Ketogenic Diets in Pancreatic Cancer and Associated Cachexia: Cellular Mechanisms and Clinical Perspectives.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and extremely therapy-resistant cancer. It is estimated that up to 80% of PDAC patients present with cachexia, a multifactorial disorder characterized by the involuntary and ongoing wasting of skeletal muscle that affects therapeutic response and survival. During the last decade, there has been an increased interest in exploring dietary interventions to complement the treatment of PDAC and associated cachexia. Ketogenic diets (KDs) have gained attention for their anti-tumor potential. Characterized by a very low carbohydrate, moderate protein, and high fat composition, this diet mimics the metabolic changes that occur in fasting. Numerous studies report that a KD reduces tumor growth and can act as an adjuvant therapy in various cancers, including pancreatic cancer. However, research on the effect and mechanisms of action of KDs on PDAC-associated cachexia is limited. In this narrative review, we summarize the evidence of the impact of KDs in PDAC treatment and cachexia mitigation. Furthermore, we discuss key cellular mechanisms that explain KDs' potential anti-tumor and anti-cachexia effects, focusing primarily on reprogramming of cell metabolism, epigenome, and the gut microbiome. Finally, we provide a perspective on future research needed to advance KDs into clinical use.

Consumption evaluation of one apple flesh a day in the initial phases prior to adenoma/adenocarcinoma in an azoxymethane rat colon carcinogenesis model.

Colorectal cancer (CRC) is the fourth cancer with the most new cases reported in 2018 worldwide. Consumption of fruit and vegetables is a protective factor against the risk of CRC. Beyond this, flavonoids could orchestrate these healthy effects. Apart from containing the typical apple flavonoids, red-fleshed apples also contain anthocyanins, mainly cyanidin-3-O-galactoside (Cy3Gal). Through an azoxymethane rat carcinogenesis model, a study was carried out in order to assess the possible protective effects of apple polyphenols, with special attention to anthocyanins. In addition, apart from negative and positive controls, a group with chemotherapy with 5-fluorouracil (5FU) was included to compare their performance against the output collected from the animal treatments with white-fleshed apple (WF), red-fleshed apple (RF) and Cy3Gal (AE). Although the 5FU group presented the best performance towards aberrant crypt foci (ACF) inhibition (70.1%), rats fed with white-fleshed apples ('Golden Smoothee') were able to achieve 41.3% ACF inhibition, while none of the challenged treatments (WF, RF and AE) suffered mucin depletion in their colonocytes. Expression changes of 17 genes related to CRC were assessed. In detail, the ACF inhibition phenotype detected in 5FU and WF groups could be explained through the expression changes detected in the apoptosis-related genes of Aurka, p53 and Cox2. Moreover, in the apple consumption groups (WF and RF), a reduced protein expression of matrix metalloproteinases with gelatinase activity (MMP-2 and 9) was detected. Overall, our study suggests an effect of apple polyphenols and apple anthocyanin Cy3Gal against colon carcinogenesis, retarding/diminishing the appearance of the precancerous markers studied.

Clinical outcomes of transarterial chemotherapy and embolization for vaginal cancer.

AIM: We report clinical outcomes of transarterial embolization in 19 cases of vaginal cancer. METHODS: From August 2011 to October 2019, 19 patients with histologically diagnosed vaginal cancer were identified in our department. Transarterial chemotherapy and embolization was performed for all patients. Patient characteristics, treatment plans and the clinical outcomes, were recorded. RESULTS: Among 19 identified cases, nine of them are squamous cell carcinoma, five of adenocarcinoma, one of adenosquamous carcinoma, two of vaginal malignant melanoma, one leiomyosarcoma and one of stromal sarcoma. Transarterial chemotherapy and embolization was successfully performed in all patients. No related complication was found after intervention treatment. Besides, eight patients received adjuvant chemotherapy, four received both adjuvant chemotherapy and radiotherapy and seven received no therapies. Four patients were cured and seven were stable during follow-up. CONCLUSION: Transarterial embolization appears safe and effective for vaginal cancer, with a currently acceptable prognosis.

Black Raspberries Suppress Colorectal Cancer by Enhancing Smad4 Expression in Colonic Epithelium and Natural Killer Cells.

Innate immune cells in the tumor microenvironment have been proposed to control the transition from benign to malignant stages. In many cancers, increased infiltration of natural killer (NK) cells associates with good prognosis. Although the mechanisms that enable NK cells to restrain colorectal cancer (CRC) are unclear, the current study suggests the involvement of Smad4. We found suppressed Smad4 expression in circulating NK cells of untreated metastatic CRC patients. Moreover, NK cell-specific Smad4 deletion promoted colon adenomas in DSS-treated ApcMin/+ mice and adenocarcinomas in AOM/DSS-treated mice. Other studies have shown that Smad4 loss or weak expression in colonic epithelium associates with poor survival in CRC patients. Therefore, targeting Smad4 in both colonic epithelium and NK cells could provide an excellent opportunity to manage CRC. Toward this end, we showed that dietary intervention with black raspberries (BRBs) increased Smad4 expression in colonic epithelium in patients with FAP or CRC and in the two CRC mouse models. Also, benzoate metabolites of BRBs, such as hippurate, upregulated Smad4 and Gzmb expression that might enhance the cytotoxicity of primary human NK cells. Of note, increased levels of hippurate is a metabolomic marker of a healthy gut microbiota in humans, and hippurate also has antitumor effects. In conclusion, our study suggests a new mechanism for the action of benzoate metabolites derived from plant-based foods. This mechanism could be exploited clinically to upregulate Smad4 in colonic epithelium and NK cells, thereby delaying CRC progression.

Efficacy of prolonged elemental diet therapy after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma: A pilot prospective randomized trial (UMIN000004108).

BACKGROUNDS AND AIMS: This randomized clinical trial examined efficacy of prolonged elemental diet (ED) therapy after pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC), which often causes postoperative malnutrition leading to worsened short- and long-term outcomes. METHODS: Thirty-nine patients with PDAC receiving PD was randomly assigned to prolonged ED group (PEDG) and control group (CG). Fat-free ED (Elental®, EA Pharma CO., Ltd., Tokyo, Japan) via tube jejunostomy was initiated on postoperative day 1 and increased to maintain with 600 kcal/day in addition to oral intake. ED was discontinued if sufficient oral intake was achieved in CG but continued during 3 postoperative months in PEDG. Primary outcome was complication necessitating readmission. Secondary outcomes were nutritional parameters, relative dose intensity (RDI) in cases of adjuvant chemotherapy, and survival outcomes. RESULTS: Twenty patients were assigned to CG and 19 to PEDG. Cumulative post-discharge readmission rate was significantly lower in PEDG than in CG (PEDG vs CG; 12.6% vs 43.7% at 12-post-discharge-month; p = 0.018). Total calorie and ED-derived protein intakes were significantly larger in PEDG than in CG up to 3-postoperative-month but thereafter similar among groups. Lymphocyte counts were significantly increased and neutrophil-to-lymphocyte-ratio (NLR) was significantly reduced in PEDG than in CG at 2-, 3-, and 6-postoperative-month. However, other outcome measures did not differ among groups. CONCLUSION: This trial failed to show survival benefit of prolonged ED therapy but demonstrated its favorable effect on increased lymphocyte counts, reduced NLR, and prevention of complications necessitating readmission, those which may lead to survival benefit with some modifications.

Serum Levels of 25-Hydroxyvitamin D at Diagnosis Are Not Associated with Overall Survival in Esophageal Adenocarcinoma.

BACKGROUND: Higher levels of circulating 25-hydroxyvitamin D [25(OH)D] are associated with longer survival in several cancers, but the results have differed across cancer sites. The association between serum 25(OH)D levels and overall survival (OS) time in esophageal adenocarcinoma remains unclear. METHODS: We utilized serum samples from 476 patients with primary esophageal adenocarcinoma, recruited from Massachusetts General Hospital (Boston, MA) between 1999 and 2015. We used log-rank tests to test the difference in survival curves across quartiles of 25(OH)D levels and extended Cox modeling to estimate adjusted HRs. We tested for interactions between clinical stage or BMI on the association between 25(OH)D and OS. We additionally performed sensitivity analyses to determine whether race or timing of blood draw (relative to treatment) affected these results. RESULTS: We found no evidence that survival differed across quartiles of 25(OH)D (log rank P = 0.48). Adjusting for confounders, we found no evidence that the hazard of death among the highest quartile of 25(OH)D (quartile 1) differed from any other quartile [quartile 2 HR = 0.90, 95% confidence interval (CI), 0.67-1.23; quartile 3 HR = 1.03, 95% CI, 0.76-1.38; quartile 4 (lowest) HR = 0.98, 95% CI, 0.72-1.33]. Sensitivity analyses yielded consistent results when accounting for race or time between diagnosis and blood draw. Moreover, we did not find evidence of interaction between 25(OH)D and clinical stage or BMI on OS. CONCLUSIONS: Serum level of 25(OH)D near time of diagnosis was not associated with OS in patients with esophageal adenocarcinoma. IMPACT: Screening 25(OH)D levels among patients with esophageal adenocarcinoma at diagnosis is not clinically relevant to their cancer prognosis based on present evidence.

Mediterranean diet adherence and risk of esophageal and gastric cancer subtypes in the Netherlands Cohort Study.

BACKGROUND: Mediterranean diet (MD) adherence has been associated with reduced risks of esophageal and gastric cancer (subtypes) in a limited number of studies. We prospectively investigated associations between MD adherence and risks of esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), gastric cardia adenocarcinoma (GCA), and gastric non-cardia adenocarcinoma (GNCA) in a Dutch cohort. METHODS: Analyses were conducted using data from the 120852 participants of the Netherlands Cohort Study (NLCS), who were aged between 55 and 69 years at enrollment. Various MD scores, with and without alcohol, were calculated to estimate MD adherence. Using 20.3 years of follow-up, 133 ESCC, 200 EAC, 191 GCA, and 586 GNCA cases could be included in multivariable Cox regression analyses. RESULTS: Of the investigated scores, the alternate Mediterranean diet score without alcohol (aMEDr) performed best. aMEDr was inversely associated with risks of GCA and GNCA in men and women. However, statistical significance was only reached in men [ptrend: 0.019 (GCA), 0.016 (GNCA)]. Furthermore, higher aMEDr values were significantly associated with a reduced ESCC risk in men [HRper two-point increment (95% CI) = 0.57 (0.41-0.80), ptrend = 0.013], but not in women (pheterogeneity = 0.008). There was no evidence of an association between aMEDr and EAC risk. Educational level was a significant effect modifier for the association between aMEDr and GNCA risk (pheterogeneity = 0.0073). CONCLUSIONS: Higher MD adherence was associated with reduced risks of ESCC, GCA, and GNCA in the NLCS. However, the decreased ESCC risk might be limited to men.

A Ketogenic Formula Prevents Tumor Progression and Cancer Cachexia by Attenuating Systemic Inflammation in Colon 26 Tumor-Bearing Mice.

Low-carbohydrate, high-fat diets (ketogenic diets) might prevent tumor progression and could be used as supportive therapy; however, few studies have addressed the effect of such diets on colorectal cancer. An infant formula with a ketogenic composition (ketogenic formula; KF) is used to treat patients with refractory epilepsy. We investigated the effect of KF on cancer and cancer cachexia in colon tumor-bearing mice. Mice were randomized into normal (NR), tumor-bearing (TB), and ketogenic formula (KF) groups. Colon 26 cells were inoculated subcutaneously into TB and KF mice. The NR and TB groups received a standard diet, and the KF mice received KF ad libitum. KF mice preserved their body, muscle, and carcass weights. Tumor weight and plasma IL-6 levels were significantly lower in KF mice than in TB mice. In the KF group, energy intake was significantly higher than that in the other two groups. Blood ketone body concentrations in KF mice were significantly elevated, and there was a significant negative correlation between blood ketone body concentration and tumor weight. Therefore, KF may suppress the progression of cancer and the accompanying systemic inflammation without adverse effects on weight gain, or muscle mass, which might help to prevent cancer cachexia.

Immunonutrition before esophagectomy: Impact on immune surveillance mechanisms.

Preoperative oral immunonutrition was demonstrated to improve immune response and to decrease the infection rate in patients with cancer. This study aimed to assess how immunonutrition could influence the immune cell response in the mucosal microenvironment of esophageal adenocarcinoma. Therefore, A prospective cohort of consecutive patients undergoing esophagectomy for esophageal adenocarcinoma was enrolled. A subgroup of them was given preoperative oral immunonutrition with Oral Impact® and was compared to those who received no preoperative supplementation. Mucosal samples from healthy esophagus were obtained at esophagectomy. Histology, immunohistochemistry, gene expression analysis, and cytofluorimetry were performed. Markers of activation of antigen-presenting cells (CD80, CD86, and HLA-I), innate immunity (TLR4 and MyD88), and cytotoxic lymphocyte infiltration and activation (CD8, CD38, CD69, and CD107) were measured. In all, 50 patients received preoperative Oral Impact® and 129 patients received no nutritional support. CD80, CD86, MyD88, and CD69 messenger RNA expression was significantly increased in patients receiving immunonutrition compared to controls. In the subgroup of patients with stages I-II cancer, the rate of epithelial cells expressing CD80 and HLA-ABC was significantly higher in those receiving immunonutrition compared to controls as well as CD8+ CD28+ cell rate. Immunonutrition administration before surgery was significantly associated to increased degranulating CD8 and natural killer cells (CD107+) infiltrating the healthy esophageal mucosa. All the comparisons were adjusted for cancer stage and preoperative therapy. In conclusion, in healthy esophageal mucosa of patients undergoing esophagectomy, a 5-day course of immunonutrition enhances expression of antigen-presenting cells activity and increased CD8+ T cell activation and degranulating activity. Further studies are warranted to understand the clinical implication in terms of cancer recurrence.

Delay of Lung Adenocarcinoma (LAC-1) Development in Mice by Dietary Oleic Acid.

Lung cancer is the leading cause of death by cancer, and is a major sanitary concern worldwide. Some nutrients, such as ω-9 fatty acids, have been proposed as anticancer agents. Thus, an olein-enriched diet was assayed in a murine model of lung adenocarcinoma (LAC-1) to evaluate neoplastic and paraneoplastic evolution in BALB/c mice. The organic assimilation of dietary fatty acids was confirmed in liver by gas chromatography. This experimental oleic acid-containing diet increased animal survival and tumour latency (analysed by the Kaplan-Meier method), improving neoplastic evolution and general status, with weak effects on the paraneoplastic syndrome (thymus atrophy, splenomegaly, splenocyte response to mitogen, blood anaemia, and leucocytosis). Tumour lipid oxidation was not involved. Thus, diet enrichment with olein, a natural source of the ω-9 oleic acid, significantly delayed progression of LAC-1 and increased tumour latency and mice survival. These results support its use in nutritional management of cancer, with further studies being encouraged.

Effects of an Alkaline Diet on EGFR-TKI Therapy in EGFR Mutation-positive NSCLC.

BACKGROUND: The acidic tumor microenvironment is associated with progression of cancers. The purpose of this study was to investigate the association between an alkaline diet and the effect of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) in non-small cell lung cancer (NSCLC) patients. PATIENTS AND METHODS: Eleven advanced or recurrent NSCLC patients with EGFR mutations treated with EGFR-TKI after being instructed to follow an alkaline diet were retrospectively evaluated. RESULTS: The median progression-free survival (PFS) and overall survival (OS) were 19.5 (range=3.1-33.8) and 28.5 (range=15.4-46.6) months. The average dosage of EGFR-TKI was 56±22% of the standard dosage. Urine pH was significantly increased after the alkaline diet (6.00±0.38 vs. 6.95±0.55; p<0.05). CONCLUSION: An alkaline diet may enhance the effect of EGFR-TKI treatment in NSCLC patients with EGFR mutations.

Can We Use Diet to Effectively Treat Esophageal Disease? A Review of the Current Literature.

PURPOSE OF REVIEW: Esophageal diseases represent a wide variety of conditions affecting esophageal anatomy, physiology, and motility. Therapy focuses on pharmacotherapy and endoscopic or surgical management. Dietary therapy can be considered in management algorithms for specific esophageal diseases. This review focuses on outlining the literature related to dietary therapy in gastroesophageal reflux disease, eosinophilic esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. RECENT FINDINGS: Currently, data are strongest for dietary manipulation in eosinophilic esophagitis, specifically the six-food elimination diet. Dietary effects on gastroesophageal reflux disease are less clear, though newer research indicates that increased fiber with reduction in simple sugar intake may improve symptoms. In terms of Barrett's esophagus and esophageal adenocarcinoma, antioxidant intake may affect carcinogenesis, though to an unknown degree. Outcomes data regarding dietary manipulation for the management of esophageal diseases is heterogeneous. Given the rising interest in non-pharmacological treatment options for these patients, continued research is warranted.

The Role of Endoscopic Ultrasound in the Management of Patients with Barrett's Esophagus and Superficial Neoplasia.

Endoscopic ultrasound (EUS) is a minimally invasive advanced imaging procedure using high-frequency sound waves to produce detailed images of the esophageal wall with fine-needle aspiration to biopsy adjacent lymph nodes. The role of EUS is well established in patients with locally advanced Barrett esophagus neoplasia. The utility of EUS in the evaluation of Barrett esophagus patients is controversial. This is a review of the evidence using EUS in BE patients. The assessment is that EUS may be a powerful tool in managing patients with BE neoplasia.

Antineoplastic effects of clove buds (Syzygium aromaticum L.) in the model of breast carcinoma.

It is supposed that plant functional foods, rich in phytochemicals, may potentially have preventive effects in carcinogenesis. In this study, the anticancer effects of cloves in the in vivo and in vitro mammary carcinoma model were assessed. Dried flower buds of cloves (CLOs) were used at two concentrations of 0.1% and 1% through diet during 13 weeks after the application of chemocarcinogen. After autopsy, histopathological and immunohistochemical analyses of rat mammary carcinomas were performed. Moreover, in vitro evaluation using MCF-7 cells was carried out. Dietary administered CLO caused the dose-dependent decrease in tumour frequency by 47.5% and 58.5% when compared to control. Analysis of carcinoma cells in animals showed bcl-2, Ki67, VEGFA, CD24 and CD44 expression decrease and Bax, caspase-3 and ALDH1 expression increase after high-dose CLO administration. MDA levels were substantially decreased in rat carcinomas in both CLO groups. The evaluation of histone modifications revealed increase in lysine trimethylations and acetylations (H4K20me3, H4K16ac) in carcinomas after CLO administration. TIMP3 promoter methylation levels of CpG3, CpG4, CpG5 islands were altered in treated cancer cells. An increase in total RASSF1A promoter methylation (three CpG sites) in CLO 1 group was found. In vitro studies showed antiproliferative and pro-apoptotic effects of CLO extract in MCF-7 cells (analyses of cytotoxicity, Brdu, cell cycle, annexin V/PI, caspase-7, Bcl-2 and mitochondrial membrane potential). This study showed a significant anticancer effect of clove buds in the mammary carcinoma model in vivo and in vitro.

Impact of carbohydrate restriction in the context of obesity on prostate tumor growth in the Hi-Myc transgenic mouse model.

BACKGROUND: Previously, we showed that carbohydrate restriction with calorie restriction slowed tumor growth in xenograft mouse prostate cancer models. Herein, we examined the impact of carbohydrate restriction without calorie restriction on tumor development within the context of diet-induced obesity in the Hi-Myc transgenic mouse model of prostate cancer. METHODS: Mice were randomized at 5 weeks of age to ad libitum western diet (WD; 40% fat, 42% carbohydrate; n=39) or ad libitum no carbohydrate ketogenic diet (NCKD; 82% fat, 1% carbohydrate; n=44). At age 3 or 6 months, mice were killed, prostates weighed and prostate histology, proliferation, apoptosis and macrophage infiltration evaluated by hematoxylin and eosin, Ki67, TUNEL and F4/80 staining, respectively. Body composition was assessed by DEXA, serum cytokines measured using multiplex, and Akt/mTOR signaling assessed by Western. RESULTS: Caloric intake was higher in the NCKD group, resulting in elevated body weights at 6 months of age, relative to the WD group (45 g vs 38g; P=0.008). Despite elevated body weights, serum monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-1α levels were lower in NCKD versus WD mice (P=0.046 and P=0.118, respectively), and macrophage infiltration was reduced in prostates of NCKD versus WD mice (P=0.028). Relative Akt phosphorylation and phospho-S6 ribosomal protein levels were reduced in prostates of NCKD versus WD mice. However, while mice randomized to NCKD had smaller prostates after adjustment for body weight at 3 and 6 months (P=0.004 and P=0.002, respectively), NCKD mice had higher rates of adenocarcinoma at 6 months compared to WD mice (100 vs 80%, P=0.04). CONCLUSIONS: Despite higher caloric intake and elevated body weights, carbohydrate restriction lowered serum MCP-1 levels, reduced prostate macrophage infiltration, reduced prostate weight, but failed to slow adenocarcinoma development. Together, these data suggest that although carbohydrate restriction within the context of obesity may reduce obesity-associated systemic inflammation and perhaps slow tumor growth, it is not sufficient to counteract obesity-associated tumor development.

Cranberry intervention in patients with prostate cancer prior to radical prostatectomy. Clinical, pathological and laboratory findings.

BACKGROUND AND OBJECTIVES: Recently, we described an inverse association between cranberry supplementation and serum prostate specific antigen (PSA) in patients with negative biopsy for prostate cancer (PCa) and chronic nonbacterial prostatitis. This double blind placebo controlled study evaluates the effects of cranberry consumption on PSA values and other markers in men with PCa before radical prostatectomy. METHODS: Prior to surgery, 64 patients with prostate cancer were randomized to a cranberry or placebo group. The cranberry group (n=32) received a mean 30 days of 1500 mg cranberry fruit powder. The control group (n=32) took a similar amount of placebo. Selected blood/urine markers as well as free and total phenolics in urine were measured at baseline and on the day of surgery in both groups. Prostate tissue markers were evaluated after surgery. RESULTS: The serum PSA significantly decreased by 22.5% in the cranberry arm (n=31, P<0.05). A trend to down-regulation of urinary beta-microseminoprotein (MSMB) and serum gamma-glutamyltranspeptidase, as well as upregulation of IGF-1 was found after cranberry supplementation. There were no changes in prostate tissue markers or, composition and concentration of phenolics in urine. CONCLUSIONS: Daily consumption of a powdered cranberry fruit lowered serum PSA in patients with prostate cancer. The whole fruit contains constituents that may regulate the expression of androgen-responsive genes.

Impact of a ketogenic diet intervention during radiotherapy on body composition: I. Initial clinical experience with six prospectively studied patients.

BACKGROUND: Based on promising preclinical data, ketogenic diets (KDs) have been proposed as supplementary measures for cancer patients undergoing standard-of-care therapy. However, data is still scarce on the tolerability and effects of KDs on cancer patients undergoing radiotherapy (RT). Here we present six cases of patients who underwent RT and concurrently consumed a self-administered KD in our clinic within a busy community hospital setting. METHODS: All patients were followed prospectively with measurements of blood parameters, quality of life and body weight and composition using bioelectrical impedance analysis. RESULTS: No adverse diet-related side effects occurred. Two patients had no elevated ketone body levels in serum despite self-reporting compliance to the diet. There was consensus that the KD was satiating and weight loss occurred in all patients, although this was only significant in two patients. Our data indicate that weight loss was mainly due to fat mass loss with concurrent preservation of muscle mass. Overall quality of life remained fairly stable, and all subjects reported feeling good on the diet. Tumor regression occurred as expected in five patients with early stage disease; however one subject with metastatic small cell lung cancer experienced slight progression during three cycles of combined chemotherapy + KD and progressed rapidly after ending the KD. CONCLUSIONS: Our data lend support to the hypothesis that KDs administered as supportive measures during standard therapy are safe and might be helpful in preservation of muscle mass. Further studies with control groups are needed to confirm these findings and address questions regarding any putative anti-tumor effects. Based on the experience with these six cases we implemented further steps to improve issues with KD compliance and initiated a clinical study that is described in a companion paper.

Effect of Metformin Use on Survival in Resectable Pancreatic Cancer: A Single-Institution Experience and Review of the Literature.

Observational studies have demonstrated that metformin use in diabetic patients is associated with reduced cancer incidence and mortality. Here, we aimed to determine whether metformin use was associated with improved survival in patients with resected pancreatic cancer. All patients with diabetes who underwent resection for pancreatic adenocarcinoma between 12/1/1986 and 4/30/2013 at our institution were categorized by metformin use. Survival analysis was done using the Kaplan-Meier method, with log-rank test and Cox proportional hazards multivariable regression models. For analyses of our data and the only other published study, we used Meta-Analysis version 2.2. We identified 44 pancreatic cancer patients with diabetes who underwent resection of the primary tumor (19 with ongoing metformin use, 25 never used metformin). There were no significant differences in major clinical and demographic characteristics between metformin and non-metformin users. Metformin users had a better median survival than nonusers, but the difference was not statistically significant (35.3 versus 20.2 months; P = 0.3875). The estimated 2-, 3-, and 5-year survival rates for non-metformin users were 42%, 28%, and 14%, respectively. Metformin users fared better with corresponding rates of 68%, 34%, and 34%, respectively. In our literature review, which included 111 patients from the two studies (46 metformin users and 65 non-users), overall hazard ratio was 0.668 (95% CI 0.397-1.125), with P = 0.129. Metformin use was associated with improved survival outcomes in patients with resected pancreatic cancer, but the difference was not statistically significant. The potential benefit of metformin should be investigated in adequately powered prospective studies.