The diversity between pancreatic head and body/tail cancers: clinical parameters and in vitro models

Long-term survival analysis based on tumor location in patients with pancreatic ductal adenocarcinoma who underwent pancreatectomy following neoadjuvant chemoradiotherapy

BACKGROUND

The study aimed at assessing whether long-term survival outcomes were different based on tumor location in pancreatic ductal adenocarcinoma (PDAC) patients who underwent pancreatectomy following neoadjuvant chemoradiotherapy (CRT).

METHODS

Following CRT, resection rate was 60.5% (286/473) and the resected patients had pancreatic head (n = 218), body (n = 34) and tail (n = 34) tumors. Survival analyses were conducted, independent predictors of disease-free survival (DFS) and overall survival (OS) were identified, and then survival outcomes were stratified by the predictors of DFS and OS.

RESULTS

Resection rates were; 64.7% (head) vs. 46.6% (body) and 54.0% (tail) cases, p = 0.009. Among these cases, pancreatic head patients exhibited a higher incidence of initial clinical stage 3 tumors; 48.2% (head) vs. 29.4% (body) and 0% (tail) cases, p < 0.001 with more unresctable-locally advanced tumors; 22.0% (head) vs. 11.8% (body) and 0% (tail), p < 0.001, but demonstrated a better response to CRT; Evans grades 3/4 in 49.1% (head) vs. 23.5% (body) and 26.5% (tail), p = 0.012. Five-year DFS rates were; 19.9% (head) vs. 11.8% (body) vs. 24.6% (tail), p = 0.565 and OS rates; 25.4% (head) vs. 27.7% (body) vs. 32.0% (tail), p = 0.341. Significant predictors of DFS and OS included post-CRT CA19-9 levels, tumor differentiation, resection margins and pathological portal vein invasion. Based on these predictors, survival outcomes were also comparable. Pathological nodal invasion influenced DFS, while pathological stage impacted OS.

CONCLUSION

Pancreatic head patients had the best resection rate and long-term survival outcomes were comparable, attributable to the better response to CRT by pancreatic head than the body and tail PDAC patients.

Reinforcement learning-based anatomical maps for pancreas subregion and duct segmentation

BACKGROUND

The pancreas is a complex abdominal organ with many anatomical variations, and therefore automated pancreas segmentation from medical images is a challenging application.

PURPOSE

In this paper, we present a framework for segmenting individual pancreatic subregions and the pancreatic duct from three-dimensional (3D) computed tomography (CT) images.

METHODS

A multiagent reinforcement learning (RL) network was used to detect landmarks of the head, neck, body, and tail of the pancreas, and landmarks along the pancreatic duct in a selected target CT image. Using the landmark detection results, an atlas of pancreases was nonrigidly registered to the target image, resulting in anatomical probability maps for the pancreatic subregions and duct. The probability maps were augmented with multilabel 3D U-Net architectures to obtain the final segmentation results.

RESULTS

To evaluate the performance of our proposed framework, we computed the Dice similarity coefficient (DSC) between the predicted and ground truth manual segmentations on a database of 82 CT images with manually segmented pancreatic subregions and 37 CT images with manually segmented pancreatic ducts. For the four pancreatic subregions, the mean DSC improved from 0.38, 0.44, and 0.39 with standard 3D U-Net, Attention U-Net, and shifted windowing (Swin) U-Net architectures, to 0.51, 0.47, and 0.49, respectively, when utilizing the proposed RL-based framework. For the pancreatic duct, the RL-based framework achieved a mean DSC of 0.70, significantly outperforming the standard approaches and existing methods on different datasets.

CONCLUSIONS

The resulting accuracy of the proposed RL-based segmentation framework demonstrates an improvement against segmentation with standard U-Net architectures.

Extranodal extension influences prognosis in pancreatic body/tail cancer: A retrospective cohort study

BACKGROUND/PURPOSE

Extranodal extension (ENE) is an established prognostic factor in various malignancies, affecting survival in pancreatic head cancer (PHC). However, its significance in pancreatic body/tail cancer (PBTC) remains unclear. Therefore, we aimed to investigate the impact of ENE on PTBC prognosis.

METHODS

We analyzed data collected from electronic medical records of patients with PBTC who underwent distal pancreatectomy at a single center between January 2011 and December 2015. The patients were categorized based on ENE presence and prognostic implications were evaluated using Kaplan-Meier survival curves and Cox proportional hazards model.

RESULTS

PBTC cases involving lymph node (LN) metastasis and ENE exhibited significantly lower disease-free (DFS) and overall survival (OS) rates compared to cases without LN metastasis or ENE (median DFS; N0, 23 months; LN+/ENE-, 10 months; LN+/ENE+, 5 months; p < .001). No statistically significant difference was observed in DFS and OS rates between patients with N1/N2 in the group without ENE and those with ENE+. Multivariate analysis confirmed ENE as a significant adverse prognostic factor.

CONCLUSIONS

ENE significantly predicts poor prognosis in PBTC, particularly in cases with nodal metastasis. The current cancer staging system for PBTC should incorporate ENE status. Moreover, different staging systems should be considered for PHC and PBTC.

Microbiota and metabolite alterations in pancreatic head and body/tail cancer patients

Pancreatic head cancer (PHC) and pancreatic body/tail cancer (PBTC) have distinct clinical and biological behaviors. The microbial and metabolic differences in PHC and PBTC have not been studied. The pancreatic microbiota and metabolome of 15 PHC and 8 PBTC tissues and their matched nontumor tissues were characterized using 16S rRNA amplicon sequencing and untargeted metabolomics. At the genus level, Bradyrhizobium was increased while Corynebacterium and Ruminococcus were decreased in the PHC tissues (Head T) compared with the matched nontumor tissues (Head N) significantly. Shuttleworthia, Bacillus, and Bifidobacterium were significantly decreased in the PBTC tissues (Body/Tail T) compared with the matched nontumor tissues (Body/Tail N). Significantly, Ileibacterium was increased whereas Pseudoxanthomonas was decreased in Head T and Body/Tail T, and Lactobacillus was increased in Head T but decreased in Body/Tail T. A total of 102 discriminative metabolites were identified between Head T and Head N, which were scattered through linoleic acid metabolism and purine metabolism pathways. However, there were only four discriminative metabolites between Body/Tail T and Body/Tail N, which were related to glycerophospholipid metabolism and autophagy pathways. The differential metabolites in PHC and PBTC were commonly enriched in alpha-linolenic acid metabolism and choline metabolism in cancer pathways. Eubacterium decreased in Head T was positively correlated with decreased linoleic acid while negatively correlated with increased arachidyl carnitine and stearoylcarnitine. Bacillus decreased in Body/Tail T was negatively correlated with increased L-carnitine. These microbiota and metabolites deserve further investigations to reveal their roles in the pathogenesis of PHC and PBTC, providing clues for future treatments.

The Importance of Reading the Skin: Cutaneous Metastases of Pancreatic Cancer, a Systematic Review

BACKGROUND

Pancreatic cancer is notorious for its aggressive nature and low survival rate, with less than 10% of patients surviving beyond five years. Early detection is difficult, but skin metastases can be a rare but significant indicator. This systematic review focuses on the epidemiology, clinical features, and histology of skin metastases from pancreatic cancer to determine their importance in early diagnosis and overall management of the disease.

MATERIALS AND METHODS

Following PRISMA guidelines, we conducted an exhaustive search of MEDLINE/PubMed, EMBASE, and SCOPUS databases up to June 2023, using specific keywords. Four independent investigators screened the studies using predefined criteria, and two investigators checked the accuracy and consistency of the data extraction. We assessed the quality of the trials using adapted criteria from the Joanna Briggs Institute. A narrative synthesis rather than a meta-analysis was chosen because of the different study designs.

RESULTS

The final analysis included 57 patients with skin metastases from pancreatic cancer. Cutaneous metastases, although rare, presented with approximately equal gender distribution and a mean age of 63.4 years. Predominantly non-umbilical (77%), these metastases showed clinical diversity, ranging from asymptomatic nodules to painful or ulcerated lesions. Notably, skin metastases often preceded the diagnosis of primary pancreatic cancer (58%). Primary tumor characteristics revealed different localizations, with adenocarcinoma being the most prevalent histological type (77%). A significant association (p = 0.008) was observed between pancreatic tumor location and the timing of presentation of skin metastases. Tumors located in the body and tail of the pancreas were more likely to manifest skin metastases as an initial clinical manifestation (62.2%) than those in the head of the pancreas (20.8%).

CONCLUSIONS

In conclusion, although skin metastases are rare, they are important indicators of pancreatic cancer, highlighting the need for multidisciplinary healthcare collaboration and thorough skin examination. Recognizing them could lead to earlier diagnosis, which is crucial in a cancer with limited treatment options.

Splenic Hilar Involvement and Sinistral Portal Hypertension in Unresectable Pancreatic Tail Cancer

BACKGROUND

Pancreatic tail cancer (PTC) frequently displays splenic hilar involvement (SHI), but its impact on clinical outcomes remains unclear. We investigated the clinical impact of SHI in patients with unresectable PTC.

METHODS

We retrospectively reviewed all patients with unresectable PTC who received first-line therapy at our institution from 2016 to 2020.

RESULTS

Of the 111 included patients, 48 had SHI at diagnosis. SHI was significantly associated with younger age, liver metastasis, peritoneal dissemination, larger tumor size, modified Glasgow prognostic score of 1 or more, splenic artery involvement, gastric varices, and splenomegaly. Shorter median overall survival (OS; 9.3 vs. 11.6 months, p = 0.003) and progression-free survival (PFS; 4.3 vs. 6.3 months, p = 0.013) were observed in SHI patients. Poor performance status of 1 or 2, tumor size > 50 mm, hepatic metastasis, mGPS of 1 or 2, and SHI (hazard ratio: 1.65, 95% confidence interval: 1.08-2.52, p = 0.020) were independent predictors of shorter OS. Splenic artery pseudoaneurysm rupture and variceal rupture were rare and only observed in cases with SHI.

CONCLUSIONS

Splenic hilar involvement is associated with worse outcomes in pancreatic tail cancer.

Dissimilar survival and clinicopathological characteristics of mucinous adenocarcinoma located in pancreatic head and body/tail

BACKGROUND

Growing evidence shows that pancreatic tumors in different anatomical locations have different characteristics, which have a significant impact on prognosis. However, no study has reported the differences between pancreatic mucinous adenocarcinoma (PMAC) in the head vs the body/tail of the pancreas.

AIM

To investigate the differences in survival and clinicopathological characteristics between PMAC in the head and body/tail of pancreas.

METHODS

A total of 2058 PMAC patients from the Surveillance, Epidemiology, and End Results database diagnosed between 1992 and 2017 were retrospectively reviewed. We divided the patients who met the inclusion criteria into pancreatic head group (PHG) and pancreatic body/tail group (PBTG). The relationship between two groups and risk of invasive factors was identified using logistic regression analysis. Kaplan-Meier analysis and Cox regression analysis were conducted to compare the overall survival (OS) and cancer-specific survival (CSS) of two patient groups.

RESULTS

In total, 271 PMAC patients were included in the study. The 1-year, 3-year, and 5-year OS rates of these patients were 51.6%, 23.5%, and 13.6%, respectively. The 1-year, 3-year, and 5-year CSS rates were 53.2%, 26.2%, and 17.4%, respectively. The median OS of PHG patients was longer than that of PBTG patients (18 vs 7.5 mo, P < 0.001). Compared to PHG patients, PBTG patients had a greater risk of metastases [odds ratio (OR) = 2.747, 95% confidence interval (CI): 1.628-4.636, P < 0.001] and higher staging (OR = 3.204, 95% CI: 1.895-5.415, P < 0.001). Survival analysis revealed that age < 65 years, male sex, low grade (G1-G2), low stage, systemic therapy, and PMAC located at the pancreatic head led to longer OS and CSS (all P < 0.05). The location of PMAC was an independent prognostic factor for CSS [hazard ratio (HR) = 0.7, 95%CI: 0.52-0.94, P = 0.017]. Further analysis demonstrated that OS and CSS of PHG were significantly better than PBTG in advanced stage (stage III-IV).

CONCLUSION

Compared to the pancreatic body/tail, PMAC located in the pancreatic head has better survival and favorable clinicopathological characteristics.

Factors predicting recurrence after left‑sided pancreatectomy for pancreatic ductal adenocarcinoma

BACKGROUND

Recurrence after resection is the main factor for poor survival. The relationship between clinicopathological factors and recurrence after curative distal pancreatectomy for PDAC has rarely been reported separately.

METHODS

Patients with PDAC after left‑sided pancreatectomy between May 2015 and August 2021 were retrospectively identified.

RESULTS

One hundred forty-one patients were included. Recurrence was observed in 97 patients (68.8%), while 44 (31.2%) patients had no recurrence. The median RFS was 8.8 months. The median OS was 24.9 months. Local recurrence was the predominant first detected recurrence site (n = 36, 37.1%), closely followed by liver recurrence (n = 35, 36.1%). Multiple recurrences occurred in 16 (16.5%) patients, peritoneal recurrence in 6 (6.2%) patients, and lung recurrence in 4 (4.1%) patients. High CA19-9 value after surgery, poor differentiation grade, and positive lymph nodes were found to be independently associated with recurrence. The patients receiving adjuvant chemotherapy had a decreased likelihood of recurrence. In the high CA19-9 value cohort, the median PFS and OS of the patients with or without chemotherapy were 8.0 VS. 5.7 months and 15.6 VS. 13.8 months, respectively. In the normal CA19-9 value cohort, there was no significant difference in PFS with or without chemotherapy (11.7 VS. 10.0 months, P = 0.147). However, OS was significantly longer in the patients with chemotherapy (26.4 VS. 13.8 months, P = 0.019).

CONCLUSIONS

Tumor biologic characteristics, such as T stage, tumor differentiation and positive lymph nodes, affecting CA19-9 value after surgery are associated with patterns and timing of recurrence. Adjuvant chemotherapy significantly reduced recurrence and improved survival. Chemotherapy is strongly recommended in patients with high CA199 after surgery.

Risk prediction of pancreatic cancer using AI analysis of pancreatic subregions in computed tomography images

Early detection of Pancreatic Ductal Adenocarcinoma (PDAC) is complicated as PDAC remains asymptomatic until cancer advances to late stages when treatment is mostly ineffective. Stratifying the risk of developing PDAC can improve early detection as subsequent screening of high-risk individuals through specialized surveillance systems reduces the chance of misdiagnosis at the initial stage of cancer. Risk stratification is however challenging as PDAC lacks specific predictive biomarkers. Studies reported that the pancreas undergoes local morphological changes in response to underlying biological evolution associated with PDAC development. Accurate identification of these changes can help stratify the risk of PDAC. In this retrospective study, an extensive radiomic analysis of the precancerous pancreatic subregions was performed using abdominal Computed Tomography (CT) scans. The analysis was performed using 324 pancreatic subregions identified in 108 contrast-enhanced abdominal CT scans with equal proportion from healthy control, pre-diagnostic, and diagnostic groups. In a pairwise feature analysis, several textural features were found potentially predictive of PDAC. A machine learning classifier was then trained to perform risk prediction of PDAC by automatically classifying the CT scans into healthy control (low-risk) and pre-diagnostic (high-risk) classes and specifying the subregion(s) likely to develop a tumor. The proposed model was trained on CT scans from multiple phases. Whereas using 42 CT scans from the venous phase, model validation was performed which resulted in ~89.3% classification accuracy on average, with sensitivity and specificity reaching 86% and 93%, respectively, for predicting the development of PDAC (i.e., high-risk). To our knowledge, this is the first model that unveiled microlevel precancerous changes across pancreatic subregions and quantified the risk of developing PDAC. The model demonstrated improved prediction by 3.3% in comparison to the state-of-the-art method that considers the global (whole pancreas) features for PDAC prediction.

Synchronous Pancreatic Ductal Adenocarcinoma in the Head and Tail, a Double Trouble: A Case Report and Literature Review

Synchronous primary pancreatic ductal adenocarcinoma (PDAC) is very rare and can be formed either through multicentric carcinogenesis or intrapancreatic metastasis. We report the case of an 80-year-old man with a history of type 2 diabetes mellitus who presented with abdominal pain and weight loss. Laboratory tests showed elevated levels of blood glucose and CA 19-9, and Computed Tomography revealed two hypoenhancing lesions in the head and tail of the pancreas. Endoscopic ultrasound, which is the imaging method of choice for pancreatic cancer, was performed with a fine needle biopsy, and the cytological analysis diagnosed PDAC in both lesions. The patient underwent total pancreatectomy, and pathologic evaluation revealed synchronous primary PDAC with moderate to poor differentiation in the head and tail in the setting of IPMN (intraductal papillary mucinous neoplasia) and chronic pancreatitis. After his recovery from postoperative pulmonary embolism, the patient was discharged home with sufficient glycemic control. Multifocal PDAC occurs more often when precursor lesions, such as IPMN, pre-exist. The optimal treatment for multiple lesions spread all over the pancreas is total pancreatectomy. Diabetes mellitus is a serious complication of total pancreatectomy (new-onset or type 3c), but overall, long-term survival has been significantly improved.

Segmentation of Pancreatic Subregions in Computed Tomography Images

The accurate segmentation of pancreatic subregions (head, body, and tail) in CT images provides an opportunity to examine the local morphological and textural changes in the pancreas. Quantifying such changes aids in understanding the spatial heterogeneity of the pancreas and assists in the diagnosis and treatment planning of pancreatic cancer. Manual outlining of pancreatic subregions is tedious, time-consuming, and prone to subjective inconsistency. This paper presents a multistage anatomy-guided framework for accurate and automatic 3D segmentation of pancreatic subregions in CT images. Using the delineated pancreas, two soft-label maps were estimated for subregional segmentation—one by training a fully supervised naïve Bayes model that considers the length and volumetric proportions of each subregional structure based on their anatomical arrangement, and the other by using the conventional deep learning U-Net architecture for 3D segmentation. The U-Net model then estimates the joint probability of the two maps and performs optimal segmentation of subregions. Model performance was assessed using three datasets of contrast-enhanced abdominal CT scans: one public NIH dataset of the healthy pancreas, and two datasets D₁ and D₂ (one for each of pre-cancerous and cancerous pancreas). The model demonstrated excellent performance during the multifold cross-validation using the NIH dataset, and external validation using D₁ and D₂. To the best of our knowledge, this is the first automated model for the segmentation of pancreatic subregions in CT images. A dataset consisting of reference anatomical labels for subregions in all images of the NIH dataset is also established.

Comparative Recurrence Analysis of Pancreatic Adenocarcinoma after Resection

Purpose

The relation between tumor sites of pancreatic ductal adenocarcinoma (PDAC) and recurrence was not fully investigated before. We aimed to describe the differences of recurrent patterns in PDAC of head and body/tail after curative surgery.

Methods

The recurrent patterns of PDAC were compared and the associations with clinical characteristics were analyzed in these patients. Prognostic factors of overall survival (OS) and progression-free survival (PFS) were analyzed and validated. Predictive systems were constructed and measured by the area under the AUC curve and concordance index (C-index).

Results

A total of 302 PDAC patients were included in this study, including 247 patients with PDAC of head and another 55 patients with PDAC of body/tail. Patients who developed tumor recurrence within 24 months after resection had significantly shorter OS in both groups. Liver metastasis occupied most of the tumor progressions and diminished while local recurrence increased gradually over time. The variation trends were similar for patients in both groups while these changes were more pronounced for patients in the head group. Local recurrence and liver-only metastasis seemed to indicate a better OS. Furthermore, predictive systems for OS and PFS prediction based on independent risk factors were established and showed significant higher values of AUC and C-indexes compared with the TNM stage system.

Conclusions

Different characteristics of progressions for PDAC of head and body/tail suggested biological heterogeneity. The exploration of these variations helps to provide personalized management of recurrence in PDAC.

Whole-tumour evaluation with MRI and radiomics features to predict the efficacy of S-1 for adjuvant chemotherapy in postoperative pancreatic cancer patients: a pilot study

Background

Multiple guidelines for pancreatic ductal adenocarcinoma (PDAC) suggest that all stages of patients need to receive postoperative adjuvant chemotherapy. S-1 is a recently emerged oral antitumour agent recommended by the guidelines. However, which population would benefit from S-1 needs to be determined, and predictors of chemotherapy response are needed for personalized precision medicine. This pilot study aimed to initially identify whether whole-tumour evaluation with MRI and radiomics features could be used for predicting the efficacy of S-1 and to find potential predictors of the efficacy of S-1 as evidence to assist personalized precision treatment.

Methods

Forty-six patients with PDAC (31 in the primary cohort and 15 in the validation cohort) who underwent curative resection and subsequently adjuvant chemotherapy with S-1 were included. Pre-operative abdominal contrast-enhanced MRI was performed, and radiomics features of the whole PDAC were extracted from the primary cohort. After univariable analysis and radiomics features selection, a multivariable Cox regression model for survival analysis was subsequently used to select statistically significant factors associated with postoperative disease-free survival (DFS). Predictive capacities of the factors were tested on the validation cohort by using Kaplan–Meier method.

Results

Multivariable Cox regression analysis identified the probability of T₁WI_NGTDM_Strength and tumour location as independent predictors of the efficacy of S-1 for adjuvant chemotherapy of PDAC (p = 0.005 and 0.013) in the primary cohort, with hazard ratios (HRs) of 0.289 and 0.293, respectively. Further survival analysis showed that patients in the low-T₁WI_NGTDM_Strength group had shorter DFS (median = 5.1 m) than those in the high-T₁WI_NGTDM_Strength group (median = 13.0 m) (p = 0.006), and patients with PDAC on the pancreatic head exhibited shorter DFS (median = 7.0 m) than patients with tumours in other locations (median = 20.0 m) (p = 0.016). In the validation cohort, the difference in DFS between patients with low-T₁WI_NGTDM_Strength and high-T₁WI_NGTDM_Strength and the difference between patients with PDAC on the pancreatic head and that in other locations were approved, with marginally significant (p = 0.073 and 0.050), respectively.

Conclusions

Whole-tumour radiomics feature of T₁WI_NGTDM_Strength and tumour location were potential predictors of the efficacy of S-1 and for the precision selection of S-1 as adjuvant chemotherapy regimen for PDAC.

Pancreatic ductal adenocarcinoma survival in South Australia: time trends and impact of tumour location

BACKGROUND

It is unclear how global developments in management of pancreatic ductal adenocarcinoma (PDAC) have affected survival of Australian patients. This study aimed to determine trends in survival of PDAC over the last three decades in South Australia and to compare survival based on cancer location (head and uncinate process versus body and tail).

METHODS

A retrospective observational cohort study to include all cases of PDAC reported to the South Australian (state) Cancer Registry from 1990 to 2017.

RESULTS

A total of 1051 patients diagnosed with PDAC between 1990 and 2017 were included. An overall increase in number of reported PDAC cases over time with more than a doubling in the crude rate from 1.73 to 3.50 per 100 000 persons between the decades 1990-1999 and 2010-2017 (P < 0.001) was noted. Overall median survival for PDAC was 7.4 months (95% confidence interval 6.8-8.0 months) and this has improved in recent decades. Overall median survival for PDAC affecting head and uncinate process of pancreas was significantly higher compared to body and tail (7.6 months versus 4.1 months; P < 0.001).

CONCLUSIONS

This study from South Australia demonstrates an increased reporting of PDAC over the last three decades. Although overall survival for patients with PDAC remains low, there has been a modest improvement in recent decades. The overall survival is significantly lower for patients with PDAC involving the body and tail compared to the head and uncinate process of pancreas. Risk factors for poor survival include the male gender and advancing age (>70 years).

The impact of different metastatic patterns on survival in patients with pancreatic cancer

BACKGROUND

The aims of this study were to compare the metastatic patterns of pancreatic ductal adenocarcinoma (PDAC) of head and body/tail and to determine the prognostic factors.

METHODS

Data of metastatic PDAC (MPC) between 2004 and 2015 from the Surveillance, Epidemiology and End Results (SEER) database was extracted and analyzed. The correlation analyses of metastatic patterns were also conducted. Multivariate Cox regression analyses were used to analyze prognosis.

RESULTS

A total of 27470 eligible MPC patients were collected from SEER database. Patients in the head group had a higher proportion of single-metastasis while those in the body/tail group had a higher proportion of two-site metastases. Similar distributions of metastatic sites were observed in cases with single-metastasis between two groups. Patients with liver and peritoneum metastases in the head group had significantly higher overall survival (OS) rates than those in the body/tail group. Also, the OS rates stratified by varied tumor sites did not differ significantly in patients with bone, brain, and lung metastases. Chemotherapy could prolong survival in almost all MPC patients while radiotherapy or surgery could only benefit certain types of metastases. Tumor site, therapy and vascular invasion were independent prognostic factors of OS in MPC patients.

CONCLUSIONS

MPC of the head and body/tail presented with different metastatic patterns. Chemotherapy benefited patients with metastases while surgery and radiotherapy could only prolong survival in patients with liver and peritoneum metastases. Our findings may provide more details for the precise management of patients with MPC in clinical practice.

Comparative genomic analysis of head and body/tail of pancreatic ductal adenocarcinoma at early and late stages

Pancreatic ductal adenocarcinoma (PDAC), one of the most lethal human cancers, can be divided into head and body/tail cancers anatomically. We previously reported a prognostic relevance of tumour location in resectable PDAC. This study aimed to further explore the mechanism underlying the molecular diversity between the head and body/tail of PDACs. We detected tumour genomes in 154 resectable (surgery) and non-resectable (biopsy) PDACs using a next-generation sequencing panel. Wilcoxon's rank test or Fisher's exact test was used for evaluating associations between clinical characteristics, mutation frequency and survival probability between the two cohorts. Compared with pancreatic head cancers, pancreatic body/tail cancers showed significantly more enriched genomic alterations in KRAS (97.1% vs 82.4%, P = 0.004) and SMAD4 (42.0% vs 21.2%, P = 0.008). At early stages (I-II), the SMAD4 mutation rate was significantly higher in pancreatic body/tail cancers than pancreatic head cancers (56.0% vs 26.5%, P = 0.021). At late stages (III-IV), pancreatic body/tail cancers presented significantly higher KRAS mutation rate (100.0% vs 75.8%, P = 0.001), higher frequency of MAPK pathway mutation (100% vs 87.8%, P = 0.040) and lower rates of druggable genomic alterations (30.8% vs 57.6%, P = 0.030) than pancreatic head cancers. Our work points out that pancreatic body/tail cancer seems to be more malignant than pancreatic head cancer at late stages.

Score for the Overall Survival Probability of Patients With Pancreatic Adenocarcinoma of the Body and Tail After Surgery: A Novel Nomogram-Based Risk Assessment

Pancreatic adenocarcinoma of the body and tail often has a dismal prognosis and lacks a specific prognostic stage. The aim of this study was to construct a nomogram for predicting survival of patients with pancreatic adenocarcinoma of the body and tail after surgery. Data of patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database and from medical records of Sun Yat-sen University Cancer Center (SYSUCC). In a multivariate analysis for overall survival (OS), the following six variables were identified as independent predictors and incorporated into the nomogram: age, tumor differentiation, tumor size, lymph node ratio (LNR), and chemotherapy. A nomogram was built based on independent risk predictors. The concordance index (C-index) for nomogram, Tumor-Node-Metastasis (TNM) 7th and 8th stage system were 0.775 [95% confidence interval (CI), 0.731–0.819], 0.617 (95%CI, 0.575–0.659), and 0.632 (95%CI, 0.588–0.676), respectively. The calibrated nomogram predicted survival rates which closely corresponded to the actual survival rates. Furthermore, the values of the area under receiver operating characteristic (ROC) curves (AUC) of the nomograms were higher than those of the TNM 7th or 8th stage system in predicting 1-, 2-, and 3-year survival of patients in training and external validation cohorts. The well-calibrated nomogram could be used to predict prognosis for patients with pancreatic adenocarcinoma of the body and tail after surgery.

Does Site Matter? Impact of Tumor Location on Pathologic Characteristics, Recurrence, and Survival of Resected Pancreatic Ductal Adenocarcinoma

BACKGROUND

The authors hypothesized that in resected pancreatic adenocarcinoma (PDAC), pathologic characteristics, oncologic outcomes, prognostic factors, and the accuracy of the American Joint Committee on Cancer (AJCC) staging system might differ based on tumor location.

METHODS

Patients undergoing pancreatectomy for PDAC at two academic institutions from 2000 to 2015 were retrieved. A comparative analysis between head (H-PDAC) and body-tail (BT-PDAC) tumors was performed using uni- and multivariable models. The accuracy of the eighth AJCC staging system was analyzed using C-statistics.

RESULTS

Among 1466 patients, 264 (18%) had BT-PDAC, which displayed greater tumor size but significantly lower rates of perineural invasion and G3/4 grading. Furthermore, BT-PDAC was associated with a lower frequency of nodal involvement and a greater representation of earlier stages. The recurrence-free survival and disease-specific survival times were longer for BT-PDAC (16 vs 14 months [p = 0.020] and 33 vs 26 months [p = 0.026], respectively), but tumor location was not an independent predictor of recurrence or survival in the multivariable analyses. The recurrence patterns did not differ. Certain prognostic factors (i.e., CA 19.9, grading, R-status, and adjuvant treatment) were common, whereas others were site-specific (i.e., preoperative pain, diabetes, and multivisceral resection). The performances of the AJCC staging system were similar (C-statistics of 0.573 for H-PDAC and 0.597 for BT-PDAC, respectively).

CONCLUSIONS

Despite differences in pathologic profile found to be in favor of BT-PDAC, tumor location was not an independent predictor of recurrence or survival after pancreatectomy. An array of site-specific prognostic factors was identified, but the AJCC staging system displayed similar prognostic power regardless of primary tumor location.

Comparative bioinformatical analysis of pancreatic head cancer and pancreatic body/tail cancer

This study is to analyze differentially expressed genes (DEGs) and mutation signatures of pancreatic head cancer and pancreatic body/tail cancer. Pancreatic Adenocarcinoma (PAAD) RNA-seq data, mutation data and clinical data were downloaded and collected from The Cancer Genome Atlas (TCGA), FireHose and CBioPortal. According to the anatomic location, the patients were divided into 146 cases of pancreatic head cancer and 28 cases of pancreatic body/tail cancer. Then survival analysis was performed by Kaplan-Meier and log-rank test. Furthermore, DEGs were screened by R package Deseq2. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) were then carried out by DAVID and String. Online tool TIMER was used to analyze the immune cells infiltration. R package maftools and GenVisR were applied to analyze frequently mutated genes and mutant-allele tumor heterogeneity (MATH) of PAAD. Survival of patients with pancreatic body/tail cancer was better than those with pancreatic head cancer (median survival, 24.05 vs 19.45 months, p = 0.048). And 496 significant DEGs (|log2 FoldChange| > 1.5,false discovery rate (FDR) < 0.05) were identified, including 253 downregulated genes and 243 upregulated genes. And there were 13 Go terms (4 biological processes, 6 cellular components and 3 molecular functions) and 3 KEGG pathways (Pancreatic secretion, Fat digestion and absorption, Protein digestion and absorption) (FDR < 0.05). B cells and CD4 + T cells infiltration were more significant in pancreatic head cancer. MATH scores of pancreatic body/tail cancer were higher than pancreatic head cancer, while χ² test of top 10 frequently mutated genes showed little difference between them. There were prognostic and genetic differences between pancreatic head cancer and pancreatic body/tail cancer. PAAD originated from different location may have different biology natures and should not be treated with same strategy.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

The diversity between curatively resected pancreatic head and body-tail cancers based on the 8th edition of AJCC staging system: a multicenter cohort study

BACKGROUND

To our knowledge, there are no studies to systematically compare the detailed clinical significance between curatively resected pancreatic head (ph) and body-tail (pbt) ductal adenocarcinoma based on the new 8th edition of AJCC staging system (8th AJCC stage) that was just applied in clinical practice in 2018.

METHODS

Three hundred fifty-one patients with curatively resected pancreatic adenocarcinoma (PC) from three center hospitals were entered into this multicenter cohort study.

RESULTS

Increasing tumor size (P < 0.001), T stage (T1 + T2 vs T3 + T4, P = 0.003), frequent postoperative liver metastasis (PLM) (P = 0.002) and 8th AJCC stage (IA to VI, P < 0.001; I + II vs III + IV, P = 0.002) were closely associated with the progression of pbt cancers compared with that in ph cancer patients. Moreover, tumor size≥3 cm (P = 0.012), 8th AJCC stage (III + IV) (P = 0.025) and PLM (P = 0.010) were identified as independent risk factors in pbt cancers in logistic analysis. Patients with pbt cancers had a significantly worse overall survival compared with ph cancer patients (P = 0.003). Moreover, pbt was an independent unfavorable factor in multivariate analysis (P = 0.011). In addition to lymph nodes metastasis, 8th AJCC stage, vascular invasion and PLM, increasing tumor size and advanced T stage were also closely associated with the poor prognosis in 131 cases of pbt cancer patients compared with Ph cancer patients.

CONCLUSION

Pbt, as an independent unfavorable factor for the prognosis of PC patients, are much more aggressive than that in ph cancers according to 8th AJCC staging system. 8th AJCC staging system are more comprehensive and sensitive to reflect the malignant biology of pbt cancers.

A Refined Staging Model for Resectable Pancreatic Ductal Adenocarcinoma Incorporating Examined Lymph Nodes, Location of Tumor and Positive Lymph Nodes Ratio

Background: Nodal status and tumor site are prognostic factors for resectable pancreatic ductal adenocarcinoma (PDAC). Parameters for nodal status are diverse, and the number of examined lymph nodes (eNs) needed for good prognosis are uncertain. We try to modify staging system of resectable PDAC with parameters mentioned above by recursive partitioning analysis.

Methods: Patients from the Surveillance, Epidemiology, and End Results (SEER) database were divided into training cohort and internal validation cohort, randomly. PDAC patients from Sun Yat-sen University Cancer Center were regarded as external validation cohort. The training cohort was used to refine staging model by recursive partitioning analysis, while the internal validation cohort and the external validation cohort were applied to assess discriminatory capacity of staging model. For parameters included in the modified model, their effects were studied.

Results: The number of eNs, tumor site and tumor size were risk factors for positive nodal status. Lymph nodes ratio (LNR), tumor site, eNs and T stages of 8^th the American Joint Committee on Cancer (AJCC) were selected to develop a refined model, dividing patients into 5 groups of different outcomes, preceding 8^th AJCC classification. Besides, we found that (1) for small PDAC (diameter < 1cm), lymph node metastasis was rarely found; (2) enough eNs were needed to ensure better prognosis of node-negative patients; (3) tumors in the head of pancreas were prone to lymph nodes metastasis; (4) for node-positive patients, LNR was a better nodal parameter compared to positive lymph nodes (pNs).

Conclusion: Our improved staging system helps to illuminate the interactions among tumor site, size and eNs.

Do patients with pancreatic body or tail cancer benefit from adjuvant therapy?A cohort study

INTRODUCTION

Evidence supporting adjuvant therapy for resected pancreatic cancer is limited primarily to head tumors. We analyzed data from the National Cancer Database (NCDB) to evaluate the relationship of tumor site with benefit from adjunctive (adjuvant, neoadjuvant, perioperative) therapy (Rx).

METHODS

All NCDB patients with clinical stage I and II pancreatic cancer, diagnosed from 2003 to 2013, who underwent surgical resection and had data on site of primary were included. Overall survival (OS) analyses with hazard ratios (HR), 95% confidence intervals (CI), and two-sided p-values are presented.

RESULTS

A total of 27,930 patients met inclusion criteria; median age 66 years, 51% males, 86% white. Primary site was coded as head (74.4%), body (9.3%), or tail (16.3%). Pathologic stage was predominantly stage II (77%); 81% had negative margins. Perioperative Rx was used in 4%, neoadjuvant in 8%, adjuvant in 48%. Median OS for the cohort was 24 months; for head, body and tail tumors, it was 21.6, 34.5, and 42.5 months, respectively. In univariable analyses, adjunctive Rx was associated with improved OS in head tumors (HR, any Rx vs. no Rx: 0.87; 95% CI 0.84-0.91; p < 0.0001) but not in body (1.82; 1.59-2.08; <0.0001) and tail (2.28; 2.05-2.53; <0.0001) tumors; multivariable models including statistically significant predictors (Charlson-Deyo comorbidity score, tumor grade and stage, positive resection margin) confirmed these results.

CONCLUSIONS

Our study suggests that the benefit of adjunctive Rx is restricted to pancreatic head tumors; body and tail tumors have a much better prognosis. These results warrant further evaluation in prospective studies.

The prognostic relevance of primary tumor location in patients undergoing resection for pancreatic ductal adenocarcinoma

Different clinical presentations and prognoses have been implied between pancreatic head and body/tail cancers. We aimed to identify the prognostic relevance of primary tumor location in patients undergoing resection for pancreatic ductal adenocarcinoma (PDAC). Thirty-two pairs of patients with strictly matched early stage (II) pancreatic head and body/tail cancers were enrolled. The molecular feature of the two subtypes of PDAC was assessed on the level of miRNA expression. Out of the 64 patients, 34 (53.1%) had tumor recurrence after radical resection during the follow-up period (2.3 ± 0.8 years). Both overall and tumor-free survival were significantly higher in the patients with pancreatic body/tail cancer compared with those with pancreatic head cancer. Patient age and tumor location were the independent prognostic factors for tumor recurrence. A remarkably lower expression of miR-501-3p and higher expression of miR-375 were found and were further verified in pancreatic body/tail cancer tissues compared with pancreatic head cancer tissues. The low expression of miR-501-3p was significantly associated with a low risk of tumor recurrence. Both, subcutaneous and orthotopic PDAC mouse models presented highly invasive tumor phenotypes upon up-regulated miR-501-3p expression. An in vitro study showed that miR-501-3p promoted the invasiveness of PDAC cells possibly via suppressing E-cadherin. In summary, at resectable early stage, pancreatic body/tail cancer presents a less malignant phenotype associated with deregulation of miR-501-3p compared with pancreatic head cancer.

Cellular and molecular mechanisms coordinating pancreas development

The pancreas is an endoderm-derived glandular organ that participates in the regulation of systemic glucose metabolism and food digestion through the function of its endocrine and exocrine compartments, respectively. While intensive research has explored the signaling pathways and transcriptional programs that govern pancreas development, much remains to be discovered regarding the cellular processes that orchestrate pancreas morphogenesis. Here, we discuss the developmental mechanisms and principles that are known to underlie pancreas development, from induction and lineage formation to morphogenesis and organogenesis. Elucidating such principles will help to identify novel candidate disease genes and unravel the pathogenesis of pancreas-related diseases, such as diabetes, pancreatitis and cancer.

Diels Alder-mediated release of gemcitabine from hybrid nanoparticles for enhanced pancreatic cancer therapy

Hybrid nanoparticles (HNPs) have shown huge potential as drug delivery vehicles for pancreatic cancer. Currently, the first line treatment, gemcitabine, is only effective in 23.8% of patients. To improve this, a thermally activated system was developed by introducing a linker between HNPs and gemcitabine. Whereby, heat generation resulting from laser irradiation of the HNPs promoted linker breakdown resulting in prodrug liberation. In vitro evaluation in pancreatic adenocarcinoma cells, showed the prodrug was 4.3 times less cytotoxic than gemcitabine, but exhibited 11-fold improvement in cellular uptake. Heat activation of the formulation led to a 56% rise in cytotoxicity causing it to outperform gemcitabine by 26%. In vivo the formulation outperformed free gemcitabine with a 62% reduction in tumor weight in pancreatic xenografts. This HNP formulation is the first of its kind and has displayed superior anti-cancer activity as compared to the current first line drug gemcitabine after heat mediated controlled release.

Outcomes and prognostic factors of patients with stage IB and IIA pancreatic cancer according to the 8th edition American Joint Committee on Cancer criteria

AIM

To evaluate the changes in the 8^th edition American Joint Committee on Cancer (AJCC) for defining stage IB and IIA pancreatic cancer and identify their prognostic factors.

METHODS

Pancreatic cancer patients were selected from the Surveillance Epidemiology and End Results database (1973-2013). The enrolled patients were divided into IB and IIA groups based on tumor size according to the 8^th edition AJCC criteria. Clinical characteristics, including age, gender, race, tumor size, primary site, and grade were summarized. Univariate and multivariate analyses were performed to explore the prognostic factors of the IB and IIA stages of pancreatic cancer under new criteria.

RESULTS

A total of 1349 pancreatic cancer patients were included. More patients had stage IB rather than stage IIA. Stage IB tumors (54.85%) were mainly located in the head of the pancreas, while stage IIA tumors were more often located in the tail and head of the pancreas (35.21% and 31.75%, respectively). The survival time of stage IB and IIA patients had no significant difference. Univariate and multivariate analyses indicated that the prognostic factors of survival for stage IB and IIA patients were different. For stage IB patients, age and primary site were the independent prognostic factors; for stage IIA patients, age and grade were the independent prognostic factors. The risk of death was lower among patients aged ≤ 65 years than those aged > 65 years.

CONCLUSION

The prognostic factors for stage IB and IIA patients are different, but age is the independent prognostic factor for all patients. The survival time of stage IB and IIA patients has no significant difference.

Clinical data combined with radiological imaging improves the accuracy of TNM staging of pancreatic body and tail adenocarcinoma

PURPOSE

Pancreatic body and tail adenocarcinoma (PBTA) remains one of the deadliest cancers, and current radiological modalities still have limitations on the staging of PBTA. Improving PBTA staging will contribute to the management of this disease.

PATIENTS AND METHODS

Clinicopathological characteristics of 91 surgically treated PBTA patients were retrospectively retrieved. Clinical data associated with postoperative tumor staging (pTNM) were assessed using ordinal logistic regression model. Discriminant analysis was performed using function formula based on multivariate analysis results; further cross-validation was conducted by Bootstrap methods.

RESULTS

Multivariate analysis showed that carbohydrate antigen 19-9 ≥955.0 U/L, albumin, and alkaline phosphatase/total bilirubin ratio were independent factors contributing to improved accuracy of pTNM staging. Discriminant analysis exhibited better performance and showed that the probability of accurate prediction of pTNM stage was 90.6% and the probability of cross-validation was 85.9%. After excluding patients with preoperative diagnosis of stage IV disease, the probability of accurate prediction of pTNM stage was 86.1% and the probability of cross-validation was 75.0%.

CONCLUSION

The combination of imaging and clinical data has higher accuracy in staging PBTA than radiological data alone. A model proposed in this study will improve the management of PBTA.

Plasma protein profiling in a stage defined pancreatic cancer cohort - Implications for early diagnosis

Pancreatic ductal adenocarcinoma (PDAC) is a disease where detection preceding clinical symptoms significantly increases the life expectancy of patients. In this study, a recombinant antibody microarray platform was used to analyze 213 Chinese plasma samples from PDAC patients and normal control (NC) individuals. The cohort was stratified according to disease stage, i.e. resectable disease (stage I/II), locally advanced (stage III) and metastatic disease (stage IV). Support vector machine analysis showed that all PDAC stages could be discriminated from controls and that the accuracy increased with disease progression, from stage I to IV. Patients with stage I/II PDAC could be discriminated from NC with high accuracy based on a plasma protein signature, indicating a possibility for early diagnosis and increased detection rate of surgically resectable tumors.

Role of Adjuvant Radiotherapy in Left-Sided Pancreatic Cancer-Population-Based Analysis with Propensity Score Matching

This population-based study evaluated the survival impact of postoperative radiotherapy (PORT) in left-sided pancreatic cancer. The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients with surgically resected left-sided pancreatic adenocarcinoma from 2004 to 2010. Propensity score matching was conducted to compare PORT and non-PORT groups. A total of 445 patients were identified, and PORT was performed in 180 (40 %) patients. In the unmatched population, there were no significant differences in overall survival (OS) (P = 0.197) and cause-specific survival (CSS) (P = 0.379) between the PORT and non-PORT groups. After propensity score matching, the patients treated with PORT had longer median OS (P = 0.012) and CSS (P = 0.039) than the non-PORT group. In propensity-adjusted multivariate analysis, non-receipt of PORT was a poor prognostic factor in OS (hazard ratio [HR] 1.39, 95 % confidence interval [CI] 1.08-1.79), and CSS (HR 1.31, 95 % CI 1.01-1.71). The log odds of positive lymph nodes (LOODS) (≥-0.73) was also associated with worse OS (P = 0.003) and CSS (P = 0.001). In left-sided pancreatic cancer, considering the addition of PORT is a reasonable option as in pancreatic head cancer. The LOODS was suggested as a strong predictive indicator of the patients' prognoses.

Inhibition of pancreatic cancer cell migration by plasma anthocyanins isolated from healthy volunteers receiving an anthocyanin-rich berry juice

PURPOSE

Pancreatic cancer is an aggressive cancer type, of which the most important characteristics are migration and metastasis. Anthocyanins (ACN) are discussed to be protective phytochemicals; however, up to now only scarce data are available regarding their effects on cancer prevention. In this study, we aimed to determine whether ACN and their metabolites from plasma (PAM), isolated from blood of healthy volunteers after ingestion of an ACN-rich juice, are effective in modulating cancer cell migration in vitro.

METHODS

PAM were isolated from blood of healthy volunteers (n = 10) after consumption of an ACN-rich berry juice. Before ingestion (PAM_0min) and after 60 min (PAM_60min), blood was taken and PAM were isolated from plasma by solid-phase extraction. Migration of pancreatic cancer cells PANC-1 and AsPC-1 was assayed in a Boyden chamber. The influence of PAM on cellular reactive oxygen species (ROS) or mitochondria-specific ROS was measured fluorimetrically. mRNA expression levels of matrix metalloproteinases (MMP-2 and MMP-9) and NF-κB mRNA were determined by real-time PCR.

RESULTS

After application of PAM_60min to PANC-1, we observed a reduced cell migration, which was associated with reduced levels of endogenously generated ROS concomitant with reduced NF-κB as well as MMP-2 and MMP-9 mRNA expression levels. In AsPC-1 cells, however, migration was not affected by PAM_60min.

CONCLUSION

It can be assumed that physiologically relevant ACN and their metabolites were able to inhibit pancreatic cancer cell migration in dependency of the phenotype of cells and may thus deserve further attention as potential bioactive phytochemicals in cancer prevention.

Intensity modulated radiotherapy for locally advanced and metastatic pancreatic cancer: a mono-institutional retrospective analysis

Background

To evaluate the role of intensity modulated radiotherapy (IMRT) for locally advanced pancreatic cancer (LAPC) and metastatic pancreatic cancer (MPC), and the prognostic factors in the setting of multidisciplinary approach strategies.

Methods

63 patients with LAPC and MPC receiving IMRT in our institution were retrospectively identified. Information on patient baseline, treatment characteristics and overall survival (OS) time were collected. Data of pain relief and toxicity were evaluated. Univariate and multivariate analyses were conducted to investigate the prognostic factors.

Results

All patients received IMRT with a median dose of 46.0 Gy. The median OS for LAPC and MPC patients were 15.7 months and 8.0 months, respectively (p = 0.029). Symptomatic improvements were observed in the 44 patients with abdominal/back pain after radiotherapy (RT) or concurrent chemoradiotherapy (CCRT), particularly in those with severe pain. Only 13.9% and 14.8% cases presented Grade ≥ 3 hematologic toxicities in RT and CCRT group, while no cases developed Grade ≥ 3 non-hematologic toxicities in both groups. Multivariate analysis indicated that tumors located in pancreas body/tail (HR 0.28, p = 0.008), pretreatment CA19-9 < 1000 U/mL (HR 0.36, p = 0.029) and concurrent chemotherapy (HR 0.37, p = 0.016) were independent favorable predictors for OS.

Conclusions

CCRT further improved OS for LAPC and MPC with acceptable toxicities, and use of RT markedly alleviated pain. Tumors located in pancreas body/tail, pretreatment CA19-9 level of < 1000 U/mL and CCRT were associated with better OS. However, regional intra-arterial chemotherapy did not show any survival benefit in our study.

Surgical management of pancreatic cancer--distal pancreatectomy

Distal pancreatectomy is the standard procedure for tumors located in the body and tail of the pancreas. In the last three decades, significant progress has been made with regard to technical aspects as well as perioperative care so that excellent mortality and morbidity rates can be achieved. Recently, there is growing evidence that distal pancreatectomy may be performed laparoscopically in selected patients, offering the advantages of minimally invasive surgery. Unfortunately, the oncologic outcomes for pancreatic adenocarcinoma remain poor, in part due to the late stage of presentation in most patients. We review the history of distal pancreatectomy, discuss current indications for performing this procedure, compare operative techniques in performing distal pancreatectomy, and review both the early complications seen in patients who have undergone a distal pancreatectomy and the long-term metabolic and oncologic outcomes of these patients.

Zn-driven discovery of a hydrothermal vent fungal metabolite clavatustide C, and an experimental study of the anti-cancer mechanism of clavatustide B

A naturally new cyclopeptide, clavatustide C, was produced as a stress metabolite in response to abiotic stress elicitation by one of the hydrothermal vent fluid components Zn in the cultured mycelia of Aspergillus clavatus C2WU, which were isolated from Xenograpsus testudinatus. X. testudinatus lives at extreme, toxic habitat around the sulphur-rich hydrothermal vents in Taiwan Kueishantao. The known compound clavatustide B was also isolated and purified. This is the first example of a new hydrothermal vent microbial secondary metabolite produced in response to abiotic Zn treatment. The structures were established by spectroscopic means. The regulation of G1-S transition in hepatocellular carcinoma cell lines by clavatustide B was observed in our previous study. The purpose of the present study was to verify these results in other types of cancer cell lines and elucidate the possible molecular mechanism for the anti-cancer activities of clavatustide B. In different human cancer cell lines, including pancreatic cancer (Panc-1), gastric cancer (MGC-803), colorectal cancer (SW-480), retinoblastoma (WERI-Rb-1) and prostate cancer (PC3), clavatustide B efficiently suppressed cell proliferations in a dose-dependent manner. Although different cancer cell lines presented variety in Max effect dose and IC₅₀ dose, all cancer cell lines showed a lower Max effect dose and IC₅₀ dose compared with human fibroblasts (hFB) (p < 0.05). Moreover, significant accumulations in G1 phases and a reduction in S phases (p < 0.05) were observed under clavatustide B treatment. The expression levels of 2622 genes including 39 cell cycle-associated genes in HepG2 cells were significantly altered by the treatment with 15 μg/mL clavatustide B after 48 h. CCNE2 (cyclin E2) was proved to be the key regulator of clavatustide B-induced G1-S transition blocking in several cancer cell lines by using real-time PCR.