New-onset diabetes in pancreatic cancer: a study in the primary care setting

Altered profile of serum microRNAs in pancreatic cancer-associated new-onset diabetes mellitus

BACKGROUND

New-onset diabetes mellitus in pancreatic cancer has been recognized as a paraneoplastic phenomenon caused by the existence of the tumor. Circulating microRNAs (miRNAs) are emerging as non-invasive biomarkers for the detection of various cancers. In the present study, we hypothesized that a specific serum miRNA profile exists in pancreatic cancer-associated new-onset diabetes mellitus (PaC-DM).

METHODS

Initial screening of differentially expressed miRNAs in pooled serum samples from 25 PaC-DM patients, 25 non-cancer new-onset type 2 diabetes mellitus (T2DM) patients, and 25 healthy controls was performed by TaqMan low-density arrays (TLDA). A stem-loop quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was conducted to confirm the relative concentrations of candidate miRNAs in 80 PaC-DM, 85 non-cancer new-onset T2DM patients, and 80 healthy controls.

RESULTS

The TLDA identified 16 serum miRNAs that were significantly increased in PaC-DM samples. A combination of six serum miRNAs (miR-483-5p, miR-19a, miR-29a, miR-20a, miR-24, miR-25) was selected by qRT-PCR as a biomarker for PaC-DM. The area under the receiver operating characteristic curve (AUC) for the six-miRNA panel training and validation sets was 0.959 (95% confidence interval [CI] 0.890-1.028) and 0.902 (95% CI 0.844-0.955), respectively. The combination of these six miRNAs enabled the discrimination of PaC-DM from non-cancer new-onset T2DM with an AUC of 0.885 (95% CI 0.784-0.986) and 0.887 (95% CI 0.823-0.952) for the training and validation sets, respectively.

CONCLUSION

The six-serum miRNA panel may have potential as a biomarker for the accurate diagnosis and discrimination of PaC-DM from healthy controls and non-cancer new-onset T2DM.

Pancreatic Expression of Immunoglobulin G in Human Pancreatic Cancer and Associated Diabetes

OBJECTIVES

The prognosis of pancreatic cancer (PC) is poor and the pathogenesis of PC-associated diabetes is unknown. We investigated the possible expression of immunoglobulin G (IgG) in human pancreatic carcinomas and adjacent pancreatic islets to gain a better understanding of these diseases.

METHODS

We employed immunohistochemistry, Western Blot, real-time polymerase chain reaction, and in situ hybridization to examine IgG expression in PC tissues and adjacent islets with and without cancer-associated diabetes. The IgG mRNA and IgG synthesizing-related enzymes were examined in PC cell lines. The IgG expression and secretion were downregulated with specific small interfering RNA and antibody to IgG followed by flow cytometry to assess its effect on apoptosis of cultured PC cells.

RESULTS

The expression of IgG was detected in pancreatic carcinoma and adjacent islets. Small interfering RNA and antibody treatments induced apoptosis in PC cell lines. In the carcinoma tissue, the levels of IgG expression varied depending on the stages of the cancers with more malignant cancers expressing more IgG (P < 0.05). The IgG levels in cancer cells were also increased when the patients had diabetes or hyperglycemia (P < 0.05). In addition, the extent of IgG expression in the seemingly normal islet cells adjacent to the tumor varied in relation to the grade of cancer differentiation and distance to the cancer nests.

CONCLUSIONS

(1) Immunoglobulin G was locally produced by PC cells and adjacent islet cells. (2) Immunoglobulin G may promote tumor growth by inhibiting cancer cell apoptosis. (3) Locally produced IgG might play a role in PC-associated diabetes.

Predictors for Pancreatic Cancer Diagnosis Following New-Onset Diabetes Mellitus

OBJECTIVES

New-onset diabetes mellitus (NODM) in adults is often an early manifestation of pancreatic cancer (PaCa), but the incidence of PaCa in this cohort is rather low. We evaluated whether combining other patient factors such as age, smoking history, the absence of obesity, the presence of chronic pancreatitis (CP), and gallstone disease can result in a more enriched cohort.

METHODS

After a washout period of 2 years to exclude pre-existing PaCa or DM, 507,378 non-diabetic patients in the veterans' administration healthcare system were identified. Patients <40 years (n=54,465) and those with PaCa diagnosed before the diagnosis of diabetes (n=22) were excluded. A total of 452,804 veterans were followed for development of DM or PaCa.

RESULTS

73,811 patients (16.3%) developed NODM during the follow-up period. One hundred and eighty-three NODM patients (0.25%) were diagnosed with PaCa within 3 years. In comparison, 434 of 378,993 remaining patients (0.11%) developed PaCa in 3 years following inclusion into the study [relative risk (RR)=2.27, 95% confidence intervals (CI) 1.96, 2.63; P<0.0001]. The risk of PaCa diagnosis was higher among patients who were non-obese (RR=1.51), were ≥65 years old (RR=2.01), were heavy smokers (RR=1.55), and had a history of CP (RR=4.72) or gallstone disease (RR=2.02). Using a combination of these risk factors in NODM patients resulted in up to 0.72% three-year risk of PaCa but captured only 17% of patients with PaCa.

CONCLUSIONS

Based on our findings, the likelihood of PaCa in adults with NODM even after adjusting for other potential risk factors for PaCa including age, body mass index, smoking, gallstones, and CP is probably not high enough to recommend routine evaluation for all these patients for underlying PaCa.

Impacts of new-onset and long-term diabetes on clinical outcome of pancreatic cancer

Patients with pancreatic cancer have a high frequency of concurrent diabetes. This study is aimed to demonstrate the impact of diabetes on clinical outcome of pancreatic cancer. Clinical and epidemiological information was collected from medical records or by personal interview in 1328 patients with pancreatic ductal adenocarcinoma. Diabetes was defined by a known medical history, or abnormal fasting blood glucose (FBG) and HbA1c levels within three months of the cancer diagnosis. Duration of ≤3 years was used as the cutoff to arbitrarily define the new-onset and long-term diabetes. Logistic regression, Kaplan-Meier plot, log-rank test and Cox regression models were employed in the data analysis. Elevated level of FBG or HbA1c was observed in 24.7% and 11.5% of the patients without a known diabetes history, respectively. The prevalence of DM was 44.4% and was comparable by strata of tumor stage. New-onset diabetes was a significant independent predictor for risk of death in metastatic patients (HR=1.35, 95% CI=1.11-1.63, P=0.002) and in all patients (HR=1.23, 95% CI=1.09-1.40, P=0.001). Both new-onset and long term diabetes were significantly associated with older age, obesity, hypertension and coronary artery disease as well as weight loss. New-onset diabetes was also significantly related to larger tumors and elevated level of CA19-9 but not to tumor site and presence of biliary obstruction. Diabetes in general and new-onset diabetes in particular, is associated with poor outcome of pancreatic cancer. New-onset and long-term diabetes share common risk factors for type 2 diabetes.

Detectable Symptomatology Preceding the Diagnosis of Pancreatic Cancer and Absolute Risk of Pancreatic Cancer Diagnosis

The survival duration for pancreatic cancer is short. Given its low lifetime risk (1.5%), established factors for the disease have insufficient specificity to identify individuals at high risk of nonfamilial cancer, and prediagnostic signs and symptoms are vague and not limited to pancreatic causes. We considered whether statistical models that incorporated both risk factors and prediagnosis symptomatology could improve prediction enough to provide practical risk estimates. We combined US Surveillance Epidemiology and End Results (SEER) incidence data from 2008 to 2010 with regression models from representative case-control data from Connecticut (2005-2009) to estimate age- and sex-specific 5-year absolute risks of pancreatic cancer diagnosis. Our risk model included current cigarette smoking (adjusted odds ratio (OR) = 3.3, 95% confidence interval (CI): 2.1, 5.0), current use of proton pump-inhibitor antiheartburn medications (OR = 6.2, 95% CI: 1.7, 23), recent diagnosis of diabetes mellitus (OR = 4.8, 95% CI: 2.2, 11), recent diagnosis of pancreatitis (OR = 19, 95% CI: 3.1, 120), Jewish ancestry (OR = 1.8, 95% CI: 1.1, 3.1), and ABO blood group other than O (OR = 1.3, 95% CI: 1.0, 1.8). In total, 0.87% of controls with combinations of these factors had estimated 5-year absolute risks greater than 5%, and for some, the risks reached more than 10%. Combining risk factors for pancreatic cancer with detectable prediagnostic symptomatology can allow investigators to begin to identify small segments of the population with risks sufficiently high enough to make screening efforts among them potentially useful.

High-risk population in sporadic pancreatic adenocarcinoma: guidelines for screening

BACKGROUND

Pancreatic cancer (PC) is one of the most deadly forms of cancer in the United States, with an annual incidence to death ratio of 0.92 because of the late stage at diagnosis. Identification of high-risk individuals (HRIs) that would be ideal for screening is needed to identify precursor lesions and small early stage disease. Those with a genetic predisposition have largely been identified, but little is known about those at high-risk for sporadic PC. This study asserts that a high-risk population does exist in sporadic pancreatic adenocarcinoma and proposes simple guidelines for screening.

METHODS

A systematic review was conducted of the literature regarding identification of and screening in high-risk groups.

RESULTS

Those with the highest genetic risk of developing PC include those with hereditary pancreatitis (87 times more likely at age 55), Peutz-Jehgers syndrome (132 times more likely at age 50), p16-Leiden mutations (48 times more likely), and familial pancreatic cancer (FPC) kindreds (32 times more likely). Those with the highest risk of developing sporadic PC include those with new-onset diabetes older than 50 y and smoking history.

CONCLUSIONS

Given that sporadic PC is the single largest patient population effected with this devastating disease, some form of screening should be initiated. Currently, the medical community does nothing to attempt early detection of PC. However, sufficient evidence now exists to begin a screening protocol in a high-risk cohort, which would be patients with new-onset diabetes older than 50 y and a smoking history.

Emerging concepts in pancreatic cancer medicine: targeting the tumor stroma

Pancreatic ductal adenocarcinoma is a stroma-rich and highly challenging cancer to treat. Over recent years, it has become increasingly evident that the complex network of soluble cytokines, growth factors, proteases, and components of the extracellular matrix collaboratively interact within the tumor microenvironment, sustaining and driving cancer cell proliferation, invasion, and early metastasis. More recently, the tumor microenvironment has also been appreciated to mediate therapeutic resistance in pancreatic ductal adenocarcinoma, thus opening numerous avenues for novel therapeutic explorations. Inert and soluble components of the tumor stroma have been targeted in order to break down the extracellular matrix scaffold, relieve vessel compression, and increase drug delivery to hypovascular tumors. Moreover, targeting of antiapoptotic, immunosuppressive, and pro-proliferative effects of the tumor stroma provides novel vantage points of attack. This review focuses on current and future developments in pancreatic cancer medicine, with a particular emphasis on biophysical and biochemical approaches that target the tumor microenvironment.

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.

The role of insulin and IGF system in pancreatic cancer

The importance of the IGF system in carcinogenesis has been established for many solid cancers. It is well known that individuals with higher circulating levels of the IGF1 ligand present an increased risk of cancer. However, therapies with monoclonal antibodies targeting the IGF1 receptor (IGF1R) have been largely unsuccessful. One of the potential reasons for this failure is the existence of the highly homologous insulin receptor (IR), which appears to be at least equally efficient as the IGF1R in the transition of mitogenic signals to the nucleus and promotion of cell growth. Furthermore, IGF1 and insulin receptors can form hybrid receptors sensitive to stimulation of all three ligands of the system: insulin, IGF1, and IGF2. Although the connection between insulin, diabetes, and cancer has been established for years now, clear evidence that demonstrate the redundancy of insulin and insulin receptors and insulin-like growth factors and their receptors in cancer is missing. In this review, we focus on the contribution of insulin and IGFs to carcinogenesis in the insulin-producing organ, the pancreas. We give a short summary on the complexity of insulin and the IGF system in the pancreas and their potential roles in pancreatic cancer, especially pancreatic ductal adenocarcinoma. Finally, we discuss drug-targeting options of this system and the rationale of simultaneous targeting of both the insulin and the IGF systems.

Diabetes and pancreatic cancer

The relationship between diabetes and pancreatic cancer is complex. Diabetes or impaired glucose tolerance is present in more than 2/3rd of pancreatic cancer patients. Epidemiological studies have consistently shown a modest increase in the risk of pancreatic cancer in type 2 diabetes, with an inverse relationship to duration of disease. Additionally, recent studies suggest that anti-diabetic medications may modulate the risk of pancreatic cancer in type 2 diabetes. Subjects >50 years of age with new onset diabetes are at higher risk of having pancreatic cancer. However, to screen new-onset diabetes for pancreatic cancer, additional markers are needed that can distinguish pancreatic cancer-associated diabetes from type 2 diabetes.

Epidural brain metastases in a patient with early onset pancreatic cancer: a case report and literature review

We present a case of early onset pancreatic cancer related extra-axial brain metastases. A 46-year-old Caucasian non-Jewish nonobese male with a history of PC diagnosed 3 months ago with metastases to the liver, omentum, malignant ascites, and a history of a pulmonary embolism was admitted to the hospital because of a new onset headache, nausea, and vomiting which started 2 days prior to the encounter. Brain MRI was ordered, which showed acute bihemispheric subdural hematomas and left hemispheric extra-axial heterogeneously enhancing lesions consisting with metastatic disease. The patient was started on ondansentron, metoclopramide, and dexamethasone. The cranial irradiation was started, and the patient's headache and nausea significantly improved. There are only 9 published reports of extra-axial brain metastases related to the pancreatic cancer, whereas our paper is the first such case reported on a patient with epidural metastases and early onset pancreatic cancer.

Early diagnosis of pancreatic cancer: challenges and new developments

Pancreatic cancer is a lethal malignancy with its incidence almost equivalent to mortality. The complex pathophysiology, absence of early diagnostic and prognostic markers and unresponsiveness to radiation and chemotherapies are major barriers against successful therapy. Poor performance of therapeutic agents, even in the initial stage of invasive cases, emphasizes the importance of early detection for improved survival. The present review discusses the challenges and advances in biomarkers including serological signatures, circulating tumor cells, autoantibodies, epigenetic markers and miRNAs that are being explored to detect this cancer at early stages. Considering the long time gap between the development of malignant lesions and full-blown primary and metastatic pancreatic cancer, unique opportunities are being contemplated for the development of potential diagnostic and prognostic markers.

Diabetes and pancreatic cancer

Epidemiological studies clearly indicate that the risk of pancreatic cancer (PC) is increased in diabetic patients, but most studies focus on overall diabetes or type 2 diabetes mellitus (T2DM), and there are few studies on the risks of type 1 and type 3c (secondary) diabetes. Possible mechanisms for increased cancer risk in diabetes include cellular proliferative effects of hyperglycemia, hyperinsulinemia, and abnormalities in insulin/IGF receptor pathways. Recently, insulin and insulin secretagogues have been observed to increase the PC risk, while metformin treatment reduces the cancer risk in diabetic subjects. In addition, anticancer drugs used to treat PC may either cause diabetes or worsen coexisting diabetes. T3cDM has emerged as a major subset of diabetes and may have the highest risk of pancreatic carcinoma especially in patients with chronic pancreatitis. T3cDM is also a consequence of PC in at least 30% of patients. Distinguishing T3cDM from the more prevalent T2DM among new-onset diabetic patients can be aided by an assessment of clinical features and confirmed by finding a deficiency in postprandial pancreatic polypeptide release. In conclusion, diabetes and PC have a complex relationship that requires more clinical attention. The risk of developing PC can be reduced by aggressive prevention and treatment of T2DM and obesity and the prompt diagnosis of T3cDM may allow detection of a tumor at a potentially curable stage.

The bidirectional interation between pancreatic cancer and diabetes

The bidirectional interation between pancreatic cancer (PanCa) and diabetes has been confirmed by epidemiological studies, which provide evidence-based medical support for further research into the mechanisms involved in the interaction. We reviewed the literature regarding the role of diabetes in the generation and progression of PanCa and the mechanism by which PanCa induces diabetes for its malignant progression. The effect of antidiabetic drugs on the occurrence and prognosis of PanCa was also reviewed. Diabetes may directly promote the progression of PanCa by pancreatic duct enlargement and hypertension, as well as by enabling an increased tumor volume. Hyperinsulinemia, insulin resistance, cytokines, hyperglycemia and genotype change are also important factors in the progression of PanCa with diabetes. Hyperglycemia may be the first clinical manifestation and is helpful in the early diagnosis of PanCa. Furthermore, antidiabetic drugs can have different effects on the occurrence and prognosis of PanCa. The bidirectional interation between PanCa and diabetes is involved in the occurrence, proliferation, invasion, metastasis and prognosis of PanCa with diabetes. The discovery of biomarkers for the early diagnosis of PanCa, as well as the novel usage of metformin for its antitumor effects and determining the potential mechanisms of these effects, may be the next direction for PanCa research and treatment.