Perineural invasion and associated pain in pancreatic cancer

Important role of lymphovascular and perineural invasion in prognosis of colorectal cancer patients with N1c disease

BACKGROUND

Lymphovascular invasion (LVI) and perineural invasion (PNI) are associated with decreased survival in colorectal cancer (CRC), but its significance in N1c stage remains to be clearly defined.

AIM

To evaluate LVI and PNI as potential prognostic indicators in N1c CRC.

METHODS

We retrospectively identified 107 consecutive patients who had CRC with N1c disease radically resected at our hospital. Tumors were reviewed for LVI and PNI by one pathologist blinded to the patients’ outcomes. Disease-free survival (DFS), overall survival (OS) and cancer-specific survival (CSS) were determined using the Kaplan-Meier method, with LVI and PNI prognosis differences determined by multivariate analysis using the Cox multiple hazards model. Results were compared using log-rank test. The receiver operating characteristic (ROC) curve was used to evaluate the prognostic predictive ability.

RESULTS

The median follow-up time was 63.17 (45.33-81.37) months for DFS, with 33.64% (36/107) of patients experiencing recurrence; 21.5% of tumors were found to be LVI positive and 44.9% PNI positive. The 5-year DFS rate was greater for patients with LVI-negative tumors compared with LVI-positive tumors (74.0% vs 35.6%), and PNI was similar (82.5% vs 45.1%). On multivariate analysis, LVI [hazard ratio (HR) = 3.368, 95% confidence interval (CI): 1.628-6.966, P = 0.001] and PNI (HR = 3.055, 95%CI: 1.478-6.313, P = 0.002) were independent prognostic factors for DFS. All patients could be divided into three groups of patients with different prognosis according to LVI and PNI. The 5-year ROC curve for LVI, PNI and their combination prediction of DFS was 0.646, 0.709 and 0.759, respectively. Similar results were seen for OS and CSS.

CONCLUSION

LVI and PNI could serve as independent prognostic factors of outcomes in N1c CRC patients. Patients with LVI or PNI should be given more attention during treatment.

Peripheral, central, and chemotherapy-induced neuropathic changes in pancreatic cancer

In pancreatic cancer, significant alterations occur in the local nervous system, including axonogenesis, neural remodeling, perineural invasion, and perineural neuritis. Pancreatic cancer can impact the central nervous system (CNS) through cancer cell-intrinsic factors or systemic factors, particularly in the context of cancer cachexia. These peripheral and central neuropathic changes exert substantial influence on cancer initiation and progression. Moreover, chemotherapy-induced neuropathy is common in pancreatic cancer, causing peripheral nerve damage and cognitive dysfunction. Targeting the crosstalk between pancreatic cancer and the nervous system, either peripherally or centrally, holds promise in cancer treatment, pain relief, and improved quality of life. Here, we summarize recent findings on the molecular mechanisms behind these neuropathic changes in pancreatic cancer and discuss potential intervention strategies.

Tumor cells induce neural DKK1 expression to promote MDSC infiltration and subsequent T cell suppression

Nerves are often overlooked as key components of the tumor microenvironment. However, the molecular mechanisms underlying the reciprocal interactions between tumors and nerves remain largely unknown. In this study, we analyzed data from The Cancer Genome Atlas (TCGA) and identified a significant association between DKK1 expression and poor prognosis, as well as a correlation between DKK1 expression and myeloid-derived suppressor cell (MDSC) infiltration in head and neck squamous cell carcinoma (HNSCC) and pancreatic ductal adenocarcinoma (PDAC), two cancer types characterized by pronounced tumor-nerve interactions. Based on these findings, we hypothesize that tumors may induce DKK1 expression in nerves, and that nerve-derived DKK1 may promote MDSC infiltration and immunosuppression. To test this hypothesis, we employed a combination of experimental approaches, including in vitro co-culture of trigeminal ganglia with tumor cells, multiplex immunohistochemistry, and in vivo administration of DKK1 neutralizing antibodies. Our results indicate that tumor cells significantly induce DKK1 expression in ganglia in co-culture experiments. Additionally, in vivo orthotopic tumor models revealed that DKK1 levels were markedly elevated in both the plasma and ganglia of tumor-bearing mice. Neutralization DKK1 in vivo led to a reduction in MDSC levels and impaired MDSC-mediated T cell suppression in both HNSCC and PDAC orthotopic models. Furthermore, conditional deletion of neuronal DKK1 elucidated its role in MDSC infiltration and immune suppression. Our findings establish a novel molecular axis in which tumor cells modulate the immune microenvironment by inducing the expression of secreted proteins in nerves, thereby enriching the research landscape of the tumor microenvironment.

NGF-mediated crosstalk: unraveling the influence of metabolic deregulation on the interplay between neural and pancreatic cancer cells and its impact on patient outcomes

Neural invasion is one of the most common routes of invasion in pancreatic cancer and it is responsible for the high rate of tumor recurrence after surgery and the pain generation associated with pancreatic cancer. Several molecules implicated in neural invasion are also responsible for pain onset including NGF belonging to the family of neutrophins. NGF released by cancer cells can sensitize sensory nerves which in turn results in severe pain. NGF receptors, TrkA and P75NTR, are expressed on both PDAC cells and nerves, strongly suggesting their role in neural invasion. The crosstalk between the nervous system and cancer cells has emerged as an important regulator of pancreatic cancer and its microenvironment. Nerve cells influence the pancreatic tumor microenvironment and these interactions are important for cancer metabolism reprogramming and tumor progression. In this review, we summarized the current knowledge on the interaction between nerves and pancreatic cancer cells and its impact on cancer metabolism.

Application of imaging technology for the diagnosis of malignancy in the pancreaticobiliary duodenal junction (Review)

The pancreaticobiliary duodenal junction (PBDJ) is the connecting area of the pancreatic duct, bile duct and duodenum. In a broad sense, it refers to a region formed by the head of the pancreas, the pancreatic segment of the common bile duct and the intraduodenal segment, the descending and the horizontal part of the duodenum, and the soft tissue around the pancreatic head. In a narrow sense, it refers to the anatomical Vater ampulla. Due to its complex and variable anatomical features, and the diversity of pathological changes, it is challenging to make an early diagnosis of malignancy at the PBDJ and define the histological type. The unique anatomical structure of this area may be the basis for the occurrence of malignant tumors. Therefore, understanding and subclassifying the anatomical configuration of the PBDJ is of great significance for the prevention and treatment of malignant tumors at their source. The present review comprehensively discusses commonly used imaging techniques and other new technologies for diagnosing malignancy at the PBDJ, offering evidence for physicians and patients to select appropriate examination methods.

Prognostic efficacy of lymph node parameters in resected ampullary adenocarcinoma based on long-term follow-up data after adjuvant treatment

BACKGROUND

Lymph node (LN) metastasis is an important prognostic factor in the ampulla of Vater (AoV) adenocarcinoma. Various LN parameters have been proposed, but their prognostic efficacy has not been compared in the same population. We aimed to evaluate the prognostic values of LN parameters in AoV adenocarcinoma patients who underwent surgical resection and adjuvant treatment based on the long-term follow-up data.

METHODS

A total of 86 patients with surgically resected AoV adenocarcinoma followed by adjuvant treatment were analyzed. We evaluated the prognostic values of various LN parameters such as pathologic N stage, number of metastatic regional LN (LNN), LN ratio (LNR), and log odds of positive LNs (LODDS). Each LN parameter was separately analyzed using Cox regression models with the same confounders.

RESULTS

The median follow-up period was 69.4 months, and the median overall survival (OS) was 114 months. The median number of dissected LNs is 15, with an interquartile range of 8 to 25. In the univariable analyses, all LN parameters showed significant prognostic efficacy for OS, disease-free survival (DFS), and distant metastasis-free survival (DMFS). In the multivariable Cox regression analyses, LNN ≥ 2 was a statistically significant prognostic factor for OS (hazard ratio (HR) 2.10, 95% confidence interval (CI), 1.11-3.97; p = 0.022), DFS (HR 2.51, 95% CI 1.28-4.93; p = 0.007), and DMFS (HR 2.74, 95% CI 1.39-5.41; p = 0.004). LNR showed significant prognostic performance for DFS (HR 2.35, 95% CI 1.23-4.50; p = 0.010), and DMFS (HR 2.26, 95% CI 1.17-4.35; p = 0.015). N stage showed significant prognostic performance in DFS (HR 1.55 for pN1; p = 0.243 and HR 4.31 for pN2; p = 0.003), DMFS (HR 1.46 for pN1; p = 0.323 and 4.59 for pN2; p = 0.002). LODDS and the presence of LN metastasis, did not demonstrate significant prognostic value across survival outcomes.

CONCLUSIONS

LN parameters showed good long-term predictive performance in AoV adenocarcinoma patients treated with curative resection and adjuvant treatments. Among LN parameters, LNN ≥ 2 showed better prognostic value than others. Further large-scale studies are needed to validate the clinical usefulness of various LN parameters.

Preoperative Prediction of Perineural Invasion in Pancreatic Ductal Adenocarcinoma Using Machine Learning Radiomics Based on Contrast-Enhanced CT Imaging

The objective of the study is to assess the clinical value of machine learning radiomics based on contrast-enhanced computed tomography (CECT) images in preoperative prediction of perineural invasion (PNI) status in pancreatic ductal adenocarcinoma (PDAC). A total of 143 patients with PDAC were enrolled in this retrospective study (training group, n = 100; test group, n = 43). Radiomics features were extracted from CECT images and selected by the Mann-Whitney U-test, Pearson correlation coefficient, and least absolute shrinkage and selection operator (LASSO). The logistic regression (LR), support vector machine (SVM), random forest (RF), extreme gradient boosting (XGBoost), and decision tree (DT) algorithms were trained to build radiomics models by radiomic features. Multivariate logistic regression was employed to identify independent predictors and establish clinical models. A combined model was constructed by integrating clinical and radiomics features. Model performances were assessed by receiver operating characteristic curves (ROCs) and decision curve analyses (DCAs). A total of 788 radiomics features were extracted from CECT images, of which 14 were identified as significant through the three-step selection process. Among the machine learning models, the SVM radiomics model exhibited the highest predictive performance in the test group, achieving an area under the curve (AUC) of 0.831, accuracy of 0.698, sensitivity of 0.677, and specificity of 0.750. After logistic regression screening, the clinical model was established using carbohydrate antigen 19-9 (CA199) levels as one independent predictor. In the test group, the clinical model demonstrated an AUC of 0.644, accuracy of 0.744, sensitivity of 0.871, and specificity of 0.417. The combined model showed improved performance compared to both the clinical and radiomics models in the test group, with an AUC of 0.844, accuracy of 0.767, sensitivity of 0.806, and specificity of 0.667. Subsequently, DCA of the combined model indicated optimal clinical value for predicting PNI status. Machine learning radiomics models can accurately predict PNI status in patients with pancreatic ductal adenocarcinoma. The combined model, which incorporates clinical and radiomics features, enhances preoperative diagnostic performance and aids in the selection of treatment methods.

Neural control of tumor immunity

Communication between the nervous system and the immune system has evolved to optimally respond to potentially dangerous stimuli both from within and outside the body. Tumors pose a severe threat to an organism and current therapies are insufficient for tumor regression in the majority of cases. Studies show that tumors are innervated by peripheral nerves from the sensory, parasympathetic and sympathetic nervous systems. Interactions between cancer cells, nerves and immune cells regulate overall tumor progression. Clinical studies have indicated the potential of targeting the peripheral nervous system for promoting anti-tumor immune responses. This view point provides an opinion on the current evidence and therapeutic potential of manipulating neuro-immune communications in cancer.

Macrophage diversity in cancer dissemination and metastasis

Invasion and metastasis are hallmarks of cancer. In addition to the well-recognized hematogenous and lymphatic pathways of metastasis, cancer cell dissemination can occur via the transcoelomic and perineural routes, which are typical of ovarian and pancreatic cancer, respectively. Macrophages are a universal major component of the tumor microenvironment and, in established tumors, promote growth and dissemination to secondary sites. Here, we review the role of tumor-associated macrophages (TAMs) in cancer cell dissemination and metastasis, emphasizing the diversity of myeloid cells in different tissue contexts (lungs, liver, brain, bone, peritoneal cavity, nerves). The generally used models of lung metastasis fail to capture the diversity of pathways and tissue microenvironments. A better understanding of TAM diversity in different tissue contexts may pave the way for tailored diagnostic and therapeutic approaches.

Perineural Invasion Is Associated With Function-evoked Pain and Altered Extracellular Matrix in Patients With Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is painful, and perineural invasion (PNI) has been associated with the worst pain. Pain due to HNSCC is diverse and may vary based on clinicopathological factors. This study aims to characterize different pain patterns linked with PNI, its influence on daily functioning, and gain insights into molecular changes and pathways associated with PNI-related pain in HNSCC patients. We conducted a cross-sectional study across 3 medical centers (n = 114), assessing pain phenotypes and their impact on daily functioning using 2 self-reported pain questionnaires, given to patients prior to their cancer surgery. Furthermore, we conducted RNA-seq analysis utilizing the The Cancer Genome Atlas dataset of HNSCC tumor from patients (n = 192) to identify genes relevant to both PNI and pain. Upon adjusting for demographic and clinicopathological variables using linear regression models, we found that PNI independently predicted function-evoked pain according to the University of Calfornia San Francisco Oral Cancer Pain Questionnaire, as well as the worst pain intensity reported in the Brief Pain Inventory. Distinct pain patterns were observed to be associated with daily activities in varying manners. Our molecular analyses revealed significant disruptions in pathways associated with the extracellular matrix structure and organization. The top differentially expressed genes linked to the extracellular matrix are implicated in cancer development, pain, and neurodegenerative diseases. Our data underscore the importance of properly categorizing pain phenotypes in future studies aiming to uncover mechanistic underpinnings of pain. Additionally, we have compiled a list of genes of interest that could serve as targets for both cancer and cancer pain management. PERSPECTIVE: PNI independently predicts function-evoked pain. Different pain phenotypes affect daily activities differently. We identified a list of candidate genes involved in the extracellular matrix structure and function that can be targeted for both cancer and cancer pain control.

Schwann cells and enteric glial cells: Emerging stars in colorectal cancer

Cancer neuroscience, a promising field dedicated to exploring interactions between cancer and the nervous system, has attracted growing attention. The gastrointestinal tracts exhibit extensive innervation, notably characterized by intrinsic innervation. The gut harbors a substantial population of glial cells, including Schwann cells wrapping axons of neurons in the peripheral nervous system and enteric glial cells intricately associated with intrinsic innervation. Glial cells play a crucial role in maintaining the physiological functions of the intestine, encompassing nutrient absorption, barrier integrity, and immune modulation. Nevertheless, it has only been in recent times that the significance of glial cells within colorectal cancer (CRC) has begun to receive considerable attention. Emerging data suggests that glial cells in the gut contribute to the progression and metastasis of CRC, by interacting with cancer cells, influencing inflammation, and modulating the tumor microenvironment. Here, we summarize the significant roles of glial cells in the development and progression of CRC and discuss the latest technologies that can be integrated into this field for in-depth exploration, as well as potential specific targeted strategies for future exploration to benefit patients.

Perineural Invasion in Cervical Cancer: A Hidden Trail for Metastasis

Perineural invasion (PNI), the neoplastic invasion of nerves, is an often overlooked pathological phenomenon in cervical cancer that is associated with poor clinical outcomes. The occurrence of PNI in cervical cancer patients has limited the promotion of Type C1 surgery. Preoperative prediction of the PNI can help identify suitable patients for Type C1 surgery. However, there is a lack of appropriate preoperative diagnostic methods for PNI, and its pathogenesis remains largely unknown. Here, we dissect the neural innervation of the cervix, analyze the molecular mechanisms underlying the occurrence of PNI, and explore suitable preoperative diagnostic methods for PNI to advance the identification and treatment of this ominous cancer phenotype.

PanIN or IPMN? Redefining Lesion Size in 3 Dimensions

Pancreatic ductal adenocarcinoma (PDAC) develops from 2 known precursor lesions: a majority (∼85%) develops from pancreatic intraepithelial neoplasia (PanIN), and a minority develops from intraductal papillary mucinous neoplasms (IPMNs). Clinical classification of PanIN and IPMN relies on a combination of low-resolution, 3-dimensional (D) imaging (computed tomography, CT), and high-resolution, 2D imaging (histology). The definitions of PanIN and IPMN currently rely heavily on size. IPMNs are defined as macroscopic: generally >1.0 cm and visible in CT, and PanINs are defined as microscopic: generally <0.5 cm and not identifiable in CT. As 2D evaluation fails to take into account 3D structures, we hypothesized that this classification would fail in evaluation of high-resolution, 3D images. To characterize the size and prevalence of PanINs in 3D, 47 thick slabs of pancreas were harvested from grossly normal areas of pancreatic resections, excluding samples from individuals with a diagnosis of an IPMN. All patients but one underwent preoperative CT scans. Through construction of cellular resolution 3D maps, we identified >1400 ductal precursor lesions that met the 2D histologic size criteria of PanINs. We show that, when 3D space is considered, 25 of these lesions can be digitally sectioned to meet the 2D histologic size criterion of IPMN. Re-evaluation of the preoperative CT images of individuals found to possess these large precursor lesions showed that nearly half are visible on imaging. These findings demonstrate that the clinical classification of PanIN and IPMN fails in evaluation of high-resolution, 3D images, emphasizing the need for re-evaluation of classification guidelines that place significant weight on 2D assessment of 3D structures.

circVAPA-rich small extracellular vesicles derived from gastric cancer promote neural invasion by inhibiting SLIT2 expression in neuronal cells

Gastric cancer (GC) is one of the most common cancer worldwide. Neural invasion (NI) is considered as the symbiotic interaction between nerves and cancers, which strongly affects the prognosis of GC patients. Small extracellular vesicles (sEVs) play a key role in intercellular communication. However, whether sEVs mediate GC-NI remains unexplored. In this study, sEVs release inhibitor reduces the NI potential of GC cells. Muscarinic receptor M3 on GC-derived sEVs regulates their absorption by neuronal cells. The enrichment of sEV-circVAPA in NI-positive patients' serum is validated by serum high throughput sEV-circRNA sequencing and clinical samples. sEV-circVAPA promotes GC-NI in vitro and in vivo. Mechanistically, sEV-circVAPA decreases SLIT2 transcription by miR-548p/TGIF2 and inhibits SLIT2 translation via binding to eIF4G1, thereby downregulates SLIT2 expression in neuronal cells and finally induces GC-NI. Together, this work identifies the preferential absorption mechanism of GC-derived sEVs by neuronal cells and demonstrates a previously undefined role of GC-derived sEV-circRNA in GC-NI, which provides new insight into sEV-circRNA based diagnostic and therapeutic strategies for NI-positive GC patients.

Associations of body composition parameters with postoperative outcome and perineural tumour invasion after oncological pancreatic resection

BACKGROUND

Pancreatic cancer is often accompanied by wasting conditions. While surgery is the primary curative approach, it poses a substantial risk of postoperative complications, hindering subsequent treatments. Therefore, identifying patients at high risk for complications and optimizing their perioperative general condition is crucial. Sarcopenia and other body composition abnormalities have shown to adversely affect surgical and oncological outcomes in various cancer patients. As most pancreatic tumours are located close to the neuronal control centre for the digestive tract, it is possible that neural infiltration in this area deranges bowel functions and contributes to malabsorption and malnutrition and ultimately worsen sarcopenia and weight loss.

METHODS

A retrospective analysis of CT scans was performed for pancreatic cancer patients who underwent surgical tumour resection at a single high-volume centre from 2007 to 2023. Sarcopenia prevalence was assessed by skeletal muscle index (SMI), and visceral obesity was determined by the visceral adipose tissue area (VAT). Obesity and malnutrition were determined by the GLIM criteria. Sarcopenic obesity was defined as simultaneous sarcopenia and obesity. Postoperative complications, mortality and perineural tumour invasion, were compared among patients with body composition abnormalities.

RESULTS

Of 437 patients studied, 46% were female, the median age was 69 (61;74) years. CT analysis revealed 54.9% of patients with sarcopenia, 23.7% with sarcopenic obesity and 45.9% with visceral obesity. Sarcopenia and sarcopenic obesity were more prevalent in elderly and male patients. Postoperative surgical complications occurred in 67.7% of patients, most of which were mild (41.6%). Severe complications occurred in 22.7% of cases and the mortality rate was 3.4%. Severe postoperative complications were significantly more common in patients with sarcopenia or sarcopenic obesity. Visceral obesity or malnutrition based on BMI alone, did not significantly impact complications. Perineural invasion was found in 80.1% of patients and was unrelated to malnutrition or body composition parameters.

CONCLUSIONS

This is the first and largest study evaluating the associations of CT-based body mass analysis with surgical outcome and histopathological perineural tumour invasion in pancreatic cancer patients. The results suggest that elderly and male patients are at high risk for sarcopenia and should be routinely evaluated by CT before undergoing pancreatic surgery, irrespective of their BMI. Confirmation of the results in prospective studies is needed to assess if pancreatic cancer patients with radiographic sarcopenia benefit from preoperative amelioration of muscle mass and function by exercise and nutritional interventions.

Schwann Cells as Orchestrators of Nerve Repair: Implications for Tissue Regeneration and Pathologies

Peripheral nerves exist in a stable state in adulthood providing a rapid bidirectional signaling system to control tissue structure and function. However, following injury, peripheral nerves can regenerate much more effectively than those of the central nervous system (CNS). This multicellular process is coordinated by peripheral glia, in particular Schwann cells, which have multiple roles in stimulating and nurturing the regrowth of damaged axons back to their targets. Aside from the repair of damaged nerves themselves, nerve regenerative processes have been linked to the repair of other tissues and de novo innervation appears important in establishing an environment conducive for the development and spread of tumors. In contrast, defects in these processes are linked to neuropathies, aging, and pain. In this review, we focus on the role of peripheral glia, especially Schwann cells, in multiple aspects of nerve regeneration and discuss how these findings may be relevant for pathologies associated with these processes.

Stiffened tumor microenvironment enhances perineural invasion in breast cancer via integrin signaling

BACKGROUND

Accumulating studies have shown that tumors are regulated by nerves, and there is abundant nerve infiltration in the tumor microenvironment. Many solid tumors including breast cancer (BRCA) have different degrees of perineural invasion (PNI), which is closely related to the tumor occurrence and progression. However, the regulatory mechanism of PNI in BRCA remains largely unexplored.

METHODS

PNI-related molecular events are analyzed by the RNAseq data of BRCA samples deposited in The Cancer Genome Atlas (TCGA) database. Extracellular matrix (ECM) components within the tumor microenvironment are analyzed by immunohistochemical staining of α-SMA, Sirius red staining, and Masson trichrome staining. Soft and stiff matrix gels, living cell imaging, and dorsal root ganglion (DRG) coculture assay are used to monitor cancer cell invasiveness towards nerves. Western blotting, qRT-PCR, enzyme-linked immunosorbent assay combined with neutralizing antibody and small molecular inhibitors are employed to decode molecular mechanisms.

RESULTS

Comparative analysis that the ECM was significantly associated with PNI status in the TCGA cohort. BRCA samples with higher α-SMA activity, fibrillar collagen, and collagen content had higher frequency of PNI. Compared with soft matrix, BRCA cells cultured in stiff matrix not only displayed higher cell invasiveness to DRG neurons but also had significant neurotrophic effects. Mechanistically, integrin β1 was identified as a functional receptor to the influence of stiff matrix on BRCA cells. Moreover, stiffened matrix-induced activation of integrin β1 transduces FAK-YAP signal cascade, which enhances cancer invasiveness and the neurotrophic effects. In clinical setting, PNI-positive BRCA samples had higher expression of ITGB1, phosphorylated FAK, YAP, and NGF compared with PNI-negative BRCA samples.

CONCLUSIONS

Our findings suggest that stiff matrix induces expression of pro-metastatic and neurotrophic genes through integrin β1-FAK-YAP signals, which finally facilitates PNI in BRCA. Thus, our study provides a new mechanism for PNI in BRCA and highlights nerve-based tumor treatment strategies.

Perineural invasion score system and clinical outcomes in resected pancreatic cancer patients

BACKGROUND/OBJECTIVES

Perineural invasion (PNI), classified according to its presence or absence in tumor specimens, is recognized as a poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC) patients. Herein, we identified five histological features of PNI and investigated their impact on survival outcomes of PDAC resected patients.

METHODS

Five histopathological features of PNI (diameter, number, site, sheath involvement, and mitotic figures within perineural invasion) were combined in an additional final score (ranging from 0 to 8), and clinical data of PDAC patients were retrospectively analyzed. PNI + patients were stratified in two categories according to the median score value (<6 and ≥ 6, respectively). Impact of PNI on disease-free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

Forty-five patients were enrolled, of whom 34 with PNI (PNI+) and 11 without PNI (PNI-). The DFS was 11 months vs. not reached (NR) (p = 0.258), while the OS was 19 months vs. NR (p = 0.040) in PNI+ and PNI- patients, respectively. A ≥6 PNI was identified as an independent predictor of worse OS vs. <6 PNI + patients (29 vs. 11 months, p < 0.001) and <6 PNI+ and PNI- patients (43 vs. 11 months, p < 0.001). PNI ≥6 was an independent negative prognostic factor of DFS vs. <6 PNI+ and PNI- patients (13 vs. 6 months, p = 0.022).

CONCLUSIONS

We report a PNI scoring system that stratifies surgically-treated PDAC patients in a graded manner that correlates with patient prognosis better than the current dichotomous (presence/absence) definition. However, further and larger studies are needed to support this PNI scoring system.

Placental growth factor promotes neural invasion and predicts disease prognosis in resectable pancreatic cancer

BACKGROUND

Surgery represents the only curative treatment option for pancreatic ductal adenocarcinoma (PDAC), but recurrence in more than 85% of patients limits the success of curative-intent tumor resection. Neural invasion (NI), particularly the spread of tumor cells along nerves into extratumoral regions of the pancreas, constitutes a well-recognized risk factor for recurrence. Hence, monitoring and therapeutic targeting of NI offer the potential to stratify recurrence risk and improve recurrence-free survival. Based on the evolutionary conserved dual function of axon and vessel guidance molecules, we hypothesize that the proangiogenic vessel guidance factor placental growth factor (PlGF) fosters NI. To test this hypothesis, we correlated PlGF with NI in PDAC patient samples and functionally assessed its role for the interaction of tumor cells with nerves.

METHODS

Serum levels of PlGF and its soluble receptor sFlt1, and expression of PlGF mRNA transcripts in tumor tissues were determined by ELISA or qPCR in a retrospective discovery and a prospective validation cohort. Free circulating PlGF was calculated from the ratio PlGF/sFlt1. Incidence and extent of NI were quantified based on histomorphometric measurements and separately assessed for intratumoral and extratumoral nerves. PlGF function on reciprocal chemoattraction and directed neurite outgrowth was evaluated in co-cultures of PDAC cells with primary dorsal-root-ganglia neurons or Schwann cells using blocking anti-PlGF antibodies.

RESULTS

Elevated circulating levels of free PlGF correlated with NI and shorter overall survival in patients with PDAC qualifying for curative-intent surgery. Furthermore, high tissue PlGF mRNA transcript levels in patients undergoing curative-intent surgery correlated with a higher incidence and greater extent of NI spreading to tumor-distant extratumoral nerves. In turn, more abundant extratumoral NI predicted shorter disease-free and overall survival. Experimentally, PlGF facilitated directional and dynamic changes in neurite outgrowth of primary dorsal-root-ganglia neurons upon exposure to PDAC derived guidance and growth factors and supported mutual chemoattraction of tumor cells with neurons and Schwann cells.

CONCLUSION

Our translational results highlight PlGF as an axon guidance factor, which fosters neurite outgrowth and attracts tumor cells towards nerves. Hence, PlGF represents a promising circulating biomarker of NI and potential therapeutic target to improve the clinical outcome for patients with resectable PDAC.

Exosomal lncRNA XIST promotes perineural invasion of pancreatic cancer cells via miR-211-5p/GDNF

Perineural invasion (PNI) is an essential form of tumor metastasis in multiple malignant cancers, such as pancreatic cancer, prostate cancer, and head and neck cancer. Growing evidence has revealed that pancreatic cancer recurrence and neuropathic pain positively correlate with PNI. Therefore, targeting PNI is a proper strategy for pancreatic cancer treatment. Exosomal lncRNA derived from pancreatic cancer cells is an essential component of the tumor microenvironment. However, whether exosomal lncXIST derived from pancreatic cancer cells can promote PNI and its exact mechanism remains to be elucidated. We show that lncXIST mediates nerve-tumor crosstalk via exosomal delivery. Our data reveal that exosomal lncXIST derived from pancreatic cancer cells is delivered to neural cells and promotes their release of glial-cell-line-derived neurotrophic factor (GDNF), essential in facilitating the PNI of pancreatic cancer. Mechanistically, microRNA-211-5p negatively regulates GDNF, and lncXIST serves as a miR-211-5p sponge. The function of exosomes in the dynamic interplay between nerves and cancer is confirmed in both in vivo and in vitro PNI models. Therefore, targeting pancreatic cancer cell-derived exosomal lncXIST may provide clues for a promising approach for developing a new strategy to combat PNI of pancreatic cancer.

The preliminary analysis of lymphatic flow around the connective tissues surrounding SMA and SpA elucidates patients' oncological condition in borderline-resectable pancreatic cancer

BACKGROUND

In pancreatic ductal adenocarcinoma (PDAC), invasion of connective tissues surrounding major arteries is a crucial prognostic factor after radical resection. However, why the connective tissues invasion is associated with poor prognosis is not well understood.

MATERIALS AND METHODS

From 2018 to 2020, 25 patients receiving radical surgery for PDAC in our institute were enrolled. HyperEye Medical System (HEMS) was used to examine lymphatic flow from the connective tissues surrounding SMA and SpA and which lymph nodes ICG accumulated in was examined.

RESULTS

HEMS imaging revealed ICG was transported down to the paraaortic area of the abdominal aorta along SMA. In pancreatic head cancer, 9 paraaortic lymph nodes among 14 (64.3%) were ICG positive, higher positivity than LN#15 (25.0%) or LN#18 (50.0%), indicating lymphatic flow around the SMA was leading directly to the paraaortic lymph nodes. Similarly, in pancreatic body and tail cancer, the percentage of ICG-positive LN #16a2 was very high, as was that of #8a, although that of #7 was only 42.9%.

CONCLUSIONS

Our preliminary result indicated that the lymphatic flow along the connective tissues surrounding major arteries could be helpful in understanding metastasis and improving prognosis in BR-A pancreatic cancer.

Mapping functional to morphological variation reveals the basis of regional extracellular matrix subversion and nerve invasion in pancreatic cancer

Intratumor morphological heterogeneity of pancreatic ductal adenocarcinoma (PDAC) predicts clinical outcomes but is only partially understood at the molecular level. To elucidate the gene expression programs underpinning intratumor morphological variation in PDAC, we investigated and deconvoluted at single cell level the molecular profiles of histologically distinct clusters of PDAC cells. We identified three major morphological and functional variants that co-exist in varying proportions in all PDACs, display limited genetic diversity, and are associated with a distinct organization of the extracellular matrix: a glandular variant with classical ductal features; a transitional variant displaying abortive ductal structures and mixed endodermal and myofibroblast-like gene expression; and a poorly differentiated variant lacking ductal features and basement membrane, and showing neuronal lineage priming. Ex vivo and in vitro evidence supports the occurrence of dynamic transitions among these variants in part influenced by extracellular matrix composition and stiffness and associated with local, specifically neural, invasion.

Molecular pathway of pancreatic cancer-associated neuropathic pain

The pancreas is a heterocrine gland that has both exocrine and endocrine parts. Most pancreatic cancer begins in the cells that line the ducts of the pancreas and is called pancreatic ductal adenocarcinoma (PDAC). PDAC is the most encountered pancreatic cancer type. One of the most important characteristic features of PDAC is neuropathy which is primarily due to perineural invasion (PNI). PNI develops tumor microenvironment which includes overexpression of fibroblasts cells, macrophages, as well as angiogenesis which can be responsible for neuropathy pain. In tumor microenvironment inactive fibroblasts are converted into an active form that is cancer-associated fibroblasts (CAFs). Neurotrophins they also increase the level of Substance P, calcitonin gene-related peptide which is also involved in pain. Matrix metalloproteases are the zinc-associated proteases enzymes which activates proinflammatory interleukin-1β into its activated form and are responsible for release and activation of Substance P which is responsible for neuropathic pain by transmitting pain signal via dorsal root ganglion. All the molecules and their role in being responsible for neuropathic pain are described below.

Dickkopf-1 drives perineural invasion via PI3K-AKT signaling pathway in head and neck squamous cancer

Perineural invasion (PNI) leads to the poor prognosis of head and neck squamous cancer (HNSCC) patients, but the mechanism of PNI remains unclear. Dickkopf-1 (DKK1), a secretory protein in the Wnt signaling pathway, was found indeed upregulated in HNSCC cells and tissues. Higher expression of DKK1 was statistically relevant to T stage, N stage, PNI, and poor prognosis of HNSCC. DKK1 overexpression enhanced the migration abilities of cancer cells. Moreover, DKK1-overexpressing cancer cells promoted cancer cells invasion of peripheral nerves in vitro and in vivo. Mechanistically, DKK1 could promote the PI3K-AKT signaling pathway. The migration abilities of neuroblastoma cells, which were enhanced by DKK1-overexpressing HNSCC cell lines, could be reversed by an inhibitor of Akt (MK2206). The association of DKK1 with PNI was also confirmed in HNSCC samples. Variables, including T stage, N stage, DKK1 expression, and PNI, were used to establish a nomogram to predict the survival probability and disease-free probability at 3 and 5 years. In summary, DKK1 can promote the PI3K-AKT signaling pathway in tumor cells and then could induce neuritogenesis and facilitate PNI. MK2206 may be a potential therapeutic target drug for HNSCC patients with PNI.

Phase II study of SOXIRI (S-1/oxaliplatin/irinotecan) chemotherapy in patients with unresectable pancreatic ductal adenocarcinoma

BACKGROUND

To provide data on the safety and efficacy of a combination chemotherapy regimen consisting of S-1, oxaliplatin, and irinotecan (SOXIRI) as a first-line therapy in unresectable pancreatic ductal adenocarcinoma (UPDA) patients.

METHODS

Patients with UPDA and no prior treatment chemotherapy in the UPDA setting were enrolled. The primary endpoint was the objective response rate (ORR). Secondary endpoints were overall survival (OS), progression-free survival (PFS) and adverse events. Patients received 80 mg/m2 S-1 twice a day for 2 weeks in an alternate-day administration cycle, 85 mg/m2 oxaliplatin on Day 1, and 150 mg/m2 irinotecan on Day 1 of a 2-week cycle.

RESULTS

In these 62 enrolled patients, the ORR was 27.4 %, median OS was 12.1 months, and median PFS was 6.5 months. Major grade 3 or 4 toxicity included neutropenia (22.3 %), leucopenia (16.1 %), nausea (9.7 %), vomiting (9.7 %), thrombocytopenia (6.5 %), anorexia (8.5 %), anemia (4.8 %), and diarrhea (1.6 %). No treatment-related deaths occurred. In addition, the analysis of 32 patients suffering pain revealed that the rate of pain relief was 34.4 %.

CONCLUSION

SOXIRI might be a standard regimen with an acceptable toxicity profile and favorable efficacy for use as chemotherapy in patients with UPDA.

From pain to tumor immunity: influence of peripheral sensory neurons in cancer

The nervous and immune systems are the primary sensory interfaces of the body, allowing it to recognize, process, and respond to various stimuli from both the external and internal environment. These systems work in concert through various mechanisms of neuro-immune crosstalk to detect threats, provide defense against pathogens, and maintain or restore homeostasis, but can also contribute to the development of diseases. Among peripheral sensory neurons (PSNs), nociceptive PSNs are of particular interest. They possess a remarkable capability to detect noxious stimuli in the periphery and transmit this information to the brain, resulting in the perception of pain and the activation of adaptive responses. Pain is an early symptom of cancer, often leading to its diagnosis, but it is also a major source of distress for patients as the disease progresses. In this review, we aim to provide an overview of the mechanisms within tumors that are likely to induce cancer pain, exploring a range of factors from etiological elements to cellular and molecular mediators. In addition to transmitting sensory information to the central nervous system, PSNs are also capable, when activated, to produce and release neuropeptides (e.g., CGRP and SP) from their peripheral terminals. These neuropeptides have been shown to modulate immunity in cases of inflammation, infection, and cancer. PSNs, often found within solid tumors, are likely to play a significant role in the tumor microenvironment, potentially influencing both tumor growth and anti-tumor immune responses. In this review, we discuss the current state of knowledge about the degree of sensory innervation in tumors. We also seek to understand whether and how PSNs may influence the tumor growth and associated anti-tumor immunity in different mouse models of cancer. Finally, we discuss the extent to which the tumor is able to influence the development and functions of the PSNs that innervate it.

Neuromedin U regulates the anti-tumor activity of CD8+ T cells and glycolysis of tumor cells in the tumor microenvironment of pancreatic ductal adenocarcinoma in an NMUR1-dependent manner

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a poor prognosis, which is lethal in approximately 90% of cases despite advanced standard therapies. A typical feature of PDAC is the immunosuppressive tumor microenvironment with multiple immunosuppressive factors including neurotransmitters. Recently, neuromedin U (NMU), a highly conserved neuropeptide with many physiological functions, has attracted attention for its roles in tumorigenesis and metastasis in several types of cancers. However, whether NMU affects PDAC progression remains unclear. In this study, using an orthotopic mouse model of PDAC in combination with bioinformatics analysis, we found that NMU was upregulated in tumor tissues from the patients with PDAC and positively correlated with a poor prognosis of the disease. Interestingly, knockout of the Nmu gene in mice enhanced the anti-tumor functions of tumor-infiltrating CD8+ T cells in an NMU receptor 1-dependent manner. Additionally, NMU promoted the glycolytic metabolism of mouse PDAC tumors. The activities of pyruvate kinase (PK) and lactate dehydrogenase (LDH), pivotal enzymes involved in the regulation of lactate production, were markedly reduced in tumor tissues from NMU-knockout mice. In vitro the presence of LDHA inhibitor can reduce the production of lactic acid stimulated by NMU, which can increase the anti-tumor activity of CD8+ T cells. Moreover, treatment of the pancreatic cancer cells with a phosphoinositide 3-kinase (PI3K) inhibitor diminished NMU-induced lactate production and the activities of PK and LDH, suggesting that NMU might regulate glycolysis via the PI3K/AKT pathway.

Tumor Neurobiology in the Pathogenesis and Therapy of Head and Neck Cancer

The neurobiology of tumors has attracted considerable interest from clinicians and scientists and has become a multidisciplinary area of research. Neural components not only interact with tumor cells but also influence other elements within the TME, such as immune cells and vascular components, forming a polygonal relationship to synergistically facilitate tumor growth and progression. This review comprehensively summarizes the current state of the knowledge on nerve-tumor crosstalk in head and neck cancer and discusses the potential underlying mechanisms. Several mechanisms facilitating nerve-tumor crosstalk are covered, such as perineural invasion, axonogenesis, neurogenesis, neural reprogramming, and transdifferentiation, and the reciprocal interactions between the nervous and immune systems in the TME are also discussed in this review. Further understanding of the nerve-tumor crosstalk in the TME of head and neck cancer may provide new nerve-targeted treatment options and help improve clinical outcomes for patients.

Tumor microenvironment crosstalk between tumors and the nervous system in pancreatic cancer: Molecular mechanisms and clinical perspectives

Pancreatic ductal adenocarcinoma (PDAC) exhibits the highest incidence of perineural invasion among all solid tumors. The intricate interplay between tumors and the nervous system plays an important role in PDAC tumorigenesis, progression, recurrence, and metastasis. Various clinical symptoms of PDAC, including anorexia and cancer pain, have been linked to aberrant neural activity, while the presence of perineural invasion is a significant prognostic indicator. The use of conventional neuroactive drugs and neurosurgical interventions for PDAC patients is on the rise. An in-depth exploration of tumor-nervous system crosstalk has revealed novel therapeutic strategies for mitigating PDAC progression and effectively relieving symptoms. In this comprehensive review, we elucidate the regulatory functions of tumor-nervous system crosstalk, provide a succinct overview of the relationship between tumor-nervous system dialogue and clinical symptomatology, and deliberate the current research progress and forthcoming avenues of neural therapy for PDAC.

Pre-Diagnosis Pain in Patients With Pancreatic Cancer Signals the Need for Aggressive Symptom Management

OBJECTIVE

This study assessed the impact of pancreatic cancer (PC) pain on associated symptoms, activities, and resource utilization from 2016 to 2020 in an online patient registry.

PATIENTS AND METHODS

Responses from PC patient volunteers (N = 1978) were analyzed from online surveys in a cross-sectional study. Comparisons were performed between PC patient groups reporting, (1) the presence vs. absence of pre-diagnosis PC pain, (2) high (4-8) vs. low (0-3) pain intensity scores on an 11-point numerical rating scale (NRS), and (3) year of PC diagnosis (2010-2020). Descriptive statistics and all bivariate analyses were performed using Chi-square or Fisher's Exact tests.

RESULTS

PC pain was the most frequently reported pre-diagnosis symptom (62%). Pre-diagnostic PC pain was reported more frequently by women, those with a younger age at diagnosis, and those with PC that spread to the liver and peritoneum. Those with pre-diagnostic PC pain vs. those without reported higher pain intensities (2.64 ± 2.54 vs.1.56 ± 2.01 NRS mean ± SD, respectively, P = .0039); increased frequencies of post-diagnosis symptoms of cramping after meals, feelings of indigestion, and weight loss (P = .02-.0001); and increased resource utilization in PC pain management: (ER visits N = 86 vs. N = 6, P = .018 and analgesic prescriptions, P < .03). The frequency of high pain intensity scores was not decreased over a recent 11-year span.

CONCLUSIONS

PC pain continues to be a prominent PC symptom. Patients reporting pre-diagnosis PC pain experience increased GI metastasis, symptoms burden, and are often undertreated. Its mitigation may require novel treatments, more resources dedicated to ongoing pain management and surveillance to improve outcomes.

Crosstalk of nervous and immune systems in pancreatic cancer

Pancreatic cancer is a highly malignant tumor known for its extremely low survival rate. The combination of genetic disorders within pancreatic cells and the tumor microenvironment contributes to the emergence and progression of this devastating disease. Extensive research has shed light on the nature of the microenvironmental cells surrounding the pancreatic cancer, including peripheral nerves and immune cells. Peripheral nerves release neuropeptides that directly target pancreatic cancer cells in a paracrine manner, while immune cells play a crucial role in eliminating cancer cells that have not evaded the immune response. Recent studies have revealed the intricate interplay between the nervous and immune systems in homeostatic condition as well as in cancer development. In this review, we aim to summarize the function of nerves in pancreatic cancer, emphasizing the significance to investigate the neural-immune crosstalk during the advancement of this malignant cancer.

Glial cell-derived soluble factors increase the metastatic potential of pancreatic adenocarcinoma cells and induce epithelial-to-mesenchymal transition

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive types of cancer, characterized by the spreading of highly metastatic cancer cells, including invasion into surrounding nerves and perineural spaces. Nerves, in turn, can invade the tumor tissue and, through the secretion of neurotrophic factors, chemokines, and cytokines, contribute to PDAC progression. However, the contribution of the nerve-associated glial cells to PDAC progression is not well characterized.

METHODS

Two murine PDAC cell lines were cultured with the conditioned media (CM) of primary enteric glial cells or IMS32 Schwann cells (SCs). Different properties of PDAC cells, such as invasiveness, migratory capacity, and resistance to gemcitabine, were measured by RT-qPCR, microscopy, and MTT assays. Using a neuronal cell line, the observed effects were confirmed to be specific to the glial lineage.

RESULTS

Compared to the control medium, PDAC cells in the glial cell-conditioned medium showed increased invasiveness and migratory capacity. These cells showed reduced E-cadherin and increased N-cadherin and Vimentin levels, all markers of epithelial-mesenchymal transition (EMT). Primary enteric glial cell CM inhibited the proliferation of PDAC cells but preserved their viability, upregulated transcription factor Snail, and increased their resistance to gemcitabine. The conditioned medium generated from the IMS32 SCs produced comparable results.

CONCLUSION

Our data suggest that glial cells can increase the metastatic potential of PDAC cells by increasing their migratory capacity and inducing epithelial-to-mesenchymal transition, a re-programming that many solid tumors use to undergo metastasis. Glial cell-conditioned medium also increased the chemoresistance of PDAC cells. These findings may have implications for future therapeutic strategies, such as targeting glial cell-derived factor signaling in PDAC.

Opioid burden in patients with inoperable pancreatic adenocarcinoma and the development of a multivariable risk prediction model for opioid use: A retrospective cohort study

INTRODUCTION

Risk prediction models to guide patient selection for early pre-emptive endoscopic ultrasound guided coeliac plexus neurolysis are lacking. This study aimed to determine in patients with inoperable pancreatic cancer: (1) opioid burden, (2) the relationship between opioid use and all-cause mortality, (3) risk factors for opioid use, and (4) develop and internally validate a risk prediction model for opioid use at three months.

METHODS

This was a single-centre retrospective cohort study of patients with confirmed pancreatic cancer. Cox proportional hazard regression estimated the association between opioid use at baseline and all-cause mortality. Logistic regression estimated the associations between clinical and radiological variables with opioid use by three months. Two risk prediction models were developed for opioid use (clinical and clinical-radiological). Model discrimination and calibration was assessed.

RESULTS

In total, 383 patients with inoperable pancreatic cancer were included. Prevalence of pain ranged between 37% and 47% at three monthly intervals in the first year of diagnosis. Opioid use at baseline was associated with poorer survival. Age, pain at presentation, performance status, tumour distance from the right ganglion, the anterior-posterior and the latero-lateral tumour dimensions were independent risk factors for the opioid use at three months. The Area Under Curve (AUC) for the clinical and clinical-radiological models was 0.81 and 0.84, respectively. Models were well calibrated.

CONCLUSIONS

Opioid use is prevalent in patients with pancreatic cancer, associated with poor prognosis, and can be predicted based on clinical and radiological variables. External validation of this predictive model is required.

Targeting the Cancer-Neuronal Crosstalk in the Pancreatic Cancer Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) represents one of the most aggressive solid tumors with a dismal prognosis and an increasing incidence. At the time of diagnosis, more than 85% of patients are in an unresectable stage. For these patients, chemotherapy can prolong survival by only a few months. Unfortunately, in recent decades, no groundbreaking therapies have emerged for PDAC, thus raising the question of how to identify novel therapeutic druggable targets to improve prognosis. Recently, the tumor microenvironment and especially its neural component has gained increasing interest in the pancreatic cancer field. A histological hallmark of PDAC is perineural invasion (PNI), whereby cancer cells invade surrounding nerves, providing an alternative route for metastatic spread. The extent of PNI has been positively correlated with early tumor recurrence and reduced overall survival. Multiple studies have shown that mechanisms involved in PNI are also involved in tumor spread and pain generation. Targeting these pathways has shown promising results in alleviating pain and reducing PNI in preclinical models. In this review, we will describe the mechanisms and future treatment strategies to target this mutually trophic interaction between cancer cells to open novel avenues for the treatment of patients diagnosed with PDAC.

Primary Tumor Staging for Oral Cancer and a Proposed Modification Incorporating Perineural Invasion: An International Multicenter Study

The objective of this study is to determine if the incorporation of perineural invasion (PNI) into the T-classification would improve the prognostic performance of TNM-8. An international, multicenter study of 1049 patients with oral cavity squamous cell carcinoma that were treated from 1994 to 2018 is performed. Various classification models are developed within each T-category and evaluated using the Harrel-concordance index (C-index), Akaike-information criterion (AIC), and visual inspection. Stratification into distinct prognostic categories, with internal validation, is performed using bootstrapping analysis (SPSS and R-software). Through multivariate analysis, PNI is significantly associated with disease-specific survival (p < 0.001). PNI integration into the staging system results in a significantly improved model compared with the current T category alone (lower AIC, p < 0.001). The PNI-integrated model is superior in predicting differential outcomes between T3 and T4 patients. A new model for T-classification of oral cavity squamous cell carcinoma is proposed, which is based on incorporating PNI into the staging system. These data can be used for future evaluations of the TNM staging system.

Transcriptome analyses reveal new insights on key determinants of perineural invasion in high-grade serous ovarian cancer

Perineural invasion (PNI) is a pathological feature of many cancers associated with poor outcomes, metastases, and recurrence. In relation to ovarian cancer (OC), there is no information about PNI's role and mechanisms. Our study found that patients with PNI-positive symptoms had significantly shorter overall survival (OS) time than patients with PNI-negative symptoms. Multivariate analyses demonstrated that PNI represented a substantial independent prognostic factor in OC patients. At the transcriptome level, it is noteworthy that PNI positivity was negatively correlated with the degree of infiltration of immune killer cells in OC tumor tissues, including macrophage, central memory CD4 T-cell, natural killer cells, monocyte, and central memory CD4 T-cell. The results of this study revealed that TAS2Rs proteins were markedly upregulated in PNI-positive OC tissues and predicted poor prognoses. Moreover, Immunohistochemical analysis demonstrated that the TAS2R10 protein was associated with poor prognoses and PNI in OC. Consequently, we found for the first time that PNI was a powerful predictor of poor prognosis in OC and analyzed its expression pattern and some preliminary biochemical characterization, providing new clues for guiding clinical prevention and treatment of OC.

Nomogram predicts risk of perineural invasion based on serum biomarkers for pancreatic cancer

BACKGROUND

Pancreatic cancer is a fatal tumor, and the status of perineural invasion (PNI) of pancreatic cancer was positively related to poor prognosis including overall survival and recurrence-free survival. This study aims to develop and validate a predictive model based on serum biomarkers to accurately predict the perineural invasion.

MATERIALS AND METHODS

The patients from No.924 Hospital of PLA Joint Logistic Support Force were included. The predictive model was developed in the training cohort using logistic regression analysis, and then tested in the validation cohort. The area under curve (AUC), calibration curves and decision curve analysis were used to validate the predictive accuracy and clinical benefits of nomogram.

RESULTS

A nomogram was developed using preoperative total bilirubin, preoperative blood glucose, preoperative CA19-9. It achieved good AUC values of 0.753 and 0.737 in predicting PNI in training and validation cohorts, respectively. Calibration curves showed nomogram had good uniformity of the practical probability of PNI. Decision curve analyses revealed that the nomogram provided higher diagnostic accuracy and superior net benefit compared to single indicators.

CONCLUSION

The present study constructed and validate a novel nomogram predicted the PNI of resectable PHAC patients with high stability and accuracy. Besides, it could better screen high-risk probability of PNI in these patients, and optimize treatment decision-making.

The bioengineered and multifunctional nanoparticles in pancreatic cancer therapy: Bioresponisive nanostructures, phototherapy and targeted drug delivery

The multidisciplinary approaches in treatment of cancer appear to be essential in term of bringing benefits of several disciplines and their coordination in tumor elimination. Because of the biological and malignant features of cancer cells, they have ability of developing resistance to conventional therapies such as chemo- and radio-therapy. Pancreatic cancer (PC) is a malignant disease of gastrointestinal tract in which chemotherapy and radiotherapy are main tools in its treatment, and recently, nanocarriers have been emerged as promising structures in its therapy. The bioresponsive nanocarriers are able to respond to pH and redox, among others, in targeted delivery of cargo for specific treatment of PC. The loading drugs on the nanoparticles that can be synthetic or natural compounds, can help in more reduction in progression of PC through enhancing their intracellular accumulation in cancer cells. The encapsulation of genes in the nanoparticles can protect against degradation and promotes intracellular accumulation in tumor suppression. A new kind of therapy for cancer is phototherapy in which nanoparticles can stimulate both photothermal therapy and photodynamic therapy through hyperthermia and ROS overgeneration to trigger cell death in PC. Therefore, synergistic therapy of phototherapy with chemotherapy is performed in accelerating tumor suppression. One of the important functions of nanotechnology is selective targeting of PC cells in reducing side effects on normal cells. The nanostructures are capable of being surface functionalized with aptamers, proteins and antibodies to specifically target PC cells in suppressing their progression. Therefore, a specific therapy for PC is provided and future implications for diagnosis of PC is suggested.

Perineural invasion: A potential driver of cancer-induced pain

Perineural invasion (PNI) is the process through which tumors invade and interact with nerves. The dynamic changes in the nerves caused by PNI may induce disturbing symptoms. PNI-related cancer pain in neuro-rich tumors has attracted much attention because the occurrence of tumor-induced pain is closely related to the invasion of nerves in the tumor microenvironment. PNI-related pain might indicate the occurrence of PNI, guide the improvement of treatment strategies, and predict the unresectability of tumors and the necessity of palliative care. Although many studies have investigated PNI, its relationship with tumor-induced pain and its common mechanisms have not been summarized thoroughly. Therefore, in this review, we evaluated the relationship between PNI and cancer-associated pain. We showed that PNI is a major cause of cancer-related pain and that this pain can predict the occurrence of PNI. We also elucidated the cellular and molecular mechanisms of PNI-induced pain. Finally, we analyzed the possible targets for alleviating PNI-related pain or combined antitumor and pain management. Our findings might provide new perspectives for improving the treatment of patients with malignant tumors.

Dysregulation of core neurodevelopmental pathways-a common feature of cancers with perineural invasion

Background: High nerve density in tumors and metastasis via nerves (perineural invasion-PNI) have been reported extensively in solid tumors throughout the body including pancreatic, head and neck, gastric, prostate, breast, and colorectal cancers. Ablation of tumor nerves results in improved disease outcomes, suggesting that blocking nerve-tumor communication could be a novel treatment strategy. However, the molecular mechanisms underlying this remain poorly understood. Thus, the aim here was to identify molecular pathways underlying nerve-tumor crosstalk and to determine common molecular features between PNI-associated cancers. Results: Analysis of head and neck (HNSCC), pancreatic, and gastric (STAD) cancer Gene Expression Omnibus datasets was used to identify differentially expressed genes (DEGs). This revealed extracellular matrix components as highly dysregulated. To enrich for pathways associated with PNI, genes previously correlated with PNI in STAD and in 2 HNSCC studies where tumor samples were segregated by PNI status were analyzed. Neurodevelopmental genes were found to be enriched with PNI. In datasets where tumor samples were not segregated by PNI, neurodevelopmental pathways accounted for 12%-16% of the DEGs. Further dysregulation of axon guidance genes was common to all cancers analyzed. By examining paralog genes, a clear pattern emerged where at least one family member from several axon guidance pathways was affected in all cancers examined. Overall 17 different axon guidance gene families were disrupted, including the ephrin-Eph, semaphorin-neuropilin/plexin, and slit-robo pathways. These findings were validated using The Cancer Genome Atlas and cross-referenced to other cancers with a high incidence of PNI including colon, cholangiocarcinoma, prostate, and breast cancers. Survival analysis revealed that the expression levels of neurodevelopmental gene families impacted disease survival. Conclusion: These data highlight the importance of the tumor as a source of signals for neural tropism and neural plasticity as a common feature of cancer. The analysis supports the hypothesis that dysregulation of neurodevelopmental programs is a common feature associated with PNI. Furthermore, the data suggested that different cancers may have evolved to employ alternative genetic strategies to disrupt the same pathways. Overall, these findings provide potential druggable targets for novel therapies of cancer management and provide multi-cancer molecular biomarkers.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

Predicting response to immunotherapy in gastric cancer via assessing perineural invasion-mediated inflammation in tumor microenvironment

BACKGROUND

The perineural invasion (PNI)-mediated inflammation of the tumor microenvironment (TME) varies among gastric cancer (GC) patients and exhibits a close relationship with prognosis and immunotherapy. Assessing the neuroinflammation of TME is important in predicting the response to immunotherapy in GC patients.

METHODS

Fifteen independent cohorts were enrolled in this study. An inflammatory score was developed and validated in GC. Based on PNI-related prognostic inflammatory signatures, patients were divided into Clusters A and B using unsupervised clustering. The characteristics of clusters and the potential regulatory mechanism of key genes were verified by RT-PCR, western-blot, immunohistochemistry and immunofluorescence in cell and tumor tissue samples.The neuroinflammation infiltration (NII) scoring system was developed based on principal component analysis (PCA) and visualized in a nomogram together with other clinical characteristics.

RESULTS

Inflammatory scores were higher in GC patients with PNI compared with those without PNI (P < 0.001). NII.clusterB patients with PNI had abundant immune cell infiltration in the TME but worse prognosis compared with patients in the NII.clusterA patients with PNI and non-PNI subgroups. Higher immune checkpoint expression was noted in NII.clusterB-PNI. VCAM1 is a specific signature of NII.clusterB-PNI, which regulates PD-L1 expression by affecting the phosphorylation of STAT3 in GC cells. Patients with PNI and high NII scores may benefit from immunotherapy. Patients with low nomogram scores had a better prognosis than those with high nomogram scores.

CONCLUSIONS

Inflammation mediated by PNI is one of the results of tumor-nerve crosstalk, but its impact on the tumor immune microenvironment is complex. Assessing the inflammation features of PNI is a potential method in predicting the response of immunotherapy effectively.

Radical Tumor Denervation Activates Potent Local and Global Cancer Treatment

This preliminary study seeks to determine the effect of R&P denervation on tumor growth and survival in immunocompetent rats bearing an aggressive and metastatic breast solid tumor. A novel microsurgical approach was applied "in situ", aiming to induce R&P denervation through the division of every single nerve fiber connecting the host with the primary tumor via its complete detachment and re-attachment, by resecting and reconnecting its supplying artery and vein (anastomosis). This preparation, known as microsurgical graft or flap, is radically denervated by definition, but also effectively delays or even impedes the return of innervation for a significant period of time, thus creating a critical and therapeutic time window. Mammary adenocarcinoma cells (HH-16.cl4) were injected into immunocompetent Sprague Dawley adult rats. When the tumors reached a certain volume, the subjects entered the study. The primary tumor, including a substantial amount of peritumoral tissue, was surgically isolated on a dominant artery and vein, which was resected and reconnected using a surgical microscope (orthotopic tumor auto-transplantation). Intending to simulate metastasis, two or three tumors were simultaneously implanted and only one was treated, using the surgical technique described herein. Primary tumor regression was observed in all of the microsurgically treated subjects, associated with a potent systemic anticancer effect and prolonged survival. In stark contrast, the subjects received a close to identical surgical operation; however, with the intact neurovascular connection, they did not achieve the therapeutic result. Animals bearing multiple tumors and receiving the same treatment in only one tumor exhibited regression in both the "primary" and remote- untreated tumors at a clinically significant percentage, with regression occurring in more than half of the treated subjects. A novel therapeutic approach is presented, which induces the permanent regression of primary and, notably, remote tumors, as well as, evidently, the naturally occurring metastatic lesions, at a high rate. This strategy is aligned with the impetus that comes from the current translational research data, focusing on the abrogation of the neuro-tumoral interaction as an alternative treatment strategy. More data regarding the clinical significance of this are expected to come up from a pilot clinical trial that is ongoing.

The acid-sensing nociceptor TRPV1 controls breast cancer progression in bone via regulating HGF secretion from sensory neurons

Cancers showing excessive innervation of sensory neurons (SN) in their microenvironments are associated with poor outcomes due to promoted growth, increased tumor recurrence, metastasis, and cancer pain, suggesting SNs play a regulatory role in cancer aggressiveness. Using a preclinical model in which mouse 4T1 breast cancer (BC) cells were injected into the bone marrow of tibiae, we found 4T1 BC cells aggressively colonized bone with bone destruction and subsequently spread to the lung. Of note, 4T1 BC colonization induced the acidic tumor microenvironment in bone in which SNs showed increased innervation and excitation with elevated expression of the acid-sensing nociceptor transient receptor potential vanilloid-1 (TRPV1), eliciting bone pain (BP) assessed by mechanical hypersensitivity. Further, these excited SNs produced increased hepatocyte growth factor (HGF). Importantly, the administration of synthetic and natural TRPV1 antagonists and genetic deletion of TRPV1 decreased HGF production in SNs and inhibited 4T1 BC colonization in bone, pulmonary metastasis from bone, and BP induction. Our results suggest the TRPV1 of SNs promotes BC colonization in bone and lung metastasis via up-regulating HGF production in SNs. The SN TRPV1 may be a novel therapeutic target for BC growing in the acidic bone microenvironment and for BP.

Perineural Invasion and Spread in Common Abdominopelvic Diseases: Imaging Diagnosis and Clinical Significance

Malignancies and other diseases may spread by multiple pathways, including direct extension, hematogenous spread, or via lymphatic vessels. A less-well-understood route is the peripheral nervous system, which is known as perineural spread (PNS). In addition to accounting for pain and other neurologic symptoms, PNS affects both disease prognosis and management. Although PNS is commonly discussed in relation to head and neck tumors, there is emerging data regarding PNS in abdominopelvic malignancies and other conditions such as endometriosis. Due to improved contrast and spatial resolution, perineural invasion, a finding heretofore diagnosed only at pathologic examination, can be detected at CT, MRI, and PET/CT. PNS most commonly manifests as abnormal soft-tissue attenuation extending along neural structures, and diagnosis of it is aided by optimizing imaging parameters, understanding pertinent anatomy, and becoming familiar with the typical neural pathways of spread that largely depend on the disease type and location. In the abdomen, the celiac plexus is a central structure that innervates the major abdominal organs and is the principal route of PNS in patients with pancreatic and biliary carcinomas. In the pelvis, the lumbosacral plexus and inferior hypogastric plexus are the central structures and principal routes of PNS in patients with pelvic malignancies. Although the imaging findings of PNS may be subtle, a radiologic diagnosis can have a substantial effect on patient care. Knowledge of anatomy and known routes of PNS and optimizing imaging parameters is of utmost importance in providing key information for prognosis and treatment planning. © RSNA, 2023 Supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Preoperative prediction of microvascular invasion and perineural invasion in pancreatic ductal adenocarcinoma with 18F-FDG PET/CT radiomics analysis

AIM

To develop and validate a predictive model based on 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/computed tomography (CT) radiomics features and clinicopathological parameters to preoperatively identify microvascular invasion (MVI) and perineural invasion (PNI), which are important predictors of poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

Preoperative ¹⁸F-FDG PET/CT images and clinicopathological parameters of 170 patients in PDAC were collected retrospectively. The whole tumour and its peritumoural variants (tumour dilated with 3, 5, and 10 mm pixels) were applied to add tumour periphery information. A feature-selection algorithm was employed to mine mono-modality and fused feature subsets, then conducted binary classification using gradient boosted decision trees.

RESULTS

For MVI prediction, the model performed best on a fused subset of ¹⁸F-FDG PET/CT radiomics features and two clinicopathological parameters, with an area under the receiver operating characteristic curve (AUC) of 83.08%, accuracy of 78.82%, recall of 75.08%, precision of 75.5%, and F1-score of 74.59%. For PNI prediction, the model achieved best prediction results only on the subset of PET/CT radiomics features, with AUC of 94%, accuracy of 89.33%, recall of 90%, precision of 87.81%, and F1 score of 88.35%. In both models, 3 mm dilation on the tumour volume produced the best results.

CONCLUSIONS

The radiomics predictors from preoperative ¹⁸F-FDG PET/CT imaging exhibited instructive predictive efficacy in the identification of MVI and PNI status preoperatively in PDAC. Peritumoural information was shown to assist in MVI and PNI predictions.

Three-dimensional analysis of human pancreatic cancer specimens by phase-contrast based X-ray tomography - the next dimension of diagnosis

BACKGROUND

The worldwide increase of pancreatic ductal adenocarcinoma (PDAC), which still has one of the lowest survival rates, requires novel imaging tools to improve early detection and to refine diagnosis. Therefore, the aim of this study was to assess the feasibility of propagation-based phase-contrast X-ray computed tomography of already paraffin-embedded and unlabeled human pancreatic tumor tissue to achieve a detailed three-dimensional (3D) view of the tumor sample in its entirety.

METHODS

Punch biopsies of areas of particular interest were taken from paraffin blocks after initial histological analysis of hematoxylin and eosin stained tumor sections. To cover the entire 3.5 mm diameter of the punch biopsy, nine individual tomograms with overlapping regions were acquired in a synchrotron parallel beam configuration and stitched together after data reconstruction. Due to the intrinsic contrast based on electron density differences of tissue components and a voxel size of 1.3 μm achieved PDAC and its precursors were clearly identified.

RESULTS

Characteristic tissue structures for PDAC and its precursors, such as dilated pancreatic ducts, altered ductal epithelium, diffuse immune cell infiltrations, increased occurrence of tumor stroma and perineural invasion were clearly identified. Certain structures of interest were visualized in three dimensions throughout the tissue punch. Pancreatic duct ectasia of different caliber and atypical shape as well as perineural infiltration could be contiguously traced by viewing serial tomographic slices and by applying semi-automatic segmentation. Histological validation of corresponding sections confirmed the former identified PDAC features.

CONCLUSION

In conclusion, virtual 3D histology via phase-contrast X-ray tomography visualizes diagnostically relevant tissue structures of PDAC in their entirety, preserving tissue integrity in label-free, paraffin embedded tissue biopsies. In the future, this will not only enable a more comprehensive diagnosis but also a possible identification of new 3D imaging tumor markers.

Cancer-nerve interplay in cancer progression and cancer-induced bone pain

INTRODUCTION

Cancer-induced bone pain (CIBP) is one of the most common and debilitating complications associated with bone metastasis. Although our understanding of the precise mechanism is limited, it has been known that bone is densely innervated, and that CIBP is elicited as a consequence of increased neurogenesis, reprogramming, and axonogenesis in conjunction with sensitization and excitation of sensory nerves (SNs) in response to the noxious stimuli that are derived from the tumor microenvironment developed in bone. Recent studies have shown that the sensitized and excited nerves innervating the tumor establish intimate communications with cancer cells by releasing various tumor-stimulating factors for tumor progression.

APPROACHES

In this review, the role of the interactions of cancer cells and SNs in bone in the pathophysiology of CIBP will be discussed with a special focus on the role of the noxious acidic tumor microenvironment, considering that bone is in nature hypoxic, which facilitates the generation of acidic conditions by cancer. Subsequently, the role of SNs in the regulation of cancer progression in the bone will be discussed together with our recent experimental findings.

CONCLUSION

It is suggested that SNs may be a newly-recognized important component of the bone microenvironment that contribute to not only in the pathophysiology of CIBP but also cancer progression in bone and dissemination from bone. Suppression of the activity of bone-innervating SNs, thus, may provide unique opportunities in the treatment of cancer progression and dissemination, as well as CIBP.

Rapid cancer cell perineural invasion utilizes amoeboid migration

The invasion of nerves by cancer cells, or perineural invasion (PNI), is potentiated by the nerve microenvironment and is associated with adverse clinical outcomes. However, the cancer cell characteristics that enable PNI are poorly defined. Here, we generated cell lines enriched for a rapid neuroinvasive phenotype by serially passaging pancreatic cancer cells in a murine sciatic nerve model of PNI. Cancer cells isolated from the leading edge of nerve invasion showed a progressively increasing nerve invasion velocity with higher passage number. Transcriptome analysis revealed an upregulation of proteins involving the plasma membrane, cell leading edge, and cell movement in the leading neuroinvasive cells. Leading cells progressively became round and blebbed, lost focal adhesions and filipodia, and transitioned from a mesenchymal to amoeboid phenotype. Leading cells acquired an increased ability to migrate through microchannel constrictions and associated more with dorsal root ganglia than nonleading cells. ROCK inhibition reverted leading cells from an amoeboid to mesenchymal phenotype, reduced migration through microchannel constrictions, reduced neurite association, and reduced PNI in a murine sciatic nerve model. Cancer cells with rapid PNI exhibit an amoeboid phenotype, highlighting the plasticity of cancer migration mode in enabling rapid nerve invasion.