A surgical resection of hepatic granuloma mimicking intrahepatic cholangiocarcinoma: a case report.

Hepatic granuloma is relatively rare, and benign tumor of the liver. Herein, we report an unusual case of hepatic granuloma mimicking intrahepatic cholangiocarcinoma (ICC). An 82-year-old woman with a history of viral hepatitis B was admitted for investigation of liver mass in the left lobe. Dynamic computed tomography revealed a mostly hypo-enhancing main tumor with a peripheral ring enhancement, and positron emission tomography demonstrated localized an abnormal accumulation of fludeoxyglucose. Considering the possibility of malignant disease, extended left hepatectomy was performed. The resected tumor was macroscopically a periductal infiltrating nodular type, 4.5 × 3.6 cm in diameter. The pathological findings showed that granuloma and coagulative necrosis were present, and diagnosis of hepatic granuloma was confirmed. Pathological studies demonstrated that periodic acid-Schiff stain, Grocott-Gomori stain and Ziehl-Neelsen stain were all negative in the lesion.

The malignant potential of pancreatic intraductal papillary mucinous neoplasm is reflected in expression levels of fucosylated glycans in α1 -acid glycoprotein.

BACKGROUND: Pancreatic intraductal papillary mucinous neoplasm (IPMN) involves multiple histopathological stages from benign to malignant lesions. Further, a biomarker to diagnose the malignant IPMN (IPMC) is clinically relevant. Recently, we found that serum fucosylated α1 -acid glycoprotein (fAGP) level markedly elevated along with disease progression in large cohorts of patients with various cancers. METHODS: The fAGP level was retrospectively analyzed in preoperative sera from 109 patients with IPMN, and the clinical relevance of fAGP was compared with currently available predictors as standard. RESULTS: The fAGP level in IPMC was found to be significantly higher than in benign IPMN (P = .0012). At a cutoff value of 27.04 U/µg, its sensitivity, specificity, and accuracy for IPMC were determined to be 83.61%, 65.96%, and 75.93%, respectively. Multivariate analyses revealed that the fAGP level was the only independent risk factor for predicting IPMC. Additionally, a combination of the fAGP level and 18 F-fluorodeoxyglucose uptake on the PET/CT imaging in the lesions seemed to offer the best diagnosis of IPMN. Accordingly, 27 of the 28 patients who were positive in both tests had IPMC, while patients who are negative had benign IPMN. CONCLUSIONS: The fAGP level appeared to be a relevant biomarker for malignant potential of IPMN.

Risk factors for lymph node metastasis in patients with pancreatic neuroendocrine neoplasms.

BACKGROUND: Although PNENs generally have a better prognosis than pancreatic cancers, some PNENs display malignant behavior including lymph node (LN) metastasis. Complete tumor resection can be the only potentially curative treatment for patients with resectable PNENs. However, the indications for LN dissection are still controversial. Over the last decade, minimally invasive surgery such as laparoscopic pancreatic surgery (LPS) has been increasingly performed for pancreatic tumors including PNENs. AIM: To investigate the risk factors for LN metastasis in PNENs and to select appropriate patients for limited surgery by LPS. METHODS: From April 2001 to December 2019, 92 patients underwent pancreatic resection for PNENs at Kumamoto University Hospital. Finally, 82 patients were enrolled in this study. Using perioperative factors, we examined the predictive factors for LN metastasis in PNENs. RESULTS: Among the 82 patients, the percentage of LN metastasis according to the pathological findings was 12% (10/82 cases). The median tumor size was 12 mm (range: 5-90 mm). The median tumor size in the LN-positive group (37 mm) was significantly larger than that in the LN-negative group (12 mm) (P = 0.0001). Multivariate analyses revealed that larger tumor size (≥ 20 mm) was an independent risk factor for LN metastasis (odds ratio 16.8, P = 0.0062). In patients with small tumors (≤ 10 mm), LN metastasis was not found. CONCLUSION: Larger tumor size (≥ 20 mm) is an independent risk factor for LN metastasis in PNENs. In smaller PNENs (≤ 10 mm), we may be able to choose limited surgery without LN dissection.

Survival impact of immune cells infiltrating peritumoral area of hepatocellular carcinoma.

Inflammatory and immune cells in the tumor microenvironment are reported to be associated with tumor progression in several cancers. In total, 225 patients who underwent initial and curative hepatectomy for hepatocellular carcinoma (HCC) from 2004 to 2013 were enrolled in this study. Tumor-associated neutrophils (TANs), M2 macrophages (TAMs; tumor-associated macrophages), CD8+ T cells, and regulatory T cells (Tregs) were evaluated by immunohistochemistry (IHC), and their relationships with patient clinicopathological characteristics and prognosis were evaluated. IHC was performed focusing on TANs first. We could not find a relationship between intratumoral and peritumoral TANs and clinicopathological features except for the fibrous capsule and infiltration of tumors into capsule. Next, TAMs, CD8+ cells and Tregs were evaluated by IHC. At the peritumoral area, TANs and TAMs (r = 0.36, p = 0.001) or Tregs (r = 0.16, p = 0.008) showed a positive correlation, whereas TANs and CD8+ cells showed a negative correlation (r = -0.16, p = 0.02). As for survival outcomes, at the peritumoral area, high TANs (p = 0.0398), low CD8+ cells (p = 0.0275), and high TAMs (p = 0.001) were significantly associated with worse overall survival (OS). In addition, high TANs (p = 0.010), and high TAMs (p = 0.00125) were significantly associated with worse disease-free survival (DFS). Finally, we established a risk signature model by combining the expression patterns of these cells. The high-risk signature group had significantly worse OS (p = 0.0277) and DFS (p = 0.0219) compared with those in the low-risk signature group. Our risk signature based on immune cells at the peritumoral area of the HCC can predict patient prognosis of HCC after curative hepatectomy.

Major postoperative complications are associated with early recurrence of hepatocellular carcinoma following hepatectomy.

BACKGROUND AND AIM: Early recurrence (ER) is a strong predictor of poor prognosis in patients with hepatocellular carcinoma (HCC) after hepatectomy. The aim of this study was to examine manageable factors associated with ER. METHODS: Overall, 475 consecutive patients with primary HCC who underwent curative hepatectomy were included (R0/R1). We defined ER as recurrence within 2 years after hepatectomy and analyzed predictors for ER. We also defined postoperative complication as Clavien-Dindo classification grade III or IV. RESULTS: ER after hepatectomy was observed in 209 cases (44.0%). Patients with ER had a significantly poor prognosis compared with those with late recurrence (log-rank p < 0.0001) and were more likely to be diagnosed with extrahepatic metastasis (p = 0.009). Significant predictors for ER were des-γ-carboxyprothrombin > 40 mAU/mL (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.36-3.14, p = 0.001), multiple tumors (OR 2.80 95%CI 1.83-4.32, p < 0.0001), cirrhosis (OR 1.53, 95%CI 1.01-2.32, p = 0.043), and postoperative complications (OR 1.72, 95% CI 1.05-2.85, p = 0.032). Blood loss (OR 1.09, 95%CI 1.05-1.13, p < 0.0001) and cirrhosis (OR 1.74, 95%CI 1.05-2.86, p = 0.031) were significant predictors for postoperative complications. CONCLUSIONS: We should pay close attention to surgical associated- and disease-specific factors in hepatectomy for HCC to prevent ER.

What are the factors predictive of postoperative complications in patients with colorectal cancer undergoing stenting as a bridge to surgery?

OBJECTIVE: Using a self-expanding metal stent as a bridge to surgery (BTS) is considered a reasonable strategy for patients with acute malignant large bowel obstruction. Since postoperative complications have a negative impact on patient survival, we aim to clarify the predictors of complications in patients undergoing BTS using a self-expanding metal stent. METHODS: We conducted a retrospective review of 61 patients with colorectal cancer (CRC) who underwent stenting as a BTS at our institution. We analyzed the association of postoperative complications with clinicopathologic, surgical, and patient factors, and with the prestenting or preoperative laboratory data. RESULTS: Both postoperative complications in general and severe complications were significantly associated with a longer stenotic-section length (p = 0.007 and p = 0.003), lower preoperative hemoglobin levels (p < 0.001 and p = 0.081), and lower prestenting hemoglobin levels (p = 0.006 and p = 0.042). Multivariate logistic regression analysis showed that lower prestenting (<13.0 g/dl) and preoperative (<11.5 g/dl) hemoglobin levels were independent predictive factors for postoperative complications (odds ratio [OR]: 4.15; 95% confidence interval [CI]: 1.07-18.90; p = 0.040; and OR: 4.93; 95% CI: 1.35-20.28; p = 0.016). A stenotic-section length of 5.0 cm or greater was predictive of severe complications (OR: 25.67; 95% CI: 1.95-1185.00; p = 0.011). CONCLUSIONS: Our data suggest that lower hemoglobin levels before stenting and a longer length of the stenotic section of bowel might predict postoperative complications in patients with CRC undergoing BTS for obstruction.

Efficacy of a newly developed bioabsorbable pancreatic clip for distal pancreatectomy in swine.

PURPOSE: At present, ≥ 20% of patients experience clinically relevant postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP). METHODS: We developed a new bioabsorbable pancreatic clip (BioPaC) made of polycaprolactone that does not crush the pancreatic parenchyma during occlusion of the pancreatic stump. We confirmed the efficacy of this BioPac in a porcine DP model and compared it to a linear stapling device (Reinforce®). RESULTS: Pigs were killed at 1 month after DP. In the BioPaC group, all swine (n = 3) survived well without POPF. In the Reinforce® group (n = 2), one pig died early at postoperative day 7 with Grade C POPF (amylase 43 700 U/l), and the other survived until 1 month at scarification with biochemical leakage of POPF (amylase 3 725 U/l). Pathologically, the main pancreatic duct and pancreatic parenchyma were well closed by BioPaC. CONCLUSION: The newly developed BioPaC is effective in a porcine DP model.

Efficacy of Ring Drape and Unused Sterile Instruments for Incisional SSI After Hepatectomy.

BACKGROUND/AIM: The aim of this study was to verify the efficacy of wound protection with a plastic ring wound protector (ring drape) and using new sterile instruments when closing the abdominal wall (wound closure set), both of which were used to prevent incisional surgical site infection (SSI) after hepatectomy. PATIENTS AND METHODS: The incidence of incisional SSIs and the clinical courses of 572 patients who underwent hepatectomy between January 2010 and December 2015 were studied retrospectively. The patients were divided into three period groups according to the period when each infection countermeasure was started. RESULTS: Incisional SSI incidence decreased significantly with additional countermeasures: 1st period 10.1%; 2nd period 2.08% (p=0.0114); 3rd period, 1.63% (1st vs. 3rd period, p=0.0016). A multivariate analysis showed that postoperative bile leakage [odds ratio (OR)=4.12, p=0.012] and not using a ring drape (OR=0.176, p=0.003) were independent factors for incisional SSI. CONCLUSION: Incisional SSI incidence was significantly reduced by using ring drape after hepatectomy.

[Safety of Pancreaticoduodenectomy in Patients of Advanced Age and Our Efforts to Prevent Postoperative Pneumonia].

With the aging of society, surgical patients are becoming older. The same trend can be seen in patients undergoing highly invasive operations, such as pancreaticoduodenectomy(PD). The risk of postoperative complications is reportedly higher in patients of advanced age, and postoperative pneumonia occurs at particularly high frequency. We investigated the safety of PD in patients of advanced age with a focus on the prevention of postoperative pneumonia. In total, 223 patients underwent PD at our department from January 2015 to December 2020. We compared various parameters between older patients(≥80 years of age, n=32)and younger patients(<80 years of age, n=191). Although older patients had lower nutrition scores, there was no significant difference in the incidence of postoperative complications between the two groups. Three older patients who were undergoing swallowing rehabilitation by a speech-language therapist did not develop postoperative pneumonia. However, one patient who did not receive swallowing rehabilitation developed postoperative pneumonia. Based on these findings, we plan to incorporate swallowing evaluation before postoperative oral intake into the clinical pathway and introduce speech-language therapy intervention in patients of advanced age.

Metabolic shift to serine biosynthesis through 3-PG accumulation and PHGDH induction promotes tumor growth in pancreatic cancer.

Cancer cells craftily adapt their energy metabolism to their microenvironment. Nutrient deprivation due to hypovascularity and fibrosis is a major characteristic of pancreatic ductal adenocarcinoma (PDAC); thus, PDAC cells must produce energy intrinsically. However, the enhancement of energy production via activating Kras mutations is insufficient to explain the metabolic rewiring of PDAC cells. Here, we investigated the molecular mechanism underlying the metabolic shift in PDAC cells under serine starvation. Amino acid analysis revealed that the concentrations of all essential amino acids and most nonessential amino acids were decreased in the blood of PDAC patients. In addition, the plasma serine concentration was significantly higher in PDAC patients with PHGDH-high tumors than in those with PHGDH-low tumors. Although the growth and tumorigenesis of PK-59 cells with PHGDH promoter hypermethylation were significantly decreased by serine starvation, these activities were maintained in PDAC cell lines with PHGDH promoter hypomethylation by serine biosynthesis through PHGDH induction. In fact, DNA methylation analysis by pyrosequencing revealed that the methylation status of the PHGDH promoter was inversely correlated with the PHGDH expression level in human PDAC tissues. In addition to PHGDH induction by serine starvation, PDAC cells showed enhanced serine biosynthesis under serine starvation through 3-PG accumulation via PGAM1 knockdown, resulting in enhanced PDAC cell growth and tumor growth. However, PHGDH knockdown efficiently suppressed PDAC cell growth and tumor growth under serine starvation. These findings provide evidence that targeting the serine biosynthesis pathway by inhibiting PHGDH is a potent therapeutic approach to eliminate PDAC cells in nutrient-deprived microenvironments.

Borderline resectable for colorectal liver metastases: Present status and future perspective.

Surgical resection for colorectal liver metastases (CRLM) may offer the best opportunity to improve prognosis. However, only about 20% of CRLM cases are indicated for resection at the time of diagnosis (initially resectable), and the remaining cases are treated as unresectable (initially unresectable). Thanks to recent remarkable developments in chemotherapy, interventional radiology, and surgical techniques, the resectability of CRLM is expanding. However, some metastases are technically resectable but oncologically questionable for upfront surgery. In pancreatic cancer, such cases are categorized as "borderline resectable", and their definition and treatment strategies are explicit. However, in CRLM, although various poor prognosis factors have been identified in previous reports, no clear definition or treatment strategy for borderline resectable has yet been established. Since the efficacy of hepatectomy for CRLM was reported in the 1970s, multidisciplinary treatment for unresectable cases has improved resectability and prognosis, and clarifying the definition and treatment strategy of borderline resectable CRLM should yield further improvement in prognosis. This review outlines the present status and the future perspective for borderline resectable CRLM, based on previous studies.

Frailty is associated with poor prognosis after resection for pancreatic cancer.

BACKGROUND: With population aging, the number of frail patients with pancreatic cancer has increased. The Clinical Frailty Scale (CFS) is a simple and validated tool to assess frailty, and higher scores predict worse clinical outcomes after cardiovascular surgery. In this retrospective study, we aimed to examine the association of preoperative frailty with prognosis after resection for pancreatic cancer. METHODS: We retrospectively analyzed data from 142 consecutive patients undergoing resection for pancreatic cancer between April 2010 and December 2018. We used the CFS: 1 (very fit) to 9 (terminally ill) to assess frailty and examined associations of the CFS scores with recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs), controlling for potential confounders. RESULTS: Of the 142 patients, 113 (80%) had CFS scores of ≤ 3, 13 (9.2%) scores of 4, and 16 (11%) scores of ≥ 5. Scores of ≥ 5 on the CFS were associated with worse CSS (univariable HR: 2.62, 95% confidence interval [CI]: 1.19-5.18, P = 0.019; multivariable HR: 2.49, 95% CI 1.05-5.34, P = 0.039) and OS (univariable HR: 2.42, 95% CI 1.19-4.46, P = 0.016; multivariable HR: 2.25, 95% CI 1.05-4.43, P = 0.038). The association between CFS scores and RFS was not significant in multivariable analysis (univariable HR: 2.11, 95% CI 1.08-3.79, P = 0.030; multivariable HR: 1.47, 95% CI 0.71-2.83, P = 0.29). CONCLUSION: Higher scores on the CFS are associated with worse CSS and OS after resection for pancreatic cancer. Preoperative measurement of frailty may improve risk assessment among patients with pancreatic cancer.

A case of primary carcinosarcoma of the liver with combined hepatocellular carcinoma and cholangiocarcinoma.

Primary carcinosarcoma of the liver is extremely rare. Here, we report an unusual case of carcinosarcoma of the liver containing combined hepatocellular carcinoma and cholangiocarcinoma. A 66-year-old man with a history of viral hepatitis B was admitted for investigation of multiple liver masses. Dynamic computed tomography revealed a mostly hypoenhancing main tumor with a peripheral ring enhancement and several satellite nodules. After transcatheter arterial chemoembolization and portal vein embolization, an extended right posterior sectionectomy was performed. The resected tumor was macroscopically a simple nodular type, 4.3 × 4.2 cm in diameter, with a dense fibrous capsule. The pathological findings showed that both carcinomatous and sarcomatous elements were present, and diagnosis of carcinosarcoma of the liver was confirmed. The carcinomatous element consisted of hepatocellular carcinoma and cholangiocarcinoma. The sarcomatous element was composed of spindle cells. Immunohistochemical studies demonstrated that cytokeratin AE1/AE3, human serum albumin, cytokeratin 7, and Arginase-1 were partially positive in tumor cells of the carcinomatous element but not in tumor cells of the sarcomatous element. Follow-up for 30 months after surgery has shown no signs of recurrence.

Multiple hepatic inflammatory pseudotumors with elevated alpha-fetoprotein and alpha-fetoprotein lectin 3 fraction with various PET accumulations: a case report.

BACKGROUND: Hepatic inflammatory pseudotumor (IPT) is a rare, benign, tumor-like lesion. Because there are no characteristic laboratory markers or radiological features, hepatic IPT is often misdiagnosed as a malignant neoplasm such as hepatocellular carcinoma (HCC). CASE PRESENTATION: A 68-year-old man with liver dysfunction due to chronic hepatitis C virus infection and alcoholic liver disease presented with hepatic tumors in segments III and VIII. The levels of serum alpha-fetoprotein (AFP) and its Lens culinaris agglutinin-reactive fraction, AFP lectin 3 (AFP-L3), were elevated to 822.8 ng/ml and 75.2%, respectively. The tumor showed contrast enhancement on contrast-enhanced computed tomography and various accumulation on positron emission tomography. Based on these biological and imaging features, HCC was suspected, and we performed laparoscopic partial hepatectomy for these two tumors. Pathological diagnosis revealed that both tumors were hepatic IPTs with no malignant characteristics. After hepatectomy, the serum AFP and AFP-L3 levels decreased to the normal range. CONCLUSION: We report a very rare case of hepatic IPT with elevated serum AFP and AFP-L3, mimicking HCC. Clinicians should include this rare neoplasm in the differential diagnoses of hepatic tumors even when the serum markers for HCC are elevated.

MicroRNA-25 Exerts an Oncogenic Function by Regulating the Ubiquitin Ligase Fbxw7 in Hepatocellular Carcinoma.

BACKGROUND: MicroRNA (miRNA) expression abnormalities are implicated in tumor progression. Previous reports have indicated that microRNA-25 (miR-25) acts as a tumor suppressor or oncogene in diverse cancers. However, its molecular mechanisms in hepatocellular carcinoma (HCC) are still unclear. F-box and WD repeat domain 7 (Fbxw7) is a critical tumor suppressor and is one of the most important deregulated proteins of the ubiquitin-proteasome system in cancer. Our objective was to elucidate the role of miR-25 and Fbxw7 in HCC and to clarify the mechanism by which Fbxw7 is regulated. METHODS: Fbxw7 expression was estimated in 210 fixed paraffin-embedded HCC samples by immunohistochemistry, and miR-25 expression was evaluated in 142 frozen HCC tissue samples by quantitative real-time PCR. Oncogenic functions of miR-25 and its role in the regulation of Fbxw7 expression were assayed in vitro. RESULTS: miR-25 was overexpressed in HCC tissue compared with adjacent normal tissue and significantly correlated with a poorer prognosis. Moreover, it was inversely correlated with Fbxw7 expression in HCC tissues. Furthermore, miR-25 inhibition significantly reduced the proliferation, migration, and invasion of HCC cells in vitro. CONCLUSION: miR-25 may promote tumor progression in HCC patients by repression of Fbxw7 and could serve as a promising molecular target for HCC treatment.

Intraoperative bile culture helps choosing antibiotics in pancreaticoduodenectomy: Mechanistic profiling study of complex rink between bacterobilia and postoperative complications.

BACKGROUND: Postoperative complications after pancreaticoduodenectomy (PD) is still a major concern. The aim of this study was to propose how to choose antibiotics, based on bacterial sensitivity profiling involved in postoperative complications after PD. METHODS: Two hundred and thirty patients underwent PD between 2008 and 2018 at Kumamoto University Hospital. We enrolled 121 patients who had both intraoperative bile culture and drain culture on postoperative day (POD) 3. The clinical impact of the bacterial profile on postoperative outcome was retrospectively analyzed. RESULTS: Multivariate regression analysis revealed that intraperitoneal contamination on POD3 was independently associated with postoperative complications (odds ratio 2.62, P = .02). The bacteria in intraperitoneal drain on POD3 showed 94.9% similarity with those in bile collected during surgery. The major species were Enterococcus (44.6%) and Enterobacter (38.5%). Enterobacter species caused a higher rate of postoperative complications than others (83% vs 54%, P = .04). Three out of five Enterococcus faecium were resistant to carbapenems that were active against all Gram-negative rods. CONCLUSIONS: Intraperitoneal contamination on POD3, which had similar bacterial species as bile collected during surgery, was correlated with postoperative complications. The bacterial antibiotic sensitivity profile may help selecting optimal antibiotics against infectious postoperative complications in PD.

High ARHGEF2 (GEF-H1) Expression is Associated with Poor Prognosis Via Cell Cycle Regulation in Patients with Pancreatic Cancer.

BACKGROUND: Pancreatic cancer has an extremely poor prognosis, even after curative resection. Treatment options for pancreatic cancer remain limited, therefore new therapeutic targets are urgently needed. We searched for genes predictive of poor prognosis in pancreatic cancer using a public database and validated the survival impact of the selected gene in a patient cohort. METHODS: We used a public database to search for genes associated with early pancreatic cancer recurrence. As a validation cohort, 201 patients who underwent radical resection in our institution were enrolled. Expression of the target gene was evaluated using immunohistochemistry (IHC). We evaluated growth and invasiveness using small interfering RNAs, then performed pathway analysis using gene set enrichment analysis. RESULTS: We extracted ARHGEF2 from GSE21501 as a gene with a high hazard ratio (HR) for early recurrence within 1 year. The high ARHGEF2 expression group had significantly poorer recurrence-free survival (RFS) and poorer overall survival (OS) than the low ARHGEF2 expression group. Multivariate analysis demonstrated that high ARHGEF2 expression was an independent poor prognostic factor for RFS (HR 1.92) and OS (HR 1.63). In vitro, ARHGEF2 suppression resulted in reduced cell growth and invasiveness. Bioinformatic analysis revealed that ARHGEF2 expression was associated with MYC, G2M, E2F, and CDC25A expression, suggesting that c-Myc and cell cycle genes are associated with high ARHGEF2 expression. IHC revealed a positive correlation between ARHGEF2 and c-Myc expression. CONCLUSIONS: High ARHGEF2 expression is associated with cell cycle progression, and predicts early recurrence and poor survival in patients with pancreatic cancer.

A case of inferior right hepatic vein-right hepatic vein bypass with interrupted inferior vena cava compressed by focal nodular hyperplasia in caudate lobe.

Focal nodular hyperplasia (FNH) is a relatively common benign liver tumor with rare indications to surgery. Budd-Chiari syndrome is a rare condition caused by interrupted hepatic venous outflow in the hepatic veins and inferior vena cava (IVC). A 42-year-old woman was referred to our department with a hepatic tumor. Patient's chief complaint was leg edema. Because of this symptom, it was difficult for the patient to stand for more than 20 min in the evening. Computed tomography (CT) showed a hypervascular mass compressing IVC in the caudate lobe of the liver. Fine needle aspiration was performed, and preoperative diagnosis was focal nodular hyperplasia (FNH). Hepatic resection of the right caudate lobe was performed. Postoperative histological examination revealed that the tumor was FNH. After surgery, the patient's leg edema disappeared, and postoperative CT revealed that severe IVC stenosis was improved. Although there have been several reports of giant FNH causing Budd-Chiari syndrome, this case shows the stenosis of IVC below the root of hepatic veins causing Budd-Chiari-like syndrome without portal hypertension. The location of the tumor considerably attributed to the congestion of venous flow in IVC causing various symptoms and intrahepatic inferior right hepatic vein-right hepatic vein bypass. The surgical indication of FNH is limited in most cases; however, the current report alerts that the location of FNH should be taken into account when monitoring it.

Trastuzumab upregulates programmed death ligand-1 expression through interaction with NK cells in gastric cancer.

BACKGROUND: The predictive significance of programmed death ligand 1 (PD-L1) for programmed death 1 (PD-1) inhibitors remains unclear in gastric cancer (GC) due to the dynamic alteration by treatments. We aimed to elucidate the effects of trastuzumab (Tmab) on PD-L1 expression in GC. METHODS: PD-L1 expression was evaluated by multicolour flow cytometry analysis after co-culturing GG cell lines and immune cells with Tmab. IFN-γ in the co-culture experiments was quantified. Immunohistochemistry (IHC) for PD-L1 expression using clinical samples was also performed to confirm PD-L1 alteration by Tmab. RESULTS: PD-L1 expression was significantly upregulated by Tmab in HER2-amplified GC cell lines co-cultured with peripheral blood mononuclear cells (PBMCs). PD-L1 upregulation by Tmab was also observed in the GC cells co-cultured with NK cells in time-dependent manner, but not with monocytes. IFN-γ concentration in conditioned media from co-cultured PBMCs and NK cells with Tmab was significantly higher and anti-IFN-γ significantly suppress the Tmab-induced PD-L1 upregulation. IHC also suggested PD-L1 upregulation after Tmab treatment. CONCLUSIONS: Tmab can upregulate PD-L1 expression on GC cells through interaction with NK cells. These results suggest clinical implications in the assessment of the predictive significance of PD-L1 expression for PD-1 inhibitors.