Long-Term Survival Outcomes After Minimally Invasive Surgery for Ileal Neuroendocrine Tumors.

BACKGROUND: Ileal neuroendocrine tumors (i-NETs) are characterized by their multifocality and bulky mesenteric mass. Having shown that minimally invasive surgery (MIS) utilizing a hand-access port device has favorable short-term outcomes and achieves the goals of surgery for i-NETs, we sought to analyze long-term survival outcomes of MIS. METHODS: One hundred and sixty-eight patients who underwent resection of primary i-NETs at a single institution between January 2007 and February 2023 were retrospectively studied. Patients were categorized into the MIS or open surgery cohorts on an intention-to-treat basis. Open surgery was selected mainly based on the need for hepatectomy or bulky mesenteric mass resection. Overall survival was analyzed using log-rank tests with propensity score matching (PSM) and Cox proportional hazards regression. PSM was performed to reduce standardized mean differences of the variables to <0.2. RESULTS: Overall, 129 (77%) patients underwent MIS and 39 (23%) underwent open surgery. Twenty-seven MIS patients were converted to an open procedure. The median follow-up time was 49 months (interquartile range 23-87 months). In the PSM cohorts, overall survival did not differ significantly between the MIS and open surgery cohorts {median 99 months (95% confidence interval [CI] 91-not applicable [NA]) vs. 103 months (95% CI 86-NA), p = 0.77; hazard ratio 0.87 (95% CI 0.33-2.2), p = 0.77}. CONCLUSIONS: MIS is an alternative to open surgery for i-NETs, achieving similar short- and long-term oncological outcomes. Bulky mesenteric mass and a plan for concurrent liver resection are potential criteria for open surgery.

Inhibition of dopamine receptor D1 signaling promotes human bile duct cancer progression via WNT signaling.

Bile duct cancer (BDC) frequently invades the nerve fibers, making complete surgical resection difficult. A single tumor mass contains cells of variable malignancy and cell-differentiation states, with cancer stem cells (CSCs) considered responsible for poor clinical outcomes. This study aimed to investigate the contribution of autosynthesized dopamine to CSC-related properties in BDC. Sphere formation assays using 13 commercially available BDC cell lines demonstrated that blocking dopamine receptor D1 (DRD1) signaling promoted CSC-related anchorage-independent growth. Additionally, we newly established four new BDC patient-derived organoids (PDOs) and found that blocking DRD1 increased resistance to chemotherapy and enabled xenotransplantation in vivo. Single-cell analysis revealed that the BDC PDO cells varied in their cell-differentiation states and responses to dopamine signaling. Further, DRD1 inhibition increased WNT7B expression in cells with bile duct-like phenotype, and it induced proliferation of other cell types expressing Wnt receptors and stem cell-like signatures. Reagents that inhibited Wnt function canceled the effect of DRD1 inhibition and reduced cell proliferation in BDC PDOs. In summary, in BDCs, DRD1 is a crucial protein involved in autonomous CSC proliferation through the regulation of endogenous WNT7B. As such, inhibition of the DRD1 feedback signaling may be a potential treatment strategy for BDC.

Preoperative Endoscopic Minor Papilla Sphincterotomy for Pancreas Divisum in a Patient with Pancreatic Cancer Who Underwent Laparoscopic Distal Pancreatectomy.

BACKGROUND: Pancreas divisum (PD) is a congenital anomaly that occurs due to failure of fusion of the dorsal and ventral pancreatic ductal systems.1-3 In PD, pancreatic juice drains mainly through the minor papilla via the dorsal duct, leading to high intraductal pressure, which can cause pancreatitis.1-3 We report a case of PD that underwent preoperative decompression using endoscopic minor papilla sphincterotomy (EMPS) before laparoscopic distal pancreatectomy (LDP) for pancreatic cancer.3 METHODS: The patient was a 74-year-old woman with pancreatic tail cancer, measuring 35 mm in size, in PD with an entirely dilated dorsal duct, implying high, intraductal pressure caused by minor papillary dysfunction. We performed EMPS to prevent postoperative pancreatitis and pancreatic fistula before LDP using a left-posterior approach, as previously described.4 As the pancreatic transection margin was positive for high-grade pancreatic intraepithelial neoplasia on intraoperative pathology, an additional resection of the pancreatic head to the right side of the portal vein was performed after the liberation of the gastroduodenal artery with both the dorsal and ventral pancreatic ducts ligated and divided. RESULTS: The operative time was 421 min, and blood loss was 70 mL. The postoperative course was uneventful, with no evidence of pancreatitis or pancreatic fistula. The patient was discharged on postoperative Day 10. Postoperative computed tomography revealed reduced dilatation of the dorsal duct. CONCLUSIONS: Preoperative EMPS may be effective in preventing pancreatic fistula after LDP in patients with PD.

Propensity Score Matching Analysis of the Safety of Completion Total Pancreatectomy for Remnant Pancreatic Tumors Versus that of Initial Total Pancreatectomy for Primary Pancreatic Tumors.

BACKGROUND: The safety and feasibility of completion total pancreatectomy (TP) for remnant pancreatic neoplasms remain controversial and are rarely compared with that of initial TP. Thus, we aimed to compare the safety of these two procedures inducing a pancreatic state. METHODS: Patients who underwent TP for pancreatic neoplasms between 2006 and 2018 at our institution were included in this study. Tumor pathologies were classified into three subgroups according to survival curves. We used 1:1 propensity score matching (PSM) to analyze age, sex, Charlson Comorbidity Index, and tumor stage. Finally, we analyzed the primary outcome Clavien-Dindo classification (CDC) grade, risks of other safety-related outcomes, and the survival rate of patients with invasive cancer. RESULTS: Of 54 patients, 16 underwent completion TP (29.6%) and 38 (70.4%) underwent initial TP. Before PSM analysis, age and Charlson Comorbidity Index were significantly higher, and T category and stage were significantly lower for the completion TP group. Upon PSM analysis, these two groups were equivalent in CDC grade [initial TP vs. completion TP: 71.4% (10/14) vs. 78.6% (11/14); p = 0.678] and other safety-related outcomes. Additionally, while the overall survival and recurrence-free survival of patients with invasive cancer were not significantly different between these two groups, the T category and stage tended to be remarkably severe in the initial TP group. CONCLUSIONS: PSM analysis for prognostic factors showed that completion TP and initial TP have similar safety-related outcomes that can be used as a decision-making reference in the surgery of pancreatic tumors.

Preoperative risk stratification of lymph node metastasis for non-functional pancreatic neuroendocrine neoplasm: An international dual-institutional study.

BACKGROUND: /Objectives: Although the presence of lymph node metastasis (LNM) defines malignant potential, preoperative prediction of LNM has not been established for non-functional pancreatic neuroendocrine neoplasm (NF-PNEN). We sought to develop a prediction system using only preoperatively available factors that would stratify the risk of LNM for NF-PNEN. METHODS: We retrospectively reviewed patients who underwent R0/1 resection of NF-PNEN at Kyoto University (2007-2019) and the University of California, San Francisco (2010-2019). Risk stratification of LNM was developed using preoperative factors by the logistic regression analysis. Long-term outcomes were compared across the risk groups. RESULTS: A total of 131 patients were included in this study. Lymph nodes were pathologically examined in 116 patients, 23 (20%) of whom had LNM. Radiological tumor size [1.5-3.5 cm (odds ratio: 13.5, 95% confidence interval: 1.77-398) and >3.5 cm (72.4, 9.06-2257) against ≤1.5 cm], <50% cystic component (8.46 × 10^6, 1.68 × 10^106-), and dilatation of main pancreatic duct ≥5 mm (31.2, 3.94-702) were independently associated with LNM. When patients were classified as the low-risk (43 patients), intermediate-risk (44 patients), and high-risk groups (29 patients), proportions of LNM differed significantly across the groups (0%, 14%, and 59%, respectively). Recurrence-free survival (RFS) of the low- and intermediate-risk groups were significantly better than that of the high-risk group (5-year RFS rates of 92.2%, 85.4%, and 47.1%, respectively). CONCLUSIONS: The prediction system using preoperative radiological factors stratifies the risk of LNM for NF-PNEN. This stratification helps to predict malignant potential and determine the surgical procedure and necessity of regional lymphadenectomy.

Nationwide registry for patients with neuroendocrine neoplasm of pancreas, gastrointestinal tract, lungs, bronchi, or thymus in Japan.

BACKGROUND: Neuroendocrine neoplasm (NEN) is a comparatively rare tumor that has been considered indolent. Due to these characteristics, detailed epidemiological data have not been analyzed in Japan. To elucidate the present status of NEN diagnosis and treatment in Japan, we started a registry cohort study in January 2015. METHODS: Patients pathologically diagnosed with NENs of the pancreas, gastrointestinal tract, lungs, bronchi, or thymus after January 2012 were enrolled in this registry after the date of ethics review committee approval in each hospital or institute. Follow-up was continued for enrolled patients. RESULTS: During 5 years of enrollment between January 2015 and December 2019, a total of 1526 participants from 63 departments were enrolled in this registry (mean, 305.2 participants/year), covering approximately 5.8% of the annual incidence of NENs in Japan. For pancreatic NEN, 41.9% of patients had metastasis and the dominant metastatic site was the liver, at twice the rate of lymph node metastasis in the current registry. In contrast, the frequency of lymph node metastasis from gastrointestinal (GI)-NEN was similar to that of the liver. The distribution of WHO 2019-based grades varied according to the primary site. Low-to-intermediate grade (G1-G2) was dominant for duodenal, jejunal/ileal, rectal, and pancreatic NENs, whereas high grade (G3 or NEC) was dominant for esophageal, stomach, and colon NENs. For PanNENs, G3 and NEC accounted only for 1.6% and 2.9%, respectively. CONCLUSIONS: These cohort data provide crucial information for clinical research to clarify the characteristics of NENs in Japan.

Patterns of chromosome 18 loss of heterozygosity in multifocal ileal neuroendocrine tumors.

Ileal neuroendocrine tumors (NETs) represent the most common neoplasm of the small intestine. Although up to 50% of patients with ileal NETs are diagnosed with multifocal disease, the mechanisms by which multifocal ileal NETs arise are not yet understood. In this study, we analyzed genome-wide sequencing data to examine patterns of copy number variation in 40 synchronous primary ileal NETs derived from three patients. Chromosome (chr) 18 loss of heterozygosity (LOH) was the most frequent copy number alteration identified; however, not all primary tumors from the same patient had evidence of this LOH. Our data revealed three distinct patterns of chr18 allelic loss, indicating that primary tumors from the same patient can present different LOH patterns including retention of either parental allele. In conclusion, our results are consistent with the model that multifocal ileal NETs originate independently. In addition, they suggest that there is no specific germline allele on chr18 that is the target of somatic LOH.

A novel stratification of mesenteric mass involvement as a predictor of challenging mesenteric lymph node dissection by minimally invasive approach for ileal neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: We classified the extent of mesenteric mass (MM) involvement that predicts challenging mesenteric lymph node dissection (mLND) by minimally invasive surgery (MIS) for ileal neuroendocrine tumors (i-NETs). METHODS: Patients who underwent surgery for i-NETs were retrospectively reviewed. MM involvement was classified as region-0: no MM; region-1: >2 cm from the origins of the ileocolic artery/vein; region-2: ≤2 cm from the origins; and region-3: more proximal superior mesenteric artery/vein. Logistic regression analysis was used to evaluate the predictive value of MM regions for gross positive mesenteric margin (mR2) and/or conversion among the MIS cohort. The open surgery cohort was used as a reference for mR2 rates. RESULTS: Of 108 patients, 83 patients (77%) underwent MIS. MMs in region-2 and region-3 were independent risk factors for mR2 and/or conversion (odds ratio [95% confidence interval]: 4.25 [1.17-16.4] and 8.51 × 107 [11.0-], respectively, against regions-0 and 1]. mR2 rates of MIS and open surgery cohorts per region did not differ significantly (4% and 7% for regions-0 and 1; 17% and 25% for region-2; and 100% and 83% for region-3). CONCLUSIONS: The novel stratification of MM regions was predictive of challenging mLND by MIS. Surgeons should have a low threshold for conversion for MMs in proximal regions.

Residual tumor volume discriminates prognosis after surgery for neuroendocrine liver metastasis.

BACKGROUND AND OBJECTIVES: We developed objective measurements of preoperative and residual tumor volume, and debulking rate, to evaluate their prognostic value for neuroendocrine liver metastasis (NELM). METHODS: Seventy-three patients who underwent surgery for NELM were analyzed retrospectively. Indices of preoperative and postoperative residual tumor volume (pre-volume index [VI] and post-VI) were calculated as the sum of the cubes of individual tumor diameters on preoperative and postoperative imaging, respectively. The debulking rate (%) was calculated as 100 - 100 × post-VI/pre-VI. The classification and regression trees method was used to classify pre-VI and post-VI. RESULTS: Overall survival (OS) was discriminated by preoperative tumor volume (5-year OS rates, 87.8% for low pre-VI and 60.1% for high pre-VI; P = .037) and residual tumor volume (5-year OS rates, 88.1% for low post-VI and 24.8% for high post-VI; P < .001). In contrast, debulking rates of 100%, ≥90%, and <90% did not discriminate OS (5-year OS rates, 88.0%, 61.9%, and 58.9%, respectively, not significant). In multivariate analysis, residual tumor volume (high post-VI, hazard ratio, 6.40; 95% confidence interval, 1.45-32.3) was an independent prognostic factor for OS. CONCLUSIONS: Objective measurement of tumor volume demonstrates that residual tumor volume is prognostic after surgery for NELM.

Risk factors for short recurrence-free survival after resection of pancreatic neuroendocrine tumor (PanNET) liver metastases: which patients should undergo resection?

Background: In the treatment of metastatic pancreatic neuroendocrine tumors (PanNETs), surgical resection is the first choice if curative resection is expected. However, most patients develop recurrence after resection of liver metastasis. Because one of the benefits of resection is to gain a tumor-free period for the patients, it is important to identify which patients achieve longer recurrence-free survival (RFS) by resection. In this study, the clinicopathological factors associated with RFS after resection of metastatic PanNETs in the liver were evaluated to identify the patient group that is suitable for resection.Methods: Consecutively diagnosed patients with PanNET liver metastasis with resection at our hospital from January 2000 to July 2019 were evaluated. A total of 26 metastatic PanNET patients with primary liver resections were evaluated. The median follow-up time was 48.3 months.Results: There were 18 NET recurrences of the total 26 resections, with a median RFS of 17.9 months. Independent risk factors for short RFS were a high Ki67 index (p = .009) and the number of resected tumors (p = .045). When the cut-off value for the Ki67 index was 5.0% and that for the number of resected tumors was 6, Ki67 > 5.0% tumors had shorter RFS (4.9 months vs. 38.2 months p = .006), and patients with tumors > = 7 tumors had shorter RFS (4.7 months vs. 27.5 months p = .001).Conclusions: These findings indicate that good candidates for resection of metastatic tumors of PanNETs could be patients with low Ki67 tumors and a small number of metastatic tumors.

Prognostic impact of a large mesenteric mass >2 cm in ileal neuroendocrine tumors.

BACKGROUND AND OBJECTIVES: Ileal neuroendocrine tumors (i-NETs) frequently metastasize to mesenteric lymph nodes and the liver. Regional lymphadenopathy is associated with desmoplasia of the mesentery forming a large mesenteric mass (LMM). Although the latest American Joint Committee on Cancer TNM staging (8th edition) defined LMM >2 cm as N2, the prognostic impact of LMM is ill-defined. We evaluated whether LMM is prognostic for patients with i-NETs. METHODS: This single-institution, retrospective cohort study included 106 patients who underwent resection of i-NETs between 2007 and 2018. Overall survival (OS) and liver progression-free survival (LPFS) were compared between patients with and without LMM. RESULTS: LMM was present in 66 patients (62%) and was not associated with the presence or absence of liver metastasis (P = .969) or the extent of liver involvement (P = .938). OS and LPFS differed significantly between patients with and without LMM (5-year OS rates of 64.8% and 92.9%, respectively, P = .011; 3-year LPFS rates of 45.3% and 67.5%, respectively, P = .025). In multivariate analysis, LMM was an independent prognostic factor for both OS (hazard ratio: 4.69, 95% confidence interval: 1.63-17.6) and LPFS (1.99, 1.08-3.88). CONCLUSION: LMM >2 cm is prognostic for OS and LPFS and represents aggressive tumor biology.

CAAT/enhancer binding protein-homologous protein deficiency attenuates liver ischemia/reperfusion injury in mice.

Ischemia/reperfusion injury (IRI) is one of the main causes of liver dysfunction after liver surgery. Involvement of endoplasmic reticulum (ER) stress in various diseases has been demonstrated, and CAAT/enhancer binding protein-homologous protein (CHOP) is a transcriptional regulator that is induced by ER stress. It is also a key regulator of ER stress-mediated apoptosis. The aim of this study was to investigate the role of CHOP in liver IRI. Wild type (WT) and CAAT/enhancer binding protein-homologous protein knockout (CHOP-/-) mice were subjected to 70% liver warm ischemia/reperfusion for 60 minutes. At different times after reperfusion, liver tissues and blood samples were collected for evaluation. Induction of ER stress including CHOP expression was ascertained. Liver damage was evaluated based on serum liver enzymes, liver histology, and neutrophil infiltration. Hepatocyte death including apoptosis was assessed. Liver warm IRI induced ER stress in both WT and CHOP-/- mice. In addition, CHOP expression was up-regulated in WT mice. At 6 hours after reperfusion, liver damage was attenuated in CHOP-/- mice. On the basis of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining, apoptotic and necrotic cells were significantly reduced in CHOP-/- mice. CHOP deficiency also reduced the cleavage of caspase 3 and expression of the proapoptotic protein B cell lymphoma 2-associated X protein. Liver IRI induces CHOP expression, and CHOP deficiency attenuates liver IRI by inhibiting apoptosis. Elucidation of the function of CHOP in liver IRI may contribute to further investigation for a therapy against liver IRI associated with the ER stress pathway. Liver Transplantation 24 645-654 2018 AASLD.

Nardilysin promotes hepatocellular carcinoma through activation of signal transducer and activator of transcription 3.

Nardilysin (NRDC) is a metalloendopeptidase of the M16 family. We previously showed that NRDC activates inflammatory cytokine signaling, including interleukin-6-signal transducer and activator of transcription 3 (STAT3) signaling. NRDC has been implicated in the promotion of breast, gastric and esophageal cancer, as well as the development of liver fibrosis. In this study, we investigated the role of NRDC in the promotion of hepatocellular carcinoma (HCC), both clinically and experimentally. We found that NRDC expression was upregulated threefold in HCC tissue compared to the adjacent non-tumor liver tissue, which was confirmed by immunohistochemistry and western blotting. We also found that high serum NRDC was associated with large tumor size (>3 cm, P = 0.016) and poor prognosis after hepatectomy (median survival time 32.0 vs 73.9 months, P = 0.003) in patients with hepatitis C (n = 120). Diethylnitrosamine-induced hepatocarcinogenesis was suppressed in heterozygous NRDC-deficient mice compared to their wild-type littermates. Gene silencing of NRDC with miRNA diminished the growth of Huh-7 and Hep3B spheroids in vitro. Notably, phosphorylation of STAT3 was decreased in NRDC-depleted Huh-7 spheroids compared to control spheroids. The effect of a STAT3 inhibitor (S3I-201) on the growth of Huh-7 spheroids was reduced in NRDC-depleted cells relative to controls. Our results show that NRDC is a promising prognostic marker for HCC in patients with hepatitis C, and that NRDC promotes tumor growth through activation of STAT3.

Feasibility of the liver-first approach for patients with initially unresectable and not optimally resectable synchronous colorectal liver metastases.

PURPOSE: To investigate the outcomes of patients with colorectal cancer and initially unresectable or not optimally resectable liver metastases, who were treated using the liver-first approach in the era of modern chemotherapy in Japan. METHODS: We analyzed and compared data retrospectively on patients with asymptomatic resectable colorectal cancer and initially unresectable or not optimally resectable liver metastases, who were treated either using the liver-first approach (n = 12, LF group) or the primary-first approach (n = 13, PF group). RESULTS: Both groups of patients completed their therapeutic plan and there was no mortality. Postoperative morbidity rates after primary resection and hepatectomy, and post-hepatectomy liver failure rate were comparable between the groups (p = 1.00, p = 0.91, and p = 0.55, respectively). Recurrence rates, median recurrence-free survival since the last operation, and 3-year overall survival rates from diagnosis were also comparable between the LF and PF groups (58.3 vs. 61.5 %, p = 0.87; 10.5 vs. 18.6 months, p = 0.57; and 87.5 vs. 82.5 %, p = 0.46, respectively). CONCLUSIONS: The liver-first approach may be an appropriate treatment sequence without adversely affecting perioperative or survival outcomes for selected patients.

Impact of Hepatic Steatosis on Disease-Free Survival in Patients with Non-B Non-C Hepatocellular Carcinoma Undergoing Hepatic Resection.

BACKGROUND: Although the prevalence of non-B non-C hepatocellular carcinoma (NBNC HCC) has increased, its clinicopathologic characteristics remain unclear. METHODS: We retrospectively analyzed 518 HCC patients who underwent hepatic resection. Hepatitis B surface antigen- and hepatitis C antibody-negative patients were categorized into the NBNC HCC group (n = 145); others were categorized into the hepatitis B or C HCC (BC HCC) group (n = 373). We subdivided the etiologies of NBNC HCC according to alcohol intake and presence of steatosis. RESULTS: NBNC HCC was associated with nonalcoholic fatty liver disease (NAFLD) (13.1 %), fatty liver disease with moderate alcohol intake (9.0 %), alcoholic liver disease (ALD) (29.7 %), cryptogenic disease (44.1 %), and other known etiologies (4.1 %). The prevalence of obesity, diabetes mellitus, and hypertension was higher and hepatic function was better in the NBNC HCC group, which had significantly larger tumors than the BC HCC group. The entire NBNC HCC group displayed similar overall and disease-free survival as the BC HCC group. Among the subdivisions, NAFLD-associated HCC patients had significantly better disease-free survival than ALD-associated HCC and BC HCC patients. Microvascular invasion (hazard ratio [HR] 2.30; 95 % confidence interval [CI] 1.33-3.96) and steatosis area <5 % of noncancerous region (HR 2.13; 95 % CI 1.21-3.93) were associated with disease-free survival in NBNC HCC patients. CONCLUSIONS: The prognosis of NBNC HCC was similar to that of BC HCC. Among NBNC HCC patients, NAFLD-associated HCC patients had a relatively low recurrence risk. Absence of steatosis in hepatic parenchyma had a significant impact on disease-free survival in NBNC HCC patients.