HIF-1α expression in liver metastasis but not primary colorectal cancer is associated with prognosis of patients with colorectal liver metastasis

Background

The role of hypoxia-inducible factor-1α (HIF-1α) in primary colorectal cancer (CRC) and colorectal liver metastasis (CRLM) has remained unclear. The aim of this study was to investigate HIF-1α expression and its association with prognosis in patients with CRLM with a focus on hepatic stellate cells (HSCs).

Methods

Colon cancer cells were cultured in HSC-conditioned medium (CM), and HIF-1α expression and cell migration were analyzed. Seventy-five patients with CRLM who underwent an initial curative hepatectomy were enrolled. We examined HIF-1α expressions and patient prognosis between primary CRCs and the matched liver metastatic specimens.

Results

Activated HSCs induced HIF-1α mRNA and protein expression in colon cancer cells (p < 0.01) and promoted cell migration (p < 0.01). The positive rates of HIF-1α expression in primary CRCs and liver metastases were 68.0 and 72.0%, respectively. There were no differences in overall (OS) and disease-free survival (DFS) of HIF-1α expression in primary CRC. However, HIF-1α expression in liver metastasis correlated to poor prognosis in both OS and DFS. Furthermore, patients with HIF-1α positive expression in liver metastasis had poor prognosis.

Conclusion

HIF-1α expression in liver metastasis determines poor prognosis of CRLM patients. HSCs might play a key role in aggressive phenotypes of tumor cells.

Impact of using a perioperative artificial endocrine pancreas in pancreatic resection

AIM

Pancreatectomy causes both hyperglycemia, secondary to surgical stress, and pancreatic diabetes, which leads to difficult-to-control postoperative blood glucose levels. We investigated whether using an artificial pancreas perioperatively to provide appropriate blood glucose control could reduce postoperative complications following pancreatectomy.

METHODS

We retrospectively enrolled 52 patients who underwent pancreatectomy at Tokushima University Hospital from 2015 to 2019. The most recent 26/52 patients received perioperative blood glucose control using an artificial pancreas. Postoperative blood glucose control with manual insulin injections based on a sliding scale was performed in the earlier 26 patients (controls). We compared surgical outcomes between the artificial pancreas group and the control group.

RESULTS

There was no significant difference in patients' white blood cell or neutrophil counts, prognostic nutritional index, neutrophil-lymphocyte ratio, and C-reactive protein-to-albumin ratio on postoperative day 1; however, lymphocyte counts were higher in the artificial pancreas group. The number of serious complications of Clavien-Dindo grade >IIIa was significantly lower in the artificial pancreas group (P < .05).

CONCLUSIONS

Using an artificial pancreas for perioperative blood glucose control in patients undergoing pancreatectomy decreased the number of serious complications through proper management of blood glucose levels without hypoglycemia, and may influence peripheral lymphocytes.

Effectiveness of repeat surgery for recurrence after primary hepatectomy in patients with intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (IHCC) has a poor prognosis, and surgery remains the only effective treatment. However, tumor recurrence after primary hepatectomy is common. We examined the significance of repeat surgery for IHCC.

METHODS

We collected data for all patients with IHCC between 1992 and 2018 (n = 67) in our database. Fifty-three (79.1%) of all 67 patients experienced recurrence after primary hepatectomy and we analyzed data for those 53 recurrent patients. We divided recurrent patients into a repeat surgery group (n = 9), chemotherapy group (n = 19), and best supportive care group (n = 25). We analyzed differences in patients' clinicopathological factors, including prognosis, between the three groups.

RESULTS

The IHCC recurrence rate after hepatectomy in our institution was 79.1%. Of the 53 patients with recurrence, nine underwent repeat surgery (17.0%). The characteristics of the patients undergoing repeat surgery was lower stage at primary hepatectomy. Recurrence sites in the repeat surgery group were liver (n = 6), lung (n = 2), and adrenal gland (n = 1), as a single nodule. The period between primary hepatectomy and recurrence was comparatively longer in the repeat surgery group, at 1.8 years. The prognosis in patients undergoing repeat surgery was significantly better compared with the other groups. Not undergoing repeat surgery (hazard ratio: 5.506; p = 0.0077) and positive lymph node metastasis (hazard ratio: 2.207; p = 0.0242) were independent poor prognostic factors.

CONCLUSIONS

Repeat surgery should be considered in patients with IHCC with a single recurrence site and negative lymph node metastasis at primary surgery and at least more than 6 months of disease-free period after primary surgery.

Predictability of postoperative recurrence on hepatocellular carcinoma through data mining method

Hepatocellular carcinoma (HCC) is a highly lethal tumor and the majority of postoperative patients experience recurrence. In the present study, we focus on the predictability of postoperative recurrence on HCC through the data mining method. In total, 323 patients with HCC who underwent hepatic resection were included in the present study, 156 of whom suffered from cancer recurrence. Clinicopathological data including prognosis were analyzed using the data mining method for the predictability of postoperative recurrence on HCC. The resulting alternating decision tree (ADT) was described using data mining method. This tree was validated using a 10-fold cross validation process. The average and standard deviation of the accuracy, sensitivity, and specificity were 69.0±8.2, 59.7±14.5 and 77.7±10.2%, respectively. The identified postoperative recurrence factors were age, viral hepatitis, stage, GOT and T-cholesterol. Data mining method could identify the factors associated at different levels of significance with postoperative recurrence of HCC. These factors could help to predict the postoperative recurrence of HCC.

Current status of hepatocyte-like cell therapy from stem cells

Organ liver transplantation and hepatocyte transplantation are not performed to their full potential because of donor shortage, which could be resolved by identifying new donor sources for the development of hepatocyte-like cells (HLCs). HLCs have been differentiated from some stem cell sources as alternative primary hepatocytes throughout the world; however, the currently available techniques cannot differentiate HLCs to the level of normal adult primary hepatocytes. The outstanding questions are as follows: which stem cells are the best cell sources? which protocol is the best way to differentiate them into HLCs? what is the definition of differentiated HLCs? how can we enforce the function of HLCs? what is the difference between HLCs and primary hepatocytes? what are the problems with HLC transplantation? This review summarizes the current status of HLCs, focusing on stem cell sources, the differentiation protocol for HLCs, the general characterization of HLCs, the generation of more functional HLCs, comparison with primary hepatocytes, and HLCs in cell-transplantation-based liver regeneration.

Cancer-associated adipocytes promote pancreatic cancer progression through SAA1 expression

Although pancreatic cancer often invades peripancreatic adipose tissue, little information is known about cancer-adipocyte interaction. We first investigated the ability of adipocytes to de-differentiate to cancer-associated adipocytes (CAAs) by co-culturing with pancreatic cancer cells. We then examined the effects of CAA-conditioned medium (CAA-CM) on the malignant characteristics of cancer cells, the mechanism underlying those effects, and their clinical relevance in pancreatic cancer. When 3T3-L1 adipocytes were co-cultured with pancreatic cancer cells (PANC-1) using the Transwell system, adipocytes lost their lipid droplets and changed morphologically to fibroblast-like cells (CAA). Adipocyte-specific marker mRNA levels significantly decreased but those of fibroblast-specific markers appeared, characteristic findings of CAA, as revealed by real-time PCR. When PANC-1 cells were cultured with CAA-CM, significantly higher migration/invasion capability, chemoresistance, and epithelial-mesenchymal transition (EMT) properties were observed compared with control cells. To investigate the mechanism underlying these effects, we performed microarray analysis of PANC-1 cells cultured with CAA-CM and found a 78.5-fold higher expression of SAA1 compared with control cells. When the SAA1 gene in PANC-1 cells was knocked down with SAA1 siRNA, migration/invasion capability, chemoresistance, and EMT properties were significantly attenuated compared with control cells. Immunohistochemical analysis on human pancreatic cancer tissues revealed positive SAA1 expression in 46/61 (75.4%). Overall survival in the SAA1-positive group was significantly shorter than in the SAA1-negative group (P = .013). In conclusion, we demonstrated that pancreatic cancer cells induced de-differentiation in adipocytes toward CAA, and that CAA promoted malignant characteristics of pancreatic cancer via SAA1 expression, suggesting that SAA1 is a novel therapeutic target in pancreatic cancer.

Significance of Frailty in Prognosis After Hepatectomy for Elderly Patients with Hepatocellular Carcinoma

BACKGROUND

The concept of frailty becomes important for patients who undergo surgery in this recent aging society. The aim of this study is to investigate the frailty as a prognostic factor in elderly patients with hepatocellular carcinoma (HCC) who underwent hepatectomy.

PATIENTS AND METHODS

A total of 92 patients over 75 years old who underwent hepatectomy were enrolled in this study. Frailty was defined as clinical frailty scale (CFS) ≥ 4. Patients were divided into two groups, i.e., frailty group (n = 21) and no-frailty group (n = 71), and clinicopathological features were compared between them.

RESULTS

The frailty group showed significant higher PIVKA-II level and larger tumor diameter (p < 0.05). CRP level and modified Glasgow prognostic score were significantly higher in the frailty group (p < 0.05). The frailty group showed higher rate of postoperative complications of Clavien-Dindo III (p = 0.06) and longer postoperative stay (p = 0.08). Cancer-specific, overall, and disease-free survival rates were significantly worse in the frailty group (p < 0.05). Frailty was detected as an independent prognostic factor on multivariate analysis of cancer-specific survival.

CONCLUSION

Frailty can estimate the prognosis of HCC patients who underwent hepatectomy.

Pancreatoduodenectomy co-morbid with celiac axis compression syndrome: a report of three cases

Background

Celiac axis compression syndrome (CACS) is a relatively rare disease. Because of the nature of the blood flow in the celiac region when a pancreatoduodenectomy (PD) is performed for CACS, the celiac region can become ischemic. The aim of this study is to report on the importance of pre-operative diagnosis of CACS in terms of the outcomes for patients post-operatively. In this study, three 3 cases of PD co-morbid with CACS are reported: one intra-operative diagnosis case and two pre-operative diagnosis cases.

Case presentation

The one case, not diagnosed with CACS prior to the operation, had a hard post-operative course because of complication caused by ischemia of the celiac region compared with the two cases diagnosed prior to the operation, who had a good post-operative course because of pre-operative or intra-operative intervention.

Conclusions

Post-operative complications due to CACS are preventable by pre-operative diagnosis and appropriate interventions.

Effect of epigenetic modulation on cancer sphere

Background : Cancer stem cell properties are highly relevant to the biology of treatment-resistant cancers. Epigenetic modification regulates gene expressions by chromatin remodeling during malignant transformation. The aim of this study was to elucidate the possible strategy for cancer stem cells focusing on epigenetic modification. Methods : We made cancer sphere from HepG2 cells, and we added Histone deacetylase (HDAC) inhibitor, valproic acid to cancer sphere. And we compared methylation status and the gene expression between normal HepG2 and cancer sphere groups, and between cancer sphere and sphere with HDAC inhibitor treatment groups. Results : Valproic acid (VPA) cancelled this spheroid formation. In comparison between normal HepG2 and cancer sphere, the number of methylation status changes more than 0.1 of beta level was 826 probes, and we could isolate some epithelial-mesenchymal transition (EMT) related genes. And VPA reduced the expressions of EMT related genes in sphere with RT-PCR. On the other hand, in comparison between cancer sphere and sphere with VPA treatment, we detected 29 probe of methylation status change, and VPA reduced the expressions of Bcl-6 in sphere. Conclusions : HDAC inhibitor affected the methylation status of cancer stem cells. Histone-acetylation might overcome treatmet-resistant cancer through the regulation of cancer stem cell. J. Med. Invest. 67 : 70-74, February, 2020.

Prognostic prediction of apparent diffusion coefficient obtained by diffusion-weighted MRI in mass-forming intrahepatic cholangiocarcinoma

BACKGROUND

We evaluated apparent diffusion coefficient (ADC) of diffusion-weighted image MRI as a prognostic factor for mass-forming intrahepatic cholangiocarcinoma (IHCC).

METHODS

We enrolled 26 patients who had undergone hepatic resections for mass-forming-type IHCC in this study, and calculated their mean ADC, using diffusion-weighted image MRI (b: 0, 20, 800 seconds/mm² ; 1.5 T MRI). Patients were divided into the ADC^High and the ADC^Low groups at the median ADC value (n = 13 for both). We also immunohistochemically evaluated hypoxia-inducible factor (HIF)-1α in tumor tissue.

RESULTS

Median age in the ADC^Low was older (P = .03), and showed significant higher rate of scirrhous tumor (P = .02). The 5-year overall survival rate in the ADC^Low group was significantly worse than in the ADC^High group (P = .04). In multivariate analysis, hilar tumor, portal vein invasion and low ADC were independent prognostic factors (P < .05). The ADC^Low group also had a higher rate of high HIF-1α expression than the ADC^High group (P < .05). Representative case of ADC^Low group showed rich stroma and high HIF-1α expression.

CONCLUSIONS

The ADC values in MRIs can predict IHCC prognosis, and correlated with stromal density and HIF-1α expression.

Hepatic Stellate Cells Contribute to the Tumor Malignancy of Hepatocellular Carcinoma Through the IL-6 Pathway

BACKGROUND/AIM

The hepatic stellate cells (HSCs) have relationship to cancer progression. The aim of this study is to investigate the effect of HSCs and the role of IL-6/Stat3 pathway on hepatocellular carcinoma (HCC) progression.

MATERIALS AND METHODS

HCCs were co-cultured with HSCs. The viability and migration ability of cancer cells were detected. Epithelial-mesenchymal transition (EMT) marker (E-cadherin), stem cell marker (CD44) and p-signal transducer and activator of transcription 3 (p-STAT3) of cancer cells were evaluated. Finally, interleukin-6 (IL-6) neutralization was performed.

RESULTS

Co-culture of HCCs with HSCs increased cancer cell viability and migration ability. EMT and stemness of cancer cells increased with HSCs. Following IL-6 neutralization, phospho-STAT3 activation, cancer cell viability and migration, as well as EMT, and stemness of cancer cells decreased.

CONCLUSION

HSCs promoted HCC progression through the IL-6/STAT3 pathway.

Evaluation of the ratio of plasma fibrinogen to platelet in resectable pancreatic cancer

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Background: Several prognostic factors were reported in pancreatic cancer such as neutrophil lymphocyte ratio (NLR), platelet lymphocyte ration (PLR) modified GPS. Fibrinogen platelet ratio (FPR) was reported as one of the prognostic factor of resectable gastric cancer (Surgery today 2019). In this report, the FPR was evaluated in patients with resectable pancreatic cancer. Methods: Between 2004 and 2019, one hundred and sixty-three patients in our institution with curative resection for pancreatic cancer were enrolled in this retrospective study. The cases of non-curative resection were excluded. The FPR was calculated with the preoperative plasma fibrinogen and the platelet counts. Cut-off value was decided with ROC curve. The patients were divided into high and low FPR group according to cut-off value. Results: The cut-off value of FPR was 25.51. In age, gender, BMI, operative factors including operative type, amount of blood loss and operative time, there was no significant difference between these two groups. Patients in low FPR group had significantly better overall survival (OS) rates and relapse-free survival (RFS) rates compared with high FPR group (p < 0.05). On multivariate analysis, the high FPR, CA19-9 > 300 U/ml and receipt of adjuvant chemotherapy were independent risk factor of post-operative recurrence. Conclusions: The FPR might be a prognostic factor of patients with resectable pancreatic cancer.

Significance of frailty in prognosis after hepatectomy in older patients with hepatocellular carcinoma

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Background: An aging society has come, and “Frailty” is becoming increasingly important in surgery. Recently, clinical frail scale (CFS), which is simple criteria for frailty, has been reported to be useful for prognostic prediction of non-cardiac surgery (Ann Surg. 2018). Herein we report a new knowledge about frailty for patients with hepatocellular carcinoma (HCC) undergoing hepatectomy. Methods: Eighty-one patients over 75 years who underwent hepatectomy for HCC between 2007 and 2018 were enrolled in this study. Frailty was diagnosed as CFS≥4, and patient were divided into 2 groups, frailty (n = 17) and no frailty (n = 64). Clinicopathological factors were compared between 2 groups. Results: Patients’ background, such as age, gender, preoperative comorbidity, and liver function showed no significant difference between 2 groups. Regarding tumor factors, frailty group showed significant larger tumor diameter, more advanced stage (p < 0.05) and tendency of high PIVKA-II (p = 0.15) compared with no frailty group. Frailty group showed significant high CRP level (p < 0.01), high modified Glasgow prognostic score (mGPS, p = 0.04) and tendency of high neutrophil-lymphocyte ratio (NLR, p = 0.14). Frailty group also showed tendency of higher rate of postoperative complication (p = 0.11) and longer postoperative hospital stay (p = 0.09). Overall and disease-free survival rate were significantly worse in frailty group (p = 0.03). In univariate analysis for overall survival, AFP≥10, PIVKA-II≥400, frailty and mGPS high (1, 2) were prognostic factor. Multivariate analysis revealed that frailty was independent prognostic factor. In univariate analysis of disease-free survival, only frailty was detected as prognostic factor. Conclusions: Frailty is an independent prognostic factor for HCC patients who underwent hepatectomy.

A change in the zinc ion concentration reflects the maturation of insulin-producing cells generated from adipose-derived mesenchymal stem cells

The generation of insulin-producing cells (IPCs) from pluripotent stem cells could be a breakthrough treatment for type 1 diabetes. However, development of new techniques is needed to exclude immature cells for clinical application. Dithizone staining is used to evaluate IPCs by detecting zinc. We hypothesised that zinc ion (Zn2+) dynamics reflect the IPC maturation status. Human adipose-derived stem cells were differentiated into IPCs by our two-step protocol using two-dimensional (2D) or 3D culture. The stimulation indexes of 2D -and 3D-cultured IPCs on day 21 were 1.21 and 3.64 (P < 0.05), respectively. The 3D-cultured IPCs were stained with dithizone during culture, and its intensity calculated by ImageJ reached the peak on day 17 (P < 0.05). Blood glucose levels of streptozotocin-induced diabetic nude mice were normalised (4/4,100%) after transplantation of 96 3D-cultured IPCs. Zn2+ concentration changes in the medium of 3D cultures had a negative value in the early period and a large positive value in the latter period. This study suggests that Zn2+ dynamics based on our observations and staining of zinc transporters have critical roles in the differentiation of IPCs, and that their measurement might be useful to evaluate IPC maturation as a non-destructive method.

Carbohydrate Antigen 19-9 Is a Prognostic Factor Which Correlates With HDAC1 and HIF-1α for Intrahepatic Cholangiocarcinoma

BACKGROUND/AIM

Carbohydrate antigen 19-9 (CA19-9) is a poor prognostic marker in intrahepatic cholangiocarcinoma (IHCC). Previous studies have shown a link between hypoxia and CA19-9 in cancer, and we have previously demonstrated a correlation between HDAC1 and HIF-1α in IHCC. Here, we evaluated the expression and correlation of CA19-9 with HIF-1 and HDAC in IHCC.

PATIENTS AND METHODS

This study included 62 patients with IHCC who underwent primary hepatectomy at our department. Clinicopathological characteristics were examined. Immunohistochemical expression of HIF-1 and HDAC1 in specimens was quantitatively evaluated.

RESULTS

Patients with high preoperative serum CA19-9 levels showed clinicopathological characteristics associated with tumour progression. High CA19-9 levels were associated with worse overall and recurrence-free survival. Univariate and multivariate analysis detected high CA19-9 levels as an independent poor prognostic factor for IHCC. Serum CA19-9 was significantly correlated with both HIF-1α and HDAC1 expression.

CONCLUSION

High serum CA19-9 level is a poor prognostic factor for overall survival in IHCC and correlates with HIF-1α and HDAC1 expression.

Clinical Impact of FOLFOXIRI Aiming for Conversion Surgery in Unresectable Multiple Colorectal Liver Metastasis

BACKGROUND/AIM

We evaluated the clinical impact of FOLFOXIRI regimen aiming for conversion surgery in patients with unresectable multiple colorectal liver metastasis (CRLM).

PATIENTS AND METHODS

A total of 42 patients with unresectable multiple CRLM who received chemotherapy with molecular agents were included in the analysis. The clinical results of FOLFOXIRI with other regimens were compared.

RESULTS

The total conversion rate of 42 unresectable CRLM was 48.1%, and conversion cases had a better prognosis. Clinicopathological characteristics of conversion cases were more frequent in FOLFOXIRI induction, liver limited disease and maximum diameter × number (MDN) over 70. FOLFOXIRI achieved a higher conversion rate compared to other regimens (72.2% vs. 37.5%, p=0.0334), and significantly reduced the medication period until conversion surgery (median 5.8 courses) with a higher tumour necrotic rate. Consequently, the overall survival of conversion cases with FOLFOXIRI was better than that with other regimens (p=0.0055).

CONCLUSION

FOLFOXIRI plus molecular agents might provide a higher probability of conversion surgery with a prognostic benefit.

The Differences in the Characteristics of Insulin-producing Cells Using Human Adipose-tissue Derived Mesenchymal Stem Cells from Subcutaneous and Visceral Tissues

The aim of this study was to investigate the characteristics of insulin producing cells (IPCs) differentiated from adipose-tissue derived stem cells (ADSCs) isolated from human subcutaneous and visceral adipose tissues and identify ADSCs suitable for differentiation into efficient and functional IPCs. Subcutaneous and visceral adipose tissues collected from four (4) patients who underwent digestive surgeries at The Tokushima University (000035546) were included in this study. The insulin secretion of the generated IPCs was investigated using surface markers by: fluorescence activated cell sorting (FACS) analysis; cytokine release; proliferation ability of ADSCs; in vitro (glucose-stimulated insulin secretion: (GSIS) test/in vivo (transplantation into streptozotocin-induced diabetic nude mice). The less fat-related inflammatory cytokines secretions were observed (P < 0.05), and the proliferation ability was higher in the subcutaneous ADSCs (P < 0.05). Insulin expression and GISI were higher in the subcutaneous IPCs (P < 0.01 and P < 0.05, respectively). The hyperglycaemic state of all mice that received IPCs from subcutaneous fat tissue converted into normo-glycaemia in thirty (30) days post-transplantation (4/4,100%). Transplanted IPCs were stained using anti-insulin and anti-human leukocyte antigen antibodies. The IPCs generated from the ADSCs freshly isolated from the human fat tissue had sufficient insulin secreting ability in vitro and in vivo.

Impact of Bevacizumab on Liver Damage After Massive Hepatectomy in Rats

BACKGROUND

The aim of this study was to evaluate the impact of pretreatment with bevacizumab on liver damage in a rat model of massive hepatectomy (Hx) model, as a surrogate model of massive Hx for liver metastasis from colorectal cancer.

MATERIALS AND METHODS

Male Wister rats (n=24) were separated into the following two groups: 90% Hx and 90% Hx plus bevacizumab group. Bevacizumab (5 mg/kg) was injected intraperitoneally 7 days before Hx. Samples of blood and remnant liver tissue were obtained 24 hours after hepatectomy and the following parameters were evaluated: Biochemical analysis; liver regeneration rate; survival rate; and real-time polymerase chain reaction for interleukin-1 beta (Il1b), tumor necrosis factor alpha (Tnfa), matrix metalloproteinase (Mmp) 2 and Mmp9 mRNA. In addition, samples of whole liver tissue were obtained immediately before Hx and real-time polymerase chain reaction was performed for X-box binding protein 1 (Xbp1), activating transcription factor 6 (Atf6), C/EBP homologous protein (Chop), glucose-regulated protein 78 (Grp78) and heat-shock protein 70 (Hsp70), as markers of endoplasmic reticulum stress response.

RESULTS

The levels of transaminases 24 hours after Hx were significantly reduced in the group pretreated with bevacizumab compared to that not pretreated (p<0.05). The liver regeneration rate at 24 hours after Hx was significantly increased in the group pretreated with bevacizumab compared with the group which underwent Hx alone (p<0.05). The survival rate for the group pretreated with bevacizumab tended to be higher than that of the Hx-only group, 72 hours after Hx (p=0.09). The expressions of Il1b, Mmp2 and Mmp9 mRNA 24 hours after Hx in the group pretreated with bevacizumab tended to be lower than that of rats which underwent Hx alone (p=0.11, 0.09 and 0.15, respectively). The expression of Xbp1, Chop, Grp78 and Hsp70 mRNA immediately before Hx in the group pretreated with bevacizumab were significantly higher than the 90% Hx group (p<0.05).

CONCLUSION

Bevacizumab pretreatment had protective effects on liver injury after massive hepatectomy in rats, apparently via the induction of the endoplasmic reticulum stress response, i.e. the so-called unfolded protein response.

Two cases of non-mucinous cystadenomas of the pancreas with pancreatobiliary phenotype and ovarian-like stroma

BACKGROUND

Diagnosis of cystic tumor of the pancreas is based on the World Health Organization criteria that classify pancreatic cystadenomas into four types: intra-ductal papillary mucinous neoplasms, mucinous cystic neoplasms (MCNs), serous cystic neoplasms, and solid pseudo-papillary neoplasms depending on their secretion and presence of ovarian-like stroma. Recently, Albores-Saavedra identified non-mucinous cystadenomas of the pancreas with pancreato-biliary phenotype and ovarian-like stroma. This precipitated examination of the proportions of these rare tumors in patients treated at Tokushima University Hospital.

CASE PRESENTATION

Case 1 was a 40-year-old woman with a cystic tumor in the tail of the pancreas. Computed tomography (CT) revealed a diffuse and non-enhanced cystic tumor in the tail of the pancreas. This tumor was diagnosed as a simple cyst at this point. However, 2 years later, the tumor had increased in size by 3 cm. Thus, laparoscopic distal pancreatectomy was performed. The content of the cyst was serous. The epithelial cells were lined with a single layer of cuboidal cells and the tumor had ovarian-like stroma pathologically. The final pathological diagnosis was non-mucinous cystadenoma of the pancreas with ovarian-like stroma. In Case 2, a cystic tumor in the pancreas was found by medical examination in a woman in her sixties who presented without symptoms. CT showed a 1.5-cm cystic tumor in the tail and body of the pancreas and a septum in the cyst. Nine years later, the tumor had grown to 2.4 cm in diameter and had a clear septum in the cyst. This tumor was diagnosed preoperatively as MCN. Thus, laparoscopic distal pancreatectomy was performed. The cyst contained serous fluid. Microscopic examination showed no ovarian-like stroma and the epithelial cells were lined by a single layer of cuboidal cells. The final pathological diagnosis was non-mucinous cystadenoma of the pancreas with ovarian-like stroma.

CONCLUSIONS

Accurate preoperative diagnosis of this type of pancreatic cystic tumor may be difficult, although it occurs more often than expected. Non-mucinous cystadenomas of the pancreas with ovarian-like stroma need to be considered as a differential diagnosis.

Development of monoclonal mouse antibodies that specifically recognize pancreatic polypeptide

Pancreatic polypeptide (PP) is a 36-amino acid peptide encoded by the Ppy gene, which is produced by a small population of cells located in the periphery of the islets of Langerhans. Owing to the high amino acid sequence similarity among neuropeptide Y family members, antibodies against PP that are currently available are not convincingly specific to PP. Here we report the development of mouse monoclonal antibodies that specifically bind to PP. We generated Ppy knockout (Ppy-KO) mice in which the Ppy-coding region was replaced by Cre recombinase. The Ppy-KO mice were immunized with mouse PP peptide, and stable hybridoma cell lines producing anti-PP antibodies were isolated. Firstly, positive clones were selected in an enzyme-linked immunosorbent assay for reactivity with PP coupled to bovine serum albumin. During the screening, hybridoma clones producing antibodies that cross-react to the peptide YY (PYY) were excluded. In the second screening, hybridoma clones in which their culture media produce no signal in Ppy-KO islets but detect specific cells in the peripheral region of wild-type islets, were selected. Further studies demonstrated that the selected monoclonal antibody (23-2D3) specifically recognizes PP-producing cells, not only in mouse, but also in human and rat islets. The monoclonal antibodies with high binding specificity for PP developed in this study will be fundamental for future studies towards elucidating the expression profiles and the physiological roles of PP.

Validity of hepatic cone-unit resection for hepatocellular carcinoma

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Background: Anatomical liver resection (ALR) has been performed widely for hepatocellular carcinoma (HCC). However, there are difficult cases with typical ALR, due to tumor location or anatomical variation. The aim of this study is to review the cases of atypical ALR and to investigate the validity of small ALR for HCC. Methods: From 2007 to 2017, hepatic resection less than 2 segments was performed to 252 patients with HCC. (1) We reviewed cases with atypical ALR (eg. posterior segment + anterior dorsal area, S4 + S8 ventral area, etc.), and (2) Regarding the validity of cone-unite resection for single HCC, we compared the clinicopathological outcome with subsegmentectomy as a control. Results: (1) Atypical ALR was performed in 10% (17/169) of ALR less than 2 segments. There were 7 cases of extended anterior segmentectomy or extended S8 resection for patients having anterior or S8 portal branch that perfused to the right side of the right hepatic vein. Most of such atypical ALR tended to be indicated in right-side hepatectomy. (2) Liver function was well preserved in both groups, and it was better in subsegment group (ICGR15: 10.5 vs. 12.3%, ALB: 4.1 vs. 3.9g/dL). Regarding the tumor factor, the diameter was larger in the subsegment group than in the cone-unite group (2.8 vs. 2.1cm), and the proportion in which subsegmentectomy was performed in the case more than 3 cm was high (32 vs. 11%). There was no difference in OS and DFS between the two groups. Even when the tumor diameter was 3 cm or less, there was no difference in DFS between subsegment (n = 28) and cone-unite resection (n = 40). Conclusions: There are a number of cases that typical ALR is difficult, especially in the right-side hepatectomy. There was no difference in the prognosis depending on the range of resection, if HCC could be resected of subsegment or less. Therefore, depending on age and comorbidity, it is necessary to determine the type of hepatectomy without sticking to the subsegmentectomy.