Diabetes and its relationship to pancreatic carcinoma

Endocrine and Metabolic Insights from Pancreatic Surgery

Although it is well established that diabetes can also develop as a result of diseases or maneuvers on the exocrine pancreas, the complex relationship between glucose disorders and underlying pancreatic disease is still debated. There is evidence that several features linked to pancreatic diseases can modify endocrine and metabolic conditions before and after surgery. However, pancreatic surgery provides a rare opportunity to correlate in vivo endocrine and metabolic pathways with ex vivo pancreatic samples, to examine the endocrine and metabolic effects of acute islet removal, and finally to clarify the pathogenesis of diabetes. This approach could therefore represent a unique method to shed light on the molecular mechanisms, predicting factors, and metabolic consequences of insulin resistance, islet plasticity, β cell failure, and type 2 diabetes.

Neuroendocrine and Behavioral Consequences of Hyperglycemia in Cancer

A hallmark of cancer is the disruption of cellular metabolism during the course of malignant growth. Major focus is now on how these cell-autonomous processes propagate to the tumor microenvironment and, more generally, to the entire host system. This chain of events can have major consequences for a patient's health and wellbeing. For example, metabolic "waste" produced by cancer cells activates systemic inflammatory responses, which can interfere with hepatic insulin receptor signaling and glucose homeostasis. Research is just now beginning to understand how these processes occur, and how they contribute to systemic symptoms prevalent across cancers, including hyperglycemia, fatigue, pain, and sleep disruption. Indeed, it is only recently that we have begun to appreciate that the brain does not play a passive role in responding to cancer-induced changes in physiology. In this review, we provide a brief discussion of how oncogene-directed metabolic reprogramming disrupts host metabolism, with a specific emphasis on cancer-induced hyperglycemia. We further discuss how the brain senses circulating glucose concentrations and how this process goes awry as a response to distant neoplastic growth. Finally, as glucose-sensing neurons control diverse aspects of physiology and behavior, we link cancer-induced changes in energy balance to neuroendocrine and behavioral consequences for the host organism.

Changes in Pancreatic Endocrine Function and Morphology After Pancreaticoduodenectomy: A Comparison Between Pancreatic Head Cancer and Other Pathologies

OBJECTIVES

It is unclear whether the improved glucose metabolism in pancreas head cancer (PHC) patients after pancreaticoduodenectomy is due to the anatomical change or the relief of pancreatic duct obstruction.

METHODS

We divided 170 patients into the PHC group (n = 54, 31.8%) and other pathology (non-PHC) group (n = 116, 68.2%). Glucose metabolic function was evaluated using the glucose tolerance index (GTI), and the pancreatic duct obstruction and dilatation was measured using the pancreatic atrophic index (PAI).

RESULTS

The preoperative GTI was significantly higher in the PHC group (mean [standard deviation {SD}], 0.84 [1.16]) than in the non-PHC group (0.41 [SD, 0.59], P = 0.000). The postoperative GTI decreased significantly in the PHC group but remained unchanged in the non-PHC group. Similarly, the preoperative PAI was higher in the PHC group (0.32 [SD, 0.19]) than in the non-PHC group (0.13 [SD, 0.09], P = 0.000). The postoperative PAI decreased significantly in the PHC group, but not in the non-PHC group.

CONCLUSIONS

The impaired glucose metabolism in PHC can be caused by pancreatic duct obstruction. After pancreaticoduodenectomy, glucose metabolism is improved by the relief of pancreatic duct obstruction, and not by the anatomical change. The patients should be counseled accordingly.

Establishment and Verification of a Scoring Model for the Differential Diagnosis of Pancreatic Cancer and Chronic Pancreatitis

OBJECTIVES

The aims of this study were to establish a scoring model for the differential diagnosis of pancreatic cancer (PC) and chronic pancreatitis (CP) and to evaluate its diagnostic efficacy.

METHODS

The data of 502 patients with PC and 210 patients with CP at the Peking Union Medical College Hospital from January 1999 to December 2013 were retrospectively analyzed. Binary logistic regression was applied to establish the prediction model for the differential diagnosis. The model was verified using the method of leave-one-out cross-validation.

RESULTS

The scoring system was established with 5 variables including age, carbohydrate antigen 19-9 level, splenic vein invasion, irregular dilatation of the pancreatic duct, and nontruncated pancreatic duct stenosis. The score range was from -2 to 3. The area under the receiver operating characteristic curve of the objects was 0.779 (95% confidence interval, 0.744-0.814) (P < 0.01), indicating that the scoring system is good at differentiation of PC with CP. With a score of 1 as the diagnostic cut-off value, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate were 71.3%, 69.0%, 70.0%, 71.4%, and 70.2%, respectively.

CONCLUSIONS

The scoring model may improve the differential diagnosis of PC and CP and be useful in clinical practice.

Blood Glucose Homeostasis in the Course of Partial Pancreatectomy--Evidence for Surgically Reversible Diabetes Induced by Cholestasis

BACKGROUND AND AIM

Partial pancreatic resection is accompanied not only by a reduction in the islet cell mass but also by a variety of other factors that are likely to interfere with glucose metabolism. The aim of this work was to characterize the patient dynamics of blood glucose homeostasis during the course of partial pancreatic resection and to specify the associated clinico-pathological variables.

METHODS

In total, 84 individuals undergoing elective partial pancreatic resection were consecutively recruited into this observational trial. The individuals were assigned based on their fasting glucose or oral glucose tolerance testing results into one of the following groups: (I) deteriorated, (II) stable or (III) improved glucose homeostasis three months after surgery. Co-variables associated with blood glucose dynamics were identified.

RESULTS

Of the 84 participants, 25 (30%) displayed a normal oGTT, 17 (20%) showed impaired glucose tolerance, and 10 (12%) exhibited pathological glucose tolerance. Elevated fasting glucose was present in 32 (38%) individuals before partial pancreatic resection. Three months after partial pancreatic resection, 14 (17%) patients deteriorated, 16 (19%) improved, and 54 (64%) retained stable glucose homeostasis. Stability and improvement was associated with tumor resection and postoperative normalization of recently diagnosed glucose dysregulation, preoperatively elevated tumor markers and markers for common bile duct obstruction, acute pancreatitis and liver cell damage. Improvement was linked to preoperatively elevated insulin resistance, which normalized after resection and was accompanied by a decrease in fasting- and glucose-stimulated insulin secretion.

CONCLUSIONS

Surgically reversible blood glucose dysregulation diagnosed concomitantly with a (peri-) pancreatic tumor appears secondary to compromised liver function due to tumor compression of the common bile duct and the subsequent increase in insulin resistance. It can be categorized as "cholestasis-induced diabetes" and thereby distinguished from other forms of hyperglycemic disorders.

Predictive factors for change of diabetes mellitus status after pancreatectomy in preoperative diabetic and nondiabetic patients

INTRODUCTION

This study aimed to determine risk factors for exacerbation of diabetes mellitus (DM) after pancreatectomy.

METHODS

Medical records of 167 patients with benign and malignant pancreaticobiliary diseases who underwent pancreaticoduodenectomy or distal pancreatectomy were retrospectively analyzed. DM was diagnosed by diabetic history or American Diabetes Association criteria. Worsened and improved DM after pancreatectomy was defined when treatment intensity or insulin/oral antidiabetic drug dosage increased or decreased, respectively, postoperatively. Long-standing DM was defined as a duration of >2 years.

RESULTS

In 76 preoperative diabetic patients, worsened and improved DM was observed postoperatively in 46 (60.5 %) and 9 (11.8 %) patients, respectively. In 91 preoperative nondiabetic patients, 22 (24.2 %) developed new-onset DM after pancreatectomy. Multivariate logistic analysis of the preoperative diabetic patients demonstrated long-standing DM and malignancy as independent predictors for postoperative worsened DM. No patients with long-standing DM or insulin treatment experienced improved DM after pancreatectomy. Multivariate logistic analysis of the preoperative nondiabetic patients showed body mass index of ≥25 and hard pancreatic texture as independent risk factors for new-onset postoperative DM.

CONCLUSIONS

These results may enable preoperative evaluation of risk factors for worsened or new-onset DM after pancreatectomy and may help plan intensive care for patients at a high risk of postoperative worsened DM.

New insights into pancreatic cancer-induced paraneoplastic diabetes

Up to 85% of patients with pancreatic cancer have diabetes or hyperglycaemia, which frequently manifests as early as 2-3 years before a diagnosis of pancreatic cancer. Conversely, patients with new-onset diabetes have a 5-8-fold increased risk of being diagnosed with pancreatic cancer within 1-3 years of developing diabetes. Emerging evidence now indicates that pancreatic cancer causes diabetes. As in type 2 diabetes, β-cell dysfunction and peripheral insulin resistance are seen in pancreatic cancer-induced diabetes. However, unlike in patients with type 2 diabetes, glucose control worsens in patients with pancreatic cancer in the face of ongoing, often profound, weight loss. Diabetes and weight loss, which precede cachexia onset by several months, are paraneoplastic phenomena induced by pancreatic cancer. Although the pathogenesis of these pancreatic cancer-induced metabolic alterations is only beginning to be understood, these are likely mechanisms to promote the survival and growth of pancreatic cancer in a hostile and highly desmoplastic microenvironment. Interestingly, these metabolic changes could enable early diagnosis of pancreatic cancer, if they can be distinguished from the ones that occur in patients with type 2 diabetes. One such possible biomarker is adrenomedullin, which is a potential mediator of β-cell dysfunction in pancreatic cancer-induced diabetes.

Predictors of malignancy in chronic calcific pancreatitis with head mass

AIM: To prospectively analyse the clinical, biochemical and radiological characteristics of the mass lesions arising in a background of chronic calcific pancreatitis (CCP).

METHODS: Eighty three patients, who presented with chronic pancreatitis (CP) and a mass lesion in the head of pancreas between February 2005 and December 2011, were included in the study. Patients who were identified to have malignancy underwent Whipple’s procedure and patients whose investigations were suggestive of a benign lesion underwent Frey’s procedure. Student t-test was used to compare the mean values of imaging findings [common bile duct (CBD), main pancreatic duct (MPD) size] and laboratory data [Serum bilirubin, carbohydrate antigen 19-9 (CA 19-9)] between the groups. Receiver operating characteristic curve (ROC curve) analysis was done to calculate the cutoff valves of serum bilirubin, CA 19-9, MPD and CBD size. The sensitivity, specificity, positive predictive valve (PPV) and negative predictive value (NPV) were calculated using these cut off points. Multivariate analysis was performed using logistic regression model.

RESULTS: The study included 56 men (67.5%) and 27 women (32.5%). Sixty (72.3%) patients had tropical calcific pancreatitis and 23 (27.7%) had alcohol related CCP. Histologically, it was confirmed that 55 (66.3%) of the 83 patients had an inflammatory head mass and 28 (33.7%) had a malignant head mass. The mean age of individuals with benign inflammatory mass and those with malignant mass was 38.4 years and 45 years respectively. Significant clinical features that predicted a malignant head mass in CP were presence of a head mass in CCP of tropics, old age, jaundice, sudden worsening abdominal pain, gastric outlet obstruction and significant weight loss (P≤ 0.05). The ROC curve analysis showed a cut off value of 5.8 mg/dL for serum bilirubin, 127 U/mL for CA 19-9, 11.5 mm for MPD size and 14.5 mm for CBD size.

CONCLUSION: Elevated Serum bilirubin and CA 19-9, and dilated MPD and CBD were useful in predicting malignancy in patients with CCP and head mass.

Pancreatic nonfunctioning neuroendocrine tumor with the main pancreatic duct obstruction presenting as excessive hyperglycemia: a case report and review of the literature

We present the case of a 65-year-old man with a pancreatic nonfunctioning neuroendocrine tumor causing main pancreatic duct obstruction that presented as excessive hyperglycemia. We considered the tumor elicited worsening of diabetes in this case, and we performed review of the relevant literature.

Pancreatic volumetric assessment as a predictor of new-onset diabetes following distal pancreatectomy

INTRODUCTION

Pancreatogenic diabetes after pancreatectomy is of growing importance due to the increasing life expectancy of pancreatectomized patients. Although reduction of pancreatic volume is thought to affect glucose metabolism, a consistent relationship has yet to be determined. This study aimed to investigate functional consequences of distal pancreatectomy (DP) in preoperatively non-diabetic patients.

METHODS

This study included 61 non-diabetic patients who underwent DP. Clinical data were obtained, and the percent resected volume (PRV) of each pancreas was determined via multi-detector row computed tomography volumetry.

RESULTS

During the follow-up period (median 26 months), 22 patients (36 %) developed new-onset diabetes within a median onset time of 8 months (range 0.5-42 months) postoperatively. The remaining 39 patients also showed impaired glucose metabolism. Multivariate analysis identified preoperative hemoglobin A1c ≥ 5.7 % (odds ratio 15.6, p = 0.001) and PRV > 44 % (odds ratio 11.3, p = 0.004) as independent risk factors for new-onset diabetes.

CONCLUSIONS

Key determinants of postoperative glycemic control include preoperative functional reserve of the endocrine pancreas and the volume reduction of pancreatic parenchyma. Our findings enable reliable preoperative evaluation of the risk of postoperative diabetes and appropriate postoperative surveillance, which is helpful for early intervention in high risk patients.

The complex exocrine-endocrine relationship and secondary diabetes in exocrine pancreatic disorders

The pancreas is a dual organ with exocrine and endocrine functions. The interrelationship of the endocrine-exocrine parts of the pancreas is a complex one, but recent clinical and experimental studies have expanded our knowledge. Many disorders primarily of the exocrine pancreas, often solely in the clinical realm of gastroenterologists are associated with diabetes mellitus (DM). Although, the DM becoming disorders are often grouped with type 2 diabetes, the pathogenesis, clinical manifestations and management differ. We review here data on the association of exocrine-endocrine pancreas, the many hormones of the pancreas and their possible effects on the exocrine functions followed by data on the epidemiology, pathogenesis, and management of DM in chronic pancreatitis, cystic fibrosis, pancreatic cancer, and clinical states after pancreatic surgery.

Gamma-glutamyltransferase and risk of cancer in a cohort of 545,460 persons - the Swedish AMORIS study

BACKGROUND

Apart from using gamma-glutamyltransferase (GGT) as a predictor of diabetes, cardiovascular and chronic kidney disease, some evidence suggests GGT as an indicator of cancer risk. We aimed to study the association between GGT and cancer in a large Swedish cohort with 37,809 primary cancers.

METHODS

In a cohort of 545,460 persons (aged >20 years) who had a measurement of GGT in the Apolipoprotein Mortality Risk (AMORIS) study, multivariate Cox proportional hazards regression was used to investigate categories of GGT (<18, 18-36,36-72, ≥72 U/L) in relation to cancer risk. Stratified analyses were conducted by gender, levels of alanine aminotransferase (ALT) (</≥ 50 U/L), glucose (</≥ 6.11 mmol/L) and triglycerides (</≥1.71 mmol/L).

RESULTS

A positive association was found between categories of GGT and overall cancer risk (HR: 1.07 (95%CI: 1.04-1.09,), 1.18 (1.14-1.22), 1.32 (1.26-1.38) for the 2nd, 3rd and 4th categories compared to the 1st). Stratified analyses showed that for those with glucose ≥6.11 mmol/L, the association between GGT and risk of prostate, breast and liver cancer became stronger (e.g. HR for GGT ≥72 U/L and prostate cancer: 1.11 (0.98-1.26) and 1.35 (1.00-1.81) for glucose <6.11 and ≥6.11 mmol/L, respectively). With pancreatic cancer, the association with GGT was weaker for those with elevated glucose levels compared to those with normal levels. No effects of ALT or triglyceride levels on risk were found.

CONCLUSION

We found evidence of associations between elevated GGT and risk of developing different cancers. The strength of this association may vary by glucose levels because hyperglycaemia can result in oxidative stress initiating damaging pathways of carcinogenesis.

[Blood glucose control and risk of progressing to a diabetic state during clinical follow up after cephalic duodenopancreatectomy]

INTRODUCTION

Pancreatic resection carries a theoretical risk of developing diabetes; however few studies have demonstrated the effect of a cephalic duodenopancreatectomy on post-operative blood glucose control.

MATERIAL AND METHODS

An analysis was made of the post-operative clinical follow up of 70 patients subjected to a cephalic duodenopancreatectomy in our Hospital between March 1993 and November 2009. The surgical indication was due to primary pancreatic disease in 30 patients (21 adenocarcinoma of the pancreas, 6 chronic pancreatitis, 1 endocrine carcinoma, 1 cystadenoma and 1 complicated pseudocyst). The pancreas was not affected in the other 40 patients (24 ampullary carcinomas, 11 cholangiocarcinomas, 3 duodenal carcinomas, 1 papillary adenoma and 1 adenomatous hyperplasia of the bile duct). Data on the pre- and post-operative diabetic state were collected.

RESULTS

Before resection, 49 patients (70.0%) had a normal glucose without the need for treatment. Seventeen patients required oral diabetic treatment, 3 subcutaneous insulin, and only one was treated by diet. The duodenopancreatectomy worsened glucose control in 47.1% of the patients (23 of the previously non-diabetics and 10 of those treated with oral diabetics). Glucose control was worse when the surgical indication was due to primary involvement of the gland (progression of 63.3%) compared with patients with disease (progression of 35.0%) (P<.05).

CONCLUSIONS

Our results show that resection of the head of the pancreas favours the appearance of post-operative diabetes, particularly when the surgical indication is due to primary pancreatic involvement.

Promoting Effects of Sucrose-rich Diet on N-Nitrosobis (2-oxopropyl) amine-induced Pancreatic Carcinogenesis in Hamsters

It has been reported that there is an association between pancreatic cancer and obesity, impaired glucose metabolism and diabetes based on excess dietary fat and sugar intakes. A number of studies have suggested that a high-fat diet increases development of carcinomas in various organs and possible risk factors for pancreatic cancer. However, how an excess sugar intake promotes pancreatic carcinogenesis is still unknown. In the present study, we investigated the influence of an excess sugar intake on pancreatic carcinogenesis by administration of a sucrose-rich diet in which starch was replaced by sucrose in order to contain the same calories and other nutrients. Two similar experiments were performed. Six-week-old male Syrian golden hamsters were given N-nitrosobis (2-oxopropyl) amine (BOP) at a dose of 50 and 20 mg/kg body weight as a carcinogen in Week 0 and 1, respectively. In Week 2, the animals were divided into control and experimental groups. In experiment 1, 15 animals received a control diet or sucrose-rich diet in which 100% of the starch was replaced by sucrose, respectively. Since five animals fed on the sucrose-rich diet died by Week 12, the diet was changed to a sucrose-rich diet in which 50% of the starch was replaced by sucrose. In experiment 2, 15 animals received a control diet or sucrose-rich diet in which 50 or 20% of the starch was replaced by sucrose, respectively. All animals were sacrificed 25 weeks after the start of the experiment, and histological examination of the pancreas was performed. No significant difference was seen in the body weight at the end of the experiment. There were no significant differences in the glycosylated hemoglobin (HbA1c) and serum triglyceride, total cholesterol and HDL-cholesterol levels between the control and sucrose-rich diet groups in experiments 1 and 2. The incidence and number of carcinomas increased in hamsters fed the sucrose-rich diet compared with the control diet in experiments 1 and 2. These results suggest that an excess sucrose intake may promote the development of pancreatic cancer in hamsters.

Hyperglycemia promotes the perineural invasion in pancreatic cancer

The role of hyperglycemia in perineural invasion in pancreatic cancer is not clear. Pancreatic cancer is characterized by extremely high frequency of perineural invasion (can be as high as 90%, even 100%), which has been associated with poorer survival. In previous epidemiologic, the prevalence of diabetes mellitus in pancreatic cancer is 34-40% and more than half of them are new-onset, which means the course of disease of diabetes mellitus is less than 24 months before cancer diagnosis. The association between diabetes mellitus and pancreatic cancer has long been recognized as that long-standing diabetes mellitus is thought to be an etiologic factor for pancreatic cancer and new-onset diabetes mellitus may be a manifestation of the cancer. Long-standing diabetes mellitus can cause peripheral neuropathy. The main morphological features of established neuropathy include a combination of demyelinization and axonal degeneration of myelinated fibers, degeneration with regeneration of unmyelinated fibers and endoneurial microangiopathy, with nerve fiber loss in its final stage. Diabetes mellitus can also induce the high expression of cytokines such as nerve growth factor to repair the damaged nerves. We present the hypothesis that hyperglycemia promotes the perineural invasion in pancreatic cancer through two mechanisms. One is that hyperglycemia enhances the proliferation of cancer cells, which subsequently increase the expression of cytokines such as nerve growth factor. The overexpression of nerve growth factor can enhance the interaction between nerve and cancer cell and neurotropism. The other is that hyperglycemia causes demyelinization and axonal degeneration of nerves, which can form defections to make cancer cells enter nerves with deeply invasion. The above two mechanisms can promote the perineural invasion in pancreatic cancer. Controlling hyperglycemia might reduce the perineural invasion in pancreatic cancer.

Changes in glucose metabolism after Kausch-Whipple pancreatectomy in pancreatic cancer and chronic pancreatitis patients

OBJECTIVE

Although changes in exocrine pancreatic function after pancreatoduodenectomy (PD) have been thoroughly analyzed in many reports, articles concerning endocrine have been few. An investigation of glucose metabolism changes in patients undergoing PD was performed.

METHODS

In the study, 20 patients were subjected to pancreatic head resection for tumorous lesions (13 neoplasmatic and 7 chronic pancreatitis) and followed-up for changes in pancreatic endocrine function. It was assessed with fasting plasma glucose measurement and oral glucose tolerance test and also the plasma insulin level during the oral glucose tolerance test. Assessment was made directly before PD followed 2 and 6 months postoperatively.

RESULTS

The percentage of neoplasmatic patients with normal glucose metabolism increased from 15% preoperatively to 39% at 2 months and 45% at 6 months after PD, whereas the diabetes/impaired glucose metabolism was observed in 31%/54%, 15%/46%, and 18%/36%, respectively. In chronic pancreatitis patients, the percentage of diabetic patients increased from 0% preoperatively to 29% at 2 months and 43% 6 months postoperatively. The average plasma insulin level decreased significantly after PD. Before the PD, the insulin curve suggested the presence of insulin resistance in pancreatic cancer patients, which was not observed after the operation.

CONCLUSIONS

Changes in glucose metabolism after PD depend on the etiology of pancreatic tumorous lesion with improvement in neoplasmatic patients and deterioration in chronic pancreatitis patients.

Risk factors for pancreatic cancer: case-control study

OBJECTIVES

Although cigarette smoking is the most well-established environmental risk factor for pancreatic cancer, the interaction between smoking and other risk factors has not been assessed. We evaluated the independent effects of multiple risk factors for pancreatic cancer and determined whether the magnitude of cigarette smoking was modified by other risk factors in men and women.

METHODS

We conducted a hospital-based case-control study involving 808 patients with pathologically diagnosed pancreatic cancer and 808 healthy frequency-matched controls. Information on risk factors was collected by personal interview, and unconditional logistic regression was used to determine adjusted odds ratios (AORs) by the maximum-likelihood method.

RESULTS

Cigarette smoking, family history of pancreatic cancer, heavy alcohol consumption (>60 mL ethanol/day), diabetes mellitus, and history of pancreatitis were significant risk factors for pancreatic cancer. We found synergistic interactions between cigarette smoking and family history of pancreatic cancer (AOR 12.8, 95% confidence interval [CI] 1.6-108.9) and diabetes mellitus (AOR 9.3, 95% CI 2.0-44.1) in women, according to an additive model. Approximately 23%, 9%, 3%, and 5% of pancreatic cancer cases in this study were related to cigarette smoking, diabetes mellitus, heavy alcohol consumption, and family history of pancreatic cancer, respectively.

CONCLUSIONS

The significant synergy between these risk factors suggests a common pathway for carcinogenesis of the pancreas. Determining the underlying mechanisms for such synergies may lead to the development of pancreatic cancer prevention strategies for high-risk individuals.

The role of positron emission tomography in the management of pancreatic cancer

The role of positron emission tomography (PET) and PET/computed tomography (CT) in the assessment of a patient presenting with cancer of the pancreas is discussed in the overall context of the management of this condition. The clinical limitations persist, with many patients presenting late with unresectable disease and poor prospects for novel drug therapies. PET and PET/CT are best at diagnosing and staging but are relatively inefficient in the detection of nodal disease. The detection of late disease manifestations such as metastatic spread is often of little clinical consequence. PET/CT may be considered as a first-line imaging investigation but evidence for this approach needs to accrue. Overall detection sensitivity at diagnosis varies between 90% and 95% and specificity from 82% to 100%, whereas for staging, sensitivity data vary from 61% to 100% and specificity data from 67% to 100%.

New-onset diabetes and pancreatic cancer

BACKGROUND & AIMS

Although many individuals with pancreatic cancer have diabetes, the association between new-onset diabetes mellitus and the subsequent incidence of pancreatic cancer is unclear.

METHODS

We conducted a retrospective cohort study to estimate the incidence of pancreatic cancer subsequent to a new diabetes diagnosis and to evaluate factors associated with a subsequent pancreatic cancer diagnosis. We used the Veterans Health Administration National Patient Care Database to assemble a cohort of 1,421,794 US veterans without prior diabetes or pancreatic cancer diagnoses. We recorded coding for new diabetes diagnoses (> or =2 International Classification of Diseases-9 codes for diabetes within a 12-month period), pancreatic cancer, age, sex, race, and common gastrointestinal symptoms.

RESULTS

A total of 36,631 (2.6%) of the 1,421,794 veterans were diagnosed with new-onset diabetes in 1999; 149 subsequently received a diagnosis of pancreatic cancer. Pancreatic cancer incidence in patients with new-onset diabetes (83.8/100,000 person-years) was 2.2-fold higher (95% confidence interval, 1.84-2.56) than in nondiabetics, and was highest during the first 2 years after diabetes diagnosis. One additional pancreatic cancer was diagnosed for every 332 new diabetics over 6 years. A subsequent pancreatic cancer diagnosis (among new-onset diabetics) was associated independently with younger age groups, changes in bowel habits, constipation, epigastric pain, and malnutrition.

CONCLUSIONS

New-onset diabetes was associated with a significantly increased rate of pancreatic cancer diagnosis, particularly in the first 2 years after diabetes diagnosis. Factors associated with pancreatic cancer diagnosis included younger age groups and the presence of gastrointestinal symptoms. The absolute incidence of pancreatic cancer was low.

Aberrant expression of PTCH (patched gene) and Smo (smoothened gene) in human pancreatic cancerous tissues and its association with hyperglycemia

OBJECTIVES

To investigate the prevalence of PTCH (patched gene) and Smo (smoothened gene) expression in human pancreatic cancerous tissues and its association with clinical characteristics.

METHODS

A rabbit polyclonal antibody against PTCH was prepared through the immunization of prokaryotic recombinant PTCH1170-1433 protein. The PTCH and Smo expression in 39 resected pancreas specimens from 28 patients with pancreatic cancer, 6 with chronic pancreatitis (as control), and 5 with pancreatic pseudocyst (as control) were detected by reverse transcriptase polymerase chain reaction and immunohistochemistry. The relationships between their expressions and pathological characteristics such as tumor sizes, degree of differentiation, nodal status, distant metastasis, and the blood sugar level were analyzed.

RESULTS

The prevalence of PTCH and Smo expressions in cancerous tissues were 71.4% (20/28) and 53.6% (15/28), respectively, whereas no expression in the nontumor pancreas tissues was found. Both PTCH and Smo expressions correlated with the low levels of tumor tissue differentiation (P < 0.05) and PTCH and Smo expressions in islet cells of cancerous tissues associated with hyperglycemia.

CONCLUSIONS

Because aberrant expressions of PTCH and Smo were common in human pancreatic carcinoma tissues and were associated with the low-level differentiation of tumor tissue and hyperglycemia, this indicated that these molecules played a fundamental role in pancreas tumorigenesis and were regarded as new targets for diagnosis and treatment of human pancreatic cancer.

Gemcitabine treatment in patients with inoperable locally advanced/metastatic pancreatic cancer and prognostic factors

OBJECTIVE

Most patients with pancreatic cancer show an inoperable locally advanced/ metastatic tumour at the time of diagnosis. The present study was aimed at determining the prognostic factors in patients with advanced pancreatic carcinoma treated with gemcitabine.

MATERIAL AND METHODS

Sixty-seven unresectable or metastatic pancreatic cancer patients treated with gemcitabine were included in the study and a total of 258 cycles of treatment were applied.

RESULTS

The overall response rate was 5%. Thirty-one percent of the patients had stable disease, whereas progressive disease was seen in 49%. Clinical benefit response rate was 15%. The median duration of response was 7.3 months. Median progression-free survival was 3 months, while median overall survival was 9 months. Univariate analysis revealed that worse results were found in patients with performance status (PS) = 2, and in patients with primary tumour location in the body or tail of the pancreas (p<0.05). Multivariate analysis of data revealed that the most important factor was PS of the patient, as the patients with PS = 2 had worse results than the patients with PS = 0-1 (p<0.05).

CONCLUSIONS

Low PS is a negative predictive factor for the survival of patients with advanced pancreatic carcinoma treated with gemcitabine.

Controlling hyperglycemia as an adjunct to cancer therapy

Hyperglycemia is commonly manifested in cancer patients. Although high intakes of sugar and refined carbohydrates and elevated blood glucose are strongly associated with the risk of cancer, much less is known about their effects on survival after cancer diagnosis. There is evidence that high carbohydrate intake is associated with poorer survival after diagnosis for early breast cancer. We measured glycated hemoglobin in a group of cancer patients (some with active disease and some in remission) and found a statistically significant lower average blood glucose in those in remission. Glycated hemoglobin provides an indication of average blood glucose over 2 to 3 months. The authors discuss lifestyle changes including diet and physical activity that can reduce average blood glucose. Ascorbic acid (AA) supplementation as an adjunct to cancer therapy is also considered. Furthermore, they present a biologically plausible explanation for how hyperglycemia can impair the actions of AA and damage immune effectiveness and hinder cancer survival. One mechanism is likely a reduction in intracellular AA; high intracellular levels of AA are necessary for optimal activity of the hexose monophosphate shunt. This metabolic pathway is important for maintaining proper cellular antioxidant status in immune cells including lymphocytes involved in cell-mediated immunity.

Expression of connexin26 in islets of Langerhans is associated with impaired glucose tolerance in patients with pancreatic adenocarcinoma

OBJECTIVES

Impairment of glucose tolerance is one of the leading clinical presentations in patients with pancreatic carcinoma. The mechanism of disturbed glucose metabolism, however, is still under debate. Using microarray technology, key mechanisms of deregulated molecular functions of cancer cell-specific mRNAs and tumor-induced mRNAs in peritumorous tissue should be identified in pancreatic ductal adenocarcinoma (PDAC) by comparison to chronic pancreatitis and normal pancreas.

METHODS

Forty-three mRNAs were abundant in tissue specimens of patients operated due to pancreatic carcinoma but absent or of low abundance in chronic pancreatitis and normal pancreas. One of these mRNAs encodes the gap junction protein connexin26, known as a tumor suppressor, which was 10.8- and 6.9-fold more abundant in pancreatic carcinoma than in normal pancreas and chronic pancreatitis, respectively. Quantitative RT-PCR was performed for connexin26, with mRNA being expressed 26.7- and 2.9-fold more than in normal pancreas (n = 6), in pancreatic carcinoma (n = 7), and chronic pancreatitis (n = 8), respectively.

RESULTS

By immunohistochemistry, connexin26 was predominantly localized to the islets in the vicinity of the pancreatic carcinoma tissue. Control sections of tissue with chronic pancreatitis and normal pancreas show connexin26 expression in the islets as well. Interestingly, the level of mRNA abundance (fold over normal pancreas) in RT-PCR correlates (r = 0.62) with the 2h value of the pre-operative oral glucose tolerance test of these patients.

CONCLUSION

Whether overexpressed connexin26 in pancreatic cancer is a cause of impaired glucose tolerance remains to be elucidated in further experimental studies.

Nutritional links to plausible mechanisms underlying pancreatic cancer: a conference report

Adenocarcinoma of the pancreas is one of most catastrophic and least understood of cancers. Evidence from clinical studies indicates that the development of pancreas cancer progresses over many years before symptoms appear. Most people with pancreatic cancer die within six months of diagnosis. The lack of early disease markers, the paucity of direct subject/patient interview data and limited availability of high quality biological samples have slowed progress toward identifying environmental and genetic disease risk factors. Much remains to be learned about the development of pancreatic cancer and about potential interventions for disease prevention. Epidemiological and mechanistic studies examining risk factors for pancreatic cancer supply little consistent or strong evidence to provide a cohesive prevention strategy for this cancer, but offer clues for future research concerning the prevention and early detection of this devastating disease. This Executive Summary provides background discussion on pancreatic cancer and summaries of each of the topics discussed at the workshop, including 1) Molecular aspects, 2) Dietary and other risk factors for pancreatic cancer, 3) The metabolic hypothesis for pancreatic cancer, 4) Preclinical studies on pancreatic cancer, 5) Methylation, 6) Oxidative stress and 7) Biomarker Profiling. This document also contains a compilation of recommendations for future research, concluding remarks, a list of speakers and participants attending the workshop, and a selection of key references to aid future research into nutritional links to mechanisms underlying pancreas cancer. The recommendations section suggests gaps in current knowledge and articulates future directions for this area of investigation.