD-L1 (detected by antibody SP142) and FOXP3 at primary and metastatic LN sites was quantified. RESULTS: The size of invasive tumor and the number of metastatic axillary LN were confirmed as prognostic markers. The numbers of both CD8+ and FOXP3+ TILs at primary sites were also recognized as prognostic markers, especially for overall survival (OS) (CD8, p = 0.026; FOXP3, p < 0.001). The presence of CD8+, FOXP3+ and PD-L1+ cells was better maintained in LN after PST and may contribute to improved antitumor immunity. Provided they were present as clusters of ≥ 70 positive cells, even < 1% of immune cells expressing PD-L1 at primary sites predicted a more favorable prognosis for both disease-free survival (DFS) (p = 0.004) and OS (p = 0.020). This was the case not only for 30 matched surgical patients, but also in all 71 surgical only patients (DFS: p < 0.001 and OS: p = 0.002). CONCLUSIONS: PD-L1+ , CD8+ or FOXP3+ immune cells in the tumor microenvironment (TME) at both primary and metastatic sites are significant on prognosis, which could be a clue to expect the potential for better responses to the combination of chemotherapy and ICI, especially for patients with ALNM.

Tumor Growth Suppression of Pancreatic Cancer Orthotopic Xenograft Model by CEA-Targeting CAR-T Cells.

Chimeric antigen receptor engineered T cell (CAR-T) therapy has high therapeutic efficacy against blood cancers, but it has not shown satisfactory results in solid tumors. Therefore, we examined the therapeutic effect of CAR-T therapy targeting carcinoembryonic antigen (CEA) in pancreatic adenocarcinoma (PDAC). CEA expression levels on the cell membranes of various PDAC cell lines were evaluated using flow cytometry and the cells were divided into high, medium, and low expression groups. The relationship between CEA expression level and the antitumor effect of anti-CEA-CAR-T was evaluated using a functional assay for various PDAC cell lines; a significant correlation was observed between CEA expression level and the antitumor effect. We created orthotopic PDAC xenograft mouse models and injected with anti-CEA-CAR-T; only the cell line with high CEA expression exhibited a significant therapeutic effect. Thus, the therapeutic effect of CAR-T therapy was related to the target antigen expression level, and the further retrospective analysis of pathological findings from PDAC patients showed a correlation between the intensity of CEA immunostaining and tumor heterogeneity. Therefore, CEA expression levels in biopsies or surgical specimens can be clinically used as biomarkers to select PDAC patients for anti-CAR-T therapy.