Two Cases of Disseminated Alveolar Echinococcosis: The Diagnosis, Management, and Differential Considerations for Liver Lesions

Alveolar echinococcosis (AE), caused by Echinococcus multilocularis, is an aggressive and potentially critical infestation that primarily affects the liver and can metastasize to any part of the body. We herein report two cases of echinococcosis, which could be differentiated from malignancy on imaging studies, with infections of the liver and mediastinal lymph nodes, and also associated with systemic disseminated lesions. AE is a very invasive infectious disease, and in order to detect such lesions at an early stage when they are still resectable, it is necessary to understand the characteristic imaging findings and determine the patient's current medical history.

Impact of Surgical Margin Status on Survival and Recurrence After Pancreaticoduodenectomy for Distal Cholangiocarcinoma: Is Microscopic Residual Tumor (R1) Associated with Higher Rates of Local Recurrence?

BACKGROUND

Patients undergoing macroscopically curative resection for distal cholangiocarcinoma (DCC) have high recurrence rates and poor prognoses. This study aimed to investigate the impact of surgical margin status on survival and recurrence after resection of DCC, specifically focusing on microscopic residual tumor (R1) and its relationship to local recurrence.

PATIENTS AND METHODS

This was a retrospective analysis of patients who had undergone pancreaticoduodenectomy (PD) for DCC between 2005 and 2021. Surgical margin was classified as R0, R1cis (positive bile duct margin with carcinoma in situ), and R1inv (positive bile duct margin with an invasive subepithelial component and/or positive radial margin).

RESULTS

In total, 29 of 133 patients (21.8%) had R1cis and 23 (17.3%) R1inv. The 5-year overall survival (OS) for R0 (55.7%) did not differ significantly from that for R1cis/R1inv (47.4%/33.6%, respectively). The 5-year recurrence-free survival (RFS) for R0 was significantly longer than that for R1inv (50.1% vs. 17.4%, p = 0.003), whereas RFS did not differ significantly between those with R0 and R1cis. R1cis/R1inv status was not an independent predictor of OS and RFS in multivariate analysis. Cumulative incidence of isolated distant recurrence was significantly higher for R1cis/R1inv than for R0 (p = 0.0343/p = 0.0226, respectively), whereas surgical margin status was not significantly associated with rates of local or local plus distant recurrence.

CONCLUSIONS

Surgical margin status does not significantly impact OS and RFS in patients undergoing PD for DCC following precise preoperative imaging evaluation. Additionally, R1 status is significantly linked to higher isolated distant recurrence rather than local recurrence, highlighting the importance of multidisciplinary therapy.

Clinicopathological Findings and Treatment Outcomes of Patients with Primary Hepatobiliary Neuroendocrine Neoplasms: A Retrospective Single-institution Analysis

Objective Primary hepatobiliary neuroendocrine neoplasms (NENs) are rare tumors exhibiting several morphological and behavioral characteristics. Considering the lack of relevant data on this topic, we evaluated the clinicopathological features and treatment outcomes of patients with primary hepatobiliary NENs. Methods/Patients We examined 43 consecutive patients treated at the National Cancer Center Hospital with pathological diagnoses of primary hepatobiliary NEN between 1980 and 2016. Results Nine patients were diagnosed with neuroendocrine tumor (NET) G1, 9 with NET G2, and 25 with neuroendocrine carcinoma (NEC) based on the World Health Organization 2019 classification. Patients with NEC had primary sites across the hepatobiliary organs, although sites in patients with NET G1 and NET G2 only included the liver and ampulla of Vater. Patients with primary extrahepatic bile duct or ampulla of Vater NENs tended to be diagnosed earlier than patients with primary gallbladder NENs. The median survival times in the NET G1, NET G2, and NEC groups were 167.9, 97.4, and 11.1 months, respectively. A good performance status, absence of distant metastases, and low tumor grade were identified as independent predictors of a favorable prognosis. Conclusion The NET-to-NEC ratio and tumor stage distribution at the diagnosis differed depending on the primary site. Patients with G1 and G2 NETs who underwent surgical resection had good prognoses, whereas those with NEC exhibited more advanced disease and poorer prognoses. The performance status, staging classification, and tumor grade are important factors to consider when devising an appropriate treatment strategy and predicting the prognoses of patients with primary hepatobiliary NEN.

The impact of rare cancer and early-line treatments on the benefit of comprehensive genome profiling-based precision oncology

BACKGROUND

Comprehensive genome profiling (CGP) serves as a guide for suitable genomically matched therapies for patients with cancer. However, little is known about the impact of the timing and types of cancer on the therapeutic benefit of CGP.

MATERIALS AND METHODS

A single hospital-based pan-cancer prospective study (TOP-GEAR; UMIN000011141) was conducted to examine the benefit of CGP with respect to the timing and types of cancer. Patients with advanced solid tumors (>30 types) who either progressed with or without standard treatments were genotyped using a single CGP test. The subjects were followed up for a median duration of 590 days to examine therapeutic response, using progression-free survival (PFS), PFS ratio, and factors associated with therapeutic response.

RESULTS

Among the 507 patients, 62 (12.2%) received matched therapies with an overall response rate (ORR) of 32.3%. The PFS ratios (≥1.3) were observed in 46.3% (19/41) of the evaluated patients. The proportion of subjects receiving such therapies in the rare cancer cohort was lower than that in the non-rare cancer cohort (9.6% and 17.4%, respectively; P = 0.010). However, ORR of the rare cancer patients was higher than that in the non-rare cancer cohort (43.8% and 20.0%, respectively; P = 0.046). Moreover, ORR of matched therapies in the first or second line after receiving the CGP test was higher than that in the third or later lines (62.5% and 21.7%, respectively; P = 0.003). Rare cancer and early-line treatment were significantly and independently associated with ORR of matched therapies in multivariable analysis (P = 0.017 and 0.004, respectively).

CONCLUSION

Patients with rare cancer preferentially benefited from tumor mutation profiling by increasing the chances of therapeutic response to matched therapies. Early-line treatments after profiling increase the therapeutic benefit, irrespective of tumor types.

Molecular subtypes of lung adenocarcinoma present distinct immune tumor microenvironments

Overcoming resistance to immune checkpoint inhibitors is an important issue in patients with non-small-cell lung cancer (NSCLC). Transcriptome analysis shows that adenocarcinoma can be divided into three molecular subtypes: terminal respiratory unit (TRU), proximal proliferative (PP), and proximal inflammatory (PI), and squamous cell carcinoma (LUSQ) into four. However, the immunological characteristics of these subtypes are not fully understood. In this study, we investigated the immune landscape of NSCLC tissues in molecular subtypes using a multi-omics dataset, including tumor-infiltrating leukocytes (TILs) analyzed using flow cytometry, RNA sequences, whole exome sequences, metabolomic analysis, and clinicopathologic findings. In the PI subtype, the number of TILs increased and the immune response in the tumor microenvironment (TME) was activated, as indicated by high levels of tertiary lymphoid structures, and high cytotoxic marker levels. Patient prognosis was worse in the PP subtype than in other adenocarcinoma subtypes. Glucose transporter 1 (GLUT1) expression levels were upregulated and lactate accumulated in the TME of the PP subtype. This could lead to the formation of an immunosuppressive TME, including the inactivation of antigen-presenting cells. The TRU subtype had low biological malignancy and "cold" tumor-immune phenotypes. Squamous cell carcinoma (LUSQ) did not show distinct immunological characteristics in its respective subtypes. Elucidation of the immune characteristics of molecular subtypes could lead to the development of personalized immune therapy for lung cancer. Immune checkpoint inhibitors could be an effective treatment for the PI subtype. Glycolysis is a potential target for converting an immunosuppressive TME into an antitumorigenic TME in the PP subtype.

DNA methylation alterations of ADCY5, MICAL2, and PLEKHG2 during the developmental stage of cryptogenic hepatocellular carcinoma

AIM

The aim of this study was to clarify the significance of DNA methylation alterations of cryptogenic hepatocellular carcinomas (HCCs).

METHODS

Using the Infinium assay, we performed genome-wide DNA methylation analysis of 250 liver tissue samples, including noncancerous liver tissue (U-N) and corresponding cancerous tissue (U-T) from patients with cryptogenic HCC without a history of excessive alcohol use and hepatitis virus infection, and whose U-N samples showed no remarkable histological features (no microscopic evidence of simple steatosis, any form of hepatitis including nonalcoholic steatohepatitis, or liver cirrhosis).

RESULTS

We identified 3272 probes that showed significant differences of DNA methylation levels between U-N and normal liver tissue samples from patients without HCC, indicating that a distinct DNA methylation profile had already been established at the precancerous U-N stage. U-Ns have a DNA methylation profile differing from that of noncancerous liver tissue of patients with nonalcoholic steatohepatitis-related, viral hepatitis-related, and alcoholic liver disease-related HCCs. Such DNA methylation alterations in U-Ns were inherited by U-Ts. The U-Ns showed DNA methylation alteration of ADCY5, resulting in alteration of its mRNA expression, whereas noncancerous liver tissue of patients with nonalcoholic steatohepatitis-, viral hepatitis-, or alcoholic liver disease-related HCCs did not. DNA methylation levels of MICAL2 and PLEKHG2 in U-Ts were correlated with larger tumor diameter and portal vein involvement, respectively.

CONCLUSIONS

U-N-specific DNA hypermethylation of ADCY5 may have significance, even from the precancerous stage in liver showing no remarkable histological features. DNA hypomethylation of MICAL2 and PLEKHG2 may determine the clinicopathological features of cryptogenic HCC.

Pathological complete response of initially unresectable multiple liver metastases achieved using combined peptide receptor radionuclide therapy and somatostatin analogs following pancreatic neuroendocrine tumor resection: a case report

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) serves as a novel and effective treatment option for somatostatin receptor-positive unresectable liver metastases of pancreatic neuroendocrine tumors (PNETs). However, there are few reported cases of surgical resection for initially unresectable liver metastases of PNET that were converted to resectable after PRRT. Here we report a case where PRRT and somatostatin analogs (SSAs) led to a pathological complete response of initially unresectable multiple liver metastases following PNET resection.

CASE PRESENTATION

A 52-year-old man underwent pylorus-preserving pancreaticoduodenectomy for PNET at age 40 and subsequent hepatectomies for resectable liver metastases at 44 and 47 years of age. At age 48, a follow-up examination revealed unresectable multiple liver metastases, and PRRT with 177Lu-DOTATATE therapy was initiated. After four cycles of PRRT, most liver metastases diminished according to imaging studies, and the remaining two hepatic lesions continued to shrink with additional lanreotide. Conversion surgery for liver metastases was successfully performed, revealing no viable tumor cells in tissue specimens. Seventeen months after surgery, imaging showed no detectable residual tumor or recurrence. We present a review of the relevant literature that highlights the significance of our findings.

CONCLUSIONS

This rare case highlights the pathological complete response of initially unresectable multiple liver metastases achieved by PRRT and SSAs following PNET resection, suggesting their potential as a multimodality treatment option for unresectable PNET.

Correlation of Vein-Rich Tumor Microenvironment of Intrahepatic Cholangiocarcinoma With Tertiary Lymphoid Structures and Patient Outcome

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive cancer composed of large-duct and small-duct types. Understanding the tumor immune microenvironment and its related vascular system is important for developing novel and efficient therapies. We focused on tertiary lymphoid structure (TLS) as a hallmark of antitumor immunity and investigated the clinicopathologic significance of TLSs and the influence of vascular microenvironment on TLS formation in iCCAs. We examined 261 iCCA cases clinicopathologically and analyzed the vascular system using immunohistochemistry. Single-cell (102,685 cells) and bulk RNA (33 iCCA cases) sequencing analyses were performed using data sets downloaded from public databases, and endothelial cell characteristics in iCCA tissues and functional networks related to the tumor microenvironment were bioinformatically examined. High densities of both intratumoral and peritumoral TLSs were significantly associated with prolonged survival only in large-duct-type iCCA. Multivariate analyses showed that peritumoral TLS was a prognostic factor for the large-duct type. TLS-rich iCCA had a significantly higher vein density and tumor-infiltrating T-cell count than TLS-poor iCCA. Both the presence of TLSs and high vein endothelial cells in iCCA tissues were significantly associated with molecular networks representing active immune responses in transcriptomic analysis. Vein density was a prognostic factor in patients with large-duct and small-duct types. This suggests that TLS formation is involved in a microenvironment with high vein density, which represents an antitumor-directed immune microenvironment.

Novel insights into the intraepithelial spread of extrahepatic cholangiocarcinoma: clinicopathological study of 382 cases on extrahepatic cholangiocarcinoma

Background

Extrahepatic cholangiocarcinoma (eCCA) is a rare and aggressive disease and consisted of conventional eCCA and intraductal papillary neoplasm of the bile duct (IPNB). Intraepithelial spread (IES) of cancer cells beyond the invasive area is often observed in IPNBs; however, the prevalence of IES remains to be examined in conventional eCCAs. Here, we evaluated the clinicopathological features of eCCAs according to tumor location, with a focus on the presence of IES. The IES extension was also compared among biliary tract cancers (BTCs).

Methods

We examined the prevalence and clinicopathological significance of IES in eCCAs (n=382) and the IES extension of BTCs, including gallbladder (n=172), cystic duct (n=20), and ampullary cancers (n=102).

Results

Among the invasive eCCAs, IPNB had a higher rate of IES (89.2%) than conventional eCCAs (57.0%). Among conventional eCCAs, distal eCCAs (75.4%) had a significantly higher prevalence of IES than perihilar eCCAs (41.3%). The presence of IES was associated with a significantly higher survival rate in patients with distal eCCAs (P=0.030). Extension of the IES into the cystic duct (CyD) in distal eCCAs that cancer cells reached the junction of the CyD was a favorable prognostic factor (P<0.001). The association of survival with IES, either on the extrahepatic bile duct or on the CyD, differed depending on the tumor location and type of eCCA. The extension properties of IES were also dependent on different types of tumors among BTCs; usually, the IES incidence became higher than 50% in the tissues that the tumor developed, whereas IES extension to other tissues decreased the incidence.

Conclusion

Thus, eCCAs have different clinicopathological characteristics depending on the tumor location and type.

Efficacy of endoscopic ultrasound-guided tissue acquisition for solid pancreatic lesions 20 mm or less in diameter suspected as neuroendocrine tumors or requiring differentiation

BACKGROUND

For non-functioning pancreatic neuroendocrine tumors (pNETs) ≤ 20 mm, most guidelines consider follow-up observations as an option; however, the various treatment strategies are defined by size alone, even though the Ki-67 index is important for malignancy grading. Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is the standard for the histopathological diagnosis of solid pancreatic lesions; however, recent results for small lesions remain unclear. Therefore, we examined the efficacy of EUS-TA for solid pancreatic lesions ≤ 20 mm suspected as pNETs or requiring differentiation and the non-increase rate in tumor size in follow-up cases.

METHODS

We retrospectively analyzed data of 111 patients (median age = 58 years) with lesions ≤ 20 mm suspected as pNETs or requiring differentiation who underwent EUS-TA. All patients underwent specimen evaluation by rapid onsite evaluation (ROSE).

RESULTS

EUS-TA led to a diagnosis of pNETs in 77 patients (69.4%) and tumors other than pNETs in 22 patients (19.8%). The histopathological diagnostic accuracy of EUS-TA was 89.2% (99/111) overall, 94.3% (50/53) for 10-20 mm lesions, and 84.5% (49/58) for ≤ 10 mm lesions, with no significant difference in diagnostic accuracy (p = 0.13). The Ki-67 index was measurable in all patients with a histopathological diagnosis of pNETs. Among 49 patients with a diagnosis of pNETs who were followed up, one patient (2.0%) showed tumor enlargement.

CONCLUSIONS

EUS-TA for solid pancreatic lesions ≤ 20 mm suspected as pNETs or requiring differentiation is safe and has adequate histopathological diagnostic accuracy, suggesting that follow-up observations of pNETs with a histological pathologic diagnosis are acceptable in the short term.

Tumor-infiltrating Leukocyte Profiling Defines Three Immune Subtypes of NSCLC with Distinct Signaling Pathways and Genetic Alterations

Resistance to immune checkpoint blockade remains challenging in patients with non-small cell lung cancer (NSCLC). Tumor-infiltrating leukocyte (TIL) quantity, composition, and activation status profoundly influence responsiveness to cancer immunotherapy. This study examined the immune landscape in the NSCLC tumor microenvironment by analyzing TIL profiles of 281 fresh resected NSCLC tissues. Unsupervised clustering based on numbers and percentages of 30 TIL types classified adenocarcinoma (LUAD) and squamous cell carcinoma (LUSQ) into the cold, myeloid cell-dominant, and CD8⁺ T cell-dominant subtypes. These were significantly correlated with patient prognosis; the myeloid cell subtype had worse outcomes than the others. Integrated genomic and transcriptomic analyses, including RNA sequencing, whole-exome sequencing, T-cell receptor repertoire, and metabolomics of tumor tissue, revealed that immune reaction-related signaling pathways were inactivated, while the glycolysis and K-ras signaling pathways activated in LUAD and LUSQ myeloid cell subtypes. Cases with ALK and ROS1 fusion genes were enriched in the LUAD myeloid subtype, and the frequency of TERT copy-number variations was higher in LUSQ myeloid subtype than in the others. These classifications of NSCLC based on TIL status may be useful for developing personalized immune therapies for NSCLC.

Significance

The precise TIL profiling classified NSCLC into novel three immune subtypes that correlates with patient outcome, identifying subtype-specific molecular pathways and genomic alterations that should play important roles in constructing subtype-specific immune tumor microenvironments. These classifications of NSCLC based on TIL status are useful for developing personalized immune therapies for NSCLC.

Effect of systemic inflammatory response on induction chemotherapy followed by chemoradiotherapy for locally advanced pancreatic cancer: an exploratory subgroup analysis on systemic inflammatory response in JCOG1106

OBJECTIVE

JCOG1106, a randomized phase II trial conducted to compare chemoradiotherapy (S-1 concurrent radiotherapy) with (Arm B) or without (Arm A) induction chemotherapy using gemcitabine in patients with locally advanced pancreatic cancer, showed a more favorable long-term survival in Arm A. This study was aimed at exploring whether some subgroups classified by the systemic inflammatory response might derive greater benefit from either treatment.

METHODS

All subjects eligible for JCOG1106 were included in this analysis (n = 51/49 in Arm A/B). This exploratory subgroup analysis was performed by Cox regression analysis to investigate the impact of the systemic inflammatory response, as assessed based on the serum C-reactive protein, serum albumin (albumin), Glasgow Prognostic Score and derived neutrophil-lymphocyte ratio, at the baseline on overall survival. P values <0.1 for the interaction were regarded as denoting significant association.

RESULTS

Glasgow prognostic score showed significant treatment interactions for overall survival. Hazard ratios of Arm B to Arm A were 1.35 (95% confidence interval, 0.82-2.23) in the Glasgow Prognostic Score 0 (C-reactive protein ≤10 mg/L and albumin ≥35 g/L) (n = 44/34 in Arm A/B) and 0.59 (95% confidence interval, 0.24-1.50) in the Glasgow Prognostic Score 1/2 (C-reactive protein >10 mg/L and/or albumin <35 g/L) (n = 7/15) (P-interaction = 0.06). C-reactive protein alone and albumin alone also showed significant treatment interactions for overall survival.

CONCLUSIONS

Survival benefits of induction chemotherapy in chemoradiotherapy for locally advanced pancreatic cancer were observed in patients with elevated Glasgow Prognostic Score, high C-reactive protein and low albumin. These results suggest that systemic inflammatory response might be considered to apply induction chemotherapy preceding chemoradiotherapy.

Novel Insights Into Immunohistochemical Analysis For Acinar Cell Neoplasm of The Pancreas: Carboxypeptidase A2, Carboxypeptidase A1, and Glycoprotein 2

Acinar cell carcinoma (ACC) is a rare and highly malignant pancreatic tumor. Owing to histologic similarity, ACC is often difficult to distinguish from other solid medullary pancreatic tumors, particularly neuroendocrine neoplasm (NEN) and intraductal tubulopapillary neoplasm (ITPN). We aimed to identify new immunohistochemical markers commonly expressed in tumor cells with acinar cell differentiation and useful for both surgical and small biopsy specimens. Candidate molecules exclusively expressed in neoplastic or non-neoplastic acinar cells in pancreatic tissues with specific and available antibodies suitable for immunohistochemistry were selected. We selected carboxypeptidase A1 (CPA1), carboxypeptidase A2 (CPA2), and glycoprotein 2 (GP2), which were expressed in 100%, 100%, and 96% of cases, respectively, in ACC (n=27) or neoplasia with acinar cell differentiation, including mixed acinar-neuroendocrine carcinoma (n=9), mixed acinar-ductal carcinoma (n=3), pancreatoblastoma (n=4), and acinar cystic transformation (n=2), in the cytoplasm of tumor cells with a granular pattern. Both CPA2 and CPA1 were not expressed in any other tumors without acinar cell differentiation, including NEN (n=44), pancreatic ductal adenocarcinoma (n=44), and ITPN (n=4). GP2 was not expressed in these tumors except in rare cases, including 14% of NEN, 15% of intraductal papillary-mucinous neoplasm, 25% of intraductal oncocytic papillary neoplasm, 25% of ITPN, and 7% of pancreatic ductal adenocarcinoma, wherein a small proportion of tumor cells expressed GP2 in their apical cell membrane. NEN cases also showed cytoplasmic GP2 expression. Therefore, CPA2, CPA1, and potentially GP2 may act as ACC markers.

Development of a novel co-culture system using human pancreatic cancer cells and human iPSC-derived stellate cells to mimic the characteristics of pancreatic ductal adenocarcinoma in vitro

Pancreatic ductal adenocarcinoma (PDAC) is a serious disease with poor prognosis and prone to chemotherapy resistance. It is speculated that the tumor microenvironment (TME) of PDAC contributes to these characteristics. However, the detailed mechanisms of interactions between pancreatic cancer cells and stroma in the TME are unclear. Therefore, the aim of this study was to establish a co-culture system that mimics the TME, using cancer cells derived from PDAC patient specimens and stellate cells from human induced pluripotent stem cells as stromal cells. We succeeded in observing the interaction between cancer cells and stellate cells and reproduced some features of PDAC in vitro using our co-culture systems. In addition, we demonstrated the applicability of our co-culture system for drug treatment in vitro. To conclude, we propose our co-culture system as a novel method to analyze cell-cell interactions, especially in the TME of PDAC.

Unusually strong electronic correlation and field-induced ordered phase in YbCo2

We report the first study of electrical resistivity, magnetization, and specific heat on YbCo₂. The measurements on a single-phased sample of YbCo₂bring no evidence of magnetic ordering down to 0.3 K in a zero magnetic field. The manifestations of low Kondo temperature are observed. The specific heat value divided by temperature,C/T, keeps increasing logarithmically beyond 7 J/mol K²with decreasing temperature down to 0.3 K without no sign of magnetic ordering, suggesting a very large electronic specific heat. Analysis of the magnetic specific heat indicates that the large portion of the low-temperature specific heat is not explained simply by the low Kondo temperature but is due to the strong intersite magnetic correlation in both the 3dand 4felectrons. Temperature-dependent measurements under static magnetic fields up to 7 T are carried out, which show the evolution of field-induced transition above 2 T. The transition temperature increases with increasing field, pointing to a ferromagnetic character. The extrapolation of the transition temperature to zero field suggests that YbCo₂is in the very proximity of the quantum critical point. These results indicate that in the unique case of YbCo₂, the itinerant electron magnetism of Co 3d-electrons and the Kondo effect within the vicinity of quantum criticality of Yb 4f-local moments can both play a role.

Abstract 4484: HER3 expression after systemic therapy and clinical characteristics in patients with hepatocellular carcinoma

Background: In hepatocellular carcinoma (HCC), several standard regimens with angiogenesis inhibitors and immune checkpoint inhibitors have been established; however, novel therapeutic strategies to target key molecules associated with HCC are further required to improve treatment options. ErbB3 (HER3), a member of the HER receptor tyrosine kinase family, has recently emerged as a promising therapeutic target in various cancers. In this study, HER3 expression status after current targeted therapies in HCC was evaluated in order to explore an opportunity for developing anti-HER3 therapy for HCC.

Methods: We collected clinical data and tumor tissue from HCC patients (pts) who received systemic therapy between January 2010 and June 2020 and the tissue samples at post systemic therapy were also obtained. Immunohistochemical staining for HER3 was conducted using HER3/ErbB3 (D22C5) XP Rabbit mAb (Cell Signaling Technology) as a primary antibody. IHC scoring (0, 1+, 2+, 3+) of membranous staining intensity was performed according to HER2 IHC gastric scoring guideline.

Results: Seventeen pts were eligible. Eight pts (47%) were HER3 2+/3+, (2+: 7, 3+: 1,), while nine pts (53%) were 0/1+ (0: 4, 1+: 5). For HER3 2+/3+ and HER3 0/1+ groups, median age (range) was 63(43-71)/69(47-78), median alpha-fetoprotein levels were 6071(4-23620)/19.1(1.2-1138) [ng/ml], and median des-gamma-carboxy prothrombin levels were 1351(135-92650)/302(10-10916) [mAU/ml], respectively. The proportions of patients with HER3 2+/3+ were 67% in HCV+ pts, 25% in HBV+ pts, and 43% in other etiologies. Median overall survival of HER3 2+/3+ and 0/1+ pts after start of first line systemic therapy was 32.3 (95% CI: 8.7-51.4) and 12.9 (95% CI: 6.1-20.7) months, respectively (HR: 0.28, 95% CI: 0.09-0.92, p=0.036).Paired pre- and post-treatment samples were available for eight pts. The median number of regimens administered between the pre- and post-treatment samples was 2(1-5). Treatment regimens were sorafenib: 7; lenvatinib: 2; ramucirumab: 1; others: 10, including duplicates. At post-treatment, HER3 was upregulated in 4 pts (1 pt: 0 to 1+, 3 pts: 1+ to 2+) and downregulated in 3 pts (all pts: 1+ to 0). Pts with HER3 upregulation had developed resistance after at least one prior tyrosine kinase inhibitor (TKI) with stable disease or partial response as best response.

Conclusion: In this study, 47% of pts were HER3 2+/3+ at post-treatment. In paired analysis, half of pts upregulated HER3 expression after systemic therapy including TKIs, suggesting HER3 might be one of the factors associated with resistance to systemic therapy.

Citation Format: Mao Okada, Chigusa Morizane, Tomoyuki Satake, Mariko Nishioka, Nobuyoshi Hiraoka, Satoshi Nara, Tomoya Kakegawa, Maki Kobayashi, Kumiko Koyama, Minoru Esaki, Takuji Okusaka. HER3 expression after systemic therapy and clinical characteristics in patients with hepatocellular carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4484.

Fine-needle biopsy with 19G needle is effective in combination with endoscopic ultrasound-guided tissue acquisition for genomic profiling of unresectable pancreatic cancer

OBJECTIVES

Comprehensive genomic profiling (CGP) has been approved in Japan since June 2019, enabling mutation-specific therapy. Although tissue sampling via endoscopic ultrasound-guided tissue acquisition (EUS-TA) is standard in pancreatic cancer, reports on obtaining appropriate samples for CGP, especially for the OncoGuide NCC Oncopanel System (NOP) and FoundationOne CDx (FOne), are lacking. Therefore, we investigated the success rate and factors related to appropriate EUS-TA sampling for CGP analysis suitability in unresectable pancreatic ductal adenocarcinoma (UR-PDAC).

METHODS

Participants comprised 150 UR-PDAC patients who underwent EUS-TA and tumor sample evaluation for CGP analysis suitability between June 2019 and December 2021. The proportion of patients meeting the criteria was evaluated considering tumor size, puncture lesion, presence of metastasis, type and size of puncture needle, suction method, number of punctures, and puncture route.

RESULTS

In total, 39.2% (60/153) of samples met NOP analysis suitability criteria and 0% met FOne analysis suitability criteria. The suitability rate was significantly higher with 19G fine-needle biopsy (FNB) (56.0%; 42/75) than with 22G FNB (32.6%; 14/43) and 22G fine-needle aspiration (11.4%; 4/35). Nineteen-gauge needle (odds ratio [OR] 2.53; 95% confidence interval [CI] 1.15-5.57; P = 0.021) and FNB (OR 3.57; 95% CI 1.05-12.20; P = 0.041) were independent factors contributing to NOP analysis suitability. Among 30 patients who underwent actual NOP analysis, the analysis success rate was 100% (30/30).

CONCLUSION

In sample collection via EUS-TA, 19G and FNB needles contribute to NOP analysis suitability.

Nucleic acid-triggered tumoral immunity propagates pH-selective therapeutic antibodies through tumor-driven epitope spreading

Important roles of humoral tumor immunity are often pointed out; however, precise profiles of dominant antigens and developmental mechanisms remain elusive. We systematically investigated the humoral antigens of dominant intratumor immunoglobulin clones found in human cancers. We found that approximately half of the corresponding antigens were restricted to strongly and densely negatively charged polymers, resulting in simultaneous reactivities of the antibodies to both densely sulfated glycosaminoglycans (dsGAGs) and nucleic acids (NAs). These anti-dsGAG/NA antibodies matured and expanded via intratumoral immunological driving force of innate immunity via NAs. These human cancer-derived antibodies exhibited acidic pH-selective affinity across both antigens and showed specific reactivity to diverse spectrums of human tumor cells. The antibody-drug conjugate exerted therapeutic effects against multiple cancers in vivo by targeting cell surface dsGAG antigens. This study reveals that intratumoral immunological reactions propagate tumor-oriented immunoglobulin clones and demonstrates a new therapeutic modality for the universal treatment of human malignancies.

Prognostic Impact of Radiological Splenic Artery Involvement in Pancreatic Ductal Adenocarcinoma of the Body and Tail

BACKGROUND

Splenic artery (SpA) involvement heralds poor prognosis in pancreatic ductal adenocarcinoma (PDAC) of the body and tail but is not included in the resectability criteria. This study evaluated the prognostic impact of radiological SpA involvement in PDAC of the body and tail.

METHODS

Preoperative computed tomography images of patients who underwent distal pancreatectomy for resectable PDAC of the body and tail (n = 242) at our hospital between 2004 and 2018 were graded according to splenic vessel involvement status as clear, abutment, or encasement. Clinicopathological prognostic factors and overall survival (OS) and recurrence-free survival (RFS) rates were compared between the three groups. The prognostic value of radiological involvement status was assessed using Harrell's concordance statistic (C-index) and time-dependent receiver-operating characteristic curve analysis and compared with pathological findings.

RESULTS

The diagnostic concordance rate was 0.87 (weighted κ statistic). Prognosis worsened with progression from clear, abutment, to encasement status. SpA encasement (hazard ratio [HR] 1.97, p = 0.04) predicted poor OS in multivariate Cox hazard regression analysis. SpA abutment (HR 1.77, p = 0.017) and encasement (HR 1.86, p = 0.034) independently predicted poor RFS. Splenic vein abutment and encasement were not significant predictors of poor OS or RFS. SpA encasement without adjuvant chemotherapy had the poorest prognosis because of early distant metastasis. The prognostic value was higher for radiological SpA involvement than for pathological SpA invasion.

CONCLUSIONS

Radiological SpA involvement status is a meaningful and reproducible prognostic indicator that can be used preoperatively for determining the treatment strategy in PDAC of the body and tail.

Effectiveness of Etoposide and Cisplatin vs Irinotecan and Cisplatin Therapy for Patients With Advanced Neuroendocrine Carcinoma of the Digestive System: The TOPIC-NEC Phase 3 Randomized Clinical Trial

Question

For patients with advanced neuroendocrine carcinoma of the digestive system, which of the 2 community standard regimens is more effective: etoposide plus cisplatin (EP) or irinotecan plus cisplatin (IP)?

Findings

In this randomized clinical trial of 170 patients who were chemotherapy naive and had recurrent or unresectable neuroendocrine carcinoma of the digestive system, median overall survival was 12.5 months in the EP arm and 10.9 months in the IP arm.

Meaning

Both EP and IP therapy remain standard first-line chemotherapy options.

Importance

Etoposide plus cisplatin (EP) and irinotecan plus cisplatin (IP) are commonly used as community standard regimens for advanced neuroendocrine carcinoma (NEC).

Objective

To identify whether EP or IP is a more effective regimen in terms of overall survival (OS) in patients with advanced NEC of the digestive system.

Design, Setting, and Participants

This open-label phase 3 randomized clinical trial enrolled chemotherapy-naive patients aged 20 to 75 years who had recurrent or unresectable NEC (according to the 2010 World Health Organization classification system) arising from the gastrointestinal tract, hepatobiliary system, or pancreas. Participants were enrolled across 50 institutions in Japan between August 8, 2014, and March 6, 2020.

Interventions

In the EP arm, etoposide (100 mg/m²/d on days 1, 2, and 3) and cisplatin (80 mg/m²/d on day 1) were administered every 3 weeks. In the IP arm, irinotecan (60 mg/m²/d on days 1, 8, and 15) and cisplatin (60 mg/m²/d on day 1) were administered every 4 weeks.

Main Outcomes and Measures

The primary end point was OS. In total, data from 170 patients were analyzed to detect a hazard ratio (HR) of 0.67 (median OS of 8 and 12 months in inferior and superior arms, respectively) with a 2-sided α of 10% and power of 80%. The pathologic findings were centrally reviewed following treatment initiation.

Results

Among the 170 patients included (median [range] age, 64 [29-75] years; 117 [68.8%] male), median OS was 12.5 months in the EP arm and 10.9 months in the IP arm (HR, 1.04; 90% CI, 0.79-1.37; P = .80). The median progression-free survival was 5.6 (95% CI, 4.1-6.9) months in the EP arm and 5.1 (95% CI, 3.3-5.7) months in the IP arm (HR, 1.06; 95% CI, 0.78-1.45). A subgroup analysis of OS demonstrated that EP produced more favorable OS in patients with poorly differentiated NEC of pancreatic origin (HR, 4.10; 95% CI, 1.26-13.31). The common grade 3 and 4 adverse events in the EP vs IP arms were neutropenia (75 of 82 [91.5%] patients vs 44 of 82 [53.7%] patients), leukocytopenia (50 of 82 [61.0%] patients vs 25 of 82 [30.5%] patients), and febrile neutropenia (FN) (22 of 82 [26.8%] patients vs 10 of 82 [12.2%] patients). While incidence of FN was initially high in the EP arm, primary prophylactic use of granulocyte colony-stimulating factor effectively reduced the incidence of FN.

Conclusions and Relevance

Results of this randomized clinical trial demonstrate that both EP and IP remain the standard first-line chemotherapy options. Although AEs were generally manageable, grade 3 and 4 AEs were more common in the EP arm.

Trial Registration

Japan Registry of Clinical Trials: jRCTs031180005; UMIN Clinical Trials Registry: UMIN000014795

Multicenter phase II trial of trastuzumab deruxtecan for HER2-positive unresectable or recurrent biliary tract cancer: HERB trial

Trastuzumab deruxtecan (DS-8201) is an antibody-drug conjugate composed of a humanized monoclonal anti-HER2 antibody, a cleavable tetrapeptide-based linker and a potent topoisomerase I inhibitor. The drug's efficacy has been proven in HER2-positive breast and gastric cancers. The rate of HER2 positivity in biliary tract cancer (BTC) has been reported to be 5-20%, and case reports and clinical trials have suggested that HER2 inhibitors might be active in HER2-positive BTC. Here we describe the rationale and design of the phase II HERB trial that will evaluate the efficacy and safety of trastuzumab deruxtecan in patients with HER2-expressing unresectable or recurrent BTC. The primary end point will be the centrally assessed objective response rate in HER2-positive patients.

Trastuzumab deruxtecan (T-DXd; DS-8201) in patients (pts) with HER2-expressing unresectable or recurrent biliary tract cancer (BTC): An investigator-initiated multicenter phase 2 study (HERB trial)

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Background: BTCs have an aggressive tumor biology with limited treatment options. With a HER2-positivity rate of 5–20% in BTCs, case series and small clinical trials have shown signs of activity for HER2 blockade in these pts. T-DXd is an antibody-drug conjugate composed of a humanized monoclonal anti-HER2 antibody, a cleavable linker, and a topoisomerase I inhibitor. The HERB trial is an investigator-initiated, multicenter, single-arm phase 2 trial of T-DXd in pts with HER2-expressing BTCs. Methods: Centrally confirmed HER2-expressing (HER2-positive: IHC3+ or IHC2+/ISH+, and HER2-low-expressing [HER2-low]: IHC/ISH status of 0/+, 1+/-, 1+/+, or 2+/-) pts with BTCs who were refractory or intolerant to gemcitabine containing regimen received 5.4 mg/kg of T-DXd every 3 weeks. The primary endpoint was the confirmed objective response rate (ORR) in HER2-positive pts by independent central review. The sample size of 22 had 80% power with one-sided alpha error of 5%; threshold ORR, 15%; and expected ORR, 40%. The ORR, disease control rate (DCR), progression-free survival (PFS), overall survival (OS) in HER2-positive/-low pts, and incidence of treatment-emergent adverse events (TEAEs) were assessed as secondary endpoints. Results: A total of 32 pts, 24 with HER2-positive and 8 with HER2-low BTCs, received T-DXd. Twenty-two pts with HER2-positive, excluding 2 ineligible pts, were identified for primary efficacy analysis. Among the 22 pts, IHC3+ and IHC2+/ISH+ were 45.5% and 54.5%, primary sites: gallbladder/extrahepatic/intrahepatic/Vater were 11/6/3/2, median number of prior regimens was 2 (range, 1–4). The confirmed ORR in HER2-positive pts was 36.4% (8/22; 2 CR and 6 PR; 90% CI, 19.6–56.1), indicating statistically significant improvement in ORR (P = 0.01). The DCR, median (m) PFS, mOS were 81.8% (95% CI, 59.7–94.8), 4.4 months (mo) (95% CI, 2.8–8.3), 7.1 mo (95% CI, 4.7–14.6), respectively. In addition, encouraging efficacy were seen even in HER2-low pts; ORR, DCR, mPFS, and mOS were 12.5% (1/8; 1 PR; 95% CI, 0.3–52.7), 75.0% (95% CI, 34.9–96.8), 4.2 mo (95% CI, 1.3–6.2), and 8.9 mo (95% CI, 3.0–12.8), respectively. In the safety analysis set (n = 32), TEAEs of > = grade (G) 3 occurred in 81.3% (26/32); the common TEAEs were anemia (53.1%), neutropenia (31.3%), and leukopenia (31.3%). TEAEs leading to drug discontinuation occurred in 8 pts (25.0%). Eight pts (25.0%) had interstitial lung disease (ILD; G1/G2/G3/G5 were 3/1/2/2) not adjudicated by an independent committee. Conclusions: T-DXd showed promising activity in pts with HER2-expressing BTCs. Although the safety profile was generally consistent with other T-DXd studies, ILD, an important identified risk of T-DXd, requires more careful monitoring and intervention. These results support further exploration of T-DXd in this patient population. Clinical trial information: JMA-IIA00423.

Hepatoid carcinoma and related entities of the extrahepatic bile duct: A clinicopathological study of four cases

Hepatoid carcinoma or related entities (HPC/RTs) are extremely rare, especially in the extrahepatic bile duct (EHBD). Only a few case reports have been published. We analyzed the clinicopathological features of HPCs/RTs in EHBD. HPC/RT of extrahepatic cholangiocarcinoma (eCCA) cases were selected based on the histological characteristics and immunohistochemical detection of spalt-like transcription factor 4 (SALL4) and/or alpha-fetoprotein (AFP). Four HPC/RT cases arose in the distal but not in the perihilar EHBD. The four patients with HPC/RT included one female and three males with a median age of 77 years. There are various macroscopic types of HPC/RT. The predominant histological features were two solid-type carcinomas that mimicked hepatocellular carcinoma and two well-differentiated tubular adenocarcinomas. Immunohistochemically, SALL4 and glypican-3 were expressed in all cases, and AFP was expressed in one case. Cancer cell phenotypes included intestinal, pancreatobiliary, and mixed pancreatobiliary and intestinal types. Focal neuroendocrine differentiation and severe perineural and lymphovascular invasions were also observed. HPC/RT recurred in two patients within 2 years, and one patient died 13 months postoperatively. It is suggested that the HPC/RT of EHBD shares common characteristics with HPC/RT arising in various organs, and has some unique characteristics. HPC/RT of EHBD might be more aggressive than conventional eCCA.

Molecular Signature of Tumor-Associated High Endothelial Venules That Can Predict Breast Cancer Survival

High endothelial venules (HEV) are specialized post-capillary venules that recruit naïve lymphocytes to lymph nodes. HEVs are essential for the development of adaptive immunity. HEVs can also develop in tumors where they are thought to be important for recruiting naïve T cells and B cells into the tumors and locally enhancing antitumor immunity by supporting the formation of tertiary lymphoid structures. Herein, we used comparative transcriptome analysis of human breast cancer to investigate genes differentially expressed between tumor-associated HEVs and the rest of the tumor vasculature. Tumor vessels highly expressing HEV-upregulated genes, such as the homeobox gene MEOX2 and the tetraspanin gene TSPAN7, were associated with extensive infiltration of T and B cells and the occurrence of tertiary lymphoid structures, which is known to predict therapeutic responses to immune-checkpoint inhibitors. Moreover, high transcript counts of these genes in clinical tumor specimens were associated with a significant survival benefit in advanced breast cancer. The molecular signature of HEVs identified herein may be useful for guiding immunotherapies and provides a new direction for investigating tumor-associated HEVs and their clinical significance. See related Spotlight by Gallimore, p. 371.

Randomized phase III study of etoposide plus cisplatin versus irinotecan plus cisplatin in advanced neuroendocrine carcinoma of the digestive system: A Japan Clinical Oncology Group study (JCOG1213)

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Background: Neuroendocrine carcinoma (NEC) arising in the digestive system is a rare and high-grade malignant tumor. Treatment guidelines for advanced NEC recommend platinum-based chemotherapy regimens. Etoposide plus cisplatin (EP) and irinotecan plus cisplatin (IP) are commonly used as community standard regimens for NEC. However, it is unknown which is more effective. This phase III study aimed to identify more effective regimen between EP and IP in terms of overall survival (OS) for patients with advanced NEC. Methods: Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable, histologically confirmed NEC (WHO2010) arising from the gastrointestinal tract (GI), hepatobiliary and pancreas (HBP), ECOG PS of 0-1, age of 20–75 years. In the EP arm, etoposide (100 mg/m2 on days 1, 2 and 3) and cisplatin (80 mg/m2 on day 1) were administered every 3 weeks. In the IP arm, irinotecan (60 mg/m2 on days 1, 8 and 15) and cisplatin (60 mg/m2 on day 1) were repeated every 4 weeks. The primary endpoint was OS. Total of 140 patients (114 events) were required to detect a hazard ratio (HR) of 0.67 (median OS; 8/12 months in inferior/superior arms) with a two-sided alpha of 10% and power of 70%. Due to a rapid accrual, the sample size was increased to 170 (power of 80%). Pathology was centrally reviewed after the start of treatment. Results: Of all enrolled 170 patients (GI: 100, HBP: 70) from Aug 2014 to March 2020, median OS was 12.5 months in EP and 10.9 months in IP (HR 1.043 [a ratio of EP to IP], 90% CI, 0.794-1.370, p= 0.797). Median progression-free survival (PFS) was 5.6 months in EP and 5.1 months in IP (HR 1.060, 95% CI, 0.777-1.445). Response rate (RR) was 54.5% (42/77) in EP and 52.5% (42/80) in IP among patients with target lesions. No interactions with OS, PFS, or RR were seen in pre-planned subgroup analyses including primary organs or pathological findings. The common Grade 3-4 AEs (EP/IP) was neutropenia (91.5%/53.7%), leukocytopenia (61.0%/30.5%), and febrile neutropenia (26.8%/12.2%). Conclusions: A superiority was not demonstrated, which indicates that both EP and IP remain standard first-line chemotherapy. Clinical trial information: UMIN000014795.

Novel insights into immunohistochemical analysis for diagnosing serous neoplasm of the pancreas: aquaporin 1, stereocilin, and transmembrane protein 255B

AIMS

Serous (cystic) neoplasm (SCN) of the pancreas is generally benign, and surgical treatment is recommended in only a limited number of cases. To avoid unnecessary surgery, an accurate diagnosis of SCN is essential. In the present study, we aimed to identify new immunohistochemical markers with which to distinguish SCN from other tumours.

METHODS AND RESULTS

We compared the comprehensive gene expression profiles of SCN with those of normal pancreas and pancreatic ductal adenocarcinoma (PDAC). We selected the candidate molecules that were up-regulated in SCN, were minimally expressed or unexpressed in PDAC, and had specific and available antibodies suitable for immunohistochemistry, and then analysed their immunohistochemical expression in various tumours. We selected aquaporin 1 (AQP1), stereocilin (STRC), fibroblast growth factor receptor 3 (FGFR3), and transmembrane protein 255B (TMEM255B), which were diffusely expressed in SCN cells in 79%, 100%, 100% and 100% of SCN cases. AQP1 was not expressed in other tumours, except in 20% of mucinous cystic neoplasms (MCNs) and 19% of PDACs. STRC was rarely expressed in MCNs, neuroendocrine neoplasms (NENs), and PDACs. FGFR3 was expressed in 31% of intraductal papillary mucinous neoplasms (IPMNs), 50% of intraductal oncocytic papillary neoplasms, 40% of NENs, 30% of acinar cell carcinomas, 40% of solid pseudopapillary neoplasms, and 52% of PDACs. TMEM255B was not expressed in the other tumours, except in 50% of MCNs, 80% of gastric-subtype IPMNs, and 29% of PDACs. All antigens were usually expressed in a small proportion of cells when they were positive in tumours other than SCN.

CONCLUSIONS

These findings indicate that AQP1 and STRC, and potentially TMEM255B, may act as SCN markers.

Clinical characteristics of pancreatic and biliary tract cancers associated with Lynch syndrome

BACKGROUND/PURPOSE

Pancreatic and biliary tract cancers are one of the Lynch syndrome-associated malignancies. There are few reports describing the patients' backgrounds and clinical characteristics.

METHODS

We retrospectively reviewed the medical records of patients with Lynch syndrome-associated pancreatic or biliary tract malignant tumors at National Cancer Center Hospital between March 1992 and October 2019.

RESULTS

Fourteen patients were included. They had a history of multiple cancers and a family history of cancer. For the six patients with pancreatic malignant tumor, the median age was 63 years. The primary tumor site of 5/6 patients with pancreatic cancer was the body or tail. Only one patient had pancreatic head cancer. The median overall survival (OS) was 68 (range, 17-198) months. For the eight patients with biliary tract malignant tumor, the median age was 65.5 years. The primary tumor site of 5/8 patients was the intrahepatic bile duct, whereas the primary site of 2/8 was the hilar bile duct. The median OS was 62 (range, 3-183) months.

CONCLUSIONS

This study brought out several observations on tumor location, late development, and favorable long-term outcomes. Additional studies are needed to identify the characteristics.

Association between the expression of core 3 synthase and survival outcomes of patients with cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly aggressive and metastatic type of malignant carcinoma that is associated with high mortality rates and is difficult to detect at early stages. Core 3 structure is a mucin-type O-glycans synthesized by β1,3-N-acetylglucosaminyltransferase 6 (core 3 synthase), which plays an important role in the digestive system, in particular gastrointestinal goblet cells. It has been reported that core 3 synthase-expressing cells show lower migratory and invasive rates, and lower metastatic activity. A immunohistochemical study also showed that this enzyme was expressed in normal epithelial cells of the colon, but completely disappeared in colorectal cancer cells. The present study aimed to identify biomarkers that could be used to predict the prognosis of patients with CCA. Pathological specimens of 185 CCA tissues were immunohistochemically stained with two antibodies, G8-144 and MECA-79, which recognize core 3 synthase and 6-sulfated N-acetyllactosamine on the extended core-1 O-glycans, respectively. The association between G8-144 or MECA-79 positivity and patient prognosis was statistically analyzed. Positive expression of G8-144 was associated with improved prognosis in patients with distal CCA (dCCA). Patients with dCCA positive for G8-144 showed lower mortality rates than those with negative expression. However, the positive expression of MECA-79 was associated with CCA progression and metastasis, indicating that it is a poor prognostic marker for CCA. In conclusion, as both antibodies resulted in mirror-image staining, the involvement of G8-144 and MECA-79 in O-glycan synthesis could be considered as potential favorable and unfavorable biomarkers, respectively, for CCA prognosis.

A newly established monoclonal antibody against ERCC1 detects major isoforms of ERCC1 in gastric cancer

Identifying patients resistant to cisplatin treatment is expected to improve cisplatin-based chemotherapy for various types of cancers. Excision repair cross-complementing group 1 (ERCC1) is involved in several repair processes of cisplatin-induced DNA crosslinks. ERCC1 overexpression is reported as a candidate prognostic factor and considered to cause cisplatin resistance in major solid cancers. However, anti-ERCC1 antibodies capable of evaluating expression levels of ERCC1 in clinical specimens were not fully optimized. A mouse monoclonal antibody against human ERCC1 was generated in this study. The developed antibody 9D11 specifically detected isoforms of 201, 202, 203 but not 204, which lacks the exon 3 coding region. To evaluate the diagnostic usefulness of this antibody, we have focused on gastric cancer because it is one of the major cancers in Japan. When ERCC1 expression was analyzed in seventeen kinds of human gastric cancer cell lines, all the cell lines were found to express either 201, 202, and/or 203 as major isoforms of ERCC1, but not 204 by Western blotting analysis. Immunohistochemical staining showed that ERCC1 protein was exclusively detected in nuclei of the cells and a moderate level of constant positivity was observed in nuclei of vascular endothelial cells. It showed a clear staining pattern in clinical specimens of gastric cancers. Antibody 9D11 may thus be useful for estimating expression levels of ERCC1 in clinical specimens.

Cross-talk among MEN1, p53 and Notch regulates the proliferation of pancreatic neuroendocrine tumor cells by modulating INSM1 expression and subcellular localization

Genomic analysis of Pancreatic Neuroendocrine Tumors (PanNETs) has revealed that these tumors often lack mutations in typical cancer-related genes such as the tumor suppressor gene p53. Instead, PanNET tumorigenesis usually involves mutations in specific PanNET-related genes, such as tumor suppressor gene MEN1. Using a PanNET mouse model, human tissues and human cell lines, we studied the cross-talk among MEN1, p53 and Notch signaling pathways and their role in PanNETs. Here, we show that reactivation of the early developmental program of islet cells underlies PanNET tumorigenesis by restoring the proliferative capacity of PanNET cells. We investigated the role of INSM1, a transcriptional regulator of islet cells' development, and revealed that its expression and subcellular localization is regulated by MEN1 and p53. Both human and mouse data show that loss of MEN1 in a p53 wild-type genetic background results in increased nuclear INSM1 expression and cell proliferation. Additionally, inhibition of Notch signaling in a p53 wild-type background reduces the proliferation of PanNET cells, due to repression of INSM1 transcription and nuclear localization. Our study elucidates the molecular mechanisms governing the interactions of INSM1 with MEN1, p53 and Notch and their roles in PanNET tumorigenesis, suggesting INSM1 as a key transcriptional regulator of PanNET cell proliferation.

Abstract 2699: Transcriptome analysis identifies molecular markers of tumor-associated high endothelial venules that predict breast cancer survival

High endothelial venules (HEVs) are specialized post-capillary venules that recruit naïve lymphocytes to the lymph nodes and are essential for the development of adaptive immunity. HEVs can develop in tumors, and these specialized tumor blood vessels are thought to be important for recruiting naïve T cells and B cells into tumors and locally enhance anti-tumor immunity by promoting tertiary lymphoid structure formation. At present, the genes involved in the development and function of tumor-associated HEVs remain largely unknown. By a comparative transcriptome analysis in human breast cancer, we identified the expression of genes that represents the molecular signature of tumor-associated HEVs distinct from the rest of the tumor vasculature. Tumor vessels highly expressing these genes were associated with the accumulation of T and B lymphocytes and the occurrence of tertiary lymphoid structures, which is known to predict therapeutic response to immune checkpoint inhibitor therapies. Moreover, the Cancer Genome Atlas (TCGA) data show that the high expression of these genes is associated with a significant survival benefit in advanced breast cancer. The molecular signature of HEVs identified here may be useful for guiding immunotherapies and provide a new direction for investigating tumor-associated HEVs and their clinical significance.

Citation Format: Junko Sawada, Nobuyoshi Hiraoka, Ashley Fournier-Goss, Masanobu Komatsu. Transcriptome analysis identifies molecular markers of tumor-associated high endothelial venules that predict breast cancer survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2699.

Natural History of Epithelioid Hemangioendothelioma of the Liver: CT Findings of 15 Cases

RATIONALE AND OBJECTIVES

Little is known about the natural history of epithelioid hemangioendothelioma (EHE) of the liver. This study aimed to assess the natural history of hepatic EHE by evaluating CT findings of patients with pathologically proven hepatic EHE during follow-up without treatment.

MATERIALS AND METHODS

CT findings of 15 patients (seven men and eight women; median age, 56 years) with pathologically proven hepatic EHE were retrospectively evaluated. The median interval between the baseline and final CT was 36 months (range, 6-144 months). The maximal diameter of the largest hepatic lesion on the baseline CT and the diameter of the same lesion on the final CT were recorded. Change in size of the largest lesion between the two studies was classified as enlargement, no change, and reduction. When a patient with the largest lesion showing reduction developed a new hepatic lesion on the final CT, it was referred to as "unpredictable growth".

RESULTS

CT revealed multiple hepatic lesions in all patients. Enlargement, no change, and reduction of the largest lesion were observed in four, five, and six patients, respectively. Unpredictable growth was observed in five patients.

CONCLUSION

During the follow-up of untreated patients with hepatic EHE, spontaneous regression and appearance of a new hepatic lesion were occasionally observed in the same patient.

Clinicopathologic Characterization of Epithelioid Hemangioendothelioma in a Series of 62 Cases: A Proposal of Risk Stratification and Identification of a Synaptophysin-positive Aggressive Subset

Epithelioid hemangioendothelioma (EHE) is a rare vascular endothelial neoplasm with characteristic histology and distinctive fusion genes. Its clinical presentation and outcome are heterogeneous, and the determinants of survival are controversial. In this study, we aimed to identify clinicopathologic prognostic factors of EHE in a retrospective cohort of 62 cases with CAMTA1/TFE3/WWTR1 alterations. The tumors were of the CAMTA1 subtype for 59 cases, TFE3 subtype for 2 cases, and variant WWTR1 subtype (WWTR1-ACTL6A) for 1 case. Twenty-two tumors (35.5%) demonstrated atypical histology, defined by having at least 2 of the following 3 findings: high mitotic activity (>1/2 mm2), high nuclear grade, and coagulative necrosis. During a median follow-up of 34 months, 11 patients (18%) died, and the 5-year overall survival rate was 78.8%. Survival did not correlate with such clinical parameters as age, sex, tumor sites, multifocality, and multiorgan involvement. Conversely, based on both univariate and multivariate analyses, large tumor size (>30 mm) and histologic atypia were significantly associated with a shorter survival. A proposed 3-tiered risk assessment system using these 2 parameters significantly stratified the patients into low-risk, intermediate-risk, and high-risk groups with 5-year overall survival rates of 100%, 81.8%, and 16.9%, respectively (P<0.001). Four tumors (6.4%) expressed synaptophysin, which all belonged to the high-risk group and pursued an aggressive course. The present study demonstrated the independent prognostic significance of large tumor size and atypical histology in EHE, as well as the value of risk stratification using these 2 factors. Moreover, we revealed a small EHE subset with aberrant synaptophysin expression, which may have potential prognostic and diagnostic implications.

Clinicopathological impacts of DNA methylation alterations on pancreatic ductal adenocarcinoma: prediction of early recurrence based on genome-wide DNA methylation profiling

PURPOSE

The present study was conducted to clarify the clinicopathological impacts of DNA methylation alterations on pancreatic ductal adenocarcinoma (PDAC).

METHODS

Genome-wide DNA methylation screening was performed using the Infinium HumanMethylation450 BeadChip, and DNA methylation quantification was verified using pyrosequencing. We analyzed fresh-frozen tissues from an initial cohort (17 samples of normal control pancreatic tissue [C] from 17 patients without PDAC, and 34 samples of non-cancerous pancreatic tissue [N] and 82 samples of cancerous tissue [T] both obtained from 82 PDAC patients) and formalin-fixed paraffin-embedded T samples from 34 patients in a validation cohort.

RESULTS

The DNA methylation profiles of N samples tended to differ from those of C samples, and 91,907 probes showed significant differences in DNA methylation levels between C and T samples. Epigenetic clustering of T samples was significantly correlated with a larger tumor diameter and early recurrence (ER), defined as relapse within 6 months after surgery. Three marker CpG sites, applicable to formalin-fixed paraffin-embedded surgically resected materials regardless of their tumor cell content, were identified for prediction of ER. The sensitivity and specificity for detection of patients belonging to the ER group using a panel combining these three marker CpG sites, including a CpG site in the CDK14 gene, were 81.8% and 71.7% and 88.9% and 70.4% in the initial and validation cohorts, respectively.

CONCLUSION

These findings indicate that DNA methylation alterations may have a clinicopathological impact on PDAC. Application of our criteria will ultimately allow prediction of ER after surgery to improve the outcome of PDAC patients.

Randomized phase II study of chemoradiotherapy with versus without induction chemotherapy for locally advanced pancreatic cancer: Japan Clinical Oncology Group trial, JCOG1106

BACKGROUND

Chemoradiotherapy is a treatment option for locally advanced pancreatic cancer. However, the efficacy of induction chemotherapy prior to chemoradiotherapy is uncertain. The aim of this randomized, multicentre phase II study is to evaluate the efficacy and safety of chemoradiotherapy with and without induction chemotherapy to determine the significance of induction chemotherapy.

METHODS

Patients with locally advanced pancreatic cancer were randomly assigned to the chemoradiotherapy arm (Arm A) or induction chemotherapy followed by the chemoradiotherapy arm (Arm B). Patients in Arm A underwent radiotherapy with concurrent S-1. Patients in Arm B received induction gemcitabine for 12 weeks, and thereafter, only patients with controlled disease underwent the same chemoradiotherapy as Arm A. After chemoradiotherapy, gemcitabine was continued until disease progression or unacceptable toxicity in both arms. The primary endpoint was overall survival.

RESULTS

Amongst 102 patients enrolled, 100 were eligible for efficacy assessment. The probability of survival was greater in Arm B in the first 12 months, but the trend was reversed in the following periods (1-year survival 66.7 vs. 69.3%, 2-year survival 36.9 vs. 18.9%). The hazard ratio was 1.255 (95% confidence interval 0.816-1.930) in favour of Arm A. Gastrointestinal toxicity was slightly more frequent and three treatment-related deaths occurred in Arm A.

CONCLUSIONS

This study suggested that the chemoradiotherapy using S-1 alone had more promising efficacy with longer-term survival, compared with induction gemcitabine followed by chemoradiotherapy for locally advanced pancreatic cancer.

CLINICAL TRIAL REGISTRATION

The study was registered at the UMIN Clinical Trials Registry as UMIN000006811.

Postoperative acute multiple organ failure after hepatectomy in a Nigerian male with sickle cell trait: a case report

Background

Sickle cell disease (SCD) is a monogenic disease characterized by sickle hemoglobin (HbS). Patients homozygous for HbS experience symptoms resulting from sickled erythrocytes no later than adolescence. However, heterozygous HbS carriers, or those with the so-called sickle cell trait (SCT), may undergo surgery without their hemoglobinopathy being known.

Case presentation

A 53-year-old Nigerian male with hepatitis C infection underwent radiofrequency ablation therapy for multiple hepatocellular carcinomas (HCCs) 17 months prior. Follow-up computed tomography (CT) revealed a solitary tumor (3.2 cm) in the medial section of the cirrhotic liver. The Child–Pugh score was five, and the indocyanine green retention rate at 15 min was 17.4%. The nontumorous liver of the medial section accounted for 10% of the total liver volume according to CT volumetry. With the diagnosis of recurrent HCC, left medial sectionectomy was performed under intermittent blood flow occlusion by Pringle’s maneuver. Intraoperative ultrasonography confirmed that hepatic blood flow had been preserved after hepatectomy. However, laboratory tests on postoperative day (POD) 1 revealed severe liver damage: aspartate aminotransferase 9250 IU/L, alanine aminotransferase 6120 IU/L, total bilirubin 2.8 mg/dL, and prothrombin time% 20.9%. The patient’s renal and respiratory functions also deteriorated; therefore, continuous hemodiafiltration and plasma exchange were initiated under mechanical ventilation. Whole-body contrast-enhanced CT showed no apparent ischemia of the remnant liver, but diffuse cerebral infarction was detected. Despite intensive treatments, he died of multiple organ failure on POD 20. The pathological examination of the resected specimen revealed that the intrahepatic peripheral vessels were occluded by sickled erythrocytes. Additionally, chromatographic analysis of hemoglobin detected the presence of abnormal hemoglobin, although microscopic examination of the peripheral blood erythrocytes did not show morphological abnormalities. Based on these findings, we determined that he had SCT and developed vaso-occlusive crisis involving multiple organs just after hepatectomy.

Conclusion

SCD is a rare disease in eastern Asia, but its prevalence is increasing globally. Surgeons should pay increased attention to this disease, especially when performing hepatectomy under blood flow occlusion.

Clinicopathological significance of core 3 O-glycan synthetic enzyme, β1,3-N-acetylglucosaminyltransferase 6 in pancreatic ductal adenocarcinoma

Mucin-type O-glycans are involved in cancer initiation and progression, although details of their biological and clinicopathological roles remain unclear. The aim of this study was to investigate the clinicopathological significance of β1,3-N-acetylglucosaminyltransferase 6 (β3Gn-T6), an essential enzyme for the synthesis of core 3 O-glycan and several other O-glycans in pancreatic ductal adenocarcinoma (PDAC). We performed immunohistochemical and lectin-histochemical analyses to detect the expression of β3Gn-T6 and several O-glycans in 156 cases of PDAC with pancreatic intraepithelial neoplasias (PanINs) and corresponding normal tissue samples. The T antigen, Tn antigen, sialyl Lewis X (sLeX) antigen, and sLeX on core 2 O-glycan were more highly expressed in PDAC cells than in normal pancreatic duct epithelial cells (NPDEs). Conversely, the expression of 6-sulfo N-acetyllactosamine on extended core 1 O-glycan was found in NPDEs and was low in PDAC cells. These glycan expression levels were not associated with patient outcomes. β3Gn-T6 was expressed in ~20% of PDAC cases and 30-40% of PanINs but not in NPDEs. Higher expression of β3Gn-T6 was found in PDAC cells in more differentiated adenocarcinoma cases showing significantly longer disease-free survival in both univariate and multivariate analyses. In addition, the expression of β3Gn-T6 in PDAC cells and PanINs significantly correlated with the expression of MUC5AC in these cells, suggesting that β3Gn-T6 expression is related to cellular differentiation status of the gastric foveolar phenotype. Thus, it is likely that β3Gn-T6 expression in PDAC cells is a favorable prognostic factor in PDAC patients, and that the expression of β3Gn-T6 correlates with the gastric foveolar phenotype in pancreatic carcinogenesis.

IAP inhibitor, Embelin increases VCAM-1 levels on the endothelium, producing lymphocytic infiltration and antitumor immunity

There is an increasing unmet need for successful immunotherapeutic interventions. Lymphocyte extravasation via tumor tissue endothelial cells (TECs) is required for lymphocyte infiltration into tumor sites. This study aimed to investigate the clinical significance of dysfunctional TECs in pancreatic ductal adenocarcinoma (PDAC) and identify chemical compounds that boost tumor-infiltrating lymphocyte (TIL) numbers. We performed immunohistochemical detection and clinicopathological analysis of VCAM-1 on TECs, which is essential for lymphocyte trafficking. We characterized the gene expression profiles of TECs from fresh PDAC tissues. We isolated compounds that upregulated VCAM-1 and E-selectin expression in TECs and examined their biological activities. Compared to endothelial cells from chronic pancreatitis tissue, TECs showed significantly lower VCAM-1 and E-selectin expression and significant weaknesses in lymphocyte adhesion and transmigration, resulting in decreased T cell infiltration around vessels. Patients with a relatively high percentage of VCAM-1⁺ vessels among all vessels in PDAC tissue had an improved prognosis. A bioinformatics survey demonstrated that TNFR1 signaling was involved in abnormal VCAM-1 and E-selectin expression in TECs. We screened compounds affecting TNFR1 signaling, and the IAP inhibitor, Embelin, induced these molecules on TECs and enhanced T cell adhesion to TECs and transmigration. Furthermore, in vivo, Embelin enhanced tumor-infiltrating T cell numbers, leading to an antitumor immune response. Embelin accelerates TIL infiltration and the antitumor immune response by recovering VCAM-1 expression in TECs. Our strategy may be a therapeutic approach for accelerating the immunotherapeutic response in immune-quiescent tumors, leading to clinical trials’ success.

Aberrant DNA methylation results in altered gene expression in non-alcoholic steatohepatitis-related hepatocellular carcinomas

PURPOSE

The aim of this study was to investigate DNA methylation alterations in non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinomas (HCCs).

METHODS

Genome-wide DNA methylation analysis was performed using the Infinium Human Methylation 450 K BeadChip, and levels of mRNA expression were analyzed by quantitative reverse transcription-PCR.

RESULTS

Compared to 36 samples of normal control liver tissue (C), DNA methylation alterations were observed on 19,281 probes in 22 samples of cancerous tissue (T) obtained from patients showing histological features compatible with NASH in their non-cancerous liver tissue (N). Among those probes, 1396 were located within CpG islands or their shores and shelves, designed around the transcription start sites of 726 genes. In representative genes, such as DCAF4L2, CKLF, TRIM4, PRC1, UBE2C and TUBA1B, both DNA hypomethylation and mRNA overexpression were observed in T samples relative to C samples, and the levels of DNA methylation and mRNA expression were inversely correlated with each other. DNA hypomethylation occurred even in N samples at the precancerous NASH stage, and this was inherited by or further strengthened in T samples. DNA hypomethylation of DCAF4L2, CKLF and UBE2C was observed in both NASH-related and viral hepatitis-related HCCs, whereas that of TRIM4, PRC1 and TUBA1B occurred in a NASH-related HCC-specific manner. DNA hypomethylation and/or mRNA overexpression of these genes was frequently associated with the necroinflammatory grade of NASH and was correlated with poorer tumor differentiation.

CONCLUSION

DNA methylation alterations may occur under the necroinflammatory conditions characteristic of NASH and participate in NASH-related hepatocarcinogenesis through aberrant expression of tumor-related genes.

Details of human epidermal growth factor receptor 2 status in 454 cases of biliary tract cancer

Human epidermal growth factor receptor 2 (HER2)-targeted therapy has improved clinical outcomes in patients with HER2-positive breast and gastric cancers, although ineffective or recurrent cases are present. One reason for this is the heterogeneity of HER2 expression in cancer cells. The aim of this study was to investigate the clinicopathological characteristics and HER2 status of patients with biliary tract cancers (BTCs). We examined HER2 protein expression by immunohistochemistry, HER2 gene amplification by fluorescence in situ hybridization, and both HER2 protein and gene levels simultaneously by gene-protein assay. Samples were collected from 454 patients who underwent surgical resection for BTCs (110 intrahepatic cholangiocarcinomas [ICC], 67 perihilar extrahepatic cholangiocarcinomas [ECC-Bp], 119 distal extrahepatic cholangiocarcinomas [ECC-Bd], 80 gallbladder carcinomas [GBC], and 79 ampullary carcinomas [AVC]). HER2 status was assessed according to the guidelines for HER2 testing in gastroesophageal adenocarcinoma. HER2-positive status was detected in 14.5% of BTCs (3.7% of ICC, 3.0% of ECC-Bp, 18.5% of ECC-Bd, 31.3% of GBC, and 16.4% of AVC). Furthermore, HER2-positivity tended to correlate with low histological grade, tumor histology, and macroscopic features in certain tumors. HER2 heterogeneity was common and highly frequent (83%) in BTC cases. Reduced HER2 protein expression in the deeper invasive areas with simultaneous dedifferentiation was frequently observed in HER2-positive cancer cells. The findings of this study suggest that a large subgroup of HER2-positive BTC cases can be considered for HER2-targeted therapy. Moreover, the HER2 status in BTCs should be determined carefully using a sensitive approach toward larger cancer tissues.

Synchronous Double Bile Duct Cancers with Distinct Genetic Features

A 69-year-old man was referred to our hospital because of appetite loss. Imaging showed a nodular tumor in the perihilar bile duct and a second flat lesion in the distal bile duct. Right hepatopancreaticoduodenectomy was performed, and the histopathological findings demonstrated that the perihilar and distal lesions were moderately and poorly differentiated adenocarcinoma, respectively, and anatomically separated. Furthermore, the resected specimens showed no pancreaticobiliary maljunction. Histological and TP53 gene analyses in a rare case of synchronous double bile duct cancers suggest that there are various genetic pathways through which bile duct cancer develops, highlighting the complexity of its pathogenesis.

Genomic characterization of malignant progression in neoplastic pancreatic cysts

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are non-invasive neoplasms that are often observed in association with invasive pancreatic cancers, but their origins and evolutionary relationships are poorly understood. In this study, we analyze 148 samples from IPMNs, MCNs, and small associated invasive carcinomas from 18 patients using whole exome or targeted sequencing. Using evolutionary analyses, we establish that both IPMNs and MCNs are direct precursors to pancreatic cancer. Mutations in SMAD4 and TGFBR2 are frequently restricted to invasive carcinoma, while RNF43 alterations are largely in non-invasive lesions. Genomic analyses suggest an average window of over three years between the development of high-grade dysplasia and pancreatic cancer. Taken together, these data establish non-invasive IPMNs and MCNs as origins of invasive pancreatic cancer, identifying potential drivers of invasion, highlighting the complex clonal dynamics prior to malignant transformation, and providing opportunities for early detection and intervention.

Expression of classical human leukocyte antigen class I antigens, HLA-E and HLA-G, is adversely prognostic in pancreatic cancer patients

The expression of classical human leukocyte antigen class I antigens (HLA-I) on the surfaces of cancer cells allows cytotoxic T cells to recognize and eliminate these cells. Reduction or loss of HLA-I is a mechanism of escape from antitumor immunity. The present study aimed to investigate the clinicopathological impacts of HLA-I and non-classical HLA-I antigens expressed on pancreatic ductal adenocarcinoma (PDAC) cells. We performed immunohistochemistry to detect expression of HLA-I antigens in PDAC using 243 PDAC cases and examined their clinicopathological influences. We also investigated the expression of immune-related genes to characterize PDAC tumor microenvironments. Lower expression of HLA-I, found in 33% of PDAC cases, was significantly associated with longer overall survival. Higher expression of both HLA-E and HLA-G was significantly associated with shorter survival. Multivariate analyses revealed that higher expression of these three HLA-I antigens was significantly correlated with shorter survival. Higher HLA-I expression on PDAC cells was significantly correlated with higher expression of IFNG, which also correlated with PD1, PD-L1 and PD-L2 expression. In vitro assay revealed that interferon gamma (IFNγ) stimulation increased surface expression of HLA-I in three PDAC cell lines. It also upregulated surface expression of HLA-E, HLA-G and immune checkpoint molecules, including PD-L1 and PD-L2. These results suggest that the higher expression of HLA-I, HLA-E and HLA-G on PDAC cells is an unfavorable prognosticator. It is possible that IFNγ promotes a tolerant microenvironment by inducing immune checkpoint molecules in PDAC tissues with higher HLA-I expression on PDAC cells.