Postoperative Prognosis According to Pathologic Categorization of Desmoplastic Reaction in Patients with Extrahepatic Cholangiocarcinoma.

BACKGROUND: Recent studies have demonstrated the importance of desmoplastic reaction (DR) in predicting postoperative prognosis for patients with colorectal carcinoma. However, the impact of DR on the prognosis of extrahepatic cholangiocarcinomas (EHCCs) is not established. This study aimed to clarify the associations of pathologic DR categories with clinicopathologic factors and postoperative prognosis of perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC). METHODS: A pathologic review of 174 patients with PHCC and 109 patients with DCC who underwent surgical resection was performed. The patients were classified into three DR categories (immature, intermediate, and mature) based on the histologic features within the fibrotic stroma in the invasive front. The association between DR categories and the distribution of fibroblasts with anti-α-smooth muscle actin (SMA) expression, seeming to be tumor-promoting cancer-associated fibroblasts (CAFs), was evaluated in 191 tissue microarray specimens of EHCCs. RESULTS: Intermediate/immature DR categories were significantly associated with a more invasive nature, including higher pT and pN stages and more tumor buds than the mature category in both PHCC and DCC. The DR categories could stratify overall survival (OS) and relapse-free survival (RFS) in both PHCC and DCC patients. In the multivariate analysis, the DR category was an independent prognostic factor for OS and RFS in both PHCC and DCC (p < 0.001). The mature and immature DR categories were significantly associated respectively with the confined and pervasive distribution of fibroblasts with α-SMA expression. CONCLUSION: In patients with EHCCs, DR categorization was an independent prognostic factor reflecting the distribution of tumor-promoting CAFs in the invasive front.

Vascular anatomical study of persistent descending mesocolon in patients undergoing laparoscopic surgery for colorectal cancer.

INTRODUCTION: Persistent descending mesocolon (PDM) is a rare congenital atypia of fixation of the descending colon, and currently, very few detailed studies exist on its vascular anatomy. This study was conducted to evaluate the features of the vascular anatomy of PDM to help avoid intraoperative lethal injury and subsequent postoperative complications in laparoscopic colorectal surgery. METHODS: We retrospectively analyzed the data of 534 patients who underwent laparoscopic left-sided colorectal surgery. PDM was diagnosed using preoperative axial computed tomography (CT) view. The vascular anatomical features were compared between PDM and non-PDM cases based on three-dimensional (3D)-CT angiography findings. Additionally, the perioperative short-term outcomes of laparoscopic surgery in the 534 patients were also compared between PDM and non-PDM cases. RESULTS: Of the total 534 patients, 13 patients (2.4%) presented with PDM. No branching pattern of the inferior mesenteric artery (IMA) specific to PDM was found. In the running direction of the IMA and sigmoidal colic artery (SA), the midline-shift of IMA and the right-shift of SA were significantly more in PDM than in non-PDM cases, respectively (38.5% vs. 2.5%, P ≤ .0001; 61.5% vs. 4.6%, P ≤ .0001). The perioperative short-term outcomes of laparoscopic surgery in the 534 patients were similar between PDM and non-PDM cases. CONCLUSION: Because changes in the direction of the vascular running are often observed due to adhesions and shortening of the mesentery in PDM cases, performing a detailed preoperative evaluation of vascular anatomy using imaging modalities such as 3D-CT angiography is important.

CCR7 Mediates Cell Invasion and Migration in Extrahepatic Cholangiocarcinoma by Inducing Epithelial-Mesenchymal Transition.

The epithelial-mesenchymal transition (EMT) contributes to the metastatic cascade in various tumors. C-C chemokine receptor 7 (CCR7) interacts with its ligand, chemokine (C-C motif) ligand 19 (CCL19), to promote EMT. However, the association between EMT and CCR7 in extrahepatic cholangiocarcinoma (EHCC) remains unknown. This study aimed to elucidate the prognostic impact of CCR7 expression and its association with clinicopathological features and EMT in EHCC. The association between CCR7 expression and clinicopathological features and EMT status was examined via the immunohistochemical staining of tumor sections from 181 patients with perihilar cholangiocarcinoma. This association was then investigated in TFK-1 and EGI-1 EHCC cell lines. High-grade CCR7 expression was significantly associated with a large number of tumor buds, low E-cadherin expression, and poor overall survival. TFK-1 showed CCR7 expression, and Western blotting revealed E-cadherin downregulation and vimentin upregulation in response to CCL19 treatment. The wound healing and Transwell invasion assays revealed that the activation of CCR7 by CCL19 enhanced the migration and invasion of TFK-1 cells, which were abrogated by a CCR7 antagonist. These results suggest that a high CCR7 expression is associated with an adverse postoperative prognosis via EMT induction and that CCR7 may be a potential target for adjuvant therapy in EHCC.

Postoperative Outcomes of Closed Versus Nonclosed Mesentery Laparoscopic Colectomy: A Retrospective Single-center Study.

PURPOSE: This study aimed to clarify the clinical significance of closing the mesenteric defect in laparoscopic colectomy. MATERIALS AND METHODS: We retrospectively evaluated 369 patients who underwent left-sided or right-sided resection via laparoscopic colectomy at our institute. Patients were stratified by open versus closed handling of the mesenteric defect. The perioperative clinical factors, surgical maneuvers, and postoperative complications were statistically analyzed. RESULTS: No significant intergroup differences were found in the perioperative clinical factors or surgical maneuvers except for number of days to the first soft diet (P=0.0214) and postoperative complications (P=0.0379). Among the postoperative complications, only ileus occurred more frequently in the closed group than in the open group (P=0.0227). CONCLUSIONS: This study revealed that closure of the mesenteric defect following laparoscopic colectomy might be associated with an increased incidence of postoperative ileus.

Impact of tumour budding grade in 310 patients who underwent surgical resection for extrahepatic cholangiocarcinoma.

AIMS: Tumour budding is a risk factor for poor prognosis in various cancers. Tumour buds may present an epithelial-mesenchymal transition (EMT) morphological phenotype. This study aimed to elucidate the prognostic impact of tumour budding grade and its association with clinicopathological and EMT-related features in perihilar cholangiocarcinoma (PHCC) or distal cholangiocarcinoma (DCC). METHODS AND RESULTS: Subjects included 195 PHCC and 115 DCC patients. The numbers of tumour buds in different patients were stratified for postoperative survival using the recursive partitioning technique. Consequently, the numbers of tumour buds in PHCC patients were classified into three grades; namely, low (0-4 buds); intermediate (5-11 buds); and high (≥12 buds); those of DCC patients were classified into two grades; namely, low (0-4 buds) and high (≥5 buds). In both PHCC and DCC patients, high tumour budding grade was associated with poor histological differentiation, higher pT factor, presence of lymphatic, venous, perineural invasion and regional lymph node metastasis. In PHCC patients, residual invasive tumour in the resected margin was also associated with high tumour budding grade. For both PHCC and DCC patients, high tumour budding grade was an independent adverse prognostic factor in multivariate analysis (P < 0001 and P = 0.046, respectively). Immunohistochemical examination revealed that the number of tumour buds increased in patients with tumours showing a mesenchymal profile (negative for E-cadherin and positive for vimentin). CONCLUSIONS: Higher tumour budding grade is associated with invasive clinicopathological features, adverse postoperative prognosis and EMT status in extrahepatic cholangiocarcinoma.

The clinicopathological characterization of small hepatocellular carcinoma with fibrous stroma.

Recent studies emphasized the significance of fibrous stroma affecting tumor biology in hepatocellular carcinoma (HCC). To further clarify fibrous stroma's significance, this study investigated the clinicopathological characteristics of HCC with fibrous stroma. A total of 214 nodules of HCC smaller than 3 cm in diameter were analyzed, and 22 (10%) were regarded as HCC with fibrous stroma. Most cases of HCC with fibrous stroma were the simple nodular type without a fibrous capsule, and histologically well- or moderately-differentiated. A subset of the scirrhous variant of HCC was included in this category, and steatohepatitic features, such as Mallory-Denk body formation and lymphoid infiltrates, were also frequently found. Foci with a histological appearance corresponding to dysplastic nodules and/or early HCC were rarely observed in HCC with fibrous stroma, suggesting that some cases occurred via a de novo carcinogenic process. The immunohistochemical expression of cytokeratin 7 and the epithelial cell adhesion molecule was more significantly increased in HCC with fibrous stroma than in conventional HCC. Furthermore, the expression of C reactive protein and serum amyloid A, indicative of the activation of the IL-6/STAT pathway, was increased in HCC with fibrous stroma. Radiologically, HCC with fibrous stroma exhibited hyperdense nodules on computed tomography and did not show a nodule-in-nodule appearance. Overall survival and disease-free survival were not significantly different between cases of HCC with fibrous stroma and conventional HCC. This study elucidated the clinicopathological features of HCC with fibrous stroma, which may represent a biologically different process occurring in HCC.

Oncocytic Type Intraductal Papillary Mucinous Neoplasm of the Pancreas with Unusually Low Mucin Production Mimicking Intraductal Tubulopapillary Neoplasm: A Report of a Case Diagnosed by a Preoperative Endoscopic Biopsy.

We herein report the case of a 78-year-old woman with an intraductal tumor with scant mucin production in a moderately dilated main pancreatic duct that resembled an intraductal tubulopapillary neoplasm (ITPN) on imaging. An endoscopic transpapillary forceps biopsy enabled an accurate preoperative diagnosis of the tumor as an oncocytic type intraductal papillary mucinous neoplasm (IPMN) of the pancreas microscopically showing papillary growth consisting of oncocytic cells with a typical mucin expression profile, although with few intraepithelial lumina containing mucin. This is the first case of an oncocytic type IPMN mimicking an ITPN that was able to be diagnosed preoperatively.

The impact of margin status determined by the one-millimeter rule on tumor recurrence and survival following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma.

PURPOSE: The tumor-node-metastasis (TNM) classification defines R1 as the presence of tumor cells at the resection margin, while the current Royal College of Pathologists guidelines for pancreaticoduodenectomy specimens regard the presence of tumor cells within 1 mm from the resection margin as R1 (the "1-mm rule"). The aims of this study were to investigate the resection margin status of pancreatic head cancer retrospectively according to both the TNM and 1-mm rule classifications, and to evaluate the postoperative survival and tumor recurrence patterns. METHODS: A total of 117 patients with pancreatic head cancer were the subjects of this study. RESULTS: R11-mm rule resection was associated with a significantly worse disease-free survival (DFS) than R01-mm rule resection (p = 0.0259), while R1TNM had no impact on DFS. R11-mm rule resection margin status correlated with the incidence of tumor recurrence in the liver (p = 0.0483). In a multivariate analysis, R11-mm rule resection was the independent variable for predicting poor DFS (hazard ratio 1.71; p = 0.0289). CONCLUSIONS: R1 resection margin status determined by the 1-mm rule may be an independent indicator for predicting disease recurrence, especially liver metastasis. These results may be useful for selecting the appropriate adjuvant therapy protocol and conducting strict surveillance in PDAC patients.

Loss of ARID1A Expression Presents a Novel Pathway of Carcinogenesis in Biliary Carcinomas.

OBJECTIVES: Given frequent inactivating mutations in a chromatin-remodeling gene (ARID1A) in intrahepatic cholangiocarcinoma in recent exome sequencing analysis, this study investigates the clinicopathologic significance of the loss of ARID1A expression in biliary carcinomas. METHODS: We examined the inactivating mutations in ARID1A by immunohistochemistry and the relationship with clinicopathologic features in 13 patients with combined hepatocellular-cholangiocarcinoma (cHC-CC), 49 with intrahepatic cholangiocarcinoma (ICC), 17 with intraductal papillary neoplasm of the bile duct (IPNB), 72 with extrahepatic cholangiocarcinoma (EHCC), and 43 with gallbladder carcinoma (GBC). RESULTS: The loss of ARID1A expression was detected in one (7.7%) cHC-CC, nine (18.4%) ICCs, zero IPNBs, 11 (15.3%) EHCCs, and four (9.1%) GBCs. Biliary carcinomas with loss of ARID1A expression showed distinct features; all were macroscopically mass forming or a flat-infiltrating type and histologically tubular adenocarcinoma with abundant fibrous stroma. IPNB, papillary adenocarcinoma, and biliary intraepithelial neoplasia (BilIN) did not harbor loss of ARID1A expression. There was no significant correlation between loss of ARID1A expression and TNM factors or International Union Against Cancer stage. There was no biliary carcinoma harboring both loss of ARID1A expression and KRAS mutations. CONCLUSIONS: Inactivating mutations in ARID1A may be involved in a novel pathway of carcinogenesis in biliary carcinomas, which is different from the pathway via IPNB and BilIN associated with KRAS mutations.

Pathological characteristics of intraductal polypoid neoplasms of bile ducts in Thailand.

Intraductal papillary or tubular neoplasms of the bile duct have recently been proposed as one of the pre-invasive lesions of cholangiocarcinoma. Herein, a total of 50 cases of intraluminal polypoid neoplasms of the bile ducts experienced in Khon Kaen University Hospital in Thailand were pathologically examined. These cases presumably had a history of infection of Opisthorchis viverrini. These neoplasms were histologically composed of high-grade intraepithelial neoplasm showing a tubular and/papillary pattern without invasion (20 cases), and with minimal and considerable invasion (15 and 15 cases, respectively). They were histologically classifiable into papillary type (10 cases), tubular type (20 cases) and papillotubular type (20 cases), and were phenotypically classifiable into gastric (17 cases), intestinal (17 cases) and pancreatobiliary types (16 cases). It was found that cases of papillary type and gastric or intestinal phenotype were less invasive, while those of tubular or papillotubular type and pancreatobiliary phenotype were more invasive. In conclusion, intraductal polypoid neoplasms in Thailand were well-differentiated papillary and/or tubular neoplasms including those with no or minimal invasion, and histological and phenotypic subclassifications seem to be useful for evaluation of the aggressive pathological behaviors of these neoplasms.

Autophagy may occur at an early stage of cholangiocarcinogenesis via biliary intraepithelial neoplasia.

Similar to the pancreatic carcinoma sequence model, cholangiocarcinoma reportedly follows a stepwise carcinogenesis process via the precursor lesion biliary intraepithelial neoplasia (BilIN). Given that autophagy plays an important role in the occurrence and development of carcinomas, we examined the involvement of autophagy in multistep cholangiocarcinogenesis. Thirty-six patients with hepatolithiasis associated with BilIN and/or cholangiocarcinoma, 7 with intrahepatic cholangiocarcinoma, 8 with intraductal papillary neoplasm of the bile duct (IPNB), and 6 with control livers were surveyed. Their lesions were categorized as follows: invasive carcinoma (n = 16), IPNB (n = 8), BIlN-3 (n = 16), BilIN-1/2 (n = 40), nonneoplastic large bile duct (n = 55), and peribiliary gland (n = 55). We examined the immunohistochemical expression of autophagy-related proteins, microtubule-associated proteins light chain 3ß (LC3), beclin-1, and p62/sequestosome-1 (p62), as well as tumor suppressor gene product p53. The extent of expression was semiquantitatively assessed. The status of KRAS mutations at codons 12 and 13 was examined in selected cases of BilIN-1/2. The expression of LC3 (cytoplasmic), beclin-1 (cytoplasmic), and p62 (cytoplasmic and nuclear) was significantly higher in BilIN-1/2, BilIN-3, IPNB, and invasive carcinoma than in large bile duct and peribiliary gland (P < .01). KRAS mutation was detected in 6 (40%) of 15 BilIN-1/2 lesions, and there was no correlation between the status of KRAS mutation and the expression of autophagy-related proteins. In conclusion, this study is the first to disclose that the expression of autophagy-related proteins, LC3, beclin-1, and p62, was increased at an early stage of multistep cholangiocarcinogenesis in hepatolithiasis. Autophagy, probably deregulated autophagy, may be related to the occurrence and development of cholangiocarcinoma.

Autophagy may promote carcinoma cell invasion and correlate with poor prognosis in cholangiocarcinoma.

The role of autophagy in cholangiocarcinoma is poorly understood. This study investigated its involvement in cholangiocarcinoma, focusing on carcinoma cell invasion and prognostic significance using cholangiocarcinoma cell lines, CCKS1 and HuCCT1, and human tissues of hilar and extrahepatic cholangiocarcinoma. Nutrient starvation induced the expression of LC3-II and the formation of LC3 puncta in both CCKS1 and HuCCT1, suggesting the occurrence of autophagy. The induction of autophagy was accompanied by the increased expression of an autophagy-related protein, Ambra1, in the cells. Under starvation conditions, the invasive activity of both cells was significantly increased, and a lysosomal inhibitor, chloroquine, attenuated this increased invasive activity. Transforming growth factor-ß1 (TGF-ß1), known as an inducer of epithelial-mesenchymal transition (EMT), increased the invasive activity of both cells, and chloroquine also significantly reduced TGF-ß1-induced cell invasion. Immunohistochemical staining using cholangiocarcinoma tissues showed that the expression of Ambra1 positively correlated with the expression of Snail, one of the major transcriptional factors of EMT. In addition, overexpression of Ambra1 significantly correlated with lymph node metastasis and poor survival rate of the patients. These results suggest that the occurrence of autophagy may be associated with a malignant phenotype and poor prognosis in cholangiocarcinoma, and autophagy is possibly involved in EMT-related cholangiocarcinoma cell invasion.

GNAS and KRAS mutations are common in intraductal papillary neoplasms of the bile duct.

Intraductal papillary neoplasms of the bile duct (IPNB) shows favorable prognosis and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. Although activating point mutations of GNAS at codon 201 have been detected in approximately two thirds of IPMNs of the pancreas, there have been few studies on GNAS mutations in IPNBs. This study investigates the status of GNAS and KRAS mutations and their association with clinicopathological factors in IPNBs. We examined the status of GNAS mutation at codon 201 and KRAS mutation at codon 12&13, degree of mucin production and immunohistochemical expressions of MUC mucin core proteins in 29 patients (M/F = 15/14) with IPNB in intrahepatic and perihilar bile ducts (perihilar IPNB) and 6 patients (M/F = 5/1) with IPNB in distal bile ducts (distal IPNB). GNAS mutations and KRAS mutations were detected in 50% and 46.2% of IPNBs, respectively. There was no significant correlation between the status of GNAS mutation and clinicopathological factors in IPNBs, whereas, the status of KRAS mutation was significantly inversely correlated with the degree of MUC2 expression in IPNBs (p<0.05). All IPNBs with GNAS mutation only showed high-mucin production. Degree of mucin production was significantly higher in perihilar IPNBs than distal IPNBs (p<0.05). MUC2 and MUC5AC expression was significantly higher in IPNBs with high-mucin production than those with low-mucin production (p<0.01 and p<0.05, respectively). In conclusions, this study firstly disclosed frequent GNAS mutations in IPNBs, similarly to IPMNs. This may suggest a common histopathogenesis of IPNBs and IPMNs. The status of KRAS mutations was inversely correlated to MUC2 expression and this may suggest heterogeneous properties of IPNBs. IPNBs with high-mucin production are characterized by perihilar location and high expression of MUC2 and MUC5AC, irrespective of the status of GNAS and KRAS mutations.

Pancreatic ductal adenocarcinomas with multiple large cystic structures: a clinicopathologic and immunohistochemical study of seven cases.

BACKGROUND/OBJECTIVES: Pancreatic ductal adenocarcinoma (PDA) with cystic change is classified into several types according to the features of the cysts; however, those tumors do not constitute a uniform group, and the classification is controversial. In this study, we have described a series of cystic PDAs that show distinctive and previously unreported morphologic and immunohistochemical features. METHODS: We analyzed 200 cases of PDA treated surgically at a single institution, and extracted the clinical and histopathological features of 7 tumors showing multiple large cystic (MLC) structure. RESULTS: Preoperative radiographic images revealed a multilocular mass in the pancreas which was similar to intraductal papillary mucinous neoplasm or mucinous cystic neoplasm. These tumors were associated with more than 5 large cystic structures and numerous intratumoral microcysts lined by epithelial cells with various degrees of atypia. The average maximal diameter of the cysts (3.7 cm) was much larger than that of previously reported. Immunohistochemically, the cyst-lining epithelia were almost negative for mucin core protein (MUC) 1, MUC2, and MUC6, and showed only focal staining for MUC5AC. Maspin, CEA, and p53 were strongly positive, and the Ki-67 labeling index was high in both cells in solid areas and cyst-lining epithelia. CONCLUSION: We considered the MLC structures in PDA to be a mixture of ectatic neoplastic glands and retention cysts with ductal cancerization or pancreatic intraepithelial neoplasia (PanIN); however, they might represent a new entity of cystic PDA because of the unusually large size of the dilated cysts.