Radical antegrade modular pancreatosplenectomy (RAMPS) versus standard retrograde pancreatosplenectomy (SRPS) for resectable body and tail pancreatic adenocarcinoma: protocol of a multicenter, prospective, randomized phase III control trial (CSPAC-3)

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy. Radical surgical resection offers the only potential cure. There is increasing agreement that radical antegrade modular pancreatosplenectomy (RAMPS) may benefit patients with tumors in the body and tail of the pancreas. To address this, the Chinese Study Group for Pancreatic Cancer (CSPAC)-3 trial is proposed to compare the effect of RAMPS and standard retrograde pancreatosplenectomy (SRPS) on patient survival and preoperative safety METHODS: The randomized controlled trial will be multicenter and two-armed with blinded outcomes and intention-to-treat analysis. Three hundred patients with resectable body and tail pancreatic adenocarcinoma will be enrolled and randomly assigned to RAMPS or SRPS. Adjuvant chemotherapy based on an initial regimen will be recommended 4-6 weeks after surgery if no serious complication occurs. The hypothesis that RAMPS improves survival outcomes compared with SRPS will be tested using a superiority trial. The primary outcome will be overall survival (OS). Secondary outcomes will include recurrence-free survival (RFS), R0 resection rate, the number of harvested lymph nodes, postoperative complications, and quality of life scores.

DISCUSSION

The use of RAMPS has increased over the past decade. It is reported that RAMPS is superior to SRPS in improving both the rate of R0 resection and lymph node yield. Despite these advantages, however, there is little high-level documentation of the superiority of RAMPS in terms of survival and this needs to be investigated. To address this issue, CSPAC has instigated the first prospective, randomized phase III control trials, aiming to explore the optimal surgical strategy for improving the prognosis and OS of patients with left-sided pancreatic cancer Trial registration Chinese Clinical Trial Registry ChiCTR2100053844; pre-results. Registered on December 1, 2021.

[Progress and reflection of conversion therapy for locally advanced pancreatic cancer]

With the improvement of nonsurgical treatment in pancreatic cancer, the increasing accuracy of subclassification of anatomy, and the continuous refinement of surgical resection techniques, more and more locally advanced pancreatic cancer(LAPC) patients have the opportunity to undergo conversion surgery and achieve survival benefits,which has attracted the attention of scholars in this field. Despite the numerous prospective clinical studies conducted, there is still a lack of high-level evidence-based medical evidence in terms of conversion treatment strategies, efficacy evaluation, surgical timing and survival prognosis, and there are not yet specific quantitative standards and guiding principles for conversion treatment for these patients in clinical practice, and the indications for surgical resection rely more on the experience of each center or surgeon, lacking consistency. Therefore,the indicators for the evaluation of the efficacy of conversion treatment in patients with LAPC were summarized to reflect on the different modes of conversion treatment and clinical outcomes currently being explored, expecting to provide more accurate recommendations and guidance for the clinic.

Characterization of intratumoral tertiary lymphoid structures in pancreatic ductal adenocarcinoma: cellular properties and prognostic significance

BACKGROUND

Tumor-associated tertiary lymphoid structures (TLSs) are functional immune-responsive niches that are not fully understood in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Fluorescent multiplex immunohistochemistry was performed on sequential sections of surgically resected tumor tissues from 380 PDAC patients without preoperative treatment (surgery alone (SA)) and 136 patients pretreated with neoadjuvant treatment (NAT). Multispectral images were processed via machine learning and image processing platforms, inForm V.2.4 and HALO V.3.2; TLS regions were segmented, and the cells were identified and quantified. The cellular composition and immunological properties of TLSs and their adjacent tissues in PDAC were scored and compared, and their association with prognosis was further examined.

RESULTS

Intratumoral TLSs were identified in 21.1% (80/380) of patients in the SA group and 15.4% (21/136) of patients in the NAT group. In the SA group, the presence of intratumoral TLSs was significantly associated with improved overall survival (OS) and progression-free survival. The existence of intratumoral TLSs was correlated with elevated levels of infiltrating CD8+T, CD4+T, B cells and activated immune cells in adjacent tissues. A nomogram model was generated with TLS presence as a variable, which successfully predicted PDAC patient OS in an external validation cohort (n=123). In the NAT group, samples exhibited a lower proportion of B cells and a higher proportion of regulatory T cells within intratumoral TLSs. Additionally, these TLSs were smaller in size, with a lower overall maturation level and reduced immune cell activation, and the prognostic value of TLS presence was insignificant in the NAT cohort.

CONCLUSION

Our study systematically revealed the cellular properties and prognostic values of intratumoral TLSs in PDAC and described the potential impact of NAT on TLS development and function.

Epigenetic regulation in the tumor microenvironment: molecular mechanisms and therapeutic targets

Over decades, researchers have focused on the epigenetic control of DNA-templated processes. Histone modification, DNA methylation, chromatin remodeling, RNA modification, and noncoding RNAs modulate many biological processes that are crucial to the development of cancers. Dysregulation of the epigenome drives aberrant transcriptional programs. A growing body of evidence suggests that the mechanisms of epigenetic modification are dysregulated in human cancers and might be excellent targets for tumor treatment. Epigenetics has also been shown to influence tumor immunogenicity and immune cells involved in antitumor responses. Thus, the development and application of epigenetic therapy and cancer immunotherapy and their combinations may have important implications for cancer treatment. Here, we present an up-to-date and thorough description of how epigenetic modifications in tumor cells influence immune cell responses in the tumor microenvironment (TME) and how epigenetics influence immune cells internally to modify the TME. Additionally, we highlight the therapeutic potential of targeting epigenetic regulators for cancer immunotherapy. Harnessing the complex interplay between epigenetics and cancer immunology to develop therapeutics that combine thereof is challenging but could yield significant benefits. The purpose of this review is to assist researchers in understanding how epigenetics impact immune responses in the TME, so that better cancer immunotherapies can be developed.

A new glance at autophagolysosomal-dependent or -independent function of transcriptional factor EB in human cancer

Autophagy-lysosome system plays a variety of roles in human cancers. In addition to being implicated in metabolism, it is also involved in tumor immunity, remodeling the tumor microenvironment, vascular proliferation, and promoting tumor progression and metastasis. Transcriptional factor EB (TFEB) is a major regulator of the autophagy-lysosomal system. With the in-depth studies on TFEB, researchers have found that it promotes various cancer phenotypes by regulating the autophagolysosomal system, and even in an autophagy-independent way. In this review, we summarize the recent findings about TFEB in various types of cancer (melanoma, pancreatic ductal adenocarcinoma, renal cell carcinoma, colorectal cancer, breast cancer, prostate cancer, ovarian cancer and lung cancer), and shed some light on the mechanisms by which it may serve as a potential target for cancer treatment.

Completely 3-dimensional laparoscopic pancreaticoduodenectomy with modified Blumgart pancreaticojejunostomy: an analysis of 100 consecutive cases

PURPOSE

Although laparoscopic pancreaticoduodenectomy (LPD) is increasingly performed in high-volume centers, pancreaticojejunostomy (PJ) is still the most challenging procedure. Pancreatic anastomotic leakage remains a major complication after PD. Thus, various technical modifications regarding PJ, such as the Blumgart technique, have been attempted to simplify the procedure and minimize anastomotic leakage. Three-dimensional (3D) laparoscopic systems have been shown to be particularly helpful in performing difficult and precise tasks. We present a modified Blumgart anastomosis in 3D-LPD and investigate its clinical outcomes.

METHODS

A retrospective analysis of 100 patients who underwent 3D-LPD with modified Blumgart PJ from September 2018 to January 2020 was conducted. Data on the preoperative characteristics, operative outcomes, and postoperative characteristics of the patients were collected and analyzed.

RESULTS

The mean operative time and duration of PJ were 348.2 and 25.1 min, respectively. The mean estimated blood loss was 112 mL. The overall rate of postoperative complications over Clavien‒Dindo classification III was 18%. The incidence of clinically relevant postoperative pancreatic fistula was 11%. The median postoperative hospital stay was 14.2 days. Only one patient required reoperation (1%), and no patient died in the hospital or 90 days after the operation. High BMI, small main pancreatic duct diameter, and soft pancreatic consistency had a significant influence on the occurrence of CR-POPF.

CONCLUSIONS

The surgical outcome of 3D-LPD with modified Blumgart PJ seems to be comparable to other studies in terms of operation time, blood loss, hospital stay, and complication incidence. We consider the modified Blumgart technique in 3D-LPD to be novel, reliable, safe, and favorable for PJ in the PD procedure.

The platelet pannexin 1-IL-1β axis orchestrates pancreatic ductal adenocarcinoma invasion and metastasis

We aimed to investigate the protumor mechanisms of platelets in pancreatic ductal adenocarcinoma (PDAC). Serum samples were collected from 656 PDAC patients and 3105 healthy people, and a Panx1 knockout tumor model and an adoptive platelet transfusion mouse model were established. We showed that the blood platelet counts were not significantly different between stage III/IV and stage I/II patients, while the number of the CD41+/CD62P+ platelets was significantly elevated in stage III/IV patients, indicating that CD41+/CD62P+ platelets are associated with a poor prognosis. Further analysis showed that a high level of CD41+/CD62P+ platelets was significantly correlated with microvascular invasion (P = 0.002), advanced 8th edition AJCC stage (P < 0.001), and a high CA19-9 level (P = 0.027) and independently predicted a poor prognosis for resectable I/II PDAC. Furthermore, we found significantly higher Panx1 expression in CD41+/CD62P+ platelets than in CD41+/CD62P- platelets in PDAC patients. Mechanistically, Panx1 was able to enhance IL-1β secretion in CD41+/CD62P+ platelets by phosphorylating p38 MAPK and consequently promoted the invasion and metastasis of PDAC cells. Finally, we synthesized a novel compound named PC63435 by the ligation of carbenoxolone (a Panx1 inhibitor) and PSGL-1 (a CD62P ligand). PC63435 specifically bound to CD41+/CD62P+ platelets, then blocked the Panx1/IL-1β pathway and reduced the proportion of CD41+/CD62P+ platelets, which suppressed PDAC tumor invasion and metastasis in vivo. These results demonstrated that the Panx1/IL-1β axis in CD41+/CD62P+ platelets enhanced PDAC cell malignancy and that this axis may be a promising target for PDAC therapy.

The added value of [68Ga]Ga-DOTA-FAPI-04 PET/CT in pancreatic cancer: a comparison to [18F]F-FDG

OBJECTIVES

We aimed to compare the diagnostic and prognostic performance of [⁶⁸Ga]Ga-DOTA-FAPI-04 and [¹⁸F]FDG PET/CT in pancreatic cancer.

METHODS

This single-center retrospective study enrolled 51 patients who underwent [⁶⁸Ga]Ga-DOTA-FAPI-04 and [¹⁸F]FDG PET/CT. The final diagnosis on PET/CT images was verified by histopathology or 1-year follow-up. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [¹⁸F]FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT were calculated to compare the diagnostic efficacy. Progression-free survival (PFS) was the endpoint for the survival analysis. Twenty-six patients were eligible for the Kaplan-Meier survival analysis using a log-rank test. And multivariate analysis including age, sex, stage, CA199 level, and SUV_max of [¹⁸F]FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 was also performed. Two-tailed p < 0.05 was considered statistically significant.

RESULTS

[⁶⁸Ga]Ga-DOTA-FAPI-04 showed a higher sensitivity than [¹⁸F]FDG for detecting primary tumor (100% vs. 95.0%), metastatic lymph nodes (96.2% vs. 61.5%), and distant metastases (100% vs. 84.0%) (p < 0.0001, respectively). For [⁶⁸Ga]Ga-DOTA-FAPI-04, the tumor-to-liver background ratio (TLBR) of liver metastases was higher (5.7 ± 3.2 vs. 3.2 ± 1.3, p < 0.0001). Furthermore, SUV_max > 14.9 on [⁶⁸Ga]Ga-DOTA-FAPI-04 was significantly associated with PFS rates (chi-square = 12.05, p = 0.001). The Cox regression analysis showed that SUV_max of [⁶⁸Ga]Ga-DOTA-FAPI-04 was an independent prognostic factor for PFS (p = 0.001; hazard ratio, 8.877).

CONCLUSIONS

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT showed a higher sensitivity and accuracy than [¹⁸F]FDG PET/CT in diagnosing pancreatic cancer and might have an independent prognostic value for pancreatic cancer patients.

KEY POINTS

• [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT had a higher sensitivity and accuracy in detecting primary tumors, metastatic lymph nodes, and distant metastases than [¹⁸F]FDG PET/CT. • SUV_max > 14.9 on [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT before chemotherapy was significantly associated with progress-free status rates (chi-square = 12.05, p = 0.001) in pancreatic cancer patients.

Glutamine is a substrate for glycosylation and CA19-9 biosynthesis through hexosamine biosynthetic pathway in pancreatic cancer

BACKGROUND

Carbohydrate antigen 19-9 (CA19-9) is the most widely used biomarker for pancreatic cancer. Since CA19-9 closely correlates with patient outcome and tumor stage in pancreatic cancer, the deciphering of CA19-9 biosynthesis provides a potential clue for treatment.

METHODS

Concentration of amino acids was detected by ultrahigh-performance liquid chromatography tandem mass spectrometry. Metabolic flux of glutamine was examined by isotope tracing untargeted metabolomics. Label-free quantitative N-glycosylation proteomics was used to examine N-glycosylation alterations.

RESULTS

Among all amino acids, glutamine was higher in CA19-9-high pancreatic cancers (> 37 U/mL, 66 cases) than in CA19-9-normal clinical specimens (≤ 37 U/mL, 37 cases). The glutamine concentration in clinical specimens was positively correlated with liver metastasis or lymphovascular invasion. Glutamine blockade using diazooxonorleucine suppressed pancreatic cancer growth and intraperitoneal and lymphatic metastasis. Glutamine promotes O-GlcNAcylation, protein glycosylation, and CA19-9 biosynthesis through the hexosamine biosynthetic pathway. UDP-N-acetylglucosamine (UDP-GlcNAc) levels correlated with the glutamine influx through hexosamine biosynthetic pathway and supported CA19-9 biosynthesis.

CONCLUSIONS

Glutamine is a substrate for CA19-9 biosynthesis in pancreatic cancer. Glutamine blockade may be a potential therapeutic strategy for pancreatic cancer.

Mesenchymal Stromal Cell-Based Targeted Therapy Pancreatic Cancer: Progress and Challenges

Pancreatic cancer is an aggressive malignancy with high mortality rates and poor prognoses. Despite rapid progress in the diagnosis and treatment of pancreatic cancer, the efficacy of current therapeutic strategies remains limited. Hence, better alternative therapeutic options for treating pancreatic cancer need to be urgently explored. Mesenchymal stromal cells (MSCs) have recently received much attention as a potential therapy for pancreatic cancer owing to their tumor-homing properties. However, the specific antitumor effect of MSCs is still controversial. To this end, we aimed to focus on the potential anti-cancer treatment prospects of the MSC-based approach and summarize current challenges in the clinical application of MSCs to treat pancreatic cancer.

Mitochondria-Related Transcriptome Characterization Associated with the Immune Microenvironment, Therapeutic Response and Survival Prediction in Pancreatic Cancer

(1) Background: Pancreatic cancer (PC) is one of the most lethal tumors. Mitochondrial dysfunction has been reported to be involved in cancer development; however, its role in PC has remained unclear. (2) Methods: The differentially expressed NMGs were selected between PC and normal pancreatic tissue. The NMG-related prognostic signature was established by LASSO regression. A nomogram was developed based on the 12-gene signature combined with other significant pathological features. An extensive analysis of the 12 critical NMGs was performed in multiple dimensions. The expression of some key genes was verified in our external cohort. (3) Results: Mitochondria-related transcriptome features was obviously altered in PC compared with normal pancreas tissue. The 12-NMG signature showed good performance in predicting prognosis in various cohorts. The high- and low-risk groups exhibited notable diversity in gene mutation characteristics, biological characteristics, chemotherapy response, and the tumor immune microenvironment. Critical gene expression was demonstrated in our cohort at the mRNA and protein levels and in organelle localization. (4) Conclusions: Our study analyzed the mitochondrial molecular characterization of PC, proving the crucial role of NMGs in PC development. The established NMG signature helps classify patient subtypes in terms of prognosis prediction, treatment response, immunological features, and biological function, providing a potential therapeutic strategy targeting mitochondrial transcriptome characterization.

Hyperglycemia predicts adverse prognosis in advanced pancreatic cancer patients

BACKGROUND

Diabetes mellitus is a prevalent comorbidity in pancreatic cancer. Previous studies have mainly concentrated on the association between diabetes and pancreatic cancer outcomes. However, research on the impact of hyperglycemia on the prognosis of patients with advanced pancreatic cancer is limited.

METHODS

Information on patients with advanced pancreatic cancer was collected from a prospectively maintained database, and the patients were divided into the hyperglycemia group (fasting blood glucose ≥7.0 mmol/L) and the normoglycemia group (fasting blood glucose < 7.0 mmol/L). Patients with preexisting diabetes were not included in these groups. The associations between hyperglycemia and clinical variables or prognosis were analyzed.

RESULTS

Among 697 patients with advanced pancreatic cancer and no prior history of diabetes, 25.3% were diagnosed with hyperglycemia. Patients older than 65 years had a higher risk of developing hyperglycemia (P = 0.044). Patients with hyperglycemia had a worse prognosis than those with normoglycemia (median survival, 7.5 vs. 8.8 months, P < 0.001). Hyperglycemia was associated with increased mortality (hazard ratio = 1.38; P = 0.003).

CONCLUSIONS

Hyperglycemia predicts worse overall survival in patients with advanced pancreatic cancer.

Recent progress of experimental model in pancreatic neuroendocrine tumors: drawbacks and challenges

The neuroendocrine neoplasm, in general, refers to a heterogeneous group of all tumors originating from peptidergic neurons and neuroendocrine cells. Neuroendocrine neoplasms are divided into two histopathological subtypes: well-differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas. Pancreatic neuroendocrine tumors account for more than 80% of pancreatic neuroendocrine neoplasms. Due to the greater proportion of pancreatic neuroendocrine tumors compared to pancreatic neuroendocrine carcinoma, this review will only focus on them. The worldwide incidence of pancreatic neuroendocrine tumors is rising year by year due to sensitive detection with an emphasis on medical examinations and the improvement of testing technology. Although the biological behavior of pancreatic neuroendocrine tumors tends to be inert, distant metastasis is common, often occurring very early. Because of the paucity of basic research on pancreatic neuroendocrine tumors, the mechanism of tumor development, metastasis, and recurrence are still unclear. In this context, the representative preclinical models simulating the tumor development process are becoming ever more widely appreciated to address the clinical problems of pancreatic neuroendocrine tumors. So far, there is no comprehensive report on the experimental model of pancreatic neuroendocrine tumors. This article systematically summarizes the characteristics of preclinical models, such as patient-derived cell lines, patient-derived xenografts, genetically engineered mouse models, and patient-derived organoids, and their advantages and disadvantages, to provide a reference for further studies of neuroendocrine tumors. We also highlight the method of establishment of liver metastasis mouse models.

Focus on mast cells in the tumor microenvironment: Current knowledge and future directions

Mast cells (MCs) are crucial cells participating in both innate and adaptive immune processes that play important roles in protecting human health and in the pathophysiology of various diseases, such as allergies, cardiovascular diseases, and autoimmune diseases. In the context of tumors, MCs are a non-negligible population of immune cells in the tumor microenvironment (TME). In most tumor types, MCs accumulate in both the tumor tissue and the surrounding tissue. MCs interact with multiple components of the TME, affecting TME remodeling and the tumor cell fate. However, controversy persists regarding whether MCs contribute to tumor progression or trigger an anti-tumor immune response. This review focuses on the context of the TME to explore the specific properties and functions of MCs and discusses the crosstalk that occurs between MCs and other components of the TME, which affect tumor angiogenesis and lymphangiogenesis, invasion and metastasis, and tumor immunity through different mechanisms. We also anticipate the potential role of MCs in cancer immunotherapy, which might expand upon the success achieved with existing cancer therapies.

Metabolic reprogramming of cancer-associated fibroblasts in pancreatic cancer contributes to the intratumor heterogeneity of PET-CT

Intratumor heterogeneity of positron emission tomography-computed tomography (PET-CT) is reflected by variable ¹⁸F-fluorodeoxyglucose (FDG) uptake. Increasing evidence has shown that neoplastic and non-neoplastic components can affect the total ¹⁸F-FDG uptake in tumors. Cancer-associated fibroblasts (CAFs) is considered as the main non-neoplastic components in tumor microenvironment (TME) of pancreatic cancer. Our study aims to explore the impact of metabolic changes in CAFs on heterogeneity of PET-CT. A total of 126 patients with pancreatic cancer underwent PET-CT and endoscopic ultrasound elastography (EUS-EG) before treatment. High maximum standardized uptake value (SUVmax) from the PET-CT was positively correlated with the EUS-derived strain ratio (SR) and indicated poor prognosis of patients. In addition, single-cell RNA analysis showed that CAV1 affected glycolytic activity and correlated with glycolytic enzyme expression in fibroblasts in pancreatic cancer. We also observed the negative correlation between CAV1 and glycolytic enzyme expression in the tumor stroma by using immunohistochemistry (IHC) assay in the SUVmax-high and SUVmax-low groups of pancreatic cancer patients. Additionally, CAFs with high glycolytic activity contributed to pancreatic cancer cell migration, and blocking CAF glycolysis reversed this process, suggesting that glycolytic CAFs promote malignant biological behavior in pancreatic cancer. In summary, our research demonstrated that the metabolic reprogramming of CAFs affects total ¹⁸F-FDG uptake in tumors. Thus, an increase in glycolytic CAFs with decreased CAV1 expression promotes tumor progression, and high SUVmax may be a marker for therapy targeting the neoplastic stroma. Further studies should clarify the underlying mechanisms.

Targeting cell death pathways for cancer therapy: recent developments in necroptosis, pyroptosis, ferroptosis, and cuproptosis research

Many types of human cells self-destruct to maintain biological homeostasis and defend the body against pathogenic substances. This process, called regulated cell death (RCD), is important for various biological activities, including the clearance of aberrant cells. Thus, RCD pathways represented by apoptosis have increased in importance as a target for the development of cancer medications in recent years. However, because tumor cells show avoidance to apoptosis, which causes treatment resistance and recurrence, numerous studies have been devoted to alternative cancer cell mortality processes, namely necroptosis, pyroptosis, ferroptosis, and cuproptosis; these RCD modalities have been extensively studied and shown to be crucial to cancer therapy effectiveness. Furthermore, evidence suggests that tumor cells undergoing regulated death may alter the immunogenicity of the tumor microenvironment (TME) to some extent, rendering it more suitable for inhibiting cancer progression and metastasis. In addition, other types of cells and components in the TME undergo the abovementioned forms of death and induce immune attacks on tumor cells, resulting in enhanced antitumor responses. Hence, this review discusses the molecular processes and features of necroptosis, pyroptosis, ferroptosis, and cuproptosis and the effects of these novel RCD modalities on tumor cell proliferation and cancer metastasis. Importantly, it introduces the complex effects of novel forms of tumor cell death on the TME and the regulated death of other cells in the TME that affect tumor biology. It also summarizes the potential agents and nanoparticles that induce or inhibit novel RCD pathways and their therapeutic effects on cancer based on evidence from in vivo and in vitro studies and reports clinical trials in which RCD inducers have been evaluated as treatments for cancer patients. Lastly, we also summarized the impact of modulating the RCD processes on cancer drug resistance and the advantages of adding RCD modulators to cancer treatment over conventional treatments.

Signaling pathways in cancer-associated fibroblasts: recent advances and future perspectives

As a critical component of the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) play important roles in cancer initiation and progression. Well-known signaling pathways, including the transforming growth factor-β (TGF-β), Hedgehog (Hh), Notch, Wnt, Hippo, nuclear factor kappa-B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)/AKT pathways, as well as transcription factors, including hypoxia-inducible factor (HIF), heat shock transcription factor 1 (HSF1), P53, Snail, and Twist, constitute complex regulatory networks in the TME to modulate the formation, activation, heterogeneity, metabolic characteristics and malignant phenotype of CAFs. Activated CAFs remodel the TME and influence the malignant biological processes of cancer cells by altering the transcriptional and secretory characteristics, and this modulation partially depends on the regulation of signaling cascades. The results of preclinical and clinical trials indicated that therapies targeting signaling pathways in CAFs demonstrated promising efficacy but were also accompanied by some failures (e.g., NCT01130142 and NCT01064622). Hence, a comprehensive understanding of the signaling cascades in CAFs might help us better understand the roles of CAFs and the TME in cancer progression and may facilitate the development of more efficient and safer stroma-targeted cancer therapies. Here, we review recent advances in studies of signaling pathways in CAFs and briefly discuss some future perspectives on CAF research.

Maximum Value on Arterial Phase Computed Tomography Predicts Prognosis and Treatment Efficacy of Sunitinib for Pancreatic Neuroendocrine Tumours

PURPOSE

This study was designed to assess the computed tomography maximum (CTmax) value on pretherapeutic arterial phase computed tomography (APCT) images to predict pancreatic neuroendocrine tumours (pNETs) recurrence and clarify its role in predicting the outcome of tumour therapy.

METHODS

This retrospective study enrolled 250 surgical patients and 24 nonsurgical patients with sunitinib-based treatment in our hospital from 2008 to 2019. CT images were assessed, the maximum value was defined as "CTmax," and recurrence-free survival (RFS) or progression-free survival (PFS) was compared between a high-CTmax group and a low-CTmax group among patients who underwent surgical resection or nonsurgical, sunitinib-based treatment according to the CTmax cutoff value.

RESULTS

In ROC curve analysis, a CTmax of 108 Hounsfield units, as the cutoff value, achieved an AUC of 0.796 in predicting recurrence. Compared with the low-CTmax group, the high-CTmax group had a longer RFS (p < 0.001). Low CTmax was identified as an independent factor for RFS (p < 0.001) in multivariate analysis; these results were confirmed using the internal validation set. The CTmax value was significantly correlated with the microvascular density (MVD) value (p < 0.001) and the vascular endothelial growth factor receptor 2 (VEGFR2) score (p < 0.001). Furthermore, the high-CTmax group had a better PFS than the low-CTmax group among the sunitinib treatment group (p = 0.007).

CONCLUSIONS

The tumour CTmax on APCT might be a potential and independent indicator for predicting recurrence in patients who have undergone surgical resection and assessing the efficacy of sunitinib for patients with advanced metastatic pNETs.

Multimodality imaging differentiation of pancreatic neuroendocrine tumors and solid pseudopapillary tumors with a nomogram model: A large single-center study

Background

Pancreatic neuroendocrine tumors (pNETs) and solid pseudopapillary tumors (SPTs) are two of the most common pancreatic neoplasms with different treatment procedures. However, the broad heterogeneity of pNETs and SPTs in clinical manifestations and radiological features often confuse the presurgical discrimination in clinical practice, and the clinical and molecular differentiation of the two tumors remains elusive to date. We presume that a large and comprehensive study into the multimodality features of pNETs and SPTs is necessary for precise clinical management.

Methods

We collected and analyzed the clinicopathological information and multimodality features of nonfunctional pNET and SPT patients, for a total of 631 cases from 2006 to 2021. Univariate analysis of imaging features, including contrast-enhanced computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound (EUS) and nuclear medicine imaging, and clinical characteristics was performed, and CT features and clinical information were integrated to establish a nomogram model.

Results

We recruited 354 nonfunctional pNET and 277 SPT patients in our cohort. Regarding demographic information, pNET patients had a lower female percentage (55.4% vs. 72.9%), smaller tumor size (2.8 vs. 4.8 cm), and older age (53.4 vs. 35.3 years). In CT imaging and EUS, pNETs tended to appear as solid and homogenous lesions with strong enhancement intensity. Multifocal lesions, duct dilation, and lymph node (LN) enlargement were more likely to be observed in pNETs, while calcification was more common in SPT lesions. On positron emission tomography (PET)/CT, pNETs exhibited significant sensitivity to somatostatin receptor scintigraphy (SRS), with positive rates of 81.4% and 95% on ⁹⁹mTc-HYNIC-TOC and ⁶⁸Ga-DOTATATE PET/CT, respectively, while SPTs were all negative on SRS. Multivariate analysis identifies tumor size, age, enhancement intensity, calcification, and LN enlargement as statistically significant variables.

Conclusions

Compared to SPT patients, pNET patients exhibit an older age and smaller tumor size. CT manifestations of strong intensity, LN enlargement, and no calcification could indicate a higher possibility of pNET. Meanwhile, the similarity in the immunohistochemical profile indicates that the two tumors could potentially develop from the same origin.

Neoadjuvant therapy alters the immune microenvironment in pancreatic cancer

Pancreatic cancer has an exclusive inhibitory tumor microenvironment characterized by a dense mechanical barrier, profound infiltration of immunosuppressive cells, and a lack of penetration of effector T cells, which constitute an important cause for recurrence and metastasis, resistance to chemotherapy, and insensitivity to immunotherapy. Neoadjuvant therapy has been widely used in clinical practice due to its many benefits, including the ability to improve the R0 resection rate, eliminate tumor cell micrometastases, and identify highly malignant tumors that may not benefit from surgery. In this review, we summarize multiple aspects of the effect of neoadjuvant therapy on the immune microenvironment of pancreatic cancer, discuss possible mechanisms by which these changes occur, and generalize the theoretical basis of neoadjuvant chemoradiotherapy combined with immunotherapy, providing support for the development of more effective combination therapeutic strategies to induce potent immune responses to tumors.

Spatiotemporal heterogeneity and clinical challenge of pancreatic neuroendocrine tumors

During the course of pancreatic neuroendocrine tumors (NETs), they generally become more heterogeneous with individual cells exhibiting distinct molecular fingerprints. This heterogeneity manifests itself through an unequal distribution of genetically-variant, tumor cell subpopulations within disease locations (i.e., spatial heterogeneity) or changes in the genomic landscape over time (i.e., temporal heterogeneity); these characteristics complicate clinical diagnosis and treatment. Effective, feasible tumor heterogeneity detection and eradication methods are essential to overcome the clinical challenges of pancreatic NETs. This review explores the molecular fingerprints of pancreatic NETs and the spectrum of tumoral heterogeneity. We then describe the challenges of assessing heterogeneity by liquid biopsies and imaging modalities and the therapeutic challenges for pancreatic NETs. In general, navigating these challenges, refining approaches for translational research, and ultimately improving patient care are available once we have a better understanding of intratumoral spatiotemporal heterogeneity.

Hyperglycemia is associated with adverse prognosis in patients with pancreatic neuroendocrine neoplasms

BACKGROUND

Although glucose has a well-recognized protumoral role and the pancreas is a critical organ in adjusting glucose metabolism, the clinical value of hyperglycemia in pancreatic neuroendocrine neoplasms (pNENs) remains largely unidentified.

METHODS

A retrospective study including 335 patients with pathologically confirmed pNENs was conducted. A baseline fasting blood glucose concentration ≥5.6 mmol/L was defined as hyperglycemia (otherwise, normal). Survival and regression analyses were performed.

RESULTS

Compared with patients with normal glucose, patients with hyperglycemia (47.8%) had a higher proportion of preexisting diabetes mellitus (DM) (36.9% vs. 4.6%, p < 0.001), lymph node involvement (31.0% vs. 14.6%, p = 0.002), distant metastasis (34.4% vs. 22.9%, p = 0.019), and carbohydrate antigen 19-9 (CA19-9) ≥ 37 U/mL (16.6% vs. 7.2%, p = 0.009). Hyperglycemia was associated with CA19-9 ≥ 37 U/mL (Odds Ratio (OR) = 3.19, 95% CI: 1.11-9.17, p = 0.031), lymph node involvement (OR = 2.32, 95% CI: 1.02-5.28, p = 0.045), nonfunctional tumors (OR = 9.90, 95% CI: 2.11-46.34, p = 0.004), and preexisting diabetes (OR = 18.24, 95% CI: 4.06-81.95, p < 0.001). Hyperglycemia was an independent determinant for overall survival in the multivariate analysis (hazard ratio (HR) = 2.65, 95% CI: 1.31-5.34, p = 0.006).

CONCLUSION

Hyperglycemia is an independent predictor of overall survival and is associated with preexisting DM or lymphatic metastasis in patients with pNENs. Patients with hyperglycemia and resectable pNENs may benefit from radical resection with dissection of regional lymph nodes.

Atypical Mucin Expression Predicts Worse Overall Survival in Resectable Pancreatic Ductal Adenocarcinoma

Background. Pancreatic ductal adenocarcinoma (PDAC) displays a typical mucin expression pattern which is characterized by MUC1 positive, MUC2 negative, and MUC5AC positive. More and more evidences show that mucins are involved in the development of pancreatic diseases. However, the relationship between mucin expression and prognosis of PDAC patients has been controversial in the past decades; therefore, we aim to figure out the association of mucin expression with survival in PDAC patients who underwent radical resection. Methods. We performed immunohistochemistry (IHC) to detect the expression of MUC1, MUC2, and MUC5AC in resected PDAC specimens from Shanghai Cancer Center, Fudan University (FUSCC, $n=427$ ) and obtained the corresponding clinical statistical data for retrospective study. Kaplan-Meier methods and Mantel-Cox tests were used to compare the survival curves, and the Cox regression model was employed for multivariate analyses to determine the independent risk factors. Survival analysis was also performed in the Queensland Centre for Medical Genomics (QCMG, $n=70$ ) PDAC cohort to verify the conclusion. Results. Both the FUSCC cohort and the QCMG cohort demonstrated that MUC1 absence was significantly correlated with worse overall survival (OS). The presence of MUC2 showed marginal significance in predicting shorter OS of PDAC patients, while MUC5AC had no prognostic value. In the FUSCC cohort, MUC1 absence was associated with increased proportion of stage III PDAC ( $p=0.011$ ), and MUC1 absence and MUC2 presence were associated with tumour perineural aggression ( $p=0.011$ and $p=0.030$ , respectively). Multivariable adjusted hazard ratios (HRs) for mortality of MUC1 and MUC2 were 0.492 (95% CI: 0.274-0.883, $p=0.017$ ) and 1.596 (95% CI: 1.061-2.401, $p=0.025$ ), respectively. Conclusions. MUC1 absence or MUC2 presence is independently associated with poor OS among patients with resectable PDAC. MUC5AC absence tended to be associated with short-term death.

Liquid-liquid phase separation in tumor biology

Liquid–liquid phase separation (LLPS) is a novel principle for explaining the precise spatial and temporal regulation in living cells. LLPS compartmentalizes proteins and nucleic acids into micron-scale, liquid-like, membraneless bodies with specific functions, which were recently termed biomolecular condensates. Biomolecular condensates are executors underlying the intracellular spatiotemporal coordination of various biological activities, including chromatin organization, genomic stability, DNA damage response and repair, transcription, and signal transduction. Dysregulation of these cellular processes is a key event in the initiation and/or evolution of cancer, and emerging evidence has linked the formation and regulation of LLPS to malignant transformations in tumor biology. In this review, we comprehensively summarize the detailed mechanisms of biomolecular condensate formation and biophysical function and review the recent major advances toward elucidating the multiple mechanisms involved in cancer cell pathology driven by aberrant LLPS. In addition, we discuss the therapeutic perspectives of LLPS in cancer research and the most recently developed drug candidates targeting LLPS modulation that can be used to combat tumorigenesis.

Neoadjuvant chemotherapy endows CD9 with prognostic value that differs between tumor and stromal areas in patients with pancreatic cancer

BACKGROUND

The selective pressure imposed by chemotherapy creates a barrier to tumor eradication and an opportunity for metastasis and recurrence. As a newly discovered stemness marker of pancreatic ductal adenocarcinoma (PDAC), the impact of CD9 on tumor progression and patient's prognosis remain controversial.

METHODS

A total of 179 and 211 PDAC patients who underwent surgical resection with or without neoadjuvant chemotherapy, respectively, were recruited for immunohistochemical analyses of CD9 expression in both tumor and stromal areas prior to statistical analyses to determine the prognostic impact and predictive accuracy of CD9.

RESULTS

The relationship between CD9 and prognostic indicators was not significant in the non-neoadjuvant group. Nevertheless, CD9 expression in both tumor (T-CD9) and stromal areas (S-CD9) was significantly correlated with the clinicopathological features in the neoadjuvant group. High levels of T-CD9 were significantly associated with worse OS (p = 0.005) and RFS (p = 0.007), while positive S-CD9 showed the opposite results (OS: p = 0.024; RFS: p = 0.008). Cox regression analyses identified CD9 in both areas as an independent prognostic factor. The T&S-CD9 risk-level system was used to stratify patients with different survival levels. The combination of T&S-CD9 risk level and TNM stage were accurate predictors of OS (C-index: 0.676; AIC: 512.51) and RFS (C-index: 0.680; AIC: 519.53). The calibration curve of the nomogram composed of the combined parameters showed excellent predictive consistency for 1-year RFS. These results were verified using a validation cohort.

CONCLUSION

Neoadjuvant chemotherapy endows CD9 with a significant prognostic value that differs between tumor and stromal areas in patients with pancreatic cancer.