Factors Affecting Nonfunctioning Small Pancreatic Neuroendocrine Neoplasms and Proposed New Treatment Strategies.

BACKGROUND & AIMS: Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases of nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs. METHODS: In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the World Health Organization 2019 classification. Overall, 1490 patients met the eligibility criteria, and 1014 were included in the analysis cohort. RESULTS: In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate. CONCLUSIONS: NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.

Significance of Comprehensive Analysis of Preoperative Sarcopenia Based on Muscle Mass, Muscle Strength, and Physical Function for the Prognosis of Patients with Esophageal Cancer.

BACKGROUND: The assessment of muscle mass loss, muscle strength, and physical function has been recommended in diagnosing sarcopenia. However, only muscle mass has been assessed in previous studies. Therefore, this study investigated the effect of comprehensively diagnosed preoperative sarcopenia on the prognosis of patients with esophageal cancer. METHODS: The study analyzed 115 patients with esophageal cancer (age ≥ 65 years) who underwent curative esophagectomy. Preoperative sarcopenia was analyzed using the skeletal mass index (SMI), handgrip strength, and gait speed based on the Asian Working Group for Sarcopenia 2019 criteria. Clinicopathologic factors, incidence of postoperative complications, and overall survival (OS) were compared between the sarcopenia and non-sarcopenia groups. The significance of the three individual parameters also was evaluated. RESULTS: The evaluation identified 47 (40.9%) patients with low SMI, 31 (27.0%) patients with low handgrip strength, and 6 (5.2%) patients with slow gait speed. Sarcopenia was diagnosed in 23 patients (20%) and associated with older age and advanced pT stage. The incidence of postoperative complications did not differ significantly between the two groups. Among the three parameters, only slow gait speed was associated with Clavien-Dindo grade 2 or greater complications. The sarcopenia group showed significantly worse OS than the non-sarcopenia group. Those with low handgrip strength tended to have worse OS, and those with slow gait speed had significantly worse OS than their counterparts. CONCLUSIONS: Preoperative sarcopenia diagnosed using skeletal muscle mass, muscle strength, and physical function may have an impact on the survival of patients with esophageal cancer.

Prognostic Significance of Biologic Factors in Patients with a Modest Radiologic Response to Neoadjuvant Treatment for Resectable and Borderline Resectable Pancreatic Cancers: Impact of the Combination Index of Sialyl-Lewis Antigen-Related Tumor Markers.

BACKGROUND: Appropriate re-evaluation after neoadjuvant treatment (NAT) is important for optimal treatment selection. Nonetheless, determining the operative eligibility of patients with a modest radiologic response remains controversial. This study aimed to assess the prognostic significance of biologic factors for patients showing a modest radiologic response to NAT and investigate the tumor markers (TMs), CA19-9 alone, DUPAN-II alone, and their combination, to create an index that combines these sialyl-Lewis antigen-related TMs associated with treatment outcomes. METHODS: This study enrolled patients deemed to have a "stable disease" by RECIST classification with slight progression (tumor size increase rate, ≤20%) as their radiologic response after NAT. A sialyl-Lewis-related index (sLe index), calculated by adding one fourth of the serum DUPAN-II value to the CA19-9 value, was created. The prognostic significances of CA19-9, DUPAN-II, and the sLe index were assessed in relation to postoperative outcomes. RESULTS: An sLe index lower than the cutoff value (45.25) was significantly associated with favorable disease-free survival. Moreover, the post-NAT sLe index had a higher area under the curve value for recurrence within 24 months than the post-NAT levels of CA19-9 or DUPAN-II alone. Multivariable analysis showed that a post-NAT sLe index higher than 45.25 was the single independent predictive factor for recurrence within 24 months. CONCLUSIONS: Additional evaluation of biologic factors can potentially enhance patient selection, particularly for patients showing a limited radiologic response to NAT. The authors' index is a simple indicator for the biologic evaluation of multiple combined sialyl-Lewis antigen-related TMs and may offer a better predictive significance.

Results of a Randomized Clinical Study of Gemcitabine Plus Nab-Paclitaxel Versus Gemcitabine Plus S-1 as Neoadjuvant Chemotherapy for Resectable and Borderline Resectable Pancreatic Ductal Adenocarcinoma (RCT, CSGO-HBP-015).

BACKGROUND: The optimal neoadjuvant chemotherapy (NAC) regimen for patients with localized pancreatic ductal adenocarcinoma (PDAC) remains uncertain. This trial aimed to evaluate the efficacy and safety of two neoadjuvant chemotherapy (NAC) regimens, gemcitabine plus nab-paclitaxel (GA) and gemcitabine plus S-1 (GS), in patients with resectable/borderline-resectable (R/BR) PDAC. PATIENTS AND METHODS: Treatment-naïve patients with R/BR-PDAC were enrolled and randomly allocated. They received two cycles (2 months) of each standard protocol, followed by radical surgery for those without tumor progression in general hospitals belonging to our intergroup. The primary endpoint was to determine the superior regimen on the basis of achieving a 10% increase in the rate of patients with progression-free survival (PFS) at 2 years from allocation. RESULTS: A total of 100 patients were enrolled, with 94 patients randomly assigned to the GS arm (N = 46) or GA arm (N = 48). The 2-year PFS rates did not show the stipulated difference [GA, 31% (24-38%)/GS, 26% (18-33%)], but the Kaplan-Myer analysis showed significance (median PFS, GA/GS 14 months/9 months, P = 0.048; HR 0.71). Secondary endpoint comparisons yielded the following results (GA/GS arm, P-value): rates of severe adverse events during NAC, 73%/78%, P = 0.55; completion rates of the stipulated NAC, 92%/83%, P = 0.71; resection rates, 85%/72%, P = 0.10; average tumor marker (CA19-9) reduction rates, -50%/-21%, P = 0.01; average numbers of lymph node metastasis, 1.7/3.2, P = 0.04; and median overall survival times, 42/22 months, P = 0.26. CONCLUSIONS: This study found that GA and GS are viable neoadjuvant treatment regimens in R/BR-PDAC. Although the GA group exhibited a favorable PFS outcome, the primary endpoint was not achieved.

Comprehensive review of pancreatic acinar cell carcinoma: epidemiology, diagnosis, molecular features and treatment.

Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from pancreatic ductal adenocarcinoma. Pancreatic acinar cell carcinoma occurs more frequently in males and can occur in children. Serum lipase is elevated in 24-58% of patients with pancreatic acinar cell carcinoma. Pancreatic acinar cell carcinomas tend to be large at diagnosis (median tumour size: ~5 cm) and are frequently located in the pancreas head. Radiologically, pancreatic acinar cell carcinoma generally exhibits a solid appearance; however, necrosis, cystic changes and intratumoral haemorrhage can occur in larger lesions. Immunostaining is essential for the definitive diagnosis of pancreatic acinar cell carcinoma. Compared with pancreatic ductal adenocarcinoma, pancreatic acinar cell carcinoma has a more favourable prognosis. Although radical surgery is recommended for patients with pancreatic acinar cell carcinoma who do not have distant metastases, the recurrence rate is high. The effectiveness of adjuvant therapy for pancreatic acinar cell carcinoma is unclear. The response to FOLFIRINOX is generally favourable, and some patients achieve a complete response. Pancreatic acinar cell carcinoma has a different genomic profile compared with pancreatic ductal adenocarcinoma. Although genomic analyses have shown that pancreatic acinar cell carcinoma rarely has KRAS, TP53 and CDKN2A mutations, it has a higher prevalence of homologous recombination-related genes, including BRCA1/2 and ATM, than pancreatic ductal adenocarcinoma, suggesting high sensitivity to platinum-containing regimens and PARP inhibitors. Targeted therapies for genomic alternations are beneficial. Therefore, genetic testing is important for patients with pancreatic acinar cell carcinoma to choose the optimal therapeutic strategy.

The preliminary analysis of lymphatic flow around the connective tissues surrounding SMA and SpA elucidates patients' oncological condition in borderline-resectable pancreatic cancer.

BACKGROUND: In pancreatic ductal adenocarcinoma (PDAC), invasion of connective tissues surrounding major arteries is a crucial prognostic factor after radical resection. However, why the connective tissues invasion is associated with poor prognosis is not well understood. MATERIALS AND METHODS: From 2018 to 2020, 25 patients receiving radical surgery for PDAC in our institute were enrolled. HyperEye Medical System (HEMS) was used to examine lymphatic flow from the connective tissues surrounding SMA and SpA and which lymph nodes ICG accumulated in was examined. RESULTS: HEMS imaging revealed ICG was transported down to the paraaortic area of the abdominal aorta along SMA. In pancreatic head cancer, 9 paraaortic lymph nodes among 14 (64.3%) were ICG positive, higher positivity than LN#15 (25.0%) or LN#18 (50.0%), indicating lymphatic flow around the SMA was leading directly to the paraaortic lymph nodes. Similarly, in pancreatic body and tail cancer, the percentage of ICG-positive LN #16a2 was very high, as was that of #8a, although that of #7 was only 42.9%. CONCLUSIONS: Our preliminary result indicated that the lymphatic flow along the connective tissues surrounding major arteries could be helpful in understanding metastasis and improving prognosis in BR-A pancreatic cancer.

Pathological Nodal and Vascular Involvement Significantly Impacts the Recurrence Risk in Different Time Frames in Patients With Resectable and Borderline Resectable Pancreatic Cancer: Long-term Conditional Recurrence-free Survival Analysis in the Setting of a Neoadjuvant Treatment Strategy.

OBJECTIVE: To investigate the long-term dynamics of recurrence risk and the significance of prognostic variables using conditional recurrence-free survival (C-RFS) analysis in neoadjuvant treatment (NAT) for resectable (R) and borderline resectable (BR) pancreatic cancer (PC). BACKGROUND: C-RFS analysis assesses the probability of achieving additional RFS according to the RFS already accrued. METHODS: Patients with NAT and subsequent resection for R/BRPC were enrolled. In the C-RFS analysis, the actual 5-year RFS (5yRFS) rate was calculated separately in the subgroup that had already gained a given amount of RFS. The significance levels of prognostic variables associated with 5yRFS were assessed regarding their time-dependent dynamics in a conditional fashion. RESULTS: Among the total 397 patients, 160 survived for more than 5 years without recurrence after surgery (actual 5yRFS rate: 45%). The probability of 5yRFS incrementally increased based on the RFS already accrued. Pathological nodal and vascular involvement were significant influencers of 5yRFS. The patients with nodal involvement consistently remained at significantly higher risk of recurrence than those without, even after 5yRFS, whereas positivity of vascular involvement was significantly associated with the risk of recurrence only during the early postoperative period and lost its significance after 3yRFS accrued. CONCLUSIONS: In NAT for R/BRPC, the probability of gaining additional RFS increases as a function of RFS already accrued, and the significance of prognostic variables time-dependently evolves in their own patterns during the long-term postoperative period.

Clinical Impact of Early Tumour Shrinkage in Metastatic or Unresectable Oesophageal Cancer Treated with Pembrolizumab plus Chemotherapy.

INTRODUCTION: Metastatic or unresectable locally advanced oesophageal cancer remains a disease with high mortality. More recently, pembrolizumab plus chemotherapy has been indicated as the first-line treatment for those patients, but the predictive factors for treatment efficacy remain controversial. This study investigated the clinical utility of early tumour shrinkage (ETS) and depth of response (DpR) in metastatic or unresectable oesophageal cancer treated with pembrolizumab plus CF therapy. METHODS: ETS and DpR, defined as the percent decreases at the second evaluation and the percentage of the maximal tumour shrinkage during treatment, were measured in 53 eligible patients. The ETS and DpR cut-off values were 20% and 30%, respectively, based on survival outcomes. RESULTS: Twenty-seven patients (51%) were treatment-naïve, while 26 (49%) had received any treatment before initiating pembrolizumab plus CF therapy. The median progression-free survival (PFS) and overall survival (OS) for ETS ≥20% and <20% were 12.7 and 5.5 months and 14.4 and 8.2 months, and 12.7 and 4.9 months and 14.4 and 8.0 months for DpR ≥30% and <30%, respectively. ETS <20% showed early tumour growth, whereas ETS ≥20% had a good response rate with sufficient longer response duration. In addition, an ETS cut-off of 20% predicted the best overall response and was not associated with prior treatment. In multivariable analysis, ETS ≥20% and DpR ≥30% were independent factors of longer PFS. CONCLUSION: Our findings suggest that an ETS is a promising on-treatment marker for early prediction of further sensitivity to pembrolizumab plus CF therapy.

Clinicopathological characteristics and survival outcomes in patients with advanced esophageal squamous cell carcinoma who were intraoperatively diagnosed non-curative.

INTRODUCTION: Curative esophagectomy is not always possible in patients with locally advanced esophageal cancer. However, few studies have investigated patients who underwent non-curative surgery with intraoperative judgment. This study aimed to investigate patient characteristics and clinical outcomes for patients undergoing non-curative surgery and compare them between non-resectional and non-radical surgery. METHODS: Among 989 consecutive patients with thoracic esophageal squamous cell carcinoma (ESCC) who were preoperatively expected for curative esophagectomy, 66 who were eligible for non-curative surgery were included in this study. RESULTS: Intraoperative diagnosis of T4b accounted for 93% of the reasons for the failure of curative surgery. In those patients, esophageal cancer locally invaded into the aortobronchial constriction (70%), trachea (25%), or pulmonary vein (5%). LN metastasis mainly invaded into the trachea (50%), or bronchus (28%).The overall survival of patients with non-curative surgery was 51.5%, 25.7%, and 10.4% at 6, 12, and 24 months after surgery, respectively. Although there were no differences in preoperative patient characteristics between non-resectional and non-radical surgery, distant metastasis, especially pleural dissemination, was significantly observed in T4b patients due to esophageal cancer with non-radical surgery than those with non-resectional surgery (35% vs. 15%, P=0.002). Even in patients with non-curative surgery, R1 resection and postoperative CRT were identified as independent factors for survival 1 year after surgery (P=0.047, and 0.019). CONCLUSIONS: T4b tumor located in aortobronchial constriction or trachea/bronchus makes it difficult to diagnose whether it is resectable or unresectable. Moreover, surgical procedures and perioperative treatment were deeply associated with the clinical outcomes.

Prognostic value of a novel index combining the prognostic nutritional index and D-dimer levels for gastric cancer after gastrectomy.

INTRODUCTION: The prognostic nutritional index and D-dimer level are two useful measures for gastric cancer prognosis. Since they each comprise different factors, it is possible to employ a more useful combined indicator. This study therefore aimed to establish a prognostic nutritional index-D score-which combines the prognostic nutritional index and D-dimer level-and validate its usefulness as a prognostic marker. METHODS: We collected data from 1,218 patients with gastric cancer who had undergone radical gastrectomy (R0) between January 2004 and December 2015. Patients were divided into three prognostic nutritional index-D score groups based on the following criteria: score 2, low prognostic nutritional index (≤46) and high D-dimer levels (>1.0 µg/ml); score 1, either a low prognostic nutritional index or high D-dimer levels; and score 0, no abnormality. We then defined the PNI-D score as low (score 0 or 1) and high (score 2). RESULTS: The prognostic nutritional index-D score was significantly associated with overall, recurrence-free, and disease-specific survival (all log-rank P<0.0001). The 5-year overall survival rates of the patients with prognostic nutritional index-D scores of low and high were 88.1% and 64.7%, respectively; their 5-year recurrence-free survival rates were 86.7% and 61.3%, respectively; and their 5-year disease-specific survival rates were 99.3% and 76.5%, respectively. Cox multivariate analysis revealed that a high prognostic nutritional index-D score was an independent, statistically significant prognostic factor for poor overall (P=0.01) survival in the patients with gastric cancer. CONCLUSIONS: The prognostic nutritional index-D is an independent prognostic factor for patients with gastric cancer.

DUPAN-II normalisation as a biological indicator during preoperative chemoradiation therapy for resectable and borderline resectable pancreatic cancer.

BACKGROUND: Duke pancreatic mono-clonal antigen type 2 (DUPAN-II) is a famous tumour maker for pancreatic cancer (PC) as well as carbohydrate antigen 19-9 (CA19-9). We evaluated the clinical implications of DUPAN-II levels as a biological indicator for PC during preoperative chemoradiation therapy (CRT). METHODS: This retrospective analysis included data from 221 consecutive patients with resectable and borderline resectable PC at diagnosis who underwent preoperative CRT between 2008 and 2017. We focused on 73 patients with elevated pre-CRT DUPAN-II levels (> 230 U/mL; more than 1.5 times the cut-off value for the normal range). Pre- and post-CRT DUPAN-II levels and the changes in DUPAN-II ratio were measured. RESULTS: Univariate analysis identified normalisation of DUPAN-II levels after CRT as a significant prognostic factor (hazard ratio [HR] = 2.06, confidence interval [CI] = 1.03-4.24, p = 0.042). Total normalisation ratio was 49% (n = 36). Overall survival (OS) in patients with normalised DUPAN-II levels was significantly longer than that in 73 patients with elevated levels (5-year survival, 55% vs. 21%, p = 0.032) and in 60 patients who underwent tumour resection (5-year survival, 59% vs. 26%, p = 0.039). CONCLUSION: Normalisation of DUPAN-II levels during preoperative CRT was a significant prognostic factor and could be an indicator to monitor treatment efficacy and predict patient prognosis.

Rubicon can predict prognosis in patients with pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy.

BACKGROUND: Despite previous therapeutic studies on autophagy in cancer, its role in the treatment of pancreatic ductal adenocarcinoma remains controversial, especially regarding its effect on chemotherapy, radiotherapy, and both combined. We focused on RUN domain Beclin-1 interacting and cysteine-rich-containing protein (Rubicon) to reveal its contribution to pancreatic ductal adenocarcinoma after chemoradiotherapy. METHODS: To evaluate the clinical significance of Rubicon, immunohistochemistry was performed, and Rubicon expression was analyzed across 81 specimens resected from patients with pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy. A gemcitabine-resistant pancreatic ductal adenocarcinoma cell line was established followed by Rubicon expression and autophagy flux estimation. Finally, gemcitabine sensitivity, invasion ability, and cell viability were evaluated using Rubicon-targeting small interfering RNA. RESULTS: Rubicon expression in resected pancreatic ductal adenocarcinoma samples after chemoradiotherapy revealed significantly worse overall survival and recurrence-free survival in the Rubicon-high expression group than in the Rubicon-low expression group (overall survival: median [years] 2.02 vs. 3.21, p = 0.0359; recurrence-free survival: median [years] 0.90 vs. 1.90, p = 0.0146). In vitro, gemcitabine-resistant pancreatic ductal adenocarcinoma cell lines exhibited higher Rubicon expression and lower autophagy flux than the parental cell line (p < 0.01). Transduction with small interfering RNA downregulated the expression without affecting gemcitabine sensitivity, but it reduced invasion ability and cell viability (p < 0.01) in the gemcitabine-resistant pancreatic ductal adenocarcinoma cell line. CONCLUSIONS: High Rubicon expression is a significant, unfavorable prognostic factor in pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy. Downregulation of Rubicon expression improves invasion ability and cell viability in gemcitabine-resistant pancreatic ductal adenocarcinoma.

Modified Collard technique is more effective than circular stapled for cervical esophagogastric anastomosis in prevention of anastomotic stricture: a propensity score-matched study.

The anastomotic technique after esophagectomy is of great interest in the prevention of anastomotic complications that adversely affect postoperative recovery. This study aimed to compare the clinical outcomes of modified Collard (MC) and circular stapled (CS) anastomoses after esophagectomy. A total of 504 consecutive patients with thoracic esophageal cancer who underwent esophagectomy and cervical esophagogastric CS or MC anastomosis from January 2013 to December 2019 were enrolled. Out of 504 patients, 134 and 370 underwent CS and MC anastomoses. The frequency of anastomotic leakage and stricture was significantly lesser in the MC group than in the CS group (3.0 vs. 10.5%, P = 0.0014 and 11.1 vs. 34.3%, P < 0.001, respectively). CS anastomosis was an independent risk factor for anastomotic stricture (odds ratio, 4.89; P < 0.001). Oral intake was significantly higher in the group without anastomotic stricture than in the group with anastomotic stricture at 2, 3, and 6 months postoperatively (P < 0.001, P = 0.013, and P < 0.001, respectively). The percentage body weight loss (%BWL) was -12.2% in the group with anastomotic stricture and -7.5% in the group without anastomotic stricture at 3 months postoperatively (P = 0.0012). Anastomotic stricture was an independent factor associated with %BWL (odds ratio, 4.86; P = 0.010). Propensity score-matched analysis, which included 88 pairs of patients, confirmed a significantly lower anastomotic stricture rate in the MC group than in the CS group (10.2 vs. 35.2%, P < 0.001). MC anastomosis is better than CS anastomosis for reducing the frequency of anastomotic stricture, which may be useful for maintaining early postoperative nutritional status.

Tumor endothelial cell-induced CD8+ T-cell exhaustion via GPNMB in hepatocellular carcinoma.

Tumor endothelial cells (TECs) promote tumor angiogenesis and regulate cytotoxic T cells in the tumor microenvironment. However, the roles of TECs for tumor-infiltrating T-cell in hepatocellular carcinoma (HCC) is still unknown. Here, we aimed to investigate how TECs influenced tumor growth and immune responses of HCC focusing on CD8+ T-cell infiltration and exhaustion. First, TECs were isolated from subcutaneous HCC tumors with murine HCC cell lines (BNL-T) with magnetic selection of CD31+ cells, and normal endothelial cells (NECs) were isolated from normal liver. Second, immunocompetent mice were injected with BNL-T alone, BNL-T + NECs, or BNL-T + TECs for tumor formation, and the functions and exhaustion of tumor-infiltrating CD8+ T cells were evaluated. The mice injected with BNL-T + TEC showed rapid tumorigenesis and a decrease in the number of infiltrating CD8+ T cells. In addition, the percentage of CD8+ T-cell exhaustion was significantly higher in tumors from the administration of BNL-T + TEC. Third, the next-generation sequencing on TECs was performed to identify mRNAs that might be a novel treatment target. The molecule of glycoprotein nonmetastatic melanoma protein B (GPNMB) was identified and the functions of GPNMB was analyzed by silencing of GPNMB expression using small interfering RNAs. The silencing of GPNMB expression in TECs induced the suppression of tumor growth and T-cell exhaustion. In conclusion, TECs induced tumor-infiltrating T-cell exhaustion via GPNMB expression and GPNMB might be a novel therapeutic target in HCC.

ACAT-1-Regulated Cholesteryl Ester Accumulation Modulates Gemcitabine Resistance in Biliary Tract Cancer.

BACKGROUND: Biliary tract cancer (BTC) has few choices of chemotherapy, including gemcitabine, therefore exploring the mechanisms of gemcitabine resistance is important. We focused on lipid metabolism because biliary tract epithelial cells are essential in cholesterol and bile acid metabolism and the messenger RNA (mRNA) microarray analysis showed high acyl coenzyme A: cholesterol acyltransferase 1 (ACAT-1) expression in BTC gemcitabine-resistant (GR) cell lines. We hypothesized that aberrant accumulation of cholesteryl ester (CE) regulated by ACAT-1 could modulate GR in BTC. METHODS: CE accumulations were measured in human BTC cell lines, and the relationships between CE levels, ACAT-1 expressions, and gemcitabine sensitivity were analyzed. We performed a small-interfering RNA (siRNA)-mediated knockdown and biochemical inhibition of ACAT-1 in BTC cell lines and alterations of gemcitabine sensitivity were evaluated. To evaluate the clinical significance of ACAT-1 in regard to GR, immunohistochemistry was performed and ACAT-1 expressions were analyzed in resected BTC specimens. RESULTS: CE levels were correlated with ACAT-1 expressions and GR in four human BTC cell lines. siRNA-mediated knockdown of ACAT-1 in two independent GR cell clones as well as ACAT-1 inhibitor treatment significantly increased gemcitabine sensitivity; knockdown of ACAT-1: 5.63- and 8.02-fold; ACAT-1 inhibitor: 8.75- and 9.13-fold, respectively. ACAT-1 expression in resected BTC specimens revealed that the disease-free survival of the ACAT-1 low-intensity group (median 2.3 years) had a significantly better outcome than that of the ACAT-1 high-intensity group (median 1.1 years) under gemcitabine treatment after surgery (*p < 0.05). CONCLUSIONS: Our findings suggest that CE and ACAT-1 might be a novel therapeutic target for GR in BTC.

Inhibition of Clusterin Represses Proliferation by Inducing Cellular Senescence in Pancreatic Cancer.

BACKGROUND: The outcome of pancreatic ductal adenocarcinoma (PDAC) is unsatisfactory, and the identification of novel therapeutic targets is urgently needed. Clinical studies on the antisense oligonucleotide that targets clusterin (CLU) expression have been conducted and have shown efficacy in other cancers. We aimed to investigate the effects of CLU in PDAC and the underlying mechanisms with a view to the clinical application of existing drugs. METHODS: We knocked down CLU in PDAC cells and evaluated changes in cell proliferation. To elucidate the mechanism responsible for these changes, we performed western blot analysis, cell cycle assay, and senescence-associated ß-galactosidase (SA-ß-gal) staining. To evaluate the clinical significance of CLU, immunohistochemistry was performed, and CLU expression was analyzed in specimens resected from PDAC patients not treated with preoperative chemotherapy. RESULTS: Knockdown of CLU significantly decreased cell proliferation and did not induce apoptosis, but did induce cellular senescence by increasing the percentage of G1-phase and SA-ß-gal staining-positive cells. A marker of DNA damage such as γH2AX and factors related to cellular senescence, such as p21 and the senescence-associated secretory phenotype, were upregulated by knockdown of CLU. CLU expression in resected PDAC specimens was located in the cytoplasm of tumor cells and revealed significantly better recurrence-free survival and overall survival in the CLU-low group than in the CLU-high group. CONCLUSIONS: We identified that CLU inhibition leads to cellular senescence in PDAC. Our findings suggest that CLU is a novel therapeutic target that contributes to the prognosis of PDAC by inducing cellular senescence.

Preoperative FDG-Positive Lymph Nodes Predict the Postoperative Prognosis in Resectable Biliary Tract Cancers.

BACKGROUND: F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used to diagnose and stage various cancers. In regard to biliary tract cancer (BTC), due to cholangitis it is difficult to evaluate FDG uptake caused by cancer. We previously showed that FDG-positive lymph nodes (LNs) of resectable BTC had a possibility of predicting postoperative prognosis. OBJECTIVE: This study aimed to validate the usability of FDG-PET for LNs using another cohort and to investigate in detail the relationship between FDG-positive LNs and the prognosis of BTC. METHODS: We measured the preoperative maximum standardized uptake value (SUVmax) at each of the 190 surgically dissected LN areas in 67 patients and investigated the prognosis using our previously determined SUVmax cut-off values of ≥ 2.8. RESULTS: Regarding the prognosis of patients with resectable BTC, a LN SUVmax ≥ 2.8 [PET N (+)] was a poor prognostic factor for recurrence-free survival (RFS) compared with a LN SUVmax < 2.8 [PET N (-)]. It was confirmed that the hazard ratio forest plot [PET N (+)/PET N (-)] for RFS indicated a similar tendency among subcategories. Moreover, we investigated patients with pN0 disease and demonstrated that the PET N (+) group also had a significantly worse RFS outcome compared with the PET N (-) group. Recurrence of the PET N (+) group has significantly occurred more often in LNs than that of the PET N (-) group. CONCLUSION: High LN SUVmax was confirmed to be the preoperatively diagnosed prognostic risk factor for RFS in resectable BTC and could be helpful for clinical decision making regarding the perioperative treatment strategy.

Recurrence Pattern Comparing Preoperative Chemoradiotherapy and Preoperative Chemotherapy with Docetaxel plus 5-Fluorouracil and Cisplatin for Advanced Esophageal Cancer.

BACKGROUND: Preoperative chemoradiation therapy (CRT) or chemotherapy (CT) followed by surgery is currently being administered for advanced esophageal cancer. However, few studies have directly compared CRT and CT for treating locally advanced esophageal carcinoma. This study aimed to assess postoperative recurrence patterns and post-recurrence outcomes in patients with radical esophagectomy after CRT or triplet CT regimen with docetaxel, cisplatin, and 5-fluorouracil (DCF). METHODS: This study included 325 consecutive patients with thoracic esophageal cancer who received preoperative CRT or DCF followed by curative esophagectomy between January 2010 and December 2019. We compared recurrence patterns after surgery and post-recurrence treatments between CRT and DCF. Locoregional recurrence was defined as recurrences at the primary tumor site or regional lymph nodes. Distant recurrence was defined as non-regional lymph node recurrences, systemic metastases, malignant pleural effusions, or peritoneal metastases. RESULTS: Among 325 patients, 74 received preoperative CF + RT and 251 received preoperative DCF. A propensity score-matched cohort of 53 with CRT and 53 with DCF was included. CRT patients had tumors located in the upper esophagus and had more advanced cancer than DCF patients; however, no differences in patient characteristics were observed in the matched cohort. CRT patients had better histopathological responses and control of locoregional recurrence than DCF patients. On the other hand, distant recurrence, especially in the non-regional lymph node, lung, and pleural dissemination, significantly developed more frequently in CRT patients. Furthermore, CRT patients may have received insufficient post-recurrence treatment, owing to fewer treatment options. Therefore, although there was no difference in recurrence rate in the two groups, CRT patients had significantly poorer post-recurrence survival than DCF patients. CONCLUSIONS: Preoperative DCF could reduce distant recurrence after surgery compared to preoperative CRT. The differences in recurrence patterns can be related to the selection of post-recurrence treatment and their prognosis after recurrence.

Pancreatic CT density is an optimal imaging biomarker for earlier detection of malignancy in the pancreas with intraductal papillary mucinous neoplasm.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) are typically detected as incidental findings by computed tomography (CT); however, the conventional surveillance is not valid for the early detection of concomitant pancreatic cancer. The pancreas of IPMN is often accompanied by fatty infiltration in the parenchyma, and pancreatic fatty infiltration could be evaluated by pancreatic CT density (pancreatic index, PI). We aimed to investigate whether PI could be an imaging biomarker for the early prediction of malignancies in the pancreas with IPMN. METHODS: Two different cohorts were investigated. (Investigation cohort): A total of 1137 patients with initially low-risk IPMN were compensated by initial IPMN findings, and 2 groups (malignancy/possible benign, 50 cases each) were investigated for yearly changes in PI and for the cutoff value of PI indicating the development of malignancies. (Validation cohort): To validate the cutoff value, 256 patients radiologically suspected of having IPMNs were investigated. RESULTS: (Investigation-cohort): The malignancy group showed a gradual decrease in PI every year, and PI significantly differed among the 2 groups 1 year prior to the last investigation. The cutoff value of PI was set at 0.65. (Validation-cohort): A total of 55% of the patients with a PI below the cutoff value had malignancy in the pancreas, including concomitant pancreatic cancer, and the cutoff value was the most significant risk factors for the development of malignancies in the pancreas compared to the conventional risk factors for IPMN. CONCLUSIONS: Decreasing PI would be an optimal imaging biomarker for earlier detection of malignancies in the pancreas with IPMN.

Clinical Significance of Acylphosphatase 1 Expression in Combined HCC-iCCA, HCC, and iCCA.

BACKGROUND: Combined hepatocellular and cholangiocarcinoma is a rare primary liver cancer with histological features of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Little is known about the prognostic features and molecular mechanism of cHCC-iCCA. Acylphosphatase 1 is a cytosolic enzyme that produces acetic acid from acetyl phosphate and plays an important role in cancer progression. AIMS: We evaluated the clinical significance of ACYP1 expression in cHCC-iCCA, HCC, and iCCA. METHODS: ACYP1 immunohistochemistry was performed in 39 cases diagnosed with cHCC-iCCA. The prognosis was evaluated in three different cohorts (cHCC-iCCA, HCC, and iCCA). The relationships between ACYP1 expression and cell viability, migration, invasiveness, and apoptosis were examined using siRNA methods in vitro. In vivo subcutaneous tumor volumes and cell apoptosis were evaluated after downregulation of ACYP1 expression. RESULTS: Almost half of the patients with cHCC-iCCA were diagnosed with high ACYP1 expression. In all three cohorts, the cases with high ACYP1 expression had significantly lower overall survival, and high ACYP1 expression was identified as an independent prognostic factor. Downregulation of ACYP1 reduced the proliferative capacity, migration, and invasiveness of both HCC and iCCA cells. Moreover, knockdown of ACYP1 increased the ratio of apoptotic cells and decreased the expression of anti-apoptosis proteins. In vivo tumor growth was significantly inhibited by the transfection of ACYP1 siRNA, and the number of apoptotic cells increased. CONCLUSION: High ACYP1 expression could influence the prognosis of cHCC-iCCA, HCC, and iCCA patients. In vitro ACYP1 expression influences the tumor growth and cell viability in both HCC and iCCA by regulating anti-apoptosis proteins.