Pain in chronic pancreatitis and pancreatic cancer

EUS/EUS-FNA for suspected pancreatic cancer: influence of chronic pancreatitis and clinical presentation with or without obstructive jaundice on performance characteristics

BACKGROUND

The clinical utility of EUS-FNA is debated in patients with obstructive jaundice (ObJ) because of a very high pretest probability of pancreatobiliary malignancy (PBM) and biliary stent-induced inflammation that can potentially confound EUS-FNA diagnosis. EUS-FNA also has lower accuracy in patients with underlying chronic pancreatitis (CP).

OBJECTIVE

Our purpose was to determine the clinical value of EUS-FNA for PBM diagnosis based on clinical presentation and presence of CP.

DESIGN

Retrospective analysis of prospective database.

SETTING

University hospital.

PATIENTS

Patients who underwent EUS-FNA from 2002 to 2006 for suspected PBM based on (1) ObJ with biliary stricture or a mass lesion or (2) abnormal pancreatic imaging by CT/MRI: a focal pancreatic "mass" lesion; dilated pancreatic duct +/- common bile duct; or an enlarged head of pancreas.

INTERVENTIONS

EUS was performed with a radial echoendoscope followed by a linear echoendoscope if a focal pancreatic lesion was identified. Fine-needle aspirates were assessed immediately by an attending cytopathologist.

MAIN OUTCOME MEASUREMENTS

(1) Prevalence of cancer and (2) performance characteristics of EUS-FNA.

RESULTS

PBM was diagnosed in 73.9% of patients with ObJ and biliary stricture or pancreatic mass, in 49.6% of patients with pancreatic mass, and in 7.0% of patients with an enlarged head of pancreas or dilated pancreatic duct +/- common bile duct. The prevalence of PBM was lower in all 3 presentations with associated CP. Both CP and presentation with ObJ lowered performance characteristics of EUS-FNA, but CP did so only in the subset of patients with ObJ. All except 1 false-negative diagnoses were due to cytologic misinterpretation.

LIMITATION

Retrospective design.

CONCLUSION

Among patients with suspected PBM, the accuracy of EUS-FNA is significantly lower only in a subset of patients with ObJ with underlying CP, largely as a result of difficulty in cytologic interpretation.

Intrathecal narcotic infusion pumps for intractable pain of chronic pancreatitis: a pilot series

OBJECTIVES

The aim of this study was to evaluate the efficacy of intrathecal narcotics pump (ITNP) as an alternative treatment for patients with pain from chronic pancreatitis (CP). ITNP offers the advantages of reversibility, lower total narcotic dose, and the pancreas remaining intact.

METHODS

Thirteen patients (8 female, 5 male), with mean age 40.6 years (s.d. 9.6 years), who had experienced intractable upper abdominal pain from CP were reviewed. Each patient had multiple other failed treatment modalities, including partial pancreatic resection (n = 6). They were offered ITNP after a successful intraspinal opioid trial. Etiologies of CP included idiopathy (n = 3), cystic fibrosis (n = 2), alcohol (n = 2), and pancreas divisum (n = 6).

RESULTS

The median duration of severe, intractable pain prior to ITNP was 6 years (2-22 years). The median follow-up time after ITNP was 29 months (range, 7-94 months). The ITNP was in situ for a mean duration of 29 months (range, 0.5-94 months). Seven patients had pump exchange or removal for various reasons; improvement of pain at month 53 (n = 1), meningitis (n = 1), meningitis with subsequent replacement (n = 1), pump failure at month 31, 68, 79, and 84 (n = 4). There were no deaths. The mean pain score prior to implantation (score = 8.3, s.d. = 0.9) was significantly higher than 1 year after (score = 2.7, s.d. = 1.9) (P < 0.01) and last follow-up (score = 0.75, s.d. = 2.1) (P < 0.01). The median oral narcotic dose before and 1 year after ITNP were morphine sulfate equivalents 337.5 mg per day (range, 67.5-1,320) and 40 mg per day (range, 0-1,680), respectively (P < 0.01). Two patients were considered failures, as they still require a high dosage of both oral and intrathecal medications to control their pain, despite significant pain-score improvement. One patient who was excluded due to meningitis was also considered a failure. Therefore, the overall success rate of ITNP based on an intention-to-treat analysis was 76.9% (10/13). The major complications of ITNP were central nervous system infection requiring pump removal (n = 1), cerebrospinal fluid leak requiring laminectomy (n = 1), and perispinal abscess with bacterial meningitis requiring pump removal (n = 1).

CONCLUSIONS

This study shows the many risks and benefits of ITNP. A longer follow-up is awaited; such pumps appear to be one alternative to aggressive surgical intervention. Failed ITNP trials leave other options open. Therapeutic trials directly comparing pancreatectomy, ITNP, and implanted nerve stimulators are of interest.

Pathogenesis of chronic pancreatitis: a comprehensive update and a look into the future

Chronic pancreatitis is a relatively frequent condition usually caused by alcoholic abuse but also due to recurrent gallstone disease, metabolic endocrine disorders and haemochromatosis, among others. Specific types such as hereditary and autoimmune pancreatitis should be particularly kept in mind and emphasized, as they require specific treatment and attention. The possibility to identify gene mutations has also increased and this is likely to decrease the overall total number of "idiopathic" chronic pancreatitis cases. Pancreatic stellate cells have been identified as potential key players in the progression of chronic pancreatitis and the development of fibrogenesis, which are activated either during repeated attacks of necro-inflammation or directly by toxic factors. The inhibition or modulation of pancreatic stellate cells could represent a way of potential intervention in patients with chronic pancreatitis in the future.

Does the pain-protective GTP cyclohydrolase haplotype significantly alter the pattern or severity of pain in humans with chronic pancreatitis?

Background

Pain is often a dominant clinical feature of chronic pancreatitis but the frequency and severity is highly variable between subjects. We hypothesized that genetic polymorphisms contribute to variations in clinical pain patterns. Since genetic variations in the GTP cyclohydrolase (GCH1) gene have been reported to protect some patients from pain, we investigated the effect of the "pain protective haplotype" in well characterized patients with chronic pancreatitis (CP) or recurrent acute pancreatitis (RAP) from the North American Pancreatitis Study 2 (NAPS2).

Results

Subjects in the NAPS2 study were asked to rank their pain in one of 5 categories reflecting different levels of pain frequency and severity. All subjects were genotyped at rs8007267 and rs3783641 to determine the frequency of the GCH1 pain-protective haplotype. In Caucasian subjects the frequency of the pain-protective GCH1 haplotype was no different in the control group (n = 236), CP patients (n = 265), RAP patients (N = 131), or in CP patients subclassified by pain category compared to previously reported haplotype frequencies in the general Caucasian population.

Conclusion

The GCH1 pain-protective haplotype does not have a significant effect on pain patterns or severity in RAP or CP. These results are important for helping to define the regulators of visceral pain, and to distinguish different mechanisms of pain.

Survival rates and cause of death in 174 patients with chronic pancreatitis

BACKGROUND

The natural history after surgery for chronic pancreatitis is rarely reported.

METHODS

Between 1970 and 1999, 174 patients underwent surgery for chronic pancreatitis and were followed until December 2006. They were divided in four groups: (1) resection 62; (2) drainage 82; (3) external drainage 7; (4) non-pancreas-directed surgery 23. A second procedure was required by 25 patients and a third by four: group 1 = 6 + 0, group 2 = 10 + 2, group 3 = 3 + 1, group 4 = 6 + 1.

RESULTS

Hospital mortality was four of 174 (2.3%). Fifty-seven patients are alive; 49 of 170 developed cancer, and 38 died: lung (22), oral, pharynx, larynx (eight), esophagus, kidney, pancreas, colon, liver (two each), breast, stomach, mediastinum, prostate, melanoma, chronic myelogenous leukemia, squamous cancer of the auricle (one each), liver metastasis from unknown primary (two). Fifteen patients died of liver cirrhosis, 13 of myocardial infarction/decompensation, six of vascular problems, five each of acute renal insufficiency or cerebral diseases, four each of acute pancreatitis, accidental trauma, complications of diabetes, bronchopneumonia, and 19 of other causes. The overall 5-, 10-, 15-, 20-, 25-, and 30-year survival rate was 84.7, 65.6, 51.6, 38.0, 28.1, and 23.5.

CONCLUSIONS

Incidence of pancreatic cancer was 1.2%. The high incidence of smoking cancers (18.8%) is explained by the smoking habits of almost 100% of our patients. Eliminating smoking and increasing tests on organs at risk may prolong survival.

The role of total pancreatectomy and islet autotransplantation for chronic pancreatitis

Total pancreatectomy and islet autotransplantation are done for chronic pancreatitis with intractable pain when other treatment measures have failed, allowing insulin secretory capacity to be preserved, minimizing or preventing diabetes, while at the same time removing the root cause of the pain. Since the first case in 1977, several series have been published. Pain relief is obtained in most patients, and insulin independence preserved long term in about a third, with another third having sufficient beta cell function so that the surgical diabetes is mild. Islet autotransplantation has been done with partial or total pancreatectomy for benign and premalignant conditions. Islet autotransplantation should be used more widely to preserve beta cell mass in major pancreatic resections.