Periostin increased by mechanical stress upregulates interleukin-6 expression in the ligamentum flavum.

Ligamentum flavum (LF) hypertrophy is a major cause of lumbar spinal canal stenosis. Although mechanical stress is thought to be a major factor involved in LF hypertrophy, the exact mechanism by which it causes hypertrophy has not yet been fully elucidated. Here, changes in gene expression due to long-term mechanical stress were analyzed using RNA-seq in a rabbit LF hypertrophy model. In combination with previously reported analysis results, periostin was identified as a molecule whose expression fluctuates due to mechanical stress. The expression and function of periostin were further investigated using human LF tissues and primary LF cell cultures. Periostin was abundantly expressed in human hypertrophied LF tissues, and periostin gene expression was significantly correlated with LF thickness. In vitro, mechanical stress increased gene expressions of periostin, transforming growth factor-ß1, α-smooth muscle actin, collagen type 1 alpha 1, and interleukin-6 (IL-6) in LF cells. Periostin blockade suppressed the mechanical stress-induced gene expression of IL-6 while periostin treatment increased IL-6 gene expression. Our results suggest that periostin is upregulated by mechanical stress and promotes inflammation by upregulating IL-6 expression, which leads to LF degeneration and hypertrophy. Periostin may be a pivotal molecule for LF hypertrophy and a promising therapeutic target for lumbar spinal stenosis.

Intended preoperative trans-arterial embolization for large hepatocellular carcinoma: a retrospective cohort study.

BACKGROUND: Generally, a large tumor size of hepatocellular carcinoma (HCC) is associated with poor visibility and uncertainty in the surgical field which results in increased surgical difficulty as well as unfavorable postoperative outcomes. We performed intended preoperative trans-arterial embolization (TAE) in patients with a large HCC. In this study, we investigated the oncological significance of intended preoperative TAE for a large HCC, using a comparison between patients with and without TAE, and detailed analyses for pre- and post-TAE status. METHODS: A total of 411 patients who underwent hepatectomy for primary HCC at the University of Yamanashi Hospital between January 2007 and December 2018 were included in this study. The patients were divided into two groups: patients with larger HCCs (≥50 mm, n=51) and those with smaller HCC (<50 mm, n=360) according to the size of their HCCs. Comparison of clinicopathological features between these groups and clinical outcomes between the TAE and non-TAE groups were compared. In addition, a detailed analysis of each case in the TAE group was conducted, comparing clinicopathological factors between pre- and post-TAE status. RESULTS: The clinical unfavorable short- and long-term outcomes of patients with large HCCs (≥50 mm) were revealed compared to those with small HCCs (<50 mm). The prognostic analyses showed that a large tumor size and increased tumor markers, multiple tumor numbers, and others were adverse prognostic factors, and vascular invasions and residual tumors were included in the multivariate analysis. Further detailed analyses revealed that the average rates of change in tumor size and tumor shrinkage after TAE were - 48.6±35.6 mm and - 30.7±17.0%, respectively. Pathological high necrotic changes in the tumor, after multiple-times TAE aiming to a better effect, were related to a better prognosis in patients with large HCC. Poor prognostic factors became less common in patients who underwent intended preoperative TAE, and these patients had better prognoses. CONCLUSIONS: The large tumor size of HCC is associated with unfavorable outcomes; the intended preoperative TAE for large HCC patients performed multiple times aiming to affect the tumor as much as possible might improve their prognoses.

Role of podoplanin and Kupffer cells in liver injury after ischemia-reperfusion in mice.

AIM: To investigate the relationship between the intrahepatic expression of podoplanin (PDPN) and Kupffer cells (KCs) in ischemia-reperfusion (I/R) liver damage. METHODS: C57Bl/6 mice were injected with 200 µl of clodronate liposomes (macrophage depletion; MDP group) to deplete KCs or control liposomes (control group) via the ophthalmic vein plexus 24 h prior to ischemia. Animals were subjected to 90 min of partial hepatic ischemia (70%), followed by reperfusion, and were then killed at designated time points. Serum and liver tissues were harvested for further analyses. RESULTS: Serum ALT levels, mortality rates, and the percentage of necrotic area in liver sections were significantly higher in the MDP group than in the control group. PDPN was expressed in the lymphatic epithelium, interlobular bile duct epithelium, and in some hepatocytes in each group. Its expression in hepatocytes was down-regulated in the MDP group. The accumulation of platelets in the sinusoid was reduced 6 h after I/R in the MDP group. Tissue HGF and IGF-1 levels decreased in the MDP group. CONCLUSIONS: These results suggest that KCs play a key role in the activation of platelets through direct contact with PDPN-positive hepatocytes in I/R livers.

Prognostic impact of lymph node micrometastasis in patients with gastric cancer.

PURPOSE: The clinical significance of lymph node micrometastasis (LNMM) remains controversial in gastric cancer (GC). In this study, we investigated the prognostic impact of LNMM in patients with GC. METHODS: A total of 624 patients with pathologically lymph node metastasis-negative (pN0) and N1 status (pN1) who underwent gastrectomy between 2004 and 2018 were enrolled in this retrospective study. The diameter of tumor cell clusters in metastatic lymph nodes was measured in 120 patients with pN1 GC. RESULTS: Patients with lymph node tumors < 1500 µm in diameter (LNMM) had a significantly better prognosis than those with tumors ≥ 1500 µm in diameter (p = 0.012; log-rank test). Cox's proportional hazards model revealed that LNMM (p = 0.016), several dissected lymph nodes (p = 0.049), and the provision of adjuvant chemotherapy (p = 0.002) were independent prognostic factors for the overall survival of patients with pN1 GC. There was no significant difference in the overall survival between patients with LNMM who received chemotherapy and those who did not (p = 0.332). CONCLUSIONS: LNMM is associated with a favorable prognosis and maybe an independent prognostic marker in patients with pN1 GC. LNMM in GC may be considered a factor preventing adjuvant chemotherapy.

[Two Cases of Carcinoma en Cuirasse, as Cutaneous Metastasis of Breast Cancer].

We present 2 cases of carcinoma en cuirasse, an uncommon clinical manifestation of metastatic cutaneous breast cancer. Case 1, a 70-year-old woman, presented with diffuse erythematous, indurated skin lesions that covered her entire anterior chest wall. Skin biopsy revealed tumor cells in the dermis which were ER and PgR positive and HER2 negative. CT showed pleural and pericardial effusion which led to a final diagnosis of cutaneous metastasis from breast cancer. Fulvestrant monotherapy was initiated and maintained a good clinical effect for 40 months. She died of multiple liver metastasis after 53 months from her first visit. Case 2 was a 71-year-old woman, with a 24 month history of a left breast tumor that gradually accompanied erythematous skin indurations and erosion, which spread to her entire left chest wall and contralateral breast. Following skin biopsy and CT, she was diagnosed to have triple negative breast cancer with multiple lymph node and cutaneous metastasis. After 4 cycles of EC, capecitabine was administrated and her skin lesions improved rapidly, including the lymph nodes. She is currently alive after 12 months since her first visit and under chemotherapy against new cutaneous metastasis.

[Long-Term Prognosis of Patients with Biliary Tract Cancer Undergoing Pancreaticoduodenectomy].

We divided the patients with biliary tract cancer who underwent pancreaticoduodenectomy(PD)at our hospital into the 5-year recurrence-free and recurrence groups and investigated the prognostic factors. Additionally, we investigated the efficacy of adjuvant chemotherapy in patients with and without lymph node (LN) metastasis. There was no significant difference between the two groups for patient characteristics and perioperative factors. However, patients with LN metastasis tended to have a higher recurrence rate. For patients without LN metastasis, the median overall survival(OS)was not significantly different between the patients who received and did not receive adjuvant chemotherapy. For patients with LN metastasis, although it was not significantly different(p=0.234), the OS of patients who received adjuvant therapy was more than 3 times than that of patients who did not(58.6 months and 18.4 months, respectively). For patients with biliary tract cancer who underwent PD, positive LN metastasis may be a poor prognostic factor, and adjuvant therapy may possibly improve prognosis.

Platelets enhance malignant behaviours of gastric cancer cells via direct contacts.

In this study, we aimed to analyse human cancer cell-platelet interactions in functional cell analyses and explore the molecular mechanisms behind tumour progression. Various functional analyses of gastric cancer (GC) cells were performed after direct/indirect co-incubation with platelets derived from GC patients. Further detailed expression and signalling analyses were performed after co-culture with direct and indirect GC cells-platelet contact. Malignant behaviours of cancer cells, such as proliferation, migration, invasion and adhesion, were significantly enhanced after direct co-incubation with platelets. Microarray analyses demonstrated changes in multiple genes, including epithelial-mesenchymal transition (EMT)-related genes. Among them, matrix metalloproteinase 9 was notably upregulated, which was validated by quantitative reverse transcription-polymerase chain reaction and western blot. Further, this change was only observed after direct co-incubation with platelets. This study demonstrated that platelets from GC patients promote malignant behaviours of GC cells through EMT-related signalling, especially by direct contact with tumour cells.

Platelet C-Type Lectin-Like Receptor 2 Reduces Cholestatic Liver Injury in Mice.

Cholestatic liver injury leads to liver dysfunction. The available evidence suggests that platelets can either promote or reduce liver injury and fibrosis. This study focused on the functions of the C-type lectin-like receptor 2 (CLEC-2), a new special platelet receptor that binds with podoplanin-activating platelets. The role of CLEC-2 and podoplanin in cholestatic liver injury was investigated. Mice were injected intraperitoneally with weekly doses of anti-CLEC-2 antibody (2A2B10) to achieve effective CLEC-2 inhibition in their platelets. Next, left and middle hepatic bile duct ligation (BDL) procedures were performed, and mice were euthanized 1 week later (2A2B10-BDL group). In addition, mice were prepared for control groups, and relevant histological and laboratory variables were compared among these groups. The inhibition of CLEC-2 resulted in increasing hepatocellular necrosis, hepatic inflammation, and liver fibrosis. In addition, podoplanin was strongly expressed in hepatic sinusoidal endothelial cells in BDL-treated mice. Moreover, in 2A2B10-BDL mice, total plasma bile acid levels were significantly increased. In summary, podoplanin is expressed on hepatic sinusoidal endothelial cells upon BDL. Platelets bind with podoplanin via CLEC-2 and become activated. As a result, the total bile acid pool is decreased. Therefore, the CLEC-2-podoplanin interaction promotes liver protection and inhibits liver fibrosis after cholestatic liver injury.

Exposure to Blood Components and Inflammation Contribute to Pancreatic Cancer Progression.

BACKGROUND: Pancreatectomy is a highly invasive procedure with extensive intraoperative blood loss (IBL) and high risk of postoperative pancreatic fistula (POPF). We conducted an experimental and retrospective clinical study to determine whether the malignant behaviors of pancreatic cancer cells were enhanced by exposure to blood components in vitro and to evaluate the oncological significance of high IBL and POPF in pancreatic cancer. METHODS: This study included 107 patients undergoing radical pancreatectomy in the University of Yamanashi Hospital between 2011 and 2017, classified into high (n = 29) and low (n = 78) IBL groups. In vitro experiments included functional analyses of Panc-1 pancreatic cancer and normal mesothelial cells exposed to patient blood components, and clinical data were used to assess the contribution of IBL and POPF to patient outcomes. RESULTS: The migration (p = 0.007), invasion (p < 0.001), and proliferation (p < 0.01) of Panc-1 cells were enhanced with platelet coculture. The ability of Panc-1 cells to adhere mesothelial cells was enhanced by plasma coincubation, especially in the presence of inflammation (p < 0.001). High IBL was associated with worse overall survival (p = 0.007) and increased locoregional recurrence (p = 0.003) in patients. POPF enhanced the negative prognostic significance of high IBL (p < 0.001 for overall survival, p = 0.001 for locoregional recurrence), indicating the oncological negative effects of high IBL and POPF. CONCLUSIONS: Blood components, especially platelets, and inflammation enhance the malignant behaviors of pancreatic cancer cells, potentially contributing to poor prognosis for pancreatic cancer patients.

Stepwise correlation of TP53 mutations from pancreaticobiliary maljunction to gallbladder carcinoma: a retrospective study.

BACKGROUND: The genetic changes underlying carcinogenesis in patients with risk factors of gallbladder carcinoma (GBC) remains controversial, especially in patients with pancreaticobiliary maljunction (PBM). This study aimed to clarify the association between risk factors of GBC and genetic changes using next-generation sequencing (NGS). METHODS: We retrospectively analyzed resected tissues of 64 patients who were diagnosed with GBC (n = 26), PBM [with GBC (n = 8), without GBC (n = 20)], and chronic cholecystitis, used as a control group (n = 10). DNA was extracted from tumors and their surrounding tissues, which were precisely separated by laser-capture microdissection. Gene alterations of 50 cancer-related genes were detected by NGS and compared with clinical information, including PBM status. RESULTS: The most frequent gene alterations in GBC tissues occurred in TP53 (50%), followed by EGFR (20.6%), RB1 (17.6%), and ERBB2 (17.6%). Gene alterations that were targetable by molecular targeted drugs were detected in 20 cases (58.8%). Statistical analysis of gene alterations and risk factors revealed that TP53 alteration rate was higher in GBC patients with PBM than those without PBM (p = 0.038), and the TP53 mutation rates in the epithelium of control patients, epithelium of PBM patients without GBC, peritumoral mucosa of GBC patients with PBM, and tumor tissue of GBC patients with PBM were 10, 10, 38, and 75%, respectively (p <  0.01). CONCLUSIONS: TP53 alteration more than KRAS mutation was revealed to underlie carcinogenesis in patients with PBM.

Liquid biopsy as a perioperative biomarker of digestive tract cancers: review of the literature.

Tissue biopsies are the gold-standard for investigating the molecular characterization of tumors. However, a "solid" biopsy is an invasive procedure that cannot capture real-time tumor dynamics and may yield inaccurate information because of intratumoral heterogeneity. In this review, we summarize the current state of knowledge about surgical treatment-associated "liquid" biopsy for patients with digestive organ tumors. A liquid biopsy is a technique involving the sampling and testing of non-solid biological materials, including blood, urine, saliva, and ascites. Previous studies have reported the potential value of blood-based biomarkers, circulating tumor cells, and cell-free nucleic acids as facilitators of cancer treatment. The applications of a liquid biopsy in a cancer treatment setting include screening and early diagnosis, prognostication, and outcome and recurrence monitoring of cancer. This technique has also been suggested as a useful tool in personalized medicine. The transition to precision medicine is still in its early stages. Soon, however, liquid biopsy is likely to form the basis of patient selection for molecular targeted therapies, predictions regarding chemotherapy sensitivity, and real-time evaluations of therapeutic effects.

MiR-10a in Pancreatic Juice as a Biomarker for Invasive Intraductal Papillary Mucinous Neoplasm by miRNA Sequencing.

New biomarkers are needed to further stratify the risk of malignancy in intraductal papillary mucinous neoplasm (IPMN). Although microRNAs (miRNAs) are expected to be stable biomarkers, they can vary owing to a lack of definite internal controls. To identify universal biomarkers for invasive IPMN, we performed miRNA sequencing using tumor-normal paired samples. A total of 19 resected tissues and 13 pancreatic juice samples from 32 IPMN patients were analyzed for miRNA expression by next-generation sequencing with a two-step normalization of miRNA sequence data. The miRNAs involved in IPMN associated with invasive carcinoma were identified from this tissue analysis and further verified with the pancreatic juice samples. From the tumor-normal paired tissue analysis of the expression levels of 2792 miRNAs, 20 upregulated and 17 downregulated miRNAs were identified. In IPMN associated with invasive carcinoma (INV), miR-10a-5p and miR-221-3p were upregulated and miR-148a-3p was downregulated when compared with noninvasive IPMN. When these findings were further validated with pancreatic juice samples, miR-10a-5p was found to be elevated in INV (p = 0.002). Therefore, three differentially expressed miRNAs were identified in tissues with INV, and the expression of miR-10a-5p was also elevated in pancreatic juice samples with INV. MiR-10a-5p is a promising additional biomarker for invasive IPMN.

[Nab-Paclitaxel plus Gemcitabine for Patients with Recurrence after Resection for Adenocarcinoma of the Pancreas].

PURPOSE: The purpose of this study was to clarify the predictors of efficacy of nab-paclitaxel plus gemcitabine(GnP)for patients with recurrence after resection for adenocarcinoma of the pancreas. METHOD: Patients who had received GnP at our hospital were divided into 2 groups; effective group and non-effective group and we compared them. In addition, we compared the therapeutic effect of patients between well-differentiated adenocarcinoma and moderately differentiated adenocarcinoma. Furthermore, we compared the efficacy depending on the time of recurrence. RESULTS: In patients with well-differentiated adenocarcinoma, the disease control rate was 93.6% and progression free survival was 8.6 months, whereas those in patients with moderately differentiated adenocarcinoma were 57.1% and 4.4 months, respectively. Patients who recurred at 7 months or later, had a better therapeutic response than the patients who recurred within 6 months after surgery. CONCLUSIONS: GnP may be effective in patients with well-differentiated adenocarcinoma and in patients who recurred at 7 months or later.

Postoperative Complications have Minimal Impact on Long-Term Prognosis in Immunodeficient Patients with Esophageal Cancer.

BACKGROUND: Postoperative complications have been recognized to have an adverse prognostic impact in various types of cancer. However, in a recent study, it has been reported that postoperative complications of total gastrectomy with splenectomy have little impact on the long-term outcomes of patients with gastric cancer. In addition, the mechanisms underlying the effect of postoperative complications on outcomes remain to be elucidated. We hypothesized that immunosuppression by postoperative complications may affect long-term outcomes in patients with esophageal cancer. METHODS: In this retrospective study, we assessed in 153 patients with esophageal cancer who underwent curative subtotal esophagectomy at our hospital and examined the correlation between postoperative complications, and multiple clinicopathological factors, and long-term outcomes with the patients stratified by total lymphocyte count (TLC). RESULTS: The median preoperative TLC was 1432. A total of 115 patients (75.2%) had a TLC of ≥ 1000/µL (high TLC group), and the remaining 38 patients (24.8%) had a TLC of < 1000/µL (low TLC group). Postoperative complications occurred in 39 of 153 cases (25.5%). There was no significant correlation between postoperative complications and any of the clinicopathological factors in either group. In the high TLC group, patients with postoperative complications had significantly lower overall and disease-free survival rates compared with those without complications (p < 0.001 and p < 0.01, respectively). In the low TLC group, no survival difference between patients with and without postoperative complications was observed. CONCLUSIONS: Postoperative complications may have a minimal impact on long-term outcomes in immunodeficient patients.

A Novel Mouse Model of Acute-on-Chronic Cholestatic Alcoholic Liver Disease: A Systems Biology Comparison With Human Alcoholic Hepatitis.

BACKGROUND: Alcohol-related liver disease is the main cause of liver-related mortality worldwide. The development of novel targeted therapies for patients with advanced forms (i.e., alcoholic hepatitis, AH) is hampered by the lack of suitable animal models. Here, we developed a novel mouse model of acute-on-chronic alcohol liver injury with cholestasis and fibrosis and performed an extensive molecular comparative analysis with human AH. METHODS: For the mouse model of acute-on-chronic liver injury, we used 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC, 0.05% w/w) diet for 8 weeks to establish cholestatic liver fibrosis. After 1-week washout period, male mice were fed intragastrically for 4 weeks with up to 24 g/kg of ethyl alcohol in a high-fat diet. This animal model was phenotyped using histopathology, clinical chemistry, microbiome, and gene expression approaches. Data were compared to the phenotypes of human alcohol-related liver disease, including AH. RESULTS: Mice with cholestatic liver fibrosis and subsequent alcohol exposure (DDC + EtOH) exhibited exacerbated liver fibrosis with a pericellular pattern, increased neutrophil infiltration, and ductular proliferation, all characteristics of human AH. DDC administration had no effect on urine alcohol concentration or liver steatosis. Importantly, DDC- and alcohol-treated mice showed a transcriptomic signature that resembled that of patients with AH. Finally, we show that mice in the DDC + EtOH group had an increased gut barrier dysfunction, mimicking an important pathophysiological mechanism of human AH. CONCLUSIONS: We developed a novel mouse model of acute-on-chronic cholestatic alcoholic liver injury that has considerable translational potential and can be used to test novel therapeutic modalities for AH.

Prognostic Significance of Hiatal Hernia in Patients with Gastric Cancer Located within the Upper-Third of the Stomach.

BACKGROUND: Gastric cancers located within the upper-third of the stomach (UGC), especially the esophagogastric junction GC (EGJGC), have distinct clinicopathological features due to their potential for multidirectional lymphatic spread. In this study, we investigated the clinical significance of hiatal hernias (HH) in patients with UGC, including EGJGC. METHODS: In this retrospective study, we assessed status of HH in 147 patients with UGC who underwent curative resection at our hospital and examined the correlation between the presence of HH (+) and multiple clinicopathological factors. RESULTS: Thirty-four patients (23%) were HH (+). However, we found no significant correlation between HH (+) and clinicopathological factors. HH (+) patients frequently developed lymph node recurrences. Prognosis was significantly better in patients with UGC and HH (-), compared to those with UGC and HH (+). Similarly, EGJGC patients who were HH (-) showed superior survival compared to HH (+) patients. Multivariate analysis found that the HH (+) (p = 0.004), histological type (p = 0.029), and nodal stage (p = 0.034) were independent prognostic factors. CONCLUSIONS: The presence of HH might affect lymphatic spread of tumor cells, and consequently prognosis of patients with UGC. Therefore, special attention is needed in developing surgical and postoperative strategies for such patients with UGC who are HH (+).

Anastomosis technique for pancreatojejunostomy and early removal of drainage tubes may reduce postoperative pancreatic fistula.

BACKGROUND: Postoperative pancreatic fistula (POPF) is one of the most serious complications after pancreaticoduodenectomy (PD). Various factors have been reported as POPF risks, but the most serious of these is soft pancreas. To reduce POPF occurrences, many changes to the PD process have been proposed. This study evaluates short-term results of anastomosis technique for PD. METHODS: In total, 123 patients with soft pancreases who had undergone PD at Yamanashi University between January 2012 and August 2020 were retrospectively analyzed. We divided these patients into two groups depending on the time PD was performed: a conventional group (n = 67) and a modified group (n = 56). RESULTS: The rate of clinically relevant POPF was significantly lower in the modified group than that in the conventional group (5.4% vs 22.4%, p value < 0.001), with there being only one case of POPF in the modified group. There were no cases of POPF-related hemorrhaging in the modified group. On the third day after the operation, the amylase levels in the drainage fluid for the modified group became less than half (1696 vs 650 U/L). Multivariate analysis showed that the modified method was the independent predictors to prevent clinical POPF (p value = 0.002). CONCLUSIONS: Our novel anastomosis technique for pancreatojejunostomy reduced POPF in PD, especially in cases where the patient had a soft pancreas.

[Pathological Complete Response of Intrapelvic Recurrence of Rectal Cancer after Chemoradiotherapy-A Case Report].

50's man who have performed anterior pelvic exenteration with lateral lymph node dissection for rectal cancer with pT4bN0M0, pStage Ⅱc about 2 years ago, was admitted to our hospital for the treatment of intrapelvic recurrence of rectal cancer. No distant metastasis was found in the computed tomography examination but the tumor invaded the dorsal side of the pubis. Because radical excision was impossible with these findings, he received chemoradiotherapy(CRT). Post-CRT imaging showed that the tumor of intrapelvic recurrence region reduced the size, and invasion of pubis had disappeared and been markedly reduced. Thus, radical excision seemed possible at this point, and we decided to attempt operation after total 6 weeks of S-1(120 mg/day)regimen and radiation(40 Gy/20 Fr). We performed Miles' operation. The final pathological examination demonstrated that no viable tumor cells remained in the resected rectum specimen, confirming that a pathological complete response(pCR)had been achieved.

Indications for extrahepatic bile duct resection due to perineural invasion in patients with gallbladder cancer.

BACKGROUND: The indications for extrahepatic bile duct (EHBD) resection remain a major controversy in the surgical management of patients with gallbladder cancer. On the other hand, perineural invasion (PNI) was reported as an important factor in patients with gallbladder cancer because gallbladder cancer cells frequently spread to the tissues surrounding the EHBD via perineural routes. We assessed the correlation of PNI with clinicopathological factors in patients with gallbladder cancer to elucidate EHBD resection indications specifically in patients with PNI. METHODS: This retrospective study assessed the PNI status of 50 patients with gallbladder cancer who underwent curative resection and examined the correlation between the presence of PNI and clinicopathological factors. RESULTS: Thirteen patients (26%) were PNI positive. PNI was significantly correlated with male sex, proximal-type tumor, lymphatic and vascular invasion, and advanced T stage. Multivariate analysis found that PNI positivity (p < 0.001), lymphatic invasion (p = 0.007), and nodal stage (p < 0.001) were independent prognostic factors. PNI was never observed in patients with stage T1 cancer. Conversely, PNI was detected rarely in distal-type tumors, all of whom developed various types of recurrences. CONCLUSIONS: These results clearly demonstrated the prognostic impact of PNI in patients with gallbladder cancer. We suggest that EHBD resection in combination with cholecystectomy may not be useful for distal-type tumors from a perspective of PNI.

The impact of histological type on the accuracy of preoperative N staging in patients with gastric cancer.

BACKGROUND: The low accuracy of preoperative diagnosis of lymph node metastasis in gastric cancer (GC) complicates decisions on patient indication for neoadjuvant chemotherapy. METHODS: We investigated the use of preoperative clinical diagnosis of lymph node involvement (cN) in GC patients compared with postoperative pathological diagnosis. RESULTS: In a series of 265 patients enrolled at the University of Yamanashi Hospital, the overall sensitivity was 44.4% and specificity was 93.4% of CT for detecting lymph node metastasis. The positive and negative predictive values were 80.0% and 73.8%, respectively. The negative predictive value was lower for undifferentiated adenocarcinoma than that for differentiated adenocarcinoma (64.9% vs. 78.7%, p = 0.034). In cT2 ≤ and cN2 ≤ GC, overdiagnosis of lymph node metastasis was significantly more frequent in patients with differentiated (50.0%) than in undifferentiated (13.3%) adenocarcinoma (p = 0.046). CONCLUSIONS: Diagnostic accuracy of lymph node involvement depended on histological type and cT-stage. Thus, considering preoperative histological type in GC, it may be useful to decide treatment plan.