Pain sensation in pancreatic diseases is not uniform: The different facets of pancreatic pain

Early versus delayed computed tomography-guided celiac plexus neurolysis for palliative pain management in patients with advanced pancreatic cancer: a retrospective cohort study

Introduction

Abdominal and back pain is the most frequent symptom in patients with pancreatic cancer, with pain management being extremely challenging. This study aimed to evaluate pain control, opioid consumption, pain-interfered quality of life, and survival after early and delayed computed tomography (CT)-guided celiac plexus neurolysis (CPN).

Methods

A retrospective analysis of pancreatic cancer patients receiving CPN for pain (n = 56) between June 2018 and June 2021 was done. The patients were grouped as early group (n = 22) and delayed group (n = 34) on the basis of the presence of persistent refractory pain according to expert consensus on refractory cancer pain.

Results

Both groups were comparable in demographic characteristics and baseline pain conditions measured using the numeric rating scale (5.77 ± 1.23 vs. 6.27 ± 1.21; p = 0.141). The pain scores were significantly reduced in both groups; early CPN resulted in significantly lower scores from 3 to 5 months. The opioid consumption gradually decreased to a minimum at 2 weeks but increased at 1 month (35.56 ± 30.14 mg and 50.48 ± 47.90 mg, respectively); significantly larger consumption from 2 to 4 months was seen in the delayed group. The total pain interference was lower than baseline in all patients, with significant improvement after early CPN in sleep, appetite, enjoyment of life, and mood. The average survival time of the two groups was comparable.

Conclusion

Early application of CT-guided CPN for patients with advanced pancreatic cancer may help reduce pain exacerbation and opioids consumption, without influencing the survival.

Prevalence of primary painless chronic pancreatitis: A systematic review and meta-analysis

BACKGROUND/OBJECTIVES

While pain is the predominant symptom of chronic pancreatitis (CP), a subset of patients may experience a painless course. This systematic review aimed to determine the prevalence of primary painless CP.

METHODS

MEDLINE (PubMed), EMBASE and Web of Science Core Collection databases were searched for published studies through September 15, 2020 that included at least 10 consecutive patients with CP and which reported the number with painless CP. The presence of a history of recurrent acute pancreatitis (RAP), exocrine pancreatic insufficiency (EPI), diabetes mellitus (DM) and pancreatic adenocarcinoma (PA) in the painless CP patients was also recorded. A random effects model was used to determine pooled prevalence estimates with 95% confidence intervals (95% CI).

RESULTS

Among the 5057 studies identified and screened, 42 full-text articles were included in the final analysis. There were a total of 14,277 patients with CP among whom 1569 had painless CP. The pooled prevalence of painless CP was 12% (95% CI 10-15%). Among a subset of studies that reported on calcifications (n = 11), DM (n = 12), EPI (n = 8) and history of RAP (n = 14), the pooled prevalence estimates were 96% (95% CI 73-100%), 51% (95% CI 32-70%), and 47% (95% CI 15-81%), respectively. Alcohol, idiopathic/genetic and other etiologies were attributed to be the cause of painless CP in 32.4%, 56.9% and 8.9% patients, respectively.

CONCLUSION

Approximately one in ten patients with CP have primary painless disease with the majority being attributable to an idiopathic/genetic etiology. Further research is needed to determine the optimal management of these patients.

A Novel Cellular Therapy to Treat Pancreatic Pain in Experimental Chronic Pancreatitis Using Human Alpha-1 Antitrypsin Overexpressing Mesenchymal Stromal Cells

Chronic pancreatitis (CP) is characterized by pancreatic inflammation, fibrosis, and abdominal pain that is challenging to treat. Mesenchymal stromal cells (MSCs) overexpressing human alpha-1 antitrypsin (hAAT-MSCs) showed improved mobility and protective functions over native MSCs in nonobese diabetic mice. We investigated whether hAAT-MSCs could mitigate CP and its associated pain using trinitrobenzene sulfonic acid (TNBS)-induced CP mouse models. CP mice were given native human MSCs or hAAT-MSCs (0.5 × 10⁶ cells/mouse, i.v., n = 6–8/group). The index of visceral pain was measured by graduated von Frey filaments. Pancreatic morphology and pancreatic mast cell count were analyzed by morphological stains. Nociceptor transient receptor potential vanilloid 1 (TRPV1) expression in dorsal root ganglia (DRG) was determined by immunohistochemistry. hAAT-MSC-treated CP mice best preserved pancreatic morphology and histology. MSC or hAAT-MSC infusion reduced abdominal pain sensitivities. hAAT-MSC therapy also suppressed TRPV1 expression in DRG and reduced pancreatic mast cell density induced by TNBS. Overall, hAAT-MSCs reduced pain and mitigated pancreatic inflammation in CP equal to MSCs with a trend toward a higher pancreatic weight and better pain relief in the hAAT-MSC group compared to the MSC group. Both MSCs and hAAT-MSCs might be used as a novel therapeutic tool for CP-related pain.

Recurrent Acute Pancreatitis and Superior Mesenteric Venous Thrombosis - Cause or Course

The management of pancreatitis can be daunting, especially when associated with other comorbidities. These complexities in management are conflicting in the presence of comorbidities with a similar presentation, such as abdominal pain. Acute pancreatitis (AP) has been associated with mesenteric thrombosis but less commonly with superior mesenteric vein thrombosis (SMVT) as a causal or complicating dilemma. This case report describes the careful intrigues and overlaps in presentation. Furthermore, this paper presents a dilemma in that contrast-enhanced computed tomography (CT) may not be recommended in the early stage of diagnosis of AP according to the 2013 American College of Gastroenterology (ACG) guideline, but SMVT, which can be fatal, sometimes, complicates AP, and contrast-enhanced CT is important in its diagnosis. This paper attempts to address this dilemma. Managing these two potentially fatal pathologies requires promptness and thoughtfulness in averting a deadly outcome. Because SMVT is fatal, in this paper, we reiterate the use of contrast-enhanced CT in the early stages of the management of AP. Fatal complications from AP should not be missed. Although contrast-enhanced CT is not recommended in the early stages of diagnosis of AP in the ACG guideline, fatal complications such as SMVT can be avoided.

[Conservative or surgical treatment of chronic pancreatitis?]

The cardinal symptom of chronic pancreatitis is severe belt-like upper abdominal pain, which requires immediate and adequate treatment. Furthermore, advanced stage chronic pancreatitis is often associated with complications, such as pancreatic pseudocysts, pancreatic duct stones and stenosis as well as biliary stenosis. The various endoscopic and surgical treatment options for chronic pancreatitis patients have been controversially discussed for decades. The new German S3 guidelines on pancreatitis now clearly define the best treatment options depending on the indications for treatment. For the treatment of pain in chronic pancreatitis it has been known for a long time that a surgical intervention is superior to endoscopic intervention concerning long-term pain relief. The recently published ESCAPE study has further underlined this by showing that early surgical intervention was superior to a step-up approach with initial endoscopic treatment. For the treatment of pancreatic pain, an initial endoscopic treatment attempt is therefore justified for short-term pain relief but in the midterm and long term, surgical intervention is the treatment of choice. In contrast, pancreatic pseudocysts, solitary proximally situated pancreatic duct stones and benign biliary strictures (except in calcifying pancreatitis) can nowadays generally be managed endoscopically. For distal pancreatic duct stones and symptomatic pancreatic duct stenosis surgical treatment is again the method of choice. This review article discusses these indication-related procedures in detail and explains them in relation to the recently published S3 guidelines on pancreatitis of the German Society for Gastroenterology, Digestive and Metabolic Diseases (DGVS).

Pancreas Cancer-Associated Pain Management

Pain is highly prevalent in patients with pancreas cancer and contributes to the morbidity of the disease. Pain may be due to pancreatic enzyme insufficiency, obstruction, and/or a direct mass effect on nerves in the celiac plexus. Proper supportive care to decrease pain is an important aspect of the overall management of these patients. There are limited data specific to the management of pain caused by pancreatic cancer. Here we review the literature and offer recommendations regarding multiple modalities available to treat pain in these patients. The dissemination and adoption of these best supportive care practices can improve quantity and quality of life for patients with pancreatic cancer. IMPLICATIONS FOR PRACTICE: Pain management is important to improve the quality of life and survival of a patient with cancer. The pathophysiology of pain in pancreas cancer is complex and multifactorial. Despite tumor response to chemotherapy, a sizeable percentage of patients are at risk for ongoing cancer-related pain and its comorbid consequences. Accordingly, the management of pain in patients with pancreas cancer can be challenging and often requires a multifaceted approach.

Surgical Therapy of Chronic Alcoholic Pancreatitis: A Literature Review of Current Options

Chronic pancreatitis (CP) is associated with alcohol abuse in 80% of cases. The primary treatment goals in CP are pain reduction and avoidance of pancreatitis-associated complications. CP should be treated in an interdisciplinary approach. A recent randomized clinical trial showed that early surgery compared with an endoscopy-first approach resulted in reduced pain levels. Surgical resections are, therefore, the most efficient treatment of pancreatitis-associated pain as well as other complications and should be performed early in the course of the disease. Since most of the patients pre-sent with chronic inflammation of the pancreatic head, pancreatic head resection is the most common treatment option. Duodenum-preserving pancreatic head resections are the surgical procedure of choice, but pancreaticoduodenectomies (Kausch-Whipple procedures) demonstrate similar outcome with regard to pain control, quality of life, and metabolic parameters. Other surgical procedures, including drainage procedures, pancreatic segmental resections, or left resections, are rarely indicated.

Pathogenesis and Treatment of Pancreatic Cancer Related Pain

Pancreatic cancer is often diagnosed due to the patient seeking medical attention for abdominal pain. It is among the most painful cancers, with pain severity strongly correlating with prognosis. Perineural invasion is a prominent feature of pancreatic cancer and often the first route of metastasis resulting in neuropathic pain. While surgical pain is present, it is generally short-lived; chemo- and radio-therapy associated side effect pain is often longer lasting and more difficult to manage. Treatment-induced mucositis in response to chemotherapy occurs throughout the GI tract resulting in infection-prone ulcers on the lip, buccal mucosa, palate or tongue. Cisplatin treatment is associated with axonal neuropathy in the dorsal root ganglion, although other large sensory fibers can be affected. Opioid-induced hyperalgesia can also emerge in patients. Along with traditional means to address pain, neurolytic celiac plexus block of afferent nociceptive fibers has been reported to be effective in 74% of patients. Moreover, as cancer treatments become more effective and result in improved survival, treatment-related side effects become more prevalent. Here, pancreatic cancer and treatment associated pain are reviewed along with current treatment strategies. Potential future therapeutic strategies to target the pathophysiology underlying pancreatic cancer and pain induction are also presented.

Pancreatic sphincterotomy improves pain symptoms due to branch-duct intrapapillary mucinous neoplasia without worrisome features: a multicenter study

Introduction Branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) require follow-up to detect worrisome features (WF). Data are missing about endoscopic pancreatic sphincterotomy (PS) for symptomatic IPMN.

Patients and methods This was a retrospective multicenter study in four expert centers. Patients treated with endoscopic PS for symptomatic (painful) BD-IPMN without WF were included. Age, sex, follow-up time, characteristics of IPMNs and endoscopic retrograde cholangiopancreatographies (ERCPs), and indications for surgery were recorded.

Results In total, 21 patients were included (median age 68 years, range 45 – 87 years). The median number of cysts was 2 (range 1 – 10), located in the head (59 %), body/tail (17 %), or multifocal (24 %). ERCP including PS was completed in all of the cases, with biliary sphincterotomy in 33 %. Clinical efficacy after one session was 81 % (17/21). Among the failures, one had a second successful PS and three were operated. The final efficacy was 86 % (18/21). Seven patients were operated after a mean of 19 months: four for WF, three for pain. The histopathology showed four low grade dysplasia, one high grade dysplasia, and two no dysplasia. No adenocarcinoma occurred during a follow-up of 99 months (range 14 – 276 months).

Conclusions Endoscopic PS for symptomatic IPMN without WF is effective in more than 80 % of cases, without increasing the risk for adenocarcinoma.

Perineural invasion in pancreatic cancer: proteomic analysis and in vitro modelling

Perineural invasion (PNI) is a common and characteristic feature of pancreatic ductal adenocarcinoma (PDAC) that is associated with poor prognosis, tumor recurrence, and generation of pain. However, the molecular alterations in cancer cells and nerves within PNI have not previously been comprehensively analyzed. Here, we describe our proteomic analysis of the molecular changes underlying neuro-epithelial interactions in PNI using liquid chromatography-mass spectrometry (LC-MS/MS) in microdissected PNI and non-PNI cancer, as well as in invaded and noninvaded nerves from formalin-fixed, paraffin-embedded PDAC tissues. In addition, an in vitro model of PNI was developed using a co-culture system comprising PDAC cell lines and PC12 cells as the neuronal element. The overall proteomic profiles of PNI and non-PNI cancer appeared largely similar. In contrast, upon invasion by cancer cells, nerves demonstrated widespread plasticity with a pattern consistent with neuronal injury. The up-regulation of SCG2 (secretogranin II) and neurosecretory protein VGF (nonacronymic) in invaded nerves in PDAC tissues was further validated using immunohistochemistry. The tested PDAC cell lines were found to be able to induce neuronal plasticity in PC12 cells in our in vitro established co-culture model. Changes in expression levels of VGF, as well as of two additional proteins previously reported to be overexpressed in PNI, Nestin and Neuromodulin (GAP43), closely recapitulated our proteomic findings in PDAC tissues. Furthermore, induction of VGF, while not necessary for PC12 survival, mediated neurite extension induced by PDAC cell lines. In summary, here we report the proteomic alterations underlying PNI in PDAC and confirm that PDAC cells are able to induce neuronal plasticity. In addition, we describe a novel, simple, and easily adaptable co-culture model for in vitro study of neuro-epithelial interactions.

Diagnostic and therapeutic recommendations in pancreatic ductal adenocarcinoma. Recommendations of the Working Group of the Polish Pancreatic Club

These recommendations refer to the current management in pancreatic ductal adenocarcinoma (PDAC), a neoplasia characterised by an aggressive course and extremely poor prognosis. The recommendations regard diagnosis, surgical, adjuvant and palliative treatment, with consideration given to endoscopic and surgical methods. A vast majority of the statements are based on data obtained in clinical studies and experts' recommendations on PDAC management, including the following guidelines: International Association of Pancreatology/European Pancreatic Club (IAP/EPC), American Society of Clinical Oncology (ASCO), European Society for Medical Oncology (ESMO), National Comprehensive Cancer Network (NCCN) and Polish Society of Gastroenterology (PSG) and The National Institute for Health and Care Excellence (NICE). All recommendations were voted on by members of the Working Group of the Polish Pancreatic Club. Results of the voting and brief comments are provided with each recommendation.

MicroRNA co-expression networks exhibit increased complexity in pancreatic ductal compared to Vater's papilla adenocarcinoma

MiRNA expression abnormalities in adenocarcinoma arising from pancreatic ductal system (PDAC) and Vater's papilla (PVAC) could be associated with distinctive pathologic features and clinical cancer behaviours. Our previous miRNA expression profiling data on PDAC (n=9) and PVAC (n=4) were revaluated to define differences/similarities in miRNA expression patterns. Afterwards, in order to uncover target genes and core signalling pathways regulated by specific miRNAs in these two tumour entities, miRNA interaction networks were wired for each tumour entity, and experimentally validated target genes underwent pathways enrichment analysis. One hundred and one miRNAs were altered, mainly over-expressed, in PDAC samples. Twenty-six miRNAs were deregulated in PVAC samples, where more miRNAs were down-expressed in tumours compared to normal tissues. Four miRNAs were significantly altered in both subgroups of patients, while 27 miRNAs were differentially expressed between PDAC and PVAC. Although miRNA interaction networks were more complex and dense in PDAC than in PVAC, pathways enrichment analysis uncovered a functional overlapping between PDAC and PVAC. However, shared signalling events were influenced by different miRNA and/or genes in the two tumour entities. Overall, specific miRNA expression patterns were involved in the regulation of a limited core signalling pathways in the biology landscape of PDAC and PVAC.

Road map for pain management in pancreatic cancer: A review

Beside its poor prognosis and its late diagnosis, pancreatic cancer remains one of the most painful malignancies. Optimal management of pain in this cancer represents a real challenge for the oncologist whose objective is to ensure a better quality of life to his patients. We aimed in this paper to review all the treatment modalities incriminated in the management of pain in pancreatic cancer going from painkillers, chemotherapy, radiation therapy and interventional techniques to agents under investigation and alternative medicine. Although specific guidelines and recommendations for pain management in pancreatic cancer are still absent, we present all the possible pain treatments, with a progression from medical multimodal treatment to radiotherapy and chemotherapy then interventional techniques in case of resistance. In addition, alternative methods such as acupuncture and hypnosis can be added at any stage and seems to contribute to pain relief.

The Analgesic Effect of the Mitochondria-Targeted Antioxidant SkQ1 in Pancreatic Inflammation

Background. Chronic pancreatitis is one of the main risk factors for pancreatic cancer. In acute and chronic pancreatitis, oxidative stress is thought to play a key role. In this respect, the recently described mitochondria-targeted antioxidant SkQ1 effectively scavenges reactive oxygen species at nanomolar concentrations. Therefore, we aimed to characterize the influence of SkQ1 on tissue injury and pain in acute and chronic pancreatitis. Methods. Both acute and chronic pancreatitis were induced in C57BL/6 mice by intraperitoneal cerulein injections and treatment with SkQ1 was carried out by peroral applications. Hyperalgesia was assessed by behavioral observation and measurement of abdominal mechanical sensitivity. Blood serum and pancreatic tissue were harvested for analysis of lipase and histology. Results. SkQ1 did not influence pain, serological, or histological parameters of tissue injury in acute pancreatitis. In chronic pancreatitis, a highly significant reduction of pain-related behavior (p < 0.0001) was evident, but histological grading revealed increased tissue injury in SkQ1-treated animals (p = 0.03). Conclusion. After SkQ1 treatment, tissue injury is not ameliorated in acute pancreatitis and increased in chronic pancreatitis. However, we show an analgesic effect in chronic pancreatitis. Further studies will need to elucidate the risks and benefits of mitochondria-targeted antioxidants as an analgesic.

Neural plasticity in pancreatitis and pancreatic cancer

Pancreatic nerves undergo prominent alterations during the evolution and progression of human chronic pancreatitis and pancreatic cancer. Intrapancreatic nerves increase in size (neural hypertrophy) and number (increased neural density). The proportion of autonomic and sensory fibres (neural remodelling) is switched, and are infiltrated by perineural inflammatory cells (pancreatic neuritis) or invaded by pancreatic cancer cells (neural invasion). These neuropathic alterations also correlate with neuropathic pain. Instead of being mere histopathological manifestations of disease progression, pancreatic neural plasticity synergizes with the enhanced excitability of sensory neurons, with Schwann cell recruitment toward cancer and with central nervous system alterations. These alterations maintain a bidirectional interaction between nerves and non-neural pancreatic cells, as demonstrated by tissue and neural damage inducing neuropathic pain, and activated neurons releasing mediators that modulate inflammation and cancer growth. Owing to the prognostic effects of pain and neural invasion in pancreatic cancer, dissecting the mechanism of pancreatic neuroplasticity holds major translational relevance. However, current in vivo models of pancreatic cancer and chronic pancreatitis contain many discrepancies from human disease that overshadow their translational value. The present Review discusses novel possibilities for mechanistically uncovering the role of the nervous system in pancreatic disease progression.