Evaluation of pancreatic cancer specimens for comprehensive genomic profiling

Inadequate specimen quality or quantity hinders comprehensive genomic profiling in identifying actionable mutations and guiding treatment strategies. We investigated the optimal conditions for pancreatic cancer specimen selection for comprehensive genomic profiling. We retrospectively analyzed 213 pancreatic cancer cases ordered for comprehensive genomic profiling and compared results from pancreatic biopsy, liver biopsy of pancreatic cancer metastases, pancreatectomy, liquid, and nonliver metastatic organ specimens. We examined preanalytical conditions, including cellularity (tumor cell count/size). The successfully tested cases were those that underwent comprehensive genomic profiling tests without any issues. The successfully tested case ratio was 72.8%. Pancreatic biopsy had the highest successfully tested case ratio (87%), with a high tumor cell percentage, despite the small number of cells (median, 3425). Pancreatic biopsy, liver biopsy of pancreatic cancer metastases, and non-liver metastatic organ had higher successfully tested case ratios than that for pancreatectomy. Liver biopsy of pancreatic cancer metastases and pancreatectomy cases with tumor size (mm2 ) × tumor ratio (%) > 150 and >3000, respectively, had high successfully tested case ratios. The success of comprehensive genomic profiling is significantly influenced by the tumor cell ratio, and pancreatic biopsy is a potentially suitable specimen for comprehensive genomic profiling.

Clinical Significance of Tryptophanyl-tRNA Synthetase 1 Gene Expression in Patients With Locally Advanced Gastric Cancer

BACKGROUND/AIM

The tryptophanyl-tRNA synthetase 1 gene (WARS1), encodes a tryptophan-tRNA synthetase involved in the amino acidification of tryptophan-tRNA and has been reported to be involved in cancer cell growth, metastasis promotion, and drug resistance in a variety of cancers. This study investigated the clinical significance of WARS1 expression as a biomarker in gastric cancer tissues obtained from patients with locally advanced gastric cancer (GC) who underwent radical resection.

PATIENTS AND METHODS

WARS1 expression in GC tissues and adjacent normal gastric mucosa of 253 patients with pStage II/III GC who underwent curative resection was determined using quantitative polymerase chain reaction (PCR). Association of WARS1 expression levels, categorized into high and low expression based on the median expression levels, with clinicopathological factors and overall survival (OS) of these patients was assessed.

RESULTS

The low-WARS1 expression group had significantly higher serosal invasion, lymph node metastasis, lymphatic invasion, venous invasion, and pathological stage than did the high-WARS1 expression group. OS was significantly worse in the low- than in the high-WARS1 expression group (5-year survival 52.2% vs. 75.9%; p=0.0001). Furthermore, in multivariate analysis, low WARS1 expression was an independent predictor for poor OS (hazard ratio=2.101; 95% confidence interval=1.328-3.322; p=0.002).

CONCLUSION

In patients with locally advanced GC, after curative resection, WARS1 expression in GC tissue may be a useful prognostic marker.

The frequency of mutations in advanced thyroid cancer in Japan: a single-center study

We analyzed the outcomes of genetic testing to study the frequency of mutations in advanced thyroid cancer in Japan. Patients (n = 96) with unresectable or metastatic thyroid carcinoma were included for retrospective chart review. Results of gene panel testing, which was performed between May 2020 and April 2023, were analyzed. The median age of the patients was 73.5 years (range, 17-88); 59 were women, and 39 were men. Overall, 17 patients had anaplastic thyroid carcinoma (ATC), 68 had papillary thyroid carcinoma (PTC), 7 had follicular thyroid carcinoma, and 6 had poorly differentiated thyroid carcinoma (PDTC). Of the 81 patients with differentiated thyroid carcinoma (DTC) and PDTC, 88.9% were radioactive iodine-refractory, and 32.7% of all cases had previously been treated with multiple kinase inhibitors. Of ATC cases, 52.9% had BRAF mutations, and 5.9% had RET fusion. Of PTC cases, 83.1% had BRAF mutations, 9.2% had RET fusion, and 1.5% had NTRK fusion. One case each of ATC and PTC had a tumor mutation burden of ≥10. ATC cases had a significantly higher prevalence of TP53 alterations than the other cases (82.3% vs. 11.8%), whereas the frequencies of TERT promoter mutations were 88.2% in ATC cases and 64.7% in the other cases, albeit without a significant difference. In conclusion, 58.8% of ATC, 93.8% of PTC, and 42.9% of PDTC had genetic alterations linked to therapeutic agents. Active gene panel testing is required to increase treatment options.

Clinical Significance of Pregnancy Zone Protein Expression in Patients With Locally Advanced Gastric Cancer After Curative Resection

BACKGROUND/AIM

Pregnancy zone protein (PZP), encoded by PZP, belongs to the α-2-macroglobulin superfamily, and plays an important role in inflammatory responses and immune cell activation in cancer. However, the relationship between gastric cancer (GC) and PZP is poorly studied. This study investigated the clinical significance of PZP expression in GC tissues of patients with locally advanced GC after curative resection.

PATIENTS AND METHODS

Using quantitative polymerase chain reaction, we measured PZP expression in GC tissues and adjacent normal gastric mucosa of 253 patients with pStage II/III GC who underwent curative resection. We compared the expression levels of PZP in GC tissues and adjacent normal gastric mucosa and examined the relationship of PZP expression in GC tissues with clinicopathological factors and overall survival (OS).

RESULTS

PZP expression was significantly associated with histology, venous invasion, and pathological stage. The high PZP expression group had significantly worse OS than did the low expression group (5-year survival 48.6% vs. 68.5%, p=0.0003). Furthermore, in multivariate analysis, high PZP expression was an independent factor for poor OS (hazard ratio=1.984, 95% confidence interval=1.307-3.012, p=0.0013).

CONCLUSION

In post-curative resection patients with locally advanced GC, PZP expression in GC tissue may be a useful prognostic marker.

Asialoglycoprotein Receptor 2 Expression in Patients With Locally Advanced Gastric Cancer After Curative Resection

BACKGROUND/AIM

The asialoglycoprotein receptor 2 gene (ASGR2) encodes a subunit of the asialoglycoprotein receptor, a transmembrane protein, which has recently been reported to be involved in gastric cancer (GC) progression. This study aimed to investigate the clinical significance of ASGR2 expression in GC tissues of patients with locally advanced gastric cancer (LAGC) after curative resection.

PATIENTS AND METHODS

ASGR2 expression was measured in GC tissues and adjacent normal gastric mucosa in 253 patients with pStage II/III GC who underwent curative resection, by using quantitative polymerase chain reaction. We compared the expression levels in GC tissues and adjacent normal stomach mucosa, and evaluated the relationship of its expression in GC tissues with clinicopathological factors and overall survival (OS).

RESULTS

ASGR2 expression was significantly associated with lymph node metastasis and venous invasion. The high ASGR2-expression group demonstrated significantly lower survival than the low expression group (5-year survival 55.5% vs. 72.6%; p=0.009). Furthermore, in multivariate analysis, high ASGR2 expression was an independent factor for poor OS (hazard ratio=2.030; 95% confidence interval=1.318-3.127; p=0.001).

CONCLUSION

ASGR2 expression in GC tissues may be a useful prognostic marker in patients with LAGC after curative resection.

Clinical Significance of Chitinase-3-like Protein 1 Gene Expression in Patients With Locally Advanced Gastric Cancer

BACKGROUND/AIM

Chitinase-3-like protein 1 (CHI3L1), encoded by CHI3L1, is thought to be involved in growth, invasion, migration, and resistance to chemotherapy in cancer. This study aimed to investigate the clinical significance of CHI3L1 expression as a biomarker in gastric cancer (GC) tissues of patients with locally advanced GC after curative resection.

PATIENTS AND METHODS

Quantitative polymerase chain reaction (PCR) was used to determined CHI3L1 expression in GC tissues and adjacent normal gastric mucosa of 253 patients with pStage II/III GC who underwent curative resection. We compared the expression levels in GC tissues and adjacent normal gastric mucosa, and examined the relationship between expression in GC tissues and clinicopathological factors and overall survival (OS) in these patients.

RESULTS

CHI3L1 expression was significantly associated with lymph-node metastasis and venous invasion. OS rate was significantly lower in the high- than in the low-CHI3L1 expression group (5-year survival 55.5% vs. 72.6%; p=0.009). Furthermore, in multivariate analysis, high CHI3L1 gene expression was an independent factor for poor OS (hazard ratio=2.030; 95% confidence interval=1.318-3.127; p=0.001).

CONCLUSION

In patients with locally advanced GC after curative resection, expression of the CHI3L1 in GC tissue may be a useful prognostic marker.

A short-term three dimensional culture-based drug sensitivity test is feasible for malignant bone tumors

The feasibility of a short-term, three-dimensional (3D) culture-based drug sensitivity test (DST) for surgically resected malignant bone tumors, including osteosarcoma (OS), was evaluated utilizing two OS cell line (KCS8 or KCS9)-derived xenograft (CDX) models. Twenty-three (KCS8) or 39 (KCS9) of 60 tested drugs were likely effective in OS cells derived from a cell line before xenografting. Fewer drugs (19: KCS8, 26: KCS9) were selected as effective drugs in cells derived from a CDX tumor, although the drug sensitivities of 60 drugs significantly correlated between both types of samples. The drug sensitivity of a CDX tumor was not significantly altered after the depletion of non-tumorous components in the sample. In a surgically resected metastatic tumor obtained from a patient with OS, for whom a cancer genome profiling test detected a pathogenic PIK3CA mutation, DST identified mTOR and AKT inhibitors as effective drugs. Of two CDX and six clinical samples of OS and Ewing's sarcoma, DST identified proteasome inhibitors (bortezomib, carfilzomib) and CEP-701 as potentially effective drugs in common. This unique method of in vitro drug testing using 3D-cell cultures is feasible in surgically resected tissues of metastatic malignant bone tumors.

Clinical Significance of Cancer Stem Cell Markers in Primary and Metastatic Tissues in Patients With Breast Cancer

BACKGROUND/AIM

This study aimed to examine the clinical significance of the protein expression of the cancer stem cell (CSC) markers ALDH1A1, CD133, CD44, and MSI-1 in primary and metastatic tissues of patients with breast cancer (BC).

PATIENTS AND METHODS

ALDH1A1, CD133, CD44, and MSI-1 protein expression in pairs of primary and metastatic tissues of 55 patients with BC with metastases treated at Kanagawa Cancer Center between January 1970 and December 2016 were evaluated using immunohistochemical assay and their association with clinicopathological factors and survival was examined.

RESULTS

There were no significant differences in CSC marker expression rates between primary and metastatic tissues for any CSC markers. Regarding the relationship between CSC marker expression in primary tissues and survival, patients with high CD133 expression had significantly lower recurrence-free survival (DFS) and overall survival. On multivariate analysis, they were also a poor independent predictor of DFS (hazard ratio=4.993, 95%CI=2.189-11.394, p=0.0001). In contrast, there was no significant association between the expression of any CSC marker in metastatic tissues and survival.

CONCLUSION

CD133 expression in the primary BC tissue may be a useful risk factor for recurrence in patients with BC.

Differential diagnosis of uterine adenosarcoma: identification of JAZF1-BCORL1 rearrangement by comprehensive cancer genomic profiling

BACKGROUND

Uterine adenosarcoma is a rare malignant tumor that accounts for 8% of all uterine sarcomas, and less than 0.2% of all uterine malignancies. However, it is frequently misdiagnosed in clinical examinations, including pathological diagnosis, and imaging studies owing to its rare and non-specific nature, which is further compounded by the lack of specific diagnostic markers.

CASE PRESENTATION

We report a case of uterine adenosarcoma for which a comprehensive genomic profiling (CGP) test provided a chance to reach the proper diagnosis. The patient, a woman in her 60s with a history of uterine leiomyoma was diagnosed with an intra-abdominal mass post presentation with abdominal distention and loss of appetite. She was suspected to have gastrointestinal stromal tumor (GIST); the laparotomically excised mass was found to comprise uniform spindle-shaped cells that grew in bundles with a herringbone architecture, and occasional myxomatous stroma. Immunostaining revealed no specific findings, and the tumor was diagnosed as a spindle cell tumor/suspicious adult fibrosarcoma. The tumor relapsed during postoperative follow-up, and showed size reduction with chemotherapy, prior to regrowth. CGP was performed to identify a possible treatment, which resulted in detection of a JAZF1-BCORL1 rearrangement. Since the rearrangement has been reported in uterine sarcomas, we reevaluated specimens of the preceding uterine leiomyoma, which revealed the presence of adenosarcoma components in the corpus uteri. Furthermore, both the uterine adenosarcoma and intra-abdominal mass were partially positive for CD10 and BCOR staining.

CONCLUSION

These results led to the conclusive identification of the abdominal tumor as a metastasis of the uterine adenosarcoma. The JAZF1-BCORL1 rearrangement is predominantly associated with uterine stromal sarcomas; thus far, ours is the second report of the same in an adenosarcoma. Adenosarcomas are rare and difficult to diagnose, especially in atypical cases with scarce glandular epithelial components. Identification of rearrangements involving BCOR or BCORL1, will encourage BCOR staining analysis, thereby potentially resulting in better diagnostic outcomes. Given that platinum-based chemotherapy was proposed as the treatment choice for this patient post diagnosis with adenosarcoma, CGP also indirectly contributed to the designing of the best-suited treatment protocol.

Clinical Significance of EREG Gene Expression in Gastric Cancer Tissue After Curative Surgery

BACKGROUND/AIM

Epiregulin (EREG) is a ligand of the epidermal growth factor receptor (EGFR) and promotes tumour progression mainly by stimulating the EGF pathway. We investigated the clinical significance of EREG mRNA expression in cancer tissues from patients with gastric cancer (GC) in pathological (p) Stage II/III who have undergone curative surgery.

PATIENTS AND METHODS

Expression of EREG mRNA was measured in cancer tissues obtained from 253 patients with pStage II/III GC who underwent curative surgery. Patients were divided into groups based on high or low expression of EREG mRNA. We examined the relationship between EREG mRNA expression levels and clinicopathological features and survival.

RESULTS

Clinicopathological features did not vary between the high and low EREG mRNA expression groups. Overall survival was significantly lower in the high-expression group compared to that in the low-expression group (5-year survival probability: 55.0% vs. 73.0%; p=0.005). Multivariate analysis showed EREG mRNA expression to be an independent predictor of poor survival (hazard ratio=1.794; 95% confidence interval=1.186-2.712; p=0.006).

CONCLUSION

Expression of EREG mRNA in cancer tissue from patients with pStage II/III GC may be a useful prognostic marker after curative surgery.

CRMP4 Up-regulates M2 Macrophages and Myeloid-derived Suppressor Cells to Promote Pancreatic Cancer in Mice

BACKGROUND/AIM

We previously observed higher prevalence of high-grade pancreatic intraepithelial neoplasia (PanIN) in LSL-KrasG12D/+; Pdx1Cre/+ (KC-Crmp4wild) mice than LSL-KrasG12D/+; Pdx1Cre/+; Crmp4-/- (KC-Crmp4-/-) mice. This study investigated the relationship between collapsin response mediator protein 4 (CRMP4) and immune cell infiltration in pancreatic cancer.

MATERIALS AND METHODS

PanIN was induced by intraperitoneal injection of caerulein into KC-Crmp4wild and KC-Crmp4-/- mice, and immune cells in PanIN lesions were compared. Subcutaneous tumors were created by injecting Pan02 cells, and tumor diameter was compared between Crmp4wild and Crmp4-/- mice every 7 days. Peritumoral immune cells were examined immunohisto chemically.

RESULTS

High-grade PanIN in KC mice showed statistically significantly high expression of CD163 (p=0.031) and CD11b (p=0.027). Following subcutaneous injection of Pan02 cells, tumor diameter was greater in Crmp4wild mice than Crmp4-/- mice. Crmp4wild mice exhibited higher CD163 and CD11b expression than Crmp4-/- mice in tumors (p<0.001).

CONCLUSION

CRMP4 might promote pancreatic cancer by up-regulating M2 macrophages and myeloid-derived suppressor cells.

Impact of nuclear factor of activated T cells (NFAT) families as a poor prognostic factor in pancreatic cancer patients

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Background: Pancreatic cancer microenvironment is crucial in cancer development, and cancer-stromal interactions have been recognized as important targets for cancer therapy. Nuclear factor of activated T-cells (NFAT) has been found in T cells as a transcriptional activator of IL-2, and known to be involved in various processes including the immune system. In cancer tissues, NFAT has been reported to be involved in metastasis. In breast and colorectal cancers, NFATc2 and NFAT5 have been reported to interact with integrins to promote cancer cell migration. On the other hand, in pancreatic cancer, NFAT5 has been reported to be a poor prognostic factor via regulation of PGK1 transcription. In the present study, we evaluated the expression of NFATc2 and NFAT5 in pancreatic cancer and examined their relationship with prognosis. Methods: One hundred and sixty five pancreatic cancer patients who underwent curative-intrent resection at our hospital between 2010 and 2020 were included in this study. We performed immunostaining for NFATc2 and NFAT5 using the tissue micro array. We evaluated the expression of NFATc2 and NFAT5 protein and examined their correlation with clinicopathological factors. Results: Of the 165 pancreatic cancer cases, we detected increased NFATc2 protein expression in cytoplasm of cancer cells in 53 cases (32.1%) and NFAT5 in 104 cases (63.0%), and NFATc2/NFAT5 co-expression in 43 cases (26.1%). NFATc2 expression was not correlated with any clinicopathological factors, NFAT5 expression was correlated with venous invasion (p = 0.047), and NFATc2/NFAT5 co-expression was slightly correlated with Stage (p = 0.054). Relapse free survival (RFS) was estimated in all 165 patients. There was no significant difference for RFS in either NFATc2-high group or NFAT5-high group (p = 0.314 or p = 0.574), however, NFATc2/NFAT5 co-expression group showed significantly poor RFS (p = 0.023). Overall survival (OS) was also estimated in all 165 patients. There was no significant difference for OS in either NFATc2-high group or NFAT5-high group (p = 0.146 or p = 0.529), however, NFATc2/NFAT5 co-expression group showed significantly poor survival (p = 0.006). In multivariate analysis, lymphatic invasion, curability and NFATc2/NFAT5 co-expression were independent prognostic factors for RFS, and lymphatic invasion, curability, presence of adjuvant therapy and NFATc2/NFAT5 co-expression were independent prognostic factors for OS. Conclusions: In pancreatic cancer, NFATc2/NFAT5 co-expression was suggested to be involved in the critical process of pancreatic cancer progression, and may be a novel therapeutic target.

Study protocol for NCCH1908 (UPFRONT-trial): a prospective clinical trial to evaluate the feasibility and utility of comprehensive genomic profiling prior to the initial systemic treatment in advanced solid tumour patients

 

Comprehensive genomic profiling has been approved for use in patients with advanced solid tumours; however, it is only indicated in advanced solid tumour patients without available standard chemotherapeutic treatment or those who have completed standard treatments in Japan, and there are no available data on the clinical feasibility and utility of comprehensive genomic profiling in treatment-naive patients. This multicentre, single-arm, prospective study aims to evaluate the feasibility and utility of the OncoGuide NCC Oncopanel System in treatment-naive patients with six advanced major malignancies: non-small cell lung cancer, breast cancer, gastric cancer, colon cancer, pancreatic cancer and biliary tract cancer (NCCH1908). This study (study cohort) will be compared with the other prospective observational study (control cohort), which enrols patients not receiving comprehensive genomic profiling prior to initial systemic treatment. A total of 200 patients will be enrolled in the study over 21 months. This study has been registered in the UMIN Clinical Trials Registry (www.umin.ac.jp/ctr/) (UMIN000040743).

CLINICAL TRIAL REGISTRATION

This study, initiated in June 2020, has been registered in the UMIN Clinical Trials Registry (www.umin.ac.jp/ctr/) (registration number: UMIN000040743). We plan to enrol a total of 200 patients over a period of 21 months.

Clinical Significance of Chemokine Receptor CXCR4 and CCR7 mRNA Expression in Patients With Colorectal Cancer

BACKGROUND/AIM

The chemokine receptors C-X-C chemokine receptor type 4 (CXCR4) and C-C chemokine receptor type 7 (CCR7) play an important role in the invasion and metastasis of cancer. This study investigated the relationship between relative expression of CXCR4 and CCR7 mRNA, clinicopathological factors, and outcomes in patients with colorectal cancer (CRC).

PATIENTS AND METHODS

We studied 202 patients who underwent surgery for CRC. The expression levels of CXCR4 and CCR7 mRNA in cancerous tissue were measured using quantitative real-time reverse-transcriptase polymerase chain reaction.

RESULTS

High CCR7 mRNA expression levels in CRC tissues were positively associated with tumour size and were more frequently associated with cancer of the rectum than of the colon. Moreover, outcomes were significantly poorer in patients with high CCR7 mRNA expression than in those with low expression. On multivariate Cox regression analysis, a higher CCR7 mRNA expression level was a significant independent predictor of poorer overall survival in patients with CRC.

CONCLUSION

Overexpression of CCR7 mRNA may be a useful independent prognostic factor in patients with CRC.

A case of lung adenocarcinoma with a novel CD74-ROS1 fusion variant identified by comprehensive genomic profiling that responded to crizotinib and entrectinib

ROS1 rearrangements are found in 1-2% of patients with non-small-cell lung cancer. The detection of the rearrangements is crucial since clinically effective molecular targeted drugs are available for them. We present a case of lung adenocarcinoma with a previously unknown ROS1-CD74 fusion variant, CD74 exon 3 fused to ROS1 exon 34, which was not detected by a conventional RT-PCR-based test for ROS1 fusion gene detection but identified by hybrid capture-based next-generation sequencing. This tumor responded to crizotinib initially and to entrectinib after relapse with brain metastasis, indicating the oncogenic activity of this novel fusion variant.

Clinical Significance of TAP1 and DLL4 Expression in Patients With Locally Advanced Gastric Cancer

BACKGROUND/AIM

Cancer stem cells (CSCs) are reported to associated with cancer metastasis, relapse, and chemoresistance. This study examined the clinical significance of the expression of two CSC markers, the transporter associated with antigen processing 1 (TAP1) and the Delta-like 4 (DLL4) protein, in patients with locally advanced GC.

PATIENTS AND METHODS

This study was performed using samples obtained from 413 pathological stage II/III GC patients after curative gastrectomy. We examined TAP1 and DLL4 expression using immunohistochemical analysis with tissue microarray and examined the association between TAP1 or DLL4 expression, clinicopathological factors and survival.

RESULTS

High TAP1 expression was associated with better overall survival compared to low TAP1 expression (p=0.004). Furthermore, in multivariate analysis, high TAP1 expression was defined as a predictive factor for good survival. There was no significant difference between DLL4 expression and clinicopathological features and overall survival.

CONCLUSION

TAP1 expression may be a useful prognostic marker in patients with locally advanced GC.

Clinical Significance of PLA2G2A Expression in Gastric Cancer Patients who Receive Gastrectomy and Adjuvant S-1

BACKGROUND/AIM

This study aimed to evaluate the prognostic significance of PLA2G2A expression in patients with locally advanced gastric cancer (GC).

PATIENTS AND METHODS

PLA2G2A expression levels in cancerous tissue specimens and adjacent normal mucosa obtained from 134 patients with stage II/III GC who received adjuvant chemotherapy with S-1 after curative resection were measured using real-time quantitative polymerase chain reaction. Subsequently, the associations of PLA2G2A expression with clinicopathological features and survival were evaluated.

RESULTS

No association was observed between clinicopathological features and PLA2G2A expression levels. Overall survival was significantly longer in patients with high PLA2G2A expression levels (p=0.022). Multivariate analysis revealed that PLA2G2A expression was a significant, independent prognostic factor (hazard ratio=0.136; 95% confidence interval=0.0185-0.992; p=0.049).

CONCLUSION

PLA2G2A mRNA expression may serve as a useful prognostic marker in patients with locally advanced GC who receive curative surgery and adjuvant chemotherapy with S-1.

Co-implantation of Tumor and Extensive Surrounding Tissue Improved the Establishment Rate of Surgical Specimens of Human-Patient Cancer in Nude Mice: Toward the Goal of Universal Individualized Cancer Therapy

BACKGROUND/AIM

The discovery of the nude mouse model enabled the experimental growth of human-patient tumors. However, the low establishment rate of tumors in nude and other immunodeficient strains of mice has limited wide-spread clinical use.

MATERIALS AND METHODS

In order to increase the establishment rate of surgical specimens of patient tumors, we transplanted tumors to nude mice subcutaneously along with large amounts of surrounding tissue of the tumor.

RESULTS

The new transplantation method increased the establishment rate in nude mice to 66% compared to the old method of implanting the surgical tumor specimen with surrounding tissue removed (14%). High stage and presence of metastasis in the patient donor are positively correlated to tumor engraftment in nude mice.

CONCLUSION

The new method can potentially allow most cancer patients who undergo surgery or biopsy to have their own mouse model for drug-sensitivity testing.

Phase II study of temozolomide monotherapy in patients with extrapulmonary neuroendocrine carcinoma

Extrapulmonary neuroendocrine carcinoma (EPNEC) is a lethal disease with a poor prognosis. Platinum-based chemotherapy is used as the standard first-line treatment for unresectable EPNEC. Several retrospective studies have reported the results of the utilization of temozolomide (TMZ) as a drug for the second-line treatment for EPNEC. Patients with unresectable EPNEC that were resistant to platinum-based combination chemotherapy were recruited for a prospective phase II study of TMZ monotherapy. A 200 mg/m2 dose of TMZ was given from day 1 to day 5, every 4 weeks. Response rate (RR) was evaluated as the primary end-point. The presence of O6 -methylguanine DNA methyltransferase (MGMT) in EPNEC patients was also evaluated as exploratory research. Thirteen patients were enrolled in this study. Primary lesions were pancreas (n = 3), stomach (n = 3), duodenum (n = 1), colon (n = 1), gallbladder (n = 1), liver (n = 1), uterus (n = 1), bladder (n = 1), and primary unknown (n = 1). Each case was defined as pathological poorly differentiated neuroendocrine carcinoma from surgically resected and/or biopsied specimens. The median Ki-67 labeling index was 60% (range, 22%-90%). The RR was 15.4%, progression-free survival was 1.8 months (95% confidence interval [CI], 1.0-2.7), overall survival (OS) was 7.8 months (95% CI, 6.0-9.5), and OS from first-line treatment was 19.2 months (95% CI, 15.1-23.3). No grade 3 or 4 hematological toxicity had occurred and there was one case of grade 3 nausea. One case presented MGMT deficiency and this case showed partial response. Temozolomide monotherapy is a feasible, modestly effective, and safe treatment for patients with unresectable EPNEC following platinum-based chemotherapy, especially those with MGMT deficiency.

Signet-ring Cell Carcinoma Component as an Indicator of Anaplastic Lymphoma Kinase Mutations in Colorectal Cancer

Objectives

Molecular profiling of marker mutations has become an essential aspect in the treatment planning for colorectal cancer (CRC). Anaplastic lymphoma kinase (ALK) mutations could be used as markers in CRC molecular profiling. However, the extremely low frequency of these mutations makes their confirmation in all patients inefficient. Thus, to determine whether ALK positivity could be indicated by morphological features, we have analyzed ALK positivity in CRC tissues with a signet-ring cell carcinoma (SRCC) component.

Methods

We screened cases of patients who underwent CRC surgical resection at the Department of Gastrointestinal Surgery of the Kanagawa Cancer Center between January 2015 and December 2019. The selected samples were then assessed immunohistochemically using an antibody against p80 ALK.

Results

In total, we were able to retrieve 29 cases of CRC with the SRCC component from the database; however, 5 cases were excluded owing to the absence of formalin-fixed paraffin-embedded tissue sections or the absence of the SRCC component when the tissues were observed. In the immunohistochemical analysis, two cases showed diffused positive immunoreactivity for ALK and were defined as ALK-positive CRC. Thus, the ALK positivity rate in CRC with SRCC was determined to be 8.3%.

Conclusions

This present study sheds light on the morphological features of ALK-positive CRC. Our findings could contribute to the effective screening and improvement of front-line therapy for CRC.

Clinical Significance of Stanniocalcin2 mRNA Expression in Patients With Colorectal Cancer

BACKGROUND/AIM

Stanniocalcin2 (STC2) is associated with proliferation, invasion, and metastasis in various cancers. We examined the clinical significance of STC2 mRNA expression in patients with colorectal cancer (CRC).

PATIENTS AND METHODS

Relative expression levels of STC2 mRNA in CRC tissues and corresponding normal mucosa obtained from 202 patients were measured using quantitative real-time reverse transcriptase-polymerase chain reaction.

RESULTS

Expression of STC2 mRNA was higher in the cancer tissue than in the adjacent normal mucosa. STC2 mRNA expression in cancer tissues was associated with tumour size, liver metastasis, venous invasion, and lymph node metastasis. High expression of STC2 mRNA was significantly associated with poorer postoperative survival (p=0.0003). Multivariate analysis showed that high expression of STC2 mRNA was an independent predictor of postoperative survival.

CONCLUSION

High expression of STC2 mRNA in CRC tissue may be a useful prognostic marker in patients with CRC.

Reduction of gender-associated M2-like tumor-associated macrophages in the tumor microenvironment of patients with pancreatic cancer after neoadjuvant chemoradiotherapy

PURPOSE

This study aimed to investigate gender-dependent antitumor immune response to neoadjuvant chemoradiotherapy (NACRT) in pancreatic ductal adenocarcinoma (PDAC) patients.

METHODS

This study enrolled 58 patients (25 females and 33 males) with borderline resectable PDAC who underwent R0 surgical resection after NACRT. The resected tumor specimens were analyzed for tumor-associated macrophages (TAMs); tumor-infiltrating lymphocytes (CD8+ and CD4+ T cells); regulatory T cells; and IRF-5-expressing cells using immunohistochemical staining for CD163, CD204, CD8, CD4, Foxp3, and IRF-5 antigen. The relationship between clinicopathological features and clinical outcomes was evaluated using multivariate Cox proportional hazard analysis.

RESULTS

Females had longer overall survival (P = .044) and relapse-free survival (P = .044) than males. The CD204+ TAM number was significantly lower in females than in males (P = .009). No significant difference occurred between female and male patients in other tumor-infiltrating immune cells. IRF-5+ cell number was significantly higher in female patients (P = .002). Negative correlation occurred between CD204+ cells and IRF-5-positive cells (P = .003, r = -.385).

CONCLUSIONS

Female gender was an independent prognostic factor possibly due to the greater reduction in CD204+ TAM infiltration in tumors after NACRT. The beneficial effects of NACRT on TAMs' infiltration might be associated with gender-dependent IRF-5 expression.

Clinical Significance of Tumour CD44v and MIST1 Expression in Patients With Non-small-cell Lung Cancer

BACKGROUND

Cancer stem cells (CSCs) are involved in cancer metastasis and relapse. Therefore, identification of CSC biomarkers might help determine the success of a treatment. In this study, we examined the expression of four CSC markers: Cluster of differentiation 44 variant (CD44v), leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), frizzled 7 (FZD7), and muscle, intestine and stomach expression 1 (MIST1), in cancer tissues of patients with non-small-cell lung cancer at >5 years after resection, and its clinical significance.

PATIENTS AND METHODS

We examined the expression of each CSC marker in 360 patients with NSCLC (n=360) who underwent curative resection by immunohistochemical analysis of tissue microarrays, and determined its relationship with survival.

RESULTS

High expression of MIST1 was related to better overall survival (p<0.05); high CD44v expression was associated with poor overall and recurrence-free survival (p<0.001 for both) and thus, CD44v was defined as an independent prognostic factor (p<0.05), according to a multivariate analysis.

CONCLUSION

Tumoral CD44v expression might be a useful prognostic marker for patients after curative resection of NSCLC.

Lung adenocarcinoma in a patient with a cis EGFR L858R-K860I doublet mutation identified using NGS-based profiling test: Negative diagnosis on initial companion test and successful treatment with osimertinib

Tyrosine kinase inhibitors are used as first‐line treatment for non‐small cell lung cancer (NSCLC) patients harboring driver mutations in EGFR, ALK, ROS1, and BRAF. Currently, standard molecular testing approaches help identify single genes for such targetable driver mutations in NSCLC; however, next‐generation sequencing (NGS)‐based genetic profiling provides a more comprehensive approach and is hence strongly recommended. This case study aimed to highlight the benefits of NGS‐based tests for the diagnosis of complex EGFR L858R mutations. A patient was diagnosed with stage IVB NSCLC using a government‐approved in vitro diagnostic test and was noted to have a high programmed death‐ligand 1 tumor proportion score. This patient was treated with pembrolizumab monotherapy followed by cisplatin and pemetrexed owing to the lack of actionable driver gene mutations, including EGFR mutations. After treatment failure, a sample harvested from the same transbronchial lung biopsy specimen (formalin‐fixed and paraffin‐embedded) used for the initial EGFR test was subjected to NGS‐based broad genetic profiling. The NGS‐based test identified an EGFR L858R‐K860I cis doublet mutation; however, neither of these mutations was identified upon initial molecular testing. The patient was then successfully treated with a third‐generation EGFR‐tyrosine kinase inhibitor, osimertinib. In this study, we delved deeper into the realm of L858R and K860I mutations in NSCLC and discuss the potential causes underlying our initial negative diagnosis. Furthermore, this study highlighted the additional benefits of replacing typical molecular tests with NGS‐based broad profiling approaches.

Key points

Significant findings of the study

The EGFR L858R‐K860I cis doublet mutation was not detected by a PCR‐based EGFR test.

A next generation sequencing (NGS)‐based test was able to identify the L858R‐K860I cis doublet mutation.

What this study adds

Osimertinib was effective in an NSCLC patient with EGFR L858R and K860I mutations.

Clinical Significance of Glioma-associated Oncogene 1 Expression in Patients With Locally Advanced Gastric Cancer Administered Adjuvant Chemotherapy With S-1 After Curative Surgery

BACKGROUND/AIM

Glioma-associated oncogene 1 (GLI1) is an important transcription factor in the hedgehog signalling pathway and tumour formation. We evaluated the clinical significance of GLI1 expression as a prognostic factor in patients with locally advanced gastric cancer (GC).

PATIENTS AND METHODS

GLI1 expression levels were measured by quantitative real-time polymerase chain reaction analysis of cancerous and adjacent normal mucosa specimens obtained from 142 patients with Stage II/III GC administered adjuvant chemotherapy with S-1 after curative resection. The associations of GLI1 expression with clinicopathological features and survival were evaluated.

RESULTS

Clinicopathological features and GLI1 expression showed no association. Overall survival was significantly poorer in the high compared to the low GLI1 expression group (p=0.04). Multivariate analysis revealed that GLI1 expression was a significant independent prognostic factor [p=0.019, hazard ratio (HR)=1.94, 95% confidence interval (CI)=1.70-3.38].

CONCLUSION

GLI1 expression may be a useful prognostic marker in patients with locally advanced GC.

Biomarker analysis to predict the pathological response to neoadjuvant chemotherapy in locally advanced gastric cancer: An exploratory biomarker study of COMPASS, a randomized phase II trial

Background: The findings of COMPASS, a randomized phase II study, suggested that the regimens and courses of neoadjuvant chemotherapy (NAC) for locally advanced gastric cancer (GC) did not affect the pathological response. However, pathological complete response was achieved in 10% patients who received four courses of either S-1/cisplatin or paclitaxel/cisplatin. We hypothesized that if relevant biomarkers could be used to predict the suitable NAC regimen before treatment initiation, further improvements could be ensured in the outcomes of locally advanced GC.

Materials and Methods: mRNA extraction, real-time polymerase chain reaction, and immunohistochemical analyses were performed using endoscopic biopsy specimens of primary tumors, collected prior to NAC, to determine the clinically relevant biomarkers.

Results: TIMP1, DSG2, RRM1, MUC2, EGFR, ZDHHC14, and CLDN18.2 were identified as biomarker candidates, since their expression was significantly associated with the pathological responses to each NAC regimen. Furthermore, TIMP1 and DSG2 were identified as predictive biomarkers of the pathological response to each NAC regimen.

Conclusions: The effective prediction of the pathological response to NAC regimens in locally advanced GC using biomarkers identified from endoscopic biopsy specimens indicates the possibility of personalizing NAC based on biomarker analysis.

Impact of the ESM-1 Gene Expression on Outcomes in Stage II/III Gastric Cancer Patients Who Received Adjuvant S-1 Chemotherapy

BACKGROUND/AIM

Endothelial cell-specific molecule-1 (ESM-1) is a soluble proteoglycan which has important role in various biological events. We investigated the impact of the ESM-1 expression in cancer tissues on outcomes in stage II/III gastric cancer patients who received adjuvant S-1 chemotherapy.

PATIENTS AND METHODS

The ESM-1 mRNA expression in cancerous tissues and adjacent normal mucosa from 253 patients was measured. The associations between the ESM-1 gene expression and the survival and clinicopathological features were investigated.

RESULTS

A significant association was observed between high ESM-1 expression and undifferentiated adenocarcinoma. The overall survival curve was significantly lower in patients with high ESM-1 expression than in those with low expression (p=0.005). High ESM-1 expression was a significant independent prognosticator (HR=2.291, p=0.007).

CONCLUSION

ESM-1 gene expression in cancerous tissues is an important prognosticator in stage II/III gastric cancer patients who received adjuvant S-1 chemotherapy.

MiR-194-5p in Pancreatic Ductal Adenocarcinoma Peritoneal Washings is Associated with Peritoneal Recurrence and Overall Survival in Peritoneal Cytology-Negative Patients

BACKGROUND

Peritoneal dissemination is one of the major recurrence patterns in patients with pancreatic ductal adenocarcinoma (PDAC) and is associated with poor prognosis. Here, we assessed the diagnostic potential of microRNA (miRNA) profiles in peritoneal washings for prediction of peritoneal dissemination in PDAC.

PATIENTS AND METHODS

From January 2016 to July 2017, peritoneal washings were obtained prospectively from 59 patients with PDAC undergoing surgery the Yokohama City University Hospital. MiRNA expression was evaluated by Agilent human miRNA microarray and quantitative reverse-transcription polymerase chain reaction.

RESULTS

Microarray analysis identified upregulated and downregulated miRNAs in peritoneal washings of patients with peritoneal dissemination. We validated four miRNAs (miR-141-3p, miR-194-3p, miR-194-5p, and miR-200c-3p) with high expression in peritoneal washings. The cumulative incidence rate of peritoneal recurrence in peritoneal cytology-negative patients in the miR-194-5p high group was significantly higher than that in the miR-194-5p low group (p = 0.002). Univariate and multivariate analyses revealed that high miR-194-5p was associated with overall survival (OS).

CONCLUSIONS

High expression of miR-194-5p in peritoneal washings is associated with peritoneal recurrence and poor OS in patients with peritoneal cytology-negative PDAC.

High gamma-glutamyl hydrolase and low folylpolyglutamate synthetase expression as prognostic biomarkers in patients with locally advanced gastric cancer who were administrated postoperative adjuvant chemotherapy with S-1

Purpose

The enzymes gamma-glutamyl hydrolase (GGH) and folylpolyglutamate synthetase (FPGS) regulate intracellular folate concentrations needed for cell proliferation, DNA synthesis, and repair. High GGH expression affects 5-FU thymidylate synthase (TS) inhibition and is a risk factor for various malignancies. Here, the clinical significance of GGH and FPGS expression was investigated in Stage II/III gastric cancer patients undergoing postoperative adjuvant chemotherapy with S-1.

Methods

Surgical specimens of cancer tissue and adjacent normal mucosa, obtained from 253 patients with previously untreated gastric cancer, were examined. GGH and FPGS mRNA expression was measured by qPCR to evaluate their clinicopathological significance in gastric cancer patients after curative resection.

Results

While FPGS expression showed no significant differences between the cancerous and normal samples, GGH expression was higher in cancer tissue than in adjacent normal mucosa. High GGH expression was correlated with age, histological type, and vascular invasion. Overall survival (OS) of patients with high GGH mRNA expression was significantly poorer than of patients with low GGH expression. Multivariate analysis showed that high GGH expression was an independent prognostic factor of OS (HR: 2.58, 95% CI 1.29–5.16). Patients who received S-1 adjuvant treatment showed a significantly poor OS between high GGH/low FPGS and low GGH/high FPGS. Patients without adjuvant treatment showed no significant difference.

Conclusion

GGH expression was significantly higher in gastric cancer tissue than in adjacent normal mucosa. High GGH and low FPGS expression is a useful independent predictor of poor outcomes in stage II/III gastric cancer patients undergoing postoperative adjuvant chemotherapy with S-1.

Patient-derived orthotopic xenograft models of sarcoma

Sarcoma is a rare and recalcitrant malignancy. Although immune and novel targeted therapies have been tested on many cancer types, few sarcoma patients have had durable responses with such therapy. Doxorubicin and cisplatinum are still first-line chemotherapy after four decades. Our laboratory has established the patient-derived orthotopic xenograft (PDOX) model using surgical orthotopic implantation (SOI). Many promising results have been obtained using the sarcoma PDOX model for identifying effective approved drugs and experimental therapeutics, as well as combinations of them for individual patients. In this review, we present our laboratory's experience with PDOX models of sarcoma, and the ability of the PDOX models to identify effective approved agents, as well as experimental therapeutics.

Clinical Significance of PRKCI Gene Expression in Cancerous Tissue in Patients With Gastric Cancer

BACKGROUND/AIM

The PRKCI gene encodes Protein kinase C iota. The overexpression of protein kinase C iota is associated with poor outcomes in patients with gastric and other cancers, but the role of the PRKCI gene in gastric cancer is not fully understood. Thus, we evaluated the clinical significance of PRKCI gene expression in gastric cancer.

MATERIALS AND METHODS

PRKCI mRNA expression levels in cancerous tissues and adjacent normal mucosa from 398 patients with gastric cancer were measured. Relationships between PRKCI gene expression and clinicopathological characteristics and outcomes were examined.

RESULTS

Overall survival was lower in patients with a high expression of PRKCI than in those with low expression (p=0.016). No other relationships were observed. A high PRKCI expression was found to be an independent prognostic factor (p=0.036, HR=1.44, 95%CI=1.02-2.02).

CONCLUSION

PRKCI gene expression in cancerous tissue might be a useful prognostic factor in patients with gastric cancer after gastrectomy.

Regorafenib regresses an imatinib-resistant recurrent gastrointestinal stromal tumor (GIST) with a mutation in exons 11 and 17 of c-kit in a patient-derived orthotopic xenograft (PDOX) nude mouse model

Gastrointestinal stromal tumor (GIST) with a mutation in exons 11 and 17 of c-kit is a rare type of sarcoma. The aim of this study was to determine drug sensitivity for a regionally-recurrent case of GIST using a patient-derived orthotopic xenograft (PDOX) model. The PDOX model was established in the anterior wall of the stomach. GIST PDOX models were randomized into 5 groups of 6 mice each when the tumor volume reached 60 mm³: G1, control group; G2, imatinib group (oral administration (p.o.), daily, for 3 weeks); G3, sunitinib group (p.o., daily, for 3 weeks); G4, regorafenib (p.o., daily, for 3 weeks); G5, pazopanib (p.o., daily, for 3 weeks). All mice were sacrificed on day 22. Tumor volume was evaluated on day 0 and day 22 by laparotomy. Body weight were measured 2 times per week. Though regorafenib is third-line therapy for GIST, it was the most effective drug and regressed the tumor significantly (p < 0.001). Sunitinib suppressed tumor growth compared to the control group (p = 0.002). Imatinib, first-line therapy for GIST, and pazopanib did not have significant efficacy compared to the control group (p = 0.886, p = 0.766). The implications of this result is discussed for GIST patients.

Abstract 31: Organoid derived from human operative sample of NET shows NET characteristics

Background: Neuroendocrine tumor is a rare neoplasm, then, it was difficult to examine using in vitro or animal models. Recently, patient-derived tumor organoid (PDTO) is considered as a promising method to analyze natural characteristics of human tumor, because PDTO is cultured in near-natural circumstances compared with cell lines. We established PDTO of neuroendocrine tumor (NET) utilizing operative samples from a pancreatic NET patient. Aim: Aim of this study is to establish organoid derived from an operative sample of pancreatic NET patient and to compare its characteristics with original tumor using immuno-histochemistry. Material and Method: A pancreatic NET tissue derived from operative sample was cut into small pieces and was treated by collagenase. Prepared tissues were 3-dimensionally cultured on the Matrigel in a serum-free medium (Advanced MEM/F12) with 4 growth factors (Respondin, EGF, Rock inhibitor, Noggin), then PDTO was established. To evaluate growth rate of PDTO, Major axis of the organoid was measured on the day 1, 2, 3, and 6. One week after primary culture of the organoid, subculture was performed. Then major axis of the 2nd, 6th and 7th filial organoid was also measured and compared with each filial. To evaluate characteristics of PDTO as neuroendocrine tumor, immunohistochemistry was performed for the 1st, 2nd and 3rd filial PDTO using anti-chromogranin-A antibody (Dako, mouse IgG), anti-synaptophysin antibody (Abcam, rabbit IgG), anti-NCAM antibody (Abcam mouse IgG) and Neuro-specific enolase (Dako, rabbit IgG). Results: Growth rate of the 2nd and 3rd filial on the day 6 did not show significant difference compared with that of the 1st filial. On the other hand, Growth rate of the 2nd and 3rd filial was significantly lower than that of the 1st filial. Expression of the 4 factors in the 1st, 2nd and 3rd filial PDTO was kept as much as the primary tumor. Conclusion: PDTO derived from neuroendocrine tumor showed the same characteristics as the primary tumor. The 6th and 7th filial PDTO might show cellular aging.

Citation Format: Yasushi Ichikawa, Yukihiko Hiroshima, Noritoshi Kobayashi, Yusaku Masuda, Ayumu Goto, Motohiko Tokuhisa, Yuma Takeda, Takashi Ishikawa, Itaru Endo. Organoid derived from human operative sample of NET shows NET characteristics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 31.

Efficacy of Tumor-Targeting Salmonella typhimurium A1-R against Malignancies in Patient-Derived Orthotopic Xenograft (PDOX) Murine Models

We developed tumor-targeting Salmonella typhimurium (S. typhimurium) A1-R, a facultative anaerobe that is an auxotroph of leucine and arginine. The tumor-targeting efficacy of S. typhimurium A1-R was demonstrated in vivo and vitro using several malignant cell lines including melanoma, sarcoma, glioma, breast, pancreatic, colon, cervical, prostate, and ovarian cancers. Our laboratory also developed a patient-derived orthotopic xenograft (PDOX) model by implanting patient-derived malignant tumor fragments into orthotopic sites in mice. We reviewed studies of S. typhimurium A1-R against recalcitrant cancers. S. typhimurium A1-R was effective against all PDOX tumor models tested and showed stronger efficacies than chemotherapy or molecular-targeting therapy against some tumors. Furthermore, the synergistic efficacy of S. typhimurium A1-R when combined with chemotherapeutic agents, molecular-targeting agents, or recombinant methioninase was also demonstrated. We suggest potential clinical uses of this S. typhimurium A1-R treatment.

The combination of gemcitabine and docetaxel arrests a doxorubicin-resistant dedifferentiated liposarcoma in a patient-derived orthotopic xenograft model

Liposarcoma (LS) is a chemotherapy-resistant disease. The aim of the present study was to find precise therapy for a recurrent dedifferentiated liposarcoma (DDLS) in a patient-derived orthotopic xenograft (PDOX) model. The DDLS PDOX models were established orthotopically in the right inguinal area of nude mice. The DDLS PDOX models were randomized into five groups: untreated; doxorubicin (DOX); gemcitabine (GEM) combined with docetaxel (DOC); pazopanib (PAZ); and yondelis (YON). On day 15, all mice were sacrificed. Measurement of tumor volume and body weight were done two times a week. The DDLS PDOX was resistant to DOX (P > 0.184). YON suppressed tumor growth significantly compared to control group (P < 0.027). However, only GEM combined with DOC arrested the tumor growth (P < 0.001). These findings suggest that GEM combined with DOC has clinical potential for this and possibly other DDLS patients.

[Differences in Concepts between Hospital Oncologists and Home Physicians]

Although many patients with terminal cancers desire to be cared for at home, frequently, such patients cannot be shifted to home care due to their unstable symptoms. In severe cases, emergency hospitalizations may be frequently required after introducinghome medical care. We report a case of makinghome medical care difficult due to repeated emergency hospitalizations despite of the patient's deep desire. Interviews were conducted with both the oncologist in charge of the case and a home physician, and their viewpoints were compared. For patients and their families to achieve desired livingconditions, it was considered necessary to give supportive medical care that meet their desires until the end of their lives as mutual viewpoints are taken in a good balance.

Surgical and histological boundary of the hepatic hilar plate system: basic study relevant to surgery for hilar cholangiocarcinoma regarding the "true" proximal ductal margin

BACKGROUND

We sought to expand the clinico-anatomical limit of the proximal ductal margin (Limit-PDM) for resectability of hilar cholangiocarcinoma (HCCA).

METHODS

The practical boundary of the hilar plate (PBHP) was defined as the location where the bile duct (BD) could not be isolated by dissection. The distance between PBHP and two well-known clinical landmarks of Limit-PDM, the right edge of the bifurcation of the anterior and posterior branch of the right portal vein (Posterior-Landmark) and the left edge of the umbilical portion of the portal vein (Left-Landmark), and histological features around the PBHP were assessed using 55 adult cadaver livers.

RESULTS

BD was almost always isolatable beyond the traditional clinical landmarks. The median distance was 6.9 mm (interquartile range [IQR] 6.0-8.3 mm) between the PBHP and the Posterior-Landmark, and 8.9 mm (IQR 6.7-10.2 mm) between the PBHP and the Left-Landmark. Histologically, the sheath surrounding the portal triad was loose, thick with few elastic fibers and small arteries near the hepatic hilum. Near the PBHP, the sheath was dense, thin, and abundant with elastic fibers and small arteries.

CONCLUSIONS

Limit-PDM is more peripheral than the traditional clinical landmark-based margin and histological transition near the PBHP was revealed.

Role of the tumor microenvironment in pancreatic cancer

Pancreatic cancer remains a highly recalcitrant disease despite the development of systemic chemotherapies. New treatment options are thus urgently required. Dense stromal formation, so-called "desmoplastic stroma," plays controversial roles in terms of pancreatic cancer growth, invasion, and metastasis. Cells such as cancer-associated fibroblasts, endothelial cells, and immune cells comprise the tumor microenvironment of pancreatic cancer. Pancreatic cancer is considered an immune-quiescent disease, but activation of immunological response in pancreatic cancer may contribute to favorable outcomes. Herein, we review the role of the tumor microenvironment in pancreatic cancer, with a focus on immunological aspects.

Combining Tumor-Selective Bacterial Therapy with Salmonella typhimurium A1-R and Cancer Metabolism Targeting with Oral Recombinant Methioninase Regressed an Ewing's Sarcoma in a Patient-Derived Orthotopic Xenograft Model

BACKGROUND

Ewing's sarcoma (ES) is a recalcitrant disease in need of transformative therapeutics.

OBJECTIVES

The aim of this study was to investigate the efficacy of tumor-selective Salmonella typhimurium A1-R combined with tumor metabolism targeting with oral administration of recombinant methioninase (o-rMETase), on an ES patient-derived orthotopic xenograft (PDOX) model.

METHODS

The ES PDOX models were previously established in the right chest wall. The ES PDOX models were randomized into 5 groups when the tumor volume reached 80 mm3: G1: untreated control; G2: doxorubicin; G3: S. typhimurium A1-R; G4: o-rMETase; G5: S. typhimurium A1-R combined with o-rMETase. All mice were sacrificed on day 15. Body weight and tumor volume were assessed twice a week.

RESULTS

S. typhimurium A1-R and o-rMETase respectively suppressed tumor growth as monotherapies (p = 0.050 and p = 0.032). S. typhimurium A1-R combined with o-rMETase regressed tumor growth significantly compared to untreated group on day 15 (p < 0.032). S. typhimurium A1-R combined with o-rMETase group was significantly more effective than S. typhimurium A1-R or o-rMETase monotherapy (p = 0.032, p = 0.032).

CONCLUSIONS

The present results suggest that the combination of S. typhimurium A1-R and o-rMETase has promise to be a transformative therapy for ES.

Gemcitabine combined with docetaxel precisely regressed a recurrent leiomyosarcoma peritoneal metastasis in a patient-derived orthotopic xenograft (PDOX) model

There are no effective treatments for leiomyosarcoma (LMS) spreading intraabdominally. The aim of this study was to develop precision chemotherapy for recurrent peritoneal LMS metastases in a patient-derived orthotopic xenograft (PDOX) model. The LMS PDOX models were established orthotopically on the dome of the bladder of nude mice. The LMS PDOX models were randomized into 6 groups when the tumor volume reached 80 mm³: G1: untreated control; G2: doxorubicin (DOX) (DOX: i.p., 3 mg/kg, weekly, 3 weeks); G3: DOX combined with olaratumab (OLA) (DOX: i.p., 3 mg/kg, weekly, 3 weeks; OLA: i.p., 40 mg/kg, 3 times/week, 3 weeks); G4: gemcitabine (GEM) combined with docetaxel (DOC) (GEM: i.p., 100  mg/kg, weekly, 3 weeks; DOC: i.p., 20  mg/kg, weekly, 3 weeks); G5: pazopanib (PAZ) (PAZ: p.o., 100  mg/kg, daily, 3 weeks); G6: palbociclib (PAL) (PAL: p.o., 100  mg/kg, daily, 3 weeks). All mice were sacrificed on day 22. Body weight was assessed twice a week. Tumor volume was measured on day 0 and day 22. Although all regimens had a significant efficacy compared to the untreated group (P < 0.001), only GEM combined with DOC regressed the tumor significantly (P < 0.001), suggesting GEM combined with DOC has clinical potential for this LMS patient.

Effect of Portal Vein Ligation Plus Venous Congestion on Liver Regeneration in Rats

INTRODUCTION AND AIM

We developed a rat model of portal vein ligation (PVL) with venous congestion (PVL+C) to investigate beneficial effect PVL plus congestion for regeneration of intact liver segments.

MATERIALS AND METHODS

In the PVL group, portal vein branches were ligated except the caudate lobe (CL). In the PVL + C group, the left lateral hepatic vein was ligated in addition to PVL. Chronological changes in the following variables were compared among the groups: CL weight to body weight ratio (CL/BW), embolized liver weight to body weight ratio (EL/BW), histological findings of the embolized/non-embolized liver, and expression of several mediators that affect liver regeneration in the non-embolized liver.

RESULTS

Weight regeneration of CL continued up to postoperative day (POD)7 in PVL + C, but terminated at POD2 in PVL. CL/BW at POD7 was significantly higher in PVL + C than in PVL (2.41 ± 0.33% vs. 1.22 ± 0.18%, P < 0.01). In contrast, EL/BW continued to decrease up to POD7 in PVL + C but reached nadir at POD2 in PVL. Furthermore, EL/BW at POD7 was significantly smaller in PVL + C than in PVL (0.35 ± 0.03% vs. 0.67 ± 0.08%, P < 0.01). Histologically-proven injury in the embolized liver was more severe in PVL + C than in PVL. Expression of Ki-67, IL-6, TNF -a, and HGF were greater and/or more prolonged in PVL + C than in PVL.

CONCLUSIONS

Our rat model of PVL + C was considered useful for investigating the beneficial effect of congestion in addition to PVC. PVL + C caused increased devastation of the embolized liver, and higher and more prolonged expression of factors promoting liver regeneration in the non-embolized liver than in PVL.

Tumor-targeting Salmonella typhimurium A1-R overcomes partial carboplatinum-resistance of a cancer of unknown primary (CUP)

Cancer of unknown primary (CUP) is metastatic disease without a known primary and therefore very difficult to identify effective therapy. Previously, we demonstrated partial efficacy of Salmonella typhimurium A1-R (S. typhimurium A1-R) alone and carboplatinum alone (CAR) on a CUP patient tumor in the patient-derived xenograft (PDOX) model. The aim of the present study was to investigate the efficacy of S. typhimurium A1-R combined with CAR on the CUP PDOX model. The CUP tumors were implanted orthotopically into the left supraclavicular fossa of nude mice to match the site from which they were resected from the patient. CUP PDOX models were divided randomly into the following 4 groups after the tumor volume reached 100 mm³: G1: untreated group; G2: CAR (30 mg/kg, i.p., weekly, 2 weeks); G3: S. typhimurium A1-R (5x10⁷ CFU/body, i.v., weekly, 2 weeks).; G4: S. typhimurium A1-R combined with CAR (S. typhimurium A1-R; 5x10⁷ CFU/body, i.v., weekly, 2 weeks; CAR, 30 mg/kg, i.p., weekly, 2 weeks). Each group comprised 7 mice. All mice were sacrificed on day 15. Tumor volume and body weight were measured twice a week. S. typhimurium A1-R and CAR moderately inhibited tumor growth compared to the untreated group on day 15 (P < 0.001 and P < 0.001, respectively). S. typhimurium A1-R combined with CAR inhibited the tumor growth significantly more compared to S. typhimurium A1-R monotherapy or CAR monotherapy on day 15 (P = 0.004 and P = 0.001, respectively). The present report demonstrates that S. typhimurium A1-R can increase the efficacy of a standard drug used for CUP in a PDOX model.

Abstract 3134: Pilot study of immune status of GEP-NETs in tumor microenvironment

Introduction: Neuroendocrine tumor (NET) is a rare cancer, however, morbidity rate is increasing every year. Recently, effective molecular targeting drugs for NET were developed and leading acceptable results, however, it is still not enough. Immune checkpoint inhibitor is becoming a very effective drug in malignant melanoma, lung cancer, and some kind of cancer showing microsatellite instability (MSI).

Aim: Aim of this study is to investigate NET about MSI status and immune status of microenvironment using NET patients' operative or biopsy samples.

Method: Patients were 20 NETs, male: 11, female: 9, G1: 6, G2: 8, G3: 6, pancreas: 11, duodenum: 4, colon: 2, liver: 1, unknown: 2. Using patients' samples by operative resection or biopsy, examinations by immunohistochemistry were performed to confirm MSI status using MSH2, MSH6, PMS2 and MLH1 antibody and count the cell number expressing PD-L1, PD-1, CD8 or Foxp3. Expression of MSH2, MSH6, PMS2, MLH1 and PD-L1 was evaluated on tumor cells. Specimens were categorized as IHC negative or positive if &lt; 1% or &gt; 1% of cells were stained by each monoclonal antibody. Expression of PD-1, CD8, Foxp3 was evaluated on the infiltrating lymphocyte of intratumor and peritumor respectively. Positive cells absolute number of each staining were counted in the 3 hot spot field (X400) and then the average of the 3 field of each specimen was utilized.

Results: MSI: Expression of the 4 mismatch repair protein could be detected in the all 20 NETs tumor, then there was no case showing MSI. PD-L1 was detected in the 15 cases (75%). PD-L1 was expressed in the surface of tumors. PD-1 was also detected 15 cases (75%). PD-1 was expressed in the surface of infiltrative intratumoral and peritumoral lymphocyte. Both of PD-L1 in the tumor and PD-1 in the lymphocyte were detected in the 12 cases (60%). PD-L1 was detected in 72.7% of pancreatic NET, 72% of gastroenteral NET. PD-L1 was detected in 100% of NET-G1, 75% of G2 and 50% of G3. The absolute number of intratumoral PD-1+ lymphocyte, CD8+ lymphocyte or Foxp3+ lymphocyte was higher in the PD-L1+ tumor than in the PD-L1- tumor. In peritumor, there was not a similar tendency. In the PD-L1 positive NET, the absolute number of intratumoral PD-1+ lymphocyte or CD8+ lymphocyte increased according to NET grade.

Conclusion: Seventy-five% of GEP-NET expressed PD-L1. It might be higher rate of PD-L1 expression compared with other cancers. The absolute number of Intratumoral infiltrating lymphocyte expressing PD-1 or CD8 was also high. There might be a fraction of a good target for immune check point therapy in NETs.

Citation Format: Yasushi Ichikawa, Noritoshi Kobayashi, Ayumu Goto, Motohiko Tokuhisa, Yukihiko Hiroshima, Takashi Ishikawa, Shoko Takano, Tomio Inoue, Itaru Endo. Pilot study of immune status of GEP-NETs in tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3134.

Abstract 4188: Preoperative supplementation of branched-chain amino acids suppresses Osteopontin expression in patients with hepatocellular carcinoma

Background: Recently, the new effect of branched-chain amino acid (BCAA) on Osteopontin (OPN), which correlates with cancer progression, has been reported. The aim of this study was that preoperative administration of BCAA could improve prognosis via degradation of OPN expression in hepatocellular carcinoma (HCC).

Methods: Human hepatocellular carcinoma cell lines were treated with BCAA (2nM), and investigated OPN expression, cell proliferation and invasion in vitro. Next, patients undergoing elective liver resections for HCC (n=72) were randomized to receive or not receive preoperative oral supplementation with BCAA. OPN protein levels in HCC patients were examined using immunohistochemistry and compared with the clinicopathologic features of the tumors.

Results: Experimentally, the expression levels of OPN were significantly decreased in HCC cells treated with BCAA. BCAA treatment significantly decreased cell invasion. In the clinical setting, OPN expression correlated with HBV or HCV infection (p = 0.03), venous invasion (p = 0.02) and liver fibrosis (p = 0.07). There was no difference in both DFS and OS between OPN-positive and OPN-negative group, and preoperative BCAA administration did not improve prognosis, either. For the patients without late recurrence, OPN-positive group showed significantly poor outcome in DFS (p = 0.047), and preoperative BCAA administration improved DFS (p = 0.062).

Conclusions: OPN expression was associated with cancer cell invasion and intrahepatic metastasis. BCAA treatment suppressed HCC cell invasion and preoperative BCAA administration prevented early intrahepatic recurrence by decreasing the expression level of OPN in HCC.

Citation Format: Yukihiko Hiroshima, Yasuhiro Yabushita, Yutaro Kikuchi, Daisuke Kawagushi, Takashi Murakami, Yasushi Ichikawa, Itaru Endo, Kuniya Tanaka. Preoperative supplementation of branched-chain amino acids suppresses Osteopontin expression in patients with hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4188.