Incretin-Based Therapy and Risk of Pancreatic Cancer in Patients with Type 2 Diabetes Mellitus: A Meta-analysis of Randomized Controlled Trials

The GLP-1R agonist semaglutide reshapes pancreatic cancer associated fibroblasts reducing collagen proline hydroxylation and favoring T lymphocyte infiltration

BACKGROUND

Metabolic syndrome represents a pancreatic ductal adenocarcinoma (PDAC) risk factor. Metabolic alterations favor PDAC onset, which occurs early upon dysmetabolism. Pancreatic neoplastic lesions evolve within a dense desmoplastic stroma, consisting in abundant extracellular matrix settled by cancer associated fibroblasts (CAFs). Hereby, dysmetabolism and PDAC association was analyzed focusing on CAF functions.

METHODS

PDAC development upon dysmetabolic conditions was investigated in: 1) high fat diet fed wild type immunocompetent syngeneic mice by orthotopic transplantation of pancreatic intraepithelial neoplasia (PanIN) organoids; and 2) primary pancreatic CAFs isolated from chemotherapy naïve PDAC patients with/without an history of metabolic syndrome.

RESULTS

The dysmetabolic-associated higher PDAC aggressiveness was paralleled by collagen fibril enrichment due to prolyl 4-hydroxylase subunit alpha 1 (P4HA1) increased function. Upon dysmetabolism, P4HA1 boosts collagen proline hydroxylation, intensifies collagen contraction strength, precluding PDAC infiltration. Noteworthy, semaglutide, an incretin agonist, prevents the higher dysmetabolism-dependent PDAC stromal deposition and allows T lymphocyte infiltration, reducing tumor development.

CONCLUSIONS

These results shed light on novel therapeutic options for PDAC patients with metabolic syndrome aimed at PDAC stroma reshape.

Cancer biology in diabetes update: Focusing on antidiabetic drugs

The association of type 2 diabetes with certain cancer risk has been of great interest for years. However, the effect of diabetic medications on cancer development is not fully understood. Prospective clinical trials have not elucidated the long-term influence of hypoglycemic drugs on cancer incidence and the safety for cancer-bearing patients with diabetes, whereas numerous preclinical studies have shown that antidiabetic drugs could have an impact on carcinogenesis processes beyond the glycemic control effect. Because there is no evidence of the safety profile of antidiabetic agents on cancer biology, careful consideration would be required when prescribing any medicines to patients with diabetes and existing tumor. In this review, we discuss the potential influence of each diabetes therapy in cancer 'initiation', 'promotion' and 'progression'.

A systematic review and meta-analysis of observational studies of the association between the use of incretin-based therapies and the risk of pancreatic cancer

BACKGROUND

Some early reports in the medical literature have raised concern about a possible increased risk of pancreatic cancer associated with the use of two broad classes of incretin-based therapies, dipeptidyl peptidase-4 inhibitors, and glucagon-like peptide-1 receptor agonists. This possibility has been somewhat mitigated by the null findings meta-analyses of randomized controlled trials, but the usefulness of their findings was hampered by serious shortcomings of lack of power and representativeness. These shortcomings can typically be addressed by observational studies, but observational studies on the topic have yielded conflicting findings. A systematic review and meta-analysis of observational studies was performed to qualitatively and quantitatively appraise the totality of evidence on the association between the use of incretin-based therapies and the risk of pancreatic cancer in routine clinical practice.

METHODS

The PubMed, Web of Science, Embase, and Google Scholar databases were searched. The study quality was appraised using the ROBINS-I tool and based on the presence of pharmacoepidemiology biases. A random-effects model was used to estimate the summary relative risks with corresponding CIs.

RESULTS

A total of 14 studies were included. The qualitative assessment revealed that all studies had inadequate follow-up (≤5 years), 12 studies were suspected to suffer from time-lag bias (due to inappropriate choice of comparator group) to varying extent, five studies included prevalent users, five studies did not implement exposure lag period, five studies had a serious risk of bias due to confounding, and one study had a time-window bias. The quantitative assessment showed no indication of an increased risk when all studies were pooled together (RR 1.04, 95% CI 0.87, 1.24) and when the analysis was restricted to the studies with the least bias (RR 0.77, 95% CI 0.51, 1.17). However, the pooled RRs were more frequently higher in the studies with less rigorous design and analysis. Specifically, a tendency toward an increased risk was observed in the studies with (RR 1.34, 95% CI 1.04, 1.72) or possibly with (RR 1.10, 95% CI 0.89, 1.36) time-lag bias, in the studies that did not apply (RR 1.23, 95% CI 0.93, 1.63) or with potentially inadequate exposure lag period of 6 months (RR 1.13, 95% CI 0.66, 1.94), in the studies that inappropriate comparator group of a combination of unspecified (RR 1.49, 95% CI 1.25, 1.78) or non-insulin (RR 1.15, 95% CI 0.93, 1.42) antidiabetic drugs, and in the studies with serious risk of bias due to confounding (RR 1.18, 95% CI 0.56, 2.49).

CONCLUSIONS

In summary, the totality of evidence from observational studies does not support the claim that the use of incretin-based therapies is associated with an increased risk of pancreatic cancer in routine clinical practice. The increased risk of pancreatic cancer observed in observational studies reflects bias resulting from suboptimal methodological approaches, which need to be avoided by future studies.

Glucagon-Like Peptide 1-Based Therapies and Risk of Pancreatic Cancer in Patients With Diabetes and Obesity

OBJECTIVES

There have been conflicting reports concerning an increased risk of pancreatic cancer (PC) in new users of glucagon-like peptide-1 agonists (GLP-1As). We aimed to explore whether the use of GLP-1A is associated with an increased risk of PC.

METHODS

A multicenter, retrospective cohort study was conducted using TriNetX. Adult patients with diabetes and/or overweight and obesity who were newly treated with GLP-1A or metformin for the first time between 2006 and 2021 were matched 1:1 using propensity score matching. The risk of PC was estimated using a Cox proportional hazards model.

RESULTS

A total of 492,760 patients were identified in the GLP-1A and 918,711 patients in the metformin group. After propensity score matching, both cohorts (370,490 each) were well matched. During follow-up, 351 patients in the GLP-1A and 956 on metformin developed PC after an exposure lag of 1 year. Glucagon-like peptide-1 agonists was associated with a significantly lower risk of PC (hazard ratio, 0.47; 95% confidence interval, 0.42-0.52).

CONCLUSIONS

The use of GLP-1A in patients with obesity/diabetes is associated with a lower risk of PC compared with a similar cohort of patients using metformin. Our study findings reassure clinicians and patients with apprehensions about any possible association between GLP-1A and PC.

Incretin based therapy and pancreatic cancer: Realising the reality

Incretin-based therapies like glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors help maintain the glycaemic control in patients with type 2 diabetes mellitus with additional systemic benefits and little risk of hypoglycaemia. These medications are associated with low-grade chronic pancreatitis in animal models inconsistently. The incidence of acute pancreatitis was also reported in some human studies. This inflammation provides fertile ground for developing pancreatic carcinoma (PC). Although the data from clinical trials and population-based studies have established safety regarding PC, the pathophysiological possibility that low-grade chronic pancreatitis leads to PC remains. We review the existing literature and describe the relationship between incretin-based therapies and PC.

Regenerative medicine of pancreatic islets

The pancreas became one of the first objects of regenerative medicine, since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted. The number of people living with diabetes mellitus is currently approaching half a billion, hence the crucial relevance of new methods to stimulate regeneration of the insulin-secreting β-cells of the islets of Langerhans. Natural restrictions on the islet regeneration are very tight; nevertheless, the islets are capable of physiological regeneration via β-cell self-replication, direct differentiation of multipotent progenitor cells and spontaneous α- to β- or δ- to β-cell conversion (trans-differentiation). The existing preclinical models of β-cell dysfunction or ablation (induced surgically, chemically or genetically) have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation. The ultimate goal, sufficient level of functional activity of β-cells or their substitutes can be achieved by two prospective broad strategies: β-cell replacement and β-cell regeneration. The "regeneration" strategy aims to maintain a preserved population of β-cells through in situ exposure to biologically active substances that improve β-cell survival, replication and insulin secretion, or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β- to β-cell conversion. The "replacement" strategy implies transplantation of β-cells (as non-disintegrated pancreatic material or isolated donor islets) or β-like cells obtained ex vivo from progenitors or mature somatic cells (for example, hepatocytes or α-cells) under the action of small-molecule inducers or by genetic modification. We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally active β-cells, the innermost hope of millions of people globally.

Neurological Manifestation of Incretin-Based Therapies in Patients with Type 2 Diabetes: A Systematic Review and Network Meta-Analysis

As a new class of antidiabetic drug, incretin-based therapies, which include dipeptidyl peptidase-4 inhibitors (DPP-4Is) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), have raised concerns about symptoms of withdrawal in patients with type 2 diabetes mellitus (T2DM), such as dizziness and headache. To systematically evaluate whether incretin-based therapies may lead to dizziness and headache in patients with T2DM compared to other traditional antidiabetic drugs or placebo. We searched Medline, Embase, the Cochrane library, and clinicaltrials.gov from inception through June 23, 2017, to identify randomized controlled trials of the safety of DPP-4Is or GLP-1 RAs versus placebo or other antidiabetic drugs in T2DM patients. We used the network meta-analysis under the frequentist framework to compare the association between multiple antidiabetic drugs and dizziness and headache. A total of 233 clinical trials with nine treatments and 147,710 patients were included: two incretin-based therapies, one placebo, and six traditional antidiabetic drugs (metformin, insulin, sulfonylurea, thiazolidinediones, alpha-glucosidase inhibitor, and sodium-glucose co-transporter 2). Compared to insulin, thiazolidinediones, or placebo, GLP-1 RAs statistically significantly increased the risk of dizziness (odds ratios [ORs]: 1.92, 1.57, and 1.40, respectively) and headache (ORs: 1.34, 1.41, and 1.18, respectively). DPP-4Is increased the risk of headache (OR: 1.22, 95% confidence interval [CI]: 1.02 to 1.46; moderate quality) and dizziness (OR: 1.46, 95% CI: 1.05 to 2.03; moderate quality) compared to insulin. Of the incretin-based therapies, DPP-4Is had a lower risk of dizziness than GLP-1 RAs (OR: 0.76, 95% CI: 0.67 to 0.87; high quality). Ranking probability analysis indicated that GLP-1 RAs may have the greatest risk of both dizziness and headache among the nine treatments (22.5% and 23.4%, respectively), whereas DPP-4Is were in the middle (46.2% and 45.0%, respectively). Incretin-based therapies increase the risk of dizziness and headache compared to insulin, thiazolidinediones, and placebo.

Treatment with incretins does not increase the risk of pancreatic diseases compared to older anti-hyperglycaemic drugs, when added to metformin: real world evidence in people with Type 2 diabetes

AIMS

In people with metformin-treated diabetes, to evaluate the risk of acute pancreatitis, pancreatic cancer and other diseases of the pancreas post second-line anti-hyperglycaemic agent initiation.

METHODS

People with Type 2 diabetes diagnosed after 2004 who received metformin plus a dipeptidyl peptidase-4 inhibitor (DPP-4i, n = 50 095), glucagon-like peptide-1 receptor agonist (GLP-1RA, n = 12 654), sulfonylurea (n = 110 747), thiazolidinedione (n = 17 597) or insulin (n = 34 805) for at least 3 months were identified in the US Centricity Electronic Medical Records. Time to developing acute pancreatitis, other diseases of the pancreas and pancreatic cancer was estimated, balancing and adjusting anti-hyperglycaemic drug groups for appropriate confounders.

RESULTS

In the DPP-4i group, the adjusted mean time to acute pancreatitis was 2.63 [95% confidence intervals (CI) 2.38, 2.88] years; time to pancreatic cancer was 2.70 (2.19, 3.21) years; and time to other diseases of the pancreas was 2.73 (2.33, 3.12) years. Compared with DPP-4i, the insulin group developed acute pancreatitis 0.48 years (P < 0.01) earlier and the GLP-1RA group developed pancreatic cancer 3 years later (P < 0.01). However, with the constraint of no event within 6 months of insulin initiation, the risk of acute pancreatitis in the insulin group was insignificant. No other significant differences were observed between groups.

CONCLUSIONS

No significant differences in the risk of developing pancreatic diseases in those treated with various anti-hyperglycaemic drug classes were found.

Exenatide use and incidence of pancreatic and thyroid cancer: A retrospective cohort study

A retrospective cohort study, supplemented with a nested case-control study, was performed using two administrative databases from commercial health plans in the United States to compare the incidence of pancreatic and thyroid cancer among users of exenatide versus other antidiabetic drugs (OADs). Patients with type 2 diabetes who initiated exenatide or OADs between 1 June 2005 and 30 June 2015 were included. Pancreatic and thyroid cancers were identified using chart-validated algorithms in the cohort study. Cases in the nested case-control study were chart-confirmed pancreatic or thyroid cancers, and controls were sampled using risk-set sampling. The time-fixed analyses comparing 33 629 exenatide initiators with 49 317 propensity-score-matched OAD initiators yielded hazard ratios of 0.76 (95% confidence interval [CI] 0.47-1.21) for pancreatic cancer and 1.46 (95% CI 0.98-2.19) for thyroid cancer. Results in the time-dependent analyses by cumulative duration or dose were similar. Nested case-control analyses yielded rate ratios of 0.61 (95%CI, 0.37-1.00) for pancreatic cancer and 0.89 (95% CI, 0.64-1.24) for thyroid cancer. This observational study suggested exenatide use was not associated with an increased risk of pancreatic or thyroid cancer.

CD26/DPP4 - a potential biomarker and target for cancer therapy

CD26/dipeptidyl peptidase (DPP)4 is a membrane-bound protein found in many cell types of the body, and a soluble form is present in body fluids. There is longstanding evidence that various primary tumors and also metastases express CD26/DPP4 to a variable extent. By cleaving dipeptides from peptides with a proline or alanine in the penultimate position at the N-terminus, it regulates the activity of incretin hormones, chemokines and many other peptides. Due to these effects and interactions with other molecules, a tumor promoting or suppressing role can be attributed to CD26/DPP4. In this review, we discuss the existing evidence on the expression of soluble or membrane-bound CD26/DPP4 in malignant diseases, along with the most recent findings on CD26/DPP4 as a therapeutic target in specific malignancies. The expression and possible involvement of the related DPP8 and DPP9 in cancer are also reviewed. A higher expression of CD26/DPP4 is found in a wide variety of tumor entities, however more research on CD26/DPP4 in the tumor microenvironment is needed to fully explore its use as a tumor biomarker. Circulating soluble CD26/DPP4 has also been studied as a cancer biomarker, however, the observed decrease in most cancer patients does not seem to be cancer specific. Encouraging results from experimental work and a recently reported first phase clinical trial targeting CD26/DPP4 in mesothelioma, renal and urological tumors pave the way for follow-up clinical studies, also in other tumor entities, possibly leading to the development of more effective complementary therapies against cancer.

Risk of Malignant Neoplasia with Glucagon-Like Peptide-1 Receptor Agonist Treatment in Patients with Type 2 Diabetes: A Meta-Analysis

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonists are effective glucose-lowering drugs, but there is concern that they may increase the risk of malignant neoplasia. The present meta-analysis examined the safety of GLP-1 receptor agonists with regard to malignant neoplasia.

METHODS

We analyzed data from randomized controlled trials with a minimum duration of 24 weeks that assessed the incidence of neoplasms in type 2 diabetes patients receiving GLP-1 receptor agonists compared with placebo or other hypoglycemic drugs. We searched the MEDLINE, Embase, and Cochrane databases with a language restriction of English through October 1, 2018, and carried out a meta-analysis of the available trial data using a fixed effects model to calculate odds ratios (ORs) for neoplasia.

RESULTS

Thirty-four relevant articles, providing data for 50452 patients, were included in the meta-analysis. Compared with the incidence of malignant neoplasia with placebo or other interventions, no increase in malignant neoplasm formation was observed with the use of GLP-1 receptor agonists (OR 1.04, 95% confidence interval (CI) 0.94-1.15; p = 0.46), liraglutide (OR 1.08, 95% CI 0.91-1.27; p = 0.38), exenatide (OR 1.00, 95% CI 0.86-1.16; p = 1.00), semaglutide (OR 0.89, 95% CI 0.35-2.22; p = 0.80), or albiglutide (OR 1.07, 95% CI 0.23-4.88; p = 0.93). A subanalysis of trials lasting longer than 3 years also showed no increase in the neoplasia risk with GLP-1 receptor agonist use (OR 1.03, 95% CI 0.92-1.15; p = 0.60). Between-trial statistical heterogeneity was low for all comparisons.

CONCLUSION

GLP-1 receptor agonists can be used without safety concerns related to malignant neoplasia in patients with type 2 diabetes.

Pancreatic Cancer and Diabetes Mellitus

PURPOSE OF REVIEW

The relationship between pancreatic ductal adenocarcinoma (PDAC) and diabetes mellitus (DM) is complex. We reviewed the recent medical literature regarding the effect of anti-diabetic medication on PDAC risk and survival, risk of PDAC in DM, and role of DM in early detection of PDAC.

RECENT FINDINGS

Studies report that while some anti-diabetic medications (e.g., metformin) may decrease the risk of PDAC, others (insulin, sulfonylureas and incretin-based therapies) may increase the risk. However, these observations may be subject to protopathic biases. Metformin's anti-tumor activity may have influence overall survival of PDAC, but epidemiological reports have largely been inconsistent to defend these findings due to heterogeneous methodologies. There is congruent data to support the association between DM and PDAC, with an inverse relationship to DM duration. Older subjects with new-onset DM are the only known high-risk group for PDAC, and strategy using this group for early detection has led to development of clinical risk prediction models that define a very high-risk PDAC group. Role of anti-diabetic medication in PDAC risk modification or survival is controversial. With successful efforts to distinguish type 2-DM from PDAC-DM using risk-stratifying models, there is an opportunity to initiate screening protocols for early detection of PDAC in a sub-set of DM subjects.

Risk of dipeptidyl peptidase-4 (DPP-4) inhibitors on site-specific cancer: A systematic review and meta-analysis

The long-term impact of dipeptidyl peptidase-4 (DPP-4) inhibition is unknown, and there are concerns about the influence of DPP-4 inhibition on carcinogenesis of the pancreas and thyroid. As DPP-4 is a rather unselective enzyme present in many tissues, we focused on all specific cancer types. PubMed and EMBASE were searched between January 2005 and April 2017 to identify studies comparing DPP-4 inhibitors with either placebo or active drugs on cancer risk. Studies were included if they reported on at least one specific cancer outcome and had a follow-up of at least 1 year after start of drug use. Methodological quality of the studies was assessed by the Cochrane Collaboration's tool and the Newcastle-Ottawa Scale. Twenty-five studies met the inclusion criteria (12 randomized controlled trials and 13 observational studies). Sample sizes of the DPP-4 inhibitor groups ranged from 29 to 8212 patients for randomized controlled trials and from 2422 to 71 137 patients for observational studies. Mean age ranged from 51 to 76 years, and mean follow-up was 1.5 years. None of the pooled (sensitivity) analyses, except the observational studies studying breast cancer (hazard ratio [95% CI]: 0.76 [0.60-0.96]), showed evidence for an association between DPP-4 inhibitors and site-specific cancer. Also for pancreatic and thyroid cancer, no statistically significant risk was found. Based on the current literature, it is not possible to conclude whether DPP-4 inhibitors were associated with an increased risk of site-specific cancer. Future studies should address the methodological limitations and follow patients for a longer period to determine the long-term cancer risk of DPP-4 inhibitors.

iGlarLixi: A New Once-Daily Fixed-Ratio Combination of Basal Insulin Glargine and Lixisenatide for the Management of Type 2 Diabetes

BACKGROUND

Patients with type 2 diabetes require treatment intensification to maintain glycemic control. Clinician reluctance, patient injection fears, hypoglycemia, weight gain, or other objections may lead to clinical inertia, whereby therapy is not intensified and patients live with uncontrolled hyperglycemia and increased risk for complications. Initiation of injectable therapy with a glucagon-like peptide (GLP)-1 receptor agonist and/or basal insulin is a recommended option for patients with type 2 diabetes inadequately controlled on one or more oral agents.

PURPOSE

This article reviews clinical evidence and provides information on dosing and administration of iGlarLixi, a titratable fixed-ratio combination of insulin glargine and the GLP-1 receptor agonist lixisenatide that effectively lowers both fasting and postprandial glucose levels.

FINDINGS

In phase 3 trials, iGlarLixi provided greater A1C reduction than insulin glargine or lixisenatide alone, without increased hypoglycemia risk compared with insulin glargine. iGlarLixi did not lead to weight gain versus insulin glargine and was associated with a lower frequency of gastrointestinal adverse effects than lixisenatide. iGlarLixi was recently approved by the U.S. Food and Drug Administration to improve glycemic control in adults with type 2 diabetes inadequately controlled on basal insulin (<60 units daily) or lixisenatide. iGlarLixi is administered by subcutaneous injection once daily, and the dose is titrated based on each patient's insulin needs using a simple titration algorithm.

CONCLUSION

iGlarLixi offers an effective and well-tolerated treatment option for patients with type 2 diabetes requiring additional glycemic control, with comparable or improved safety outcomes than its separate components. Because of its simple regimen and low rate of adverse effects, iGlarLixi may improve adherence and, consequently, therapeutic outcomes.