Controlling hyperglycemia as an adjunct to cancer therapy

Hyperglycemia Enhances Immunosuppression and Aerobic Glycolysis of Pancreatic Cancer Through Upregulating Bmi1-UPF1-HK2 Pathway

BACKGROUND & AIMS

Accumulating evidence strongly suggests that hyperglycemia promotes the progression of pancreatic cancer (PC). Approximately 80% of patients with PC are intolerant to hyperglycemic conditions. In this study, we define the role of Bmi1, a stemness-related oncogene, in controlling the Warburg effect, and immune suppression under hyperglycemia conditions.

METHODS

The diabetes mellitus model was established by intraperitoneal injection of streptozotocin. The role of the hyperglycemia-Bmi1-HK2 axis in glycolysis-related immunosuppression was examined in both orthotopic and xenograft in vivo models. Evaluation of immune infiltrates was carried out by flow cytometry. Human PC cell lines, SW1990, BxPC-3, and CFPAC-1, were used for mechanistic in vitro studies.

RESULTS

Through bioinformatics analysis, we found that hyperglycemia was strongly related to aerobic glycolysis, immunosuppression, and cancer cell stemness. High glucose condition in the tumor microenvironment promotes immune suppression by upregulating glycolysis in PC cells, which can be rescued via knockdown Bmi1 expression or after 2-deoxy-D-glucose treatment. Through gain-/loss-of-function assessments, we found that Bmi1 upregulated the expression of UPF1, which enhanced the stability of HK2 mRNA and thereby increased the expression of HK2. The role of the hyperglycemia-Bmi-HK2 pathway in the inhibition of antitumor immunity was further verified via the immune-competent and immunodeficient mice model. We also demonstrated that hyperglycemia promotes the expression of Bmi1 by elevating the intracellular acetyl-CoA levels and histone H4 acetylation levels.

CONCLUSIONS

Our results suggest that the previously unreported Bmi1-UPF1-HK2 pathway contributes to PC progression and immunosuppression, which may bring in new targets for developing effective therapies to treat patients with PC.

Cancer and diabetes: the interlinking metabolic pathways and repurposing actions of antidiabetic drugs

Cancers are regarded as one of the main causes of death and result in high health burden worldwide. The management of cancer include chemotherapy, surgery and radiotherapy. The chemotherapy, which involves the use of chemical agents with cytotoxic actions is utilised as a single treatment or combined treatment. However, these managements of cancer such as chemotherapy poses some setbacks such as cytotoxicity on normal cells and the problem of anticancer drug resistance. Therefore, the use of other therapeutic agents such as antidiabetic drugs is one of the alternative interventions used in addressing some of the limitations in the use of anticancer agents. Antidiabetic drugs such as sulfonylureas, biguanides and thiazolidinediones showed beneficial and repurposing actions in the management of cancer, thus, the activities of these drugs against cancer is attributed to some of the metabolic links between the two disorders and these includes hyperglycaemia, hyperinsulinemia, inflammation, and oxidative stress as well as obesity. Furthermore, some studies showed that the use of antidiabetic drugs could serve as risk factors for the development of cancerous cells particularly pancreatic cancer. However, the beneficial role of these chemical agents overweighs their detrimental actions in cancer management. Hence, the present review indicates the metabolic links between cancer and diabetes and the mechanistic actions of antidiabetic drugs in the management of cancers.

Relationship Between Pre-operative Blood Glucose Level and Length of Hospital Stay in Patients With Renal Cell Carcinoma Undergoing Laparoscopic Nephrectomy

Purpose: The aim of this study was to assess the effect of pre-operative blood glucose (POBG) levels on the length of stay (LOS) in patients with renal cell carcinoma (RCC) undergoing laparoscopic nephrectomy.

Methods: We collected clinical data on 338 patients with RCC who underwent laparoscopic nephrectomy between 2014 and 2019. Univariate and multivariate logistic regression and dose-response analysis curves of restricted cubic spline function were used to investigate the relationship between POBG and LOS.

Results: According to the level of POBG, we divided the patients into three groups: <4.94 mmol/L group, 4.94 to <7.11 mmol/L group, and ≥7.11 mmol/L group. According to the dose-response analysis curves, we found that the adjusted risk of LOS > 2 weeks and LOS > 3 weeks gradually increased with increasing POBG. In addition, we found that among all patients, patients with POBG levels ≥ 7.11 mmol/L had a 115% higher risk of LOS > 2 weeks than patients with POBG levels <4.94 mmol/L [adjusted odds risk (aOR) 2.15; 95% CI 1.11-4.20; p = 0.024] and patients with POBG levels ≥ 7.11 mmol/L had a 129% higher risk of LOS > 3 weeks than patients with POBG levels <4.94 mmol/L (aOR 2.29; 95% CI 1.16-4.52; p = 0.017). Moreover, similar results were observed in the most subgroups analysis.

Conclusion: We found that in patients with RCC undergoing laparoscopic nephrectomy, higher POBG levels were significantly associated with prolonged LOS.

Epidemiological link between obesity, type 2 diabetes mellitus and cancer

There exists a complex interaction between obesity, type 2 diabetes mellitus (T2DM) and cancer, and an increase in the incidence of cancer is expected with the growing obesity-diabetes pandemic. The association of cancer with diabetes mellitus and obesity appears to be site-specific, the highest risk being for post-menopausal breast cancer, endometrial cancer, and colorectal cancer. Moreover, there is worsening of hyperglycaemia with the onset of cancer, evidencing a bi-directional link between cancer and diabetes mellitus and the need for monitoring for diabetes in cancer survivors. In this review, we look at the epidemiological evidence from observational studies and Mendelian randomization studies linking obesity, diabetes, and cancer, as well as the complex pathophysiological mechanisms involved, including insulin resistance with associated hyperinsulinaemia, the effect of chronic low-grade inflammation, and the effect of various adipokines that are associated with obesity and T2DM. Additionally, we describe the novel therapeutic strategies, based on their role on the discrete pathophysiological mechanisms involved in the tumourigenesis.

Dietary Constituents: Relationship with Breast Cancer Prognostic (MCC-SPAIN Follow-Up)

The aim of this study was to characterize the relationship between the intake of the major nutrients and prognosis in breast cancer. A cohort based on 1350 women with invasive (stage I-IV) breast cancer (BC) was followed up. Information about their dietary habits before diagnosis was collected using a semi-quantitative Food Frequency Questionnaire. Participants without FFQ or with implausible energy intake were excluded. The total amount consumed of each nutrient (Kcal/day) was divided into tertiles, considering as “high intakes” those above third tertile. The main effect studied was overall survival. Cox regression was used to assess the association between death and nutrient intake. During a median follow-up of 6.5 years, 171 deaths were observed. None of the nutrients analysed was associated with mortality in the whole sample. However, in normal-weight women (BMI 18.5–25 kg/m²) a high intake of carbohydrates (≥809 Kcal/day), specifically monosaccharides (≥468 Kcal/day), worsened prognostic compared to lowest (≤352 Kcal/day). Hazard Ratios (HRs) for increasing tertiles of intake were HR:2.22 95% CI (1.04 to 4.72) and HR:2.59 95% CI (1.04 to 6.48), respectively (p trend = 0.04)). Conversely, high intakes of polyunsaturated fats (≥135 Kcal/day) improved global survival (HR: 0.39 95% CI (0.15 to 1.02) p-trend = 0.05) compared to the lowest (≤92.8 kcal/day). In addition, a protective effect was found substituting 100 kcal of carbohydrates with 100 kcal of fats in normal-weight women (HR: 0.76 95% CI (0.59 to 0.98)). Likewise, in premenopausal women a high intake of fats (≥811 Kcal/day) showed a protective effect (HR:0.20 95% CI (0.04 to 0.98) p trend = 0.06). Finally, in Estrogen Receptors (ER) negative tumors, we found a protective effect of high intake of animal proteins (≥238 Kcal/day, HR: 0.24 95% CI (0.06 to 0.98). According to our results, menopausal status, BMI and ER status could play a role in the relationship between diet and BC survival and must be taken into account when studying the influence of different nutrients.

Biomechanical and Biophysical Properties of Breast Cancer Cells Under Varying Glycemic Regimens

Diabetes accelerates cancer cell proliferation and metastasis, particularly for cancers of the pancreas, liver, breast, colon, and skin. While pathways linking the 2 disease conditions have been explored extensively, there is a lack of information on whether there could be cytoarchitectural changes induced by glucose which predispose cancer cells to aggressive phenotypes. It was thus hypothesized that exposure to diabetes/high glucose alters the biomechanical and biophysical properties of cancer cells more than the normal cells, which aids in advancing the cancer. For this study, atomic force microscopy indentation was used through microscale probing of multiple human breast cancer cells (MCF-7, MDA-MB-231), and human normal mammary epithelial cells (MCF-10A), under different levels of glycemic stress. These were used to study both benign and malignant breast tissue behaviors. Benign cells (MCF-10A) recorded higher Young's modulus values than malignant cells (MCF-7 and MDA-231) under normoglycemic conditions, which agrees with the current literature. Moreover, exposure to high glucose (for 48 hours) decreased Young's modulus in both benign and malignant cells, to the effect that the cancer cells showed a complete loss in elasticity with high glucose. This provides a possible insight into a link between glycemic stress and cytoskeletal strength. This work suggests that reducing glycemic stress in cancer patients and those at risk can prove beneficial in restoring normal cytoskeletal structure.

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.

Consideration of Ketogenic Metabolic Therapy as a Complementary or Alternative Approach for Managing Breast Cancer

Breast cancer remains as a significant cause of morbidity and mortality in women. Ultrastructural and biochemical evidence from breast biopsy tissue and cancer cells shows mitochondrial abnormalities that are incompatible with energy production through oxidative phosphorylation (OxPhos). Consequently, breast cancer, like most cancers, will become more reliant on substrate level phosphorylation (fermentation) than on oxidative phosphorylation (OxPhos) for growth consistent with the mitochondrial metabolic theory of cancer. Glucose and glutamine are the prime fermentable fuels that underlie therapy resistance and drive breast cancer growth through substrate level phosphorylation (SLP) in both the cytoplasm (Warburg effect) and the mitochondria (Q-effect), respectively. Emerging evidence indicates that ketogenic metabolic therapy (KMT) can reduce glucose availability to tumor cells while simultaneously elevating ketone bodies, a non-fermentable metabolic fuel. It is suggested that KMT would be most effective when used together with glutamine targeting. Information is reviewed for suggesting how KMT could reduce systemic inflammation and target tumor cells without causing damage to normal cells. Implementation of KMT in the clinic could improve progression free and overall survival for patients with breast cancer.

Impact of Poor Preoperative Glycemic Control on Outcomes among Patients with Cervical Cancer Undergoing a Radical Hysterectomy

BACKGROUND

The impact of preoperative glycemic control on the survival outcomes of patients undergoing a radical hysterectomy (RH) for cervical cancer has not been investigated.

PATIENTS AND METHODS

We reviewed patients who underwent a type III RH for cervical cancer between January 2004 and June 2011 in our institution.

RESULTS

A total of 431 patients were included and 83 (19.3%) were diagnosed with diabetes mellitus (DM). Poorly controlled DM (preoperative hemoglobin A1c [HbA1c] ≥7.0%) was observed in 49 (59.0%) diabetic patients. Compared to patients without DM and diabetic patients with good glycemic control (preoperative HbA1c <7.0%), diabetic patients with poor glycemic control had significantly higher risks of tumor recurrence, cervical cancer-specific death, and overall death. In multivariate analysis, DM with poor glycemic control independently predicted recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS). We excluded patients without DM and performed a sensitivity analysis. When HbA1c levels were treated as a dichotomous variable, preoperative HbA1c ≥7.0% was independently associated with RFS, CSS, and OS. When HbA1c level was treated as a continuous variable, it remained an independent predictor of RFS, CSS, and OS.

CONCLUSION

DM with poor glycemic control prior to RH was significantly associated with an increased risk of recurrence and mortality in cervical cancer patients. These results underscore the importance of intensive glycemic control and close follow-up for diabetic patients.

Preoperative fasting hyperglycemia is an independent prognostic factor for postoperative survival after gallbladder carcinoma radical surgery

BACKGROUND

Preoperative high blood glucose levels are closely associated with poor performance and high mortality in cancer patients. This study was designed to investigate the relationship between preoperative fasting hyperglycemia and the prognosis of patients with gallbladder cancer (GBC) after undergoing GBC radical surgery.

PATIENTS AND METHODS

A retrospective analysis of 83 eligible patients who underwent GBC radical surgery between 2007 and 2016 was performed. Factors affecting overall survival (OS) and recurrence-free survival (RFS) were analyzed by univariate and multivariate analyses.

RESULTS

Of the 83 patients, 35 (42.2%) had preoperative fasting hyperglycemia. The median OS of the enrolled patients was 12 months. The median OS in patients with fasting hyperglycemia before surgery was 18 months, which was shorter than for patients with normal fasting blood glucose levels before surgery (47 months, P<0.001). Preoperative fasting hyperglycemia was associated with shorter survival times in univariate analyses (HR, 3.215; 95% CI, 1.846-5.601; P<0.001). Multivariate analysis showed that patients with preoperative fasting hyperglycemia had a lower OS (HR, 2.832; 95% CI, 1.480-5.418; P=0.002) and RFS (HR, 2.051; 95% CI, 1.127-3.733; P=0.019) than patients with normal preoperative fasting blood glucose levels.

CONCLUSION

Preoperative fasting hyperglycemia is an independent indicator of poor prognosis in GBC patients after GBC radical surgery.

Association between glucose-lowering treatment and cancer metastasis among patients with preexisting type 2 diabetes and incident malignancy

Preclinical data suggested that dipeptidyl peptidase-4 (DPP-4) inhibitors may promote metastatic progression of preexisting cancer via nuclear factor erythroid 2-related factor 2 (NRF2) activation. We aimed to investigate the association between different glucose-lowering treatments, including DPP-4 inhibitors and metformin, both with potential NRF2 modulating effects, and new-onset metastatic cancer among type 2 diabetes patients with comorbid incident cancer. This population-based cohort study included 223,530 diabetic patients newly diagnosed with primary cancer during 2009-2011 in Korea. The patients were categorized into five study cohorts in accordance with treatment modalities during the follow-up until the end of 2016: no-antidiabetic drugs (no-AD), metformin, DPP-4 inhibitors, metformin+DPP-4 inhibitors, and insulin treatment. After propensity score (PS) matching in a 1:1 ratio against the no-AD group, 18,805 patients in metformin, 1,865 in DPP-4 inhibitors, 31,074 in metformin+DPP-4 inhibitors, and 1,895 patients in insulin groups were identified for cohort entry and analyzed against the corresponding number of no-AD patients in each PS-matched comparison pair. Metastatic risk was lower with metformin plus or minus DPP-4 inhibitors (HR 0.84, 95% CI 0.79-0.90 and 0.87, 0.80-0.95, respectively), not significantly associated with DPP-4 inhibitors (0.99, 0.77-1.29) except after thyroid cancer (3.89, 1.01-9.64), and higher with insulin therapy (1.81, 1.46-2.24) compared to no-AD use for all cancers combined. In conclusion, DPP-4 inhibitor therapy was not associated with significant risk of cancer metastasis relative to no-AD therapy, irrespective of patient age and sex, except after thyroid cancer, while metastatic risk was decreased with metformin treatment among type 2 diabetes patients with preexisting cancer.

FOXO transcription factors at the interface of metabolism and cancer

Diabetes refers to a group of metabolic diseases characterized by impaired insulin signalling and high blood glucose. A growing body of epidemiological evidence links diabetes to several types of cancer but the underlying molecular mechanisms are poorly understood. The signalling cascade connecting insulin and FOXO proteins provides a compelling example for a conserved pathway at the interface between insulin signalling and cancer. FOXOs are transcription factors that orchestrate programs of gene expression known to control a variety of processes in response to cellular stress. Genes regulated by this family of proteins are involved in the regulation of cellular energy production, oxidative stress resistance and cell viability and proliferation. Accordingly, FOXO factors have been shown to play an important role in the suppression of tumour growth and in the regulation of metabolic homeostasis. There is emerging evidence that deregulation of FOXO factors might account for the association between insulin resistance-related metabolic disorders and cancer.

Survival benefits in colorectal adenocarcinoma with the use of metformin among a black diabetic inner city population

We assessed the association of metformin use with survival in colorectal cancer in a population consists mostly of African-American and Afro-Caribbean patients. We identified 585 colorectal cancer patients, 167 (28.6%) and 418 (71.5%) were as diabetic (DM) and nondiabetic, respectively. The diagnosis of diabetes did not impact cancer survival or extent of disease. Overall, DMs with metformin use (D+M+) have better overall survival than both DMs without metformin use (D+M∼) and nondiabetics (D∼M∼), with a mean survival of 109.9 months compared with 95.7 and 106.1 months, respectively (log-rank p < 0.05). The use of metformin shows significant reduction of risk of mortality compared with nonusers (hazard ratio: 0.34; 95% CI: 0.15-0.81; p = 0.01). Use of insulin and status of diabetes did not have a significant impact on overall cancer survival.

Insulin, insulin receptors, and cancer

Insulin is a major regulator of cell metabolism but, in addition, is also a growth factor. Insulin effects in target cells are mediated by the insulin receptor (IR), a transmembrane protein with enzymatic (tyrosine kinase) activity. The insulin receptor, however, is represented by a heterogeneous family of proteins, including two different IR isoforms and also hybrid receptors resulting from the IR hemireceptor combination with a hemireceptor of the cognate IGF-1 receptor. These different receptors may bind insulin and its analogs with different affinity and produce different biologic effects. Since many years, it is known that many cancer cells require insulin for optimal in vitro growth. Recent data indicate that: (1) insulin stimulates growth mainly via its own receptor and not the IGF-1 receptor; (2) in many cancer cells, the IR is overexpressed and the A isoform, which has a predominant mitogenic effect, is more represented than the B isoform. These characteristics provide a selective growth advantage to malignant cells when exposed to insulin. For this reason, all conditions of hyperinsulinemia, both endogenous (prediabetes, metabolic syndrome, obesity, type 2 diabetes before pancreas exhaustion and polycystic ovary syndrome) and exogenous (type 1 diabetes) will increase the risk of cancer. Cancer-related mortality is also increased in patients exposed to hyperinsulinemia but other factors, related to the different diseases, may also contribute. The complexity of the diseases associated with hyperinsulinemia and their therapies does not allow a precise evaluation of the cancer-promoting effect of hyperinsulinemia, but its detrimental effect on cancer incidence and mortality is well documented.

The double trouble of metabolic diseases: the diabetes-cancer link

The recent recognition of the clinical association between type 2 diabetes (T2D) and several types of human cancer has been further highlighted by reports of antidiabetic drugs treating or promoting cancer. At the cellular level, a plethora of molecules operating within distinct signaling pathways suggests cross-talk between the multiple pathways at the interface of the diabetes–cancer link. Additionally, a growing body of emerging evidence implicates homeostatic pathways that may become imbalanced during the pathogenesis of T2D or cancer or that become chronically deregulated by prolonged drug administration, leading to the development of cancer in diabetes and vice versa. This notion underscores the importance of combining clinical and basic mechanistic studies not only to unravel mechanisms of disease development but also to understand mechanisms of drug action. In turn, this may help the development of personalized strategies in which drug doses and administration durations are tailored to individual cases at different stages of the disease progression to achieve more efficacious treatments that undermine the diabetes–cancer association.

Poor Preoperative Glycemic Control Is Associated with Dismal Prognosis after Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma: A Korean Multicenter Study

Purpose

The purpose of this study is to evaluate the effect of diabetes mellitus (DM) and preoperative glycemic control on prognosis in Korean patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNU).

Materials and Methods

A total of 566 patients who underwent RNU at six institutions between 2004 and 2014 were reviewed retrospectively. Kaplan-Meier and Cox regression analyses were performed to assess the association between DM, preoperative glycemic control, and recurrence-free, cancer-specific, and overall survival.

Results

The median follow-up period was 33.8 months (interquartile range, 41.4 months). A total of 135 patients (23.8%) had DM and 67 patients (11.8%) had poor preoperative glycemic control. Patients with poor preoperative glycemic control had significantly shorter median recurrence-free, cancer-specific, and overall survival than patients with good preoperative glycemic control and non-diabetics (all, p=0.001). In multivariable Cox regression analysis, DM with poor preoperative glycemic control showed association with worse recurrence-free survival (hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.31 to 3.90; p=0.003), cancer-specific survival (HR, 2.96; 95% CI, 1.80 to 4.87; p=0.001), and overall survival (HR, 2.13; 95% CI, 1.40 to 3.22; p=0.001).

Conclusion

Diabetic UTUC patients with poor preoperative glycemic control had significantly worse oncologic outcomes than diabetic UTUC patients with good preoperative glycemic control and non-diabetics. Further investigation is needed to elucidate the exact mechanism underlying the impact of glycemic control on UTUC treatment outcome.

Metformin for the Prevention of Bladder Cancer Recurrence: Is it Effective?

Background

Many methods have been used for preventing and reducing recurrences of bladder cancers. In recent years, some investigators have examined the use of metformin for this purpose. First lines of evidence have shown that metformin inhibits cancer cell growth and prevents cancer occurrence in patients with type 2 diabetes.

Objectives

This study is designed to assess metformin usage in the prevention of bladder cancer recurrence after the trans-urethral resection of a bladder tumor (TUR-T).

Patients and Methods

In the present study, metformin was administered in the treatment of 32 patients with a history of bladder cancer, and their results were compared with those of 33 patients with bladder cancer recurrence (placebo group). Patients in the metformin group received 1000 mg metformin (2 tablets 500 mg) for 1 year. Frequency of tumor recurrence was calculated and compared with the placebo group.

Results

There was no statistical difference between the 2 groups with respect to the recurrence rate (P > 0.05). Although the recurrence interval was longer for the metformin group, this increase was not statistical significant (P > 0.05). Furthermore, tumor recurrence had no correlation with sex or the grade of the tumors.

Conclusions

According to our findings, it seems that metformin has no considerable inhibitory effect on the recurrence rate of bladder cancer, but that it can delay tumor recurrence.

Impact of body mass on recurrence and progression in Chinese patients with Ta, T1 urothelial bladder cancer

OBJECTIVE

To evaluate the impact of body mass on recurrence and progression in patients with Ta, T1 urothelial bladder cancer.

METHODS

Data from 469 patients with Ta, T1 bladder cancer who were treated with transurethral resection of bladder tumor at our center during 2006-2014 were retrospectively studied. According to body mass index (BMI), patients were divided into three groups: normal weight (BMI < 24 kg/m(2)), overweight (24 kg/m(2) ≤ BMI < 28 kg/m(2)) and obesity (BMI ≥ 28 kg/m(2)). Clinicopathologic features were compared across groups. Kaplan-Meier curves and Cox proportional hazards regression analyses were employed to assess the association between body mass and oncologic outcomes.

RESULTS

Compared with patients with normal weight, overweight and obese counterparts showed significantly shorter recurrence-free or progression-free survival. In multivariate analyses, being overweight was an independent factor for recurrence and obesity was for both recurrence and progression. The presence of diabetes mellitus (DM) was not a strong risk factor for the entire cohort, while it became a significant predictor for both recurrence and progression in the subgroup of overweight and obese patients.

CONCLUSION

Excessive body mass seems to act as independent risk factors for worse oncologic outcomes of Ta, T1 bladder cancer. Further studies should be carried out to elucidate the exact impact of obesity, DM or even other metabolic disorders.

Preoperative glycemic control status as a significant predictor of biochemical recurrence in prostate cancer patients after radical prostatectomy

Background

The effect of diabetes mellitus (DM) on prostate cancer (PCa) outcome remains controversial. Thus, we investigated the association of DM history, glycemic control, and metformin use with oncologic outcomes after radical prostatectomy (RP).

Methods

We reviewed the records of 746 contemporary patients who had hemoglobin A1c (HbA1c) measured within the 6 months preceding RP. The associations between clinical variables and risk of adverse pathological features and biochemical recurrence (BCR) were tested using a multivariate logistic regression and multiple Cox-proportional hazards model, respectively. BCR was defined as prostatic specific antigen (PSA) > 0.2 ng/mL in 2 consecutive tests.

Results

There were no significant differences in the rates of adverse pathologic features and BCR-free survival between patients with (n = 209) and without (n = 537) a history of DM diagnosis (all p > 0.05). In multivariate analyses, high HbA1c level (≥ 6.5%) was significantly related with high pathologic Gleason score (≥ 4+3; odds ratio [OR] 1.704, p = 0.019) and BCR-free survival (OR 1.853, p = 0.007). Metformin use was not associated with BCR-free survival (OR 0.662, p = 0.125).

Conclusions

Poor glycemic control was significantly associated with BCR after RP. Meanwhile, metformin use was not associated with biochemical outcome after RP. Further investigation would be needed to identify exact mechanism underlying the impact of glycemic control on PCa treatment outcome.

Hyperglycemia as a risk factor for cancer progression

As the prevalence of diabetes mellitus is substantially increasing worldwide, associated diseases such as renal failure, cardiovascular diseases, fatty liver, and cancers have also increased. A number of cancers such as pancreatic, liver, breast, and female reproductive cancers have shown an increased prevalence and a higher mortality rate in diabetic patients compared to healthy subjects. Thus, this suggests an association between diabetes, especially type 2 diabetes and cancer incidence and progression. Recent studies have suggested that hyperinsulinemia, chronic inflammation and hyperglycemia, all frequently seen in diabetics, may lead to increased tumor growth; the underlying molecular mechanisms of this association are not fully understood. In particular, chronic hyperglycemic episodes could serve as a direct or indirect mediator of the increase in tumor cell growth. Here, we will discuss our current understanding how hyperglycemia and cancer risk may be linked, and what the implications are for the treatment of diabetic cancer patients.

Diabetes mellitus: influences on cancer risk

Diabetes mellitus and cancer are common conditions, and their co-diagnosis in the same individual is not infrequent. The relative risks associated with type 2 diabetes are greater than twofold for hepatic, pancreatic, and endometrial cancers. The relative risk is somewhat lower, at 1.2-1.5-fold for colorectal, breast, and bladder cancers. In comparison, the relative risk of lung cancer is less than 1. The evidence for other malignancies (e.g. kidney, non-Hodgkin lymphoma) is inconclusive, whereas prostatic cancer occurs less frequently in male patients with diabetes. The potential biologic links between the two diseases are incompletely understood. Evidence from observational studies suggests that some medications used to treat hyperglycemia are associated with either increased or reduced risk of cancer. Whereas anti-diabetic drugs have a minor influence on cancer risk, drugs used to treat cancer may either cause diabetes or worsen pre-existing diabetes. If hyperinsulinemia acts as a critical link between the observed increased cancer risk and type 2 diabetes, one would predict that patients with type 1 diabetes would have a different cancer risk pattern than patients with type 2 diabetes because the former patients are exposed to lower levels of exogenous administered insulin. Obtained results showed that patients with type 1 diabetes had elevated risks of cancers of the stomach, cervix, and endometrium. Type 1 diabetes is associated with a modest excess cancer risk overall and risks of specific cancers that differ from those associated with type 2 diabetes.

Genetic analysis of the Warburg effect in yeast

We recently discovered that the Warburg effect, defined by the dramatically enhanced metabolism of glucose to pyruvate, even in well-oxygenated cancer cells, can occur as a consequence of mutations that enhance lipid biosynthesis at the expense of respiratory capacity. Specifically, mutations in the E1 subunit of either of two respiratory enzymes, pyruvate dehydrogenase (PDC) or α-ketoglutarate dehydrogenase (KGDC), change substrate specificity from the 3-carbon α-ketoacid pyruvate, or the 5-carbon α-ketoacid α-ketoglutarate, to the 4-carbon α-ketoacid oxaloacetate (OADC). These mutations result in OADC-catalyzed synthesis of malonyl-CoA (MaCoA), the essential precursor of all fatty acids. These mutants arose as spontaneous suppressors of a yeast acc1(cs) cold-sensitive mutation encoding an altered form of AcCoA carboxylase (Acc1) that fails to produce MaCoA at the restrictive temperature (16 °C). Notably, these suppressors are respiratory defective as a result of the same nuclear mutations that suppress acc1(cs). These mutants also suppress sensitivity to Soraphen A, a potent inhibitor of Acc1 activity, at normal temperature (30 °C). To our knowledge, OADC activity has never been identified in eukaryotic cells. Our results offer a novel perspective on the Warburg effect: the reprogramming of energy metabolism in cancer cells as a consequence of mutational impairment of respiration to meet the fatty acid requirements of rapidly proliferating cells. We suggest OADC activity is a common feature of cancer cells and represents a novel target for the development of chemotherapeutics.

Does cancer risk increase with HbA1c, independent of diabetes?

Background:

The risks for several cancer types are increased in people with diabetes. Hyperglycaemia, hyperinsulinaemia, inflammation and altered hormonal concentrations are common characteristics between the two diseases and can all be linked to hyperglycaemia.

Methods:

Here, we use glycated haemoglobin (HbA_1c) as a biomarker for chronic hyperglycaemia. We explore whether cancer risk increases with HbA_1c, independent of diabetes, and, therefore, if risk is already increased below the diabetic HbA_1c range, by analysing data from current studies linking HbA_1c to risk of several cancer types.

Results:

The data reveal that chronic hyperglycaemia correlates with increased cancer risk for a number of cancers, except prostate cancer. Evidence is also provided that risk is already increased in the pre-diabetic and normal ranges for several cancers.

Conclusions:

These results merit urgent investigation into the risks and advantages of updating recommendations for stricter glycaemic control in diabetic and non-diabetic subjects, as this could help reduce the risk of cancer incidence and mortality.

A new link between diabetes and cancer: enhanced WNT/β-catenin signaling by high glucose

Extensive epidemiological studies suggest that the diabetic population is at higher risk of site-specific cancers. The diabetes-cancer link has been hypothesized to rely on various hormonal (insulin, IGF1, adipokines), immunological (inflammation), or metabolic (hyperglycemia) characteristics of the disease and even on certain treatments. Inflammation may have an important but incompletely understood role. As a growth factor, insulin directly, or indirectly through IGF1, has been considered the major link between diabetes and cancer, while high glucose has been considered as a subordinate cause. Here we discuss the evidence that supports a role for insulin/IGF1 in general in cancer, and the mechanism by which hyperglycemia may enhance the appearance, growth and survival of diabetes-associated cancers. High glucose triggers several direct and indirect mechanisms that cooperate to promote cancer cell proliferation, migration, invasion and immunological escape. In particular, high glucose enhancement of WNT/β-catenin signaling in cancer cells promotes proliferation, survival and senescence bypass, and represents a previously unrecognized direct mechanism linking diabetes-associated hyperglycemia to cancer. Increased glucose uptake is a hallmark of tumor cells and may ensure enhanced WNT signaling for continuous proliferation. Mechanistically, high glucose unbalances acetylation through increased p300 acetyl transferase and decreased sirtuin 1 deacetylase activity, leading to β-catenin acetylation at lysine K354, a requirement for nuclear accumulation and transcriptional activation of WNT-target genes. The impact of high glucose on β-catenin illustrates the remodeling of cancer-associated signaling pathways by metabolites. Metabolic remodeling of cancer-associated signaling will receive much research attention in the coming years. Future epidemiological studies may be guided and complemented by the identification of these metabolic interplays. Together, these studies should lead to the development of new preventive strategies for diabetes-associated cancers.

Fasting blood glucose and long-term prognosis of non-metastatic breast cancer: a cohort study

High circulating glucose has been associated with increased risk of breast cancer (BC). There may also be a link between serum glucose and prognosis in women treated for BC. We assessed the effect of peridiagnostic fasting blood glucose and body mass index (BMI) on long-term BC prognosis. We retrospectively investigated 1,261 women diagnosed and treated for stage I-III BC at the National Cancer Institute, Milan, in 1996, 1999 and 2000. Data on blood tests and follow-up were obtained by linking electronic archives, with follow-up to end of 2009. Multivariate Cox modelling estimated hazard ratios (HR) with 95 % confidence intervals (CI) for distant metastasis, recurrence and death (all causes) in relation to categorized peridiagnostic fasting blood glucose and BMI. Mediation analysis investigated whether blood glucose mediated the BMI-breast cancer prognosis association. The risks of distant metastasis were significantly higher for all other quintiles compared to the lowest glucose quintile (reference <87 mg/dL) (respective HRs: 1.99 95 % CI 1.23-3.24, 1.85 95 % CI 1.14-3.0, 1.73 95 % CI 1.07-2.8, and 1.91 95 % CI 1.15-3.17). The risk of recurrence was significantly higher for all other glucose quintiles compared to the first. The risk of death was significantly higher than reference in the second, fourth and fifth quintiles. Women with BMI ≥ 25 kg/m(2) had significantly greater risks of recurrence and distant metastasis than those with BMI < 25 kg/m(2), irrespective of blood glucose. The increased risks remained invariant over a median follow-up of 9.5 years. Mediation analysis indicated that glucose and BMI had independent effects on BC prognosis. Peridiagnostic high fasting glucose and obesity predict worsened short- and long-term outcomes in BC patients. Maintaining healthy blood glucose levels and normal weight may improve prognosis.

Diabetes and risk of cancer

Diabetes and cancer represent two complex, diverse, chronic, and potentially fatal diseases. Cancer is the second leading cause of death, while diabetes is the seventh leading cause of death with the latter still likely underreported. There is a growing body of evidence published in recent years that suggest substantial increase in cancer incidence in diabetic patients. The worldwide prevalence of diabetes was estimated to rise from 171 million in 2000 to 366 million in 2030. About 26.9% of all people over 65 have diabetes and 60% have cancer. Overall, 8–18% of cancer patients have diabetes. In the context of epidemiology, the burden of both diseases, small association between diabetes and cancer will be clinically relevant and should translate into significant consequences for future health care solutions. This paper summarizes most of the epidemiological association studies between diabetes and cancer including studies relating to the general all-site increase of malignancies in diabetes and elevated organ-specific cancer rate in diabetes as comorbidity. Additionally, we have discussed the possible pathophysiological mechanisms that likely may be involved in promoting carcinogenesis in diabetes and the potential of different antidiabetic therapies to influence cancer incidence.

Yeast and cancer cells - common principles in lipid metabolism

One of the paradigms in cancer pathogenesis is the requirement of a cell to undergo transformation from respiration to aerobic glycolysis - the Warburg effect - to become malignant. The demands of a rapidly proliferating cell for carbon metabolites for the synthesis of biomass, energy and redox equivalents, are fundamentally different from the requirements of a differentiated, quiescent cell, but it remains open whether this metabolic switch is a cause or a consequence of malignant transformation. One of the major requirements is the synthesis of lipids for membrane formation to allow for cell proliferation, cell cycle progression and cytokinesis. Enzymes involved in lipid metabolism were indeed found to play a major role in cancer cell proliferation, and most of these enzymes are conserved in the yeast, Saccharomyces cerevisiae. Most notably, cancer cell physiology and metabolic fluxes are very similar to those in the fermenting and rapidly proliferating yeast. Both types of cells display highly active pathways for the synthesis of fatty acids and their incorporation into complex lipids, and imbalances in synthesis or turnover of lipids affect growth and viability of both yeast and cancer cells. Thus, understanding lipid metabolism in S. cerevisiae during cell cycle progression and cell proliferation may complement recent efforts to understand the importance and fundamental regulatory mechanisms of these pathways in cancer.

Fasting blood glucose is a novel prognostic indicator for extranodal natural killer/T-cell lymphoma, nasal type

Background:

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL) is an aggressive disease with poor prognosis, requiring risk stratification. However, the prognosis of ENKTL is not fully defined and needs supplementation. We hypothesised that fasting blood glucose (FBG) may be a new prognostic factor for ENKTL.

Methods:

We retrospectively analysed 130 patients newly diagnosed with ENKTL.

Results:

Both univariate analysis and multivariate analysis revealed that FBG >100 mg dl⁻¹ was associated with a poor outcome. Patients with FBG >100 mg dl⁻¹ at diagnosis had more adverse clinical features, achieved lower complete remission rates (P=0.003) and had worse overall survival (P<0.001) and progression-free survival (P<0.001) compared with low-FBG patients. Measurement of FBG was helpful in differentiating between low-risk patients using the International Prognostic Index (IPI) and Prognosis Index for peripheral T-cell lymphoma (PIT) scoring and patients in a different category using the Korean Prognostic Index (KPI) scores with different survival outcomes (P<0.05).

Conclusion:

Our data suggest that measuring FBG levels at diagnosis is a novel, independent predictor of prognosis in ENKTL and helps to distinguish low-risk patients with poor survival, and this holds true in patients considered low-risk by IPI, PIT and KPI.

Obesity, type 2 diabetes, and cancer: the insulin and IGF connection

Epidemiological studies suggest a positive association between obesity and type 2 diabetes mellitus (T2D) with the risk of cancer and cancer-related mortality. Insulin resistance, hyperinsulinemia, increased levels of IGF, elevated levels of steroid and peptide hormones, and inflammatory markers appear to play a role in the connection between these different diseases. Medications, such as metformin and exogenous insulin, used to treat T2D may affect the risk of cancer and cancer-related mortality. Newer therapies targeting the insulin and IGF1 systems are being developed for use in cancer therapy.

Is there a role for carbohydrate restriction in the treatment and prevention of cancer?

Over the last years, evidence has accumulated suggesting that by systematically reducing the amount of dietary carbohydrates (CHOs) one could suppress, or at least delay, the emergence of cancer, and that proliferation of already existing tumor cells could be slowed down. This hypothesis is supported by the association between modern chronic diseases like the metabolic syndrome and the risk of developing or dying from cancer. CHOs or glucose, to which more complex carbohydrates are ultimately digested, can have direct and indirect effects on tumor cell proliferation: first, contrary to normal cells, most malignant cells depend on steady glucose availability in the blood for their energy and biomass generating demands and are not able to metabolize significant amounts of fatty acids or ketone bodies due to mitochondrial dysfunction. Second, high insulin and insulin-like growth factor (IGF)-1 levels resulting from chronic ingestion of CHO-rich Western diet meals, can directly promote tumor cell proliferation via the insulin/IGF1 signaling pathway. Third, ketone bodies that are elevated when insulin and blood glucose levels are low, have been found to negatively affect proliferation of different malignant cells in vitro or not to be usable by tumor cells for metabolic demands, and a multitude of mouse models have shown anti-tumorigenic properties of very low CHO ketogenic diets. In addition, many cancer patients exhibit an altered glucose metabolism characterized by insulin resistance and may profit from an increased protein and fat intake.

In this review, we address the possible beneficial effects of low CHO diets on cancer prevention and treatment. Emphasis will be placed on the role of insulin and IGF1 signaling in tumorigenesis as well as altered dietary needs of cancer patients.

The impact of type 2 diabetes and antidiabetic drugs on cancer cell growth

Despite investigations into mechanisms linking type 2 diabetes and cancer, there is a gap in knowledge about pharmacotherapy for diabetes in cancer patients. Epidemiological studies have shown that diabetic cancer patients on different antidiabetic treatments have different survival. The clinically relevant question is whether some antidiabetic pharmacotherapeutic agents promote cancer whereas others inhibit cancer progression. We investigated the hypothesis that various antidiabetic drugs had differential direct impact on cancer cells using four human cell lines (pancreatic cancer: MiaPaCa2, Panc-1; breast cancer: MCF7, HER18). We found that insulin and glucose promoted cancer cell proliferation and contributed to chemoresistance. Metformin and rosiglitazone suppressed cancer cell growth and induced apoptosis. Both drugs affected signalling in the protein kinases B (AKT)/mammalian target of rapamycin pathway; metformin activated adenosine monophosphate (AMP)-activated protein kinase whereas rosiglitazone increased chromosome ten level. Although high insulin and glucose concentrations promoted chemoresistance, the combination of metformin or rosiglitazone with gemcitabine or doxorubicin, resulted in an additional decrease in live cancer cells and increase in apoptosis. In contrast, exenatide did not have direct effect on cancer cells. In conclusion, different types of antidiabetic pharmacotherapy had a differential direct impact on cancer cells. This study provides experimental evidence to support further investigation of metformin and rosiglitazone as first-line therapies for type 2 diabetes in cancer patients.

Diabetes, gestational diabetes and the risk of cancer in women: epidemiologic evidence and possible biologic mechanisms

At present, more than 10% of adult American women are diagnosed with diabetes mellitus (DM). As the prevalence of the disease increases, there is greater interest in the relationship between DM and other major health issues, such as cancer - one of the leading causes of death in the western world. This paper reviews the literature on the relationship between Type 2 DM and different types of cancer among women. We discuss the possible biological mechanisms that may link diabetes and cancer, important confounders, shared risk factors and a short review of the epidemiologic literature on the association between Type 2 DM and cancer of specific organs (pancreas, liver, colorectal, bladder, endometrial, non-Hodgkin's lymphoma and breast). We also examine the association between gestational diabetes, a closely related risk factor for DM in women, and subsequent risk of cancer. Cancer survival of diabetic women is also briefly discussed. The paper concludes with an agenda for future research targeting the relationship between diabetes and cancer.

The impact of diabetes on survival in women with ovarian cancer

OBJECTIVE

Diabetes is increasingly common among cancer patients and plausible biologic mechanisms exist by which diabetes may influence cancer prognosis. We aimed to investigate the impact of diabetes on ovarian cancer outcomes.

METHODS

We assessed the outcomes of 570 non-diabetic and 72 diabetic patients with epithelial ovarian, fallopian tube, and primary peritoneal cancer over a ten-year period. All inpatient and outpatient records were reviewed. The primary end points were overall and disease-free survival.

RESULTS

Of the 642 cases, 11.2% had type II diabetes. Diabetics were more likely to be older, had a higher BMI (33.4 vs. 27.8), and had more comorbid conditions. Diabetics were less likely to have been surgically staged as compared to non-diabetics (p=0.04) although stage, grade, and likelihood of optimal cytoreduction were similar between groups. Over a period of 10 years, with an average of 44 months of follow-up, the median overall survival for diabetics was 1503 days. The median overall survival for non-diabetics was 2464 days (log rank test, p=0.02). In a Cox proportional hazards multivariable model, diabetes remained a significant predictor of overall survival (HR=2.04, p<0.01).

CONCLUSIONS

Diabetics with ovarian cancer demonstrate strikingly poorer survival. The underlying reason for this is yet unknown and deserves further attention. Differences in care, competing risks of death, and changes within the tumor biology are plausible mechanisms for the observed difference in survival.

Diabetogenic glucose and insulin concentrations modulate transcriptome and protein levels involved in tumour cell migration, adhesion and proliferation

Background:

During the last decade, epidemiological studies uncovered the tremendous impact of metabolic syndrome/diabetes mellitus type 2 (DM T2) as risk factors of the progression of cancer. Therefore, we studied the impact of diabetogenic glucose and insulin concentrations on the activities of tumour cells, because little is known about how high glucose and insulin levels are influencing gene activities causing changes in the signal cascade activities with respect to kinases involved in the proliferation and migration of cancer cells.

Methods:

To address this question we analysed the activity of more than 400 gene signatures related to (i) cell cycle, (ii) cell movement as well as (iii) signal transduction. We examined transcriptoms of kinases (PKCα, PI3K), cadherins (E-, N- VE-), integrins and cyclins by comparing physiological (5.5 mM) vs diabetogenic (11 mM) glucose concentrations (without and with insulin).

Results:

Proliferation assays revealed that high levels of glucose (11 mM) and insulin (100 ng ml⁻¹) did promote the proliferation of the tumour cell lines HT29, SW480, MCF-7, MDA MB468, PC3 and T24. Using a 3D-migration assay, we have shown that high glucose concentrations caused increased motility rates of the tumour cells. The increase in migratory activity at high glucose and insulin concentrations was mediated by an activation of PI3K, PKCα and MLCK, as figured out by the pharmacological inhibitors wortmannin, Go6976 and ML-7.

Conclusion:

We present molecular and functional data, which could help to understand how hyperglycaemia and hyperinsulinemia might trigger tumour cell proliferation and motility in patients, too.

[Antidiabetic therapy--a new possibility in the complex therapy of cancer?]

Nowadays the lack of exercise and improper eating habits are main characteristics of modern life style. This favors not only formation of type 2 diabetes or cardiovascular diseases, but also increaseas the incidence and prevalence of malignant tumors. Today there are many epidemiologic trials that demonstrate the connection between type 2 diabetes and formation of several malignomas. Its cause should be searched in common paths of pathologic processes. One of this is the birth of hyperinsulinsulinemia, which accompanies insulin resistance. Hyperinsulinemia of the host leads to increased glucose uptake in the highly insuline sensitive tumor cells which supports tumor growth. This makes type 2 diabetes a metabolic state favoring tumor formation, suggesting a potential application of oral insulin sensitizers in cancer therapy. Currently several international trials are testing the anti-tumor activity of metformin and thiazolidinedions (TZD). Besides this, encouraging results were obtained with the use of anti-IGFR antibodies in the treatment of tumors. A common therapy of diabetes and tumor may lead to new possibilities in the treatment of malignant tumor diseases. By doing this we could be able to weaken the tumor and strengthen the body, enabling it to fight against cancer. Bánhegyi RJ, Rus-Gal PO, Nagy AK, Martyin T, Varga R, Pikó B. Correlation between type 2 diabetes and malignant tumors - new possibilities in the complex therapy of cancers?

High glucose promotes cell proliferation and enhances GDNF and RET expression in pancreatic cancer cells

Hyperglycemia promotes pancreatic cancer progression, while the underlying mechanism is uncertain. We investigated the cell proliferation, glial cell line-derived neurotrophic factor (GDNF) and its tyrosine kinase receptor RET expression in BxPC-3 and MIA PaCa-2 cells when exposed to different concentrations of glucose. Proliferation of both cells was effected by glucose in a concentration-dependent manner. Definite expression of GDNF and RET was detected in both cells. Glucose concentrations could alter the expression of GDNF and RET in a concentration-dependent manner, correspondingly with the alterations of cell proliferation. Up-regulation of GDNF and RET ligand-receptor interaction might participate in the glucose-induced cancer progression.

Enhanced tumorigenesis of forestomach tumors induced by N-Methyl-N'-nitro-N-nitrosoguanidine in rats with hypoinsulinemic diabetes

Hyperinsulinemia and hyperglycemia in prediabetic and diabetic patients are thought to increase the risk of developing neoplasms because insulin is a growth factor with pre-eminent metabolic but also mitogenic effects. To determine the effect of hypoinsulinemic diabetic conditions on carcinogenesis, we examined N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced forestomach carcinogenesis in hypoinsulinemic diabetic WBN/Kob rats aged about 45 weeks (DM) compared with non-diabetic younger WBN/Kob rats (C1), non-diabetic Wistar rats age-matched to DM (C2), and non-diabetic Wistar rats age-matched to C1 (C3). All rats were treated with MNNG by gavage and were killed at 40 weeks after dosing. Various-sized tumors were disseminated throughout the forestomach of all rats, and the ratio of the area of tumors to the whole forestomach area was 23.3% in the DM group and was higher than in the C1-3 (4.2-14.3%) groups. The incidence of carcinoma was much higher in the DM group (36.8%) than in the C1-3 (7.1-16.7%) groups, and the incidence of papilloma was also significantly higher in the DM group (84.2%) than in the C1-3 (28.5-50.0%) groups. The average thickness of the squamous epithelium in the non-neoplastic mucosa was significantly greater in the DM group (50.8 mum) than in the C1-3 (29.6-37.9 microm) groups. Immunohistochemically, the Ki-67-positive index in the non-tumorous mucosa of the DM group (42.0%) was significantly higher than that of the C1-3 groups (18.8-33.3%). These results suggest that prolonged hyperglycemic conditions without hyperinsulinemia enhance tumorigenesis of MNNG-induced tumors by enhanced proliferative activity of the squamous epithelium in the rat forestomach.

Anticancer Role of PPARgamma Agonists in Hematological Malignancies Found in the Vasculature, Marrow, and Eyes

The use of targeted cancer therapies in combination with conventional chemotherapeutic agents and/or radiation treatment has increased overall survival of cancer patients. However, longer survival is accompanied by increased incidence of comorbidities due, in part, to drug side effects and toxicities. It is well accepted that inflammation and tumorigenesis are linked. Because peroxisome proliferator-activated receptor (PPAR)-gamma agonists are potent mediators of anti-inflammatory responses, it was a logical extension to examine the role of PPARgamma agonists in the treatment and prevention of cancer. This paper has two objectives: first to highlight the potential uses for PPARgamma agonists in anticancer therapy with special emphasis on their role when used as adjuvant or combined therapy in the treatment of hematological malignancies found in the vasculature, marrow, and eyes, and second, to review the potential role PPARgamma and/or its ligands may have in modulating cancer-associated angiogenesis and tumor-stromal microenvironment crosstalk in bone marrow.

Glucose as a prognostic factor in non-diabetic women with locally advanced cervical cancer (IIB-IVA)

OBJECTIVE

The aim of this study was to evaluate the association between pretreatment random plasma glucose levels and cancer prognosis in non-diabetic women with locally advanced cervical cancer treated with CCRT (concurrent chemoradiation) or RT (radiation therapy) only.

METHODS

We investigated the non-fasting plasma glucose levels checked during the initial work up before treatment in 134 non-diabetic patients with locally advanced cervical cancer. Based on the survival time and the progression-free interval (PFI) recorded in the electronic medical records Cox proportional hazard regression models were used to estimate the hazard ratio (HR) for overall survival and PFI according to the various level of glucose and a cut-off level (<102 mg/dL and >or=102 mg/dL), adjusting for clinical covariates.

RESULTS

A shorter overall survival and PFI was observed in the group with higher glucose levels (HR, 1.03; p=0.002, HR, 1.02; p=0.001, respectively) and more than 102 mg/dL, by univariate analyses (HR, 3.21; p=0.012, HR, 2.20; p=0.006, respectively). Multivariate analysis, adjusting for clinical FIGO stage, performance status, treatment type (CCRT vs. RT) and chemotherapeutic regimen types showed that patients with higher glucose levels or more than >or=102 mg/dL had shorter overall survival times (HR, 1.02; p=0.015, HR, 2.54; p=0.049, respectively) and PFI (HR, 1.02; p=0.003, HR, 1.88; p=0.031, respectively).

CONCLUSION

This investigation provides evidence supporting the prognostic value of glucose levels in non-diabetic women with locally advanced cervical cancer treated with radiation therapy and/or concurrent chemotherapy; high glucose levels were associated with a greater risk for recurrence and mortality in these patients.

Persistent outpatient hyperglycemia is independently associated with survival, recurrence and malignant degeneration following surgery for hemispheric low grade gliomas

OBJECTIVE

Hyperglycemia has been shown to augment tumor growth in vitro. However, the effects of persistent hyperglycemia on survival, recurrence and malignant degeneration in patients undergoing surgery for low grade gliomas remain unknown.

METHODS

All patients who underwent a craniotomy for hemispheric low grade glioma (WHO grade II) from 1996 to 2006 at a single institution were retrospectively reviewed. Persistent hyperglycemia was defined as serum glucose >180 microg/dl occurring three or more times between 1 and 3 months post-operatively. The independent association of outpatient glucose levels and recorded clinical and treatment variables with overall survival, tumor recurrence and malignant degeneration was assessed via separate multivariate proportional-hazards regression analyses.

RESULTS

In this study, 182 patients (89 fibrillary astrocytomas, 82 oligodendrogliomas and 11 mixed gliomas) were available for analysis. Eighteen (10%) patients experienced persistent hyperglycemia. Patients experiencing persistent hyperglycemia were older (44 +/- 16 versus 34 +/- 15) and more frequently diabetic [3 (17%) versus 4 (2%)]. All other clinical and treatment variables were not significantly different between the two cohorts. After adjusting for inter-group differences including age and diabetes and variables associated with survival and recurrence, persistent hyperglycemia was independently associated with decreased survival (p=0.001), increased recurrence (p=0.0001) and increased malignant degeneration (p<0.0001). This remained true after excluding all patients with diabetes and those on continued steroid administration. Five-year overall survival, progression-free survival and malignancy-free survival for persistent hyperglycemia versus relatively euglycemic cohorts were 43% versus 84%, 16% versus 46% and 46% versus 77%, respectively.

DISCUSSION

These findings may provide useful insight for increasing survival, decreasing tumor recurrence and decreasing malignant degeneration in patients undergoing surgery for low grade gliomas.

Significance of preoperative HbA1c level in patients with diabetes mellitus and clinically localized prostate cancer

INTRODUCTION

We investigated potential relationships of history of diabetes mellitus (DM) and glycemic control, represented by hemoglobin A1c (HbA1c) level, with characteristics of tumor among patients who received radical prostatectomy (RP) for clinically localized prostate cancer.

METHODS

We reviewed data of 740 patients who underwent RP for clinically localized prostate cancer between 2004 and 2008 without receiving preoperative radiation or hormonal treatment. Univariate and multivariate logistic regression analyses addressed the associations of history of DM and HbA1c level with known prognostic variables of prostate cancer.

RESULTS

No significant differences were observed in various preoperative and pathological parameters between those with (n = 89) and without DM (n = 651). When only the subjects with DM were divided into two groups (group 1 and 2) according to HbA1c level (<6.5% vs. >/=6.5%), group 2 demonstrated significantly higher rate of extraprostatic extension of tumor (P = 0.043) and high (>/=7) pathological Gleason score (P = 0.005) than group 1. Also among those with DM, HbA1c level was observed to be an independent predictor for high pathologic Gleason score (P = 0.010) and extraprostatic extension of tumor (P = 0.035), respectively in multivariate analyses.

CONCLUSION

Although simple history of having DM may not be a significant factor regarding aggressiveness of clinically localized prostate cancer, the glycemic control, as represented by HbA1c level, may be a useful preoperative predictor of aggressive tumor profile among patients with DM who are also diagnosed with clinically localized prostate cancer.

Glucose as a prognostic factor in ovarian carcinoma

BACKGROUND

Research suggests that glucose levels in cancer patients may be an important prognostic indicator. In ovarian tumors, increased expression of glucose transporter 1 (GLUT1), a transmembrane protein responsible for glucose uptake, is related to shorter survival time in ovarian cancer patients. This study tested the hypothesis that higher presurgical glucose levels predict shorter disease-specific survival time and time to recurrence in ovarian cancer patients.

METHODS

Nonfasting plasma glucose levels were determined for 74 patients with ovarian cancer at the time of their presurgical consultation and for 125 ovarian cancer patients in an independent validation set. Survival time and time to recurrence (disease-free interval [DFI]) were ascertained from medical records. Cox proportional hazards regression models were used to estimate the hazard ratio (HR) for survival time and DFI in relation to glucose level, adjusting for body mass index (BMI), stage, grade, and cytoreduction as appropriate.

RESULTS

Higher glucose levels were associated with shorter survival times in univariate analyses (HR, 1.88; P = .05). Multivariate analysis adjusting for stage showed that higher glucose levels were associated with shorter survival times (HR, 2.01; P = .04) and DFI (HR, 2.32; P = .05). In the validation set, higher glucose levels were associated with shorter survival times (HR, 2.01; P = .02) and DFI (HR, 2.48; P = .001) in univariate analysis, although glucose was not independent of the effect of cytoreduction when predicting survival time in this latter set.

CONCLUSIONS

These findings contribute to mounting evidence that glucose levels have prognostic value in ovarian carcinoma.

PERSISTENT OUTPATIENT HYPERGLYCEMIA IS INDEPENDENTLY ASSOCIATED WITH DECREASED SURVIVAL AFTER PRIMARY RESECTION OF MALIGNANT BRAIN ASTROCYTOMAS

OBJECTIVE

Patients with malignant brain astrocytomas are at high risk for developing hyperglycemia secondary to frequent corticosteroid administration. Several clinical studies have shown that hyperglycemia is associated with poor outcome in multiple disease states. Furthermore, hyperglycemia augments in vitro astrocytoma growth, whereas hypoglycemia attenuates in vitro astrocytoma cell growth. We hypothesized that persistent hyperglycemic states in the outpatient setting may serve as a prognostic marker of decreased survival in patients with malignant brain astrocytomas.

METHODS

We retrospectively reviewed 367 cases of craniotomy for malignant brain astrocytomas (World Health Organization Grade III or IV). Persistent hyperglycemia was defined as serum glucose greater than 180 mg/dL occurring three or more times between 1 and 3 months postoperatively. Isolated hyperglycemia was defined as an isolated occurrence of serum glucose greater than 180 mg/dL. The independent association of outpatient glucose levels and recorded clinical and treatment variables with overall survival was assessed via multivariate proportional-hazards regression analysis.

RESULTS

A total of 367 craniotomies (209 primary, 158 secondary) were performed for malignant brain astrocytomas (glioblastoma multiforme, 297; anaplastic astrocytomas, 70); 68 (19%) and 28 (8%) of the patients experienced isolated or persistent outpatient hyperglycemia, respectively. Patients experiencing persistent hyperglycemia were older (59 ± 13 versus 51 ± 14 yr), were diabetic more frequently (7 [25%] versus 10 [3%]), continued to receive corticosteroids more frequently (21 [75%] versus 35 [10%]); and received temozolomide less often (4 [14%] versus 116 [34%]). Adjusting for intergroup differences and variables associated with survival in this model, age (P = 0.001), Karnofsky Performance Scale score (P = 0.001), tumor grade (P = 0.001), primary versus secondary resection (P = 0.008), temozolomide (P = 0.007), subsequent resection (P = 0.07), and continued outpatient dexamethasone therapy, persistent outpatient hyperglycemia (relative risk, 1.79; 95% confidence interval, 1.05–3.05, P = 0.03) remained independently associated with decreased survival. Median survival for persistently hyperglycemic versus normal-glycemic cohorts was 5 and 11 months, respectively.

CONCLUSION

In our experience, persistent outpatient hyperglycemia was associated with decreased survival in patients undergoing surgical resection for malignant astro- cytomas and was independent of the degree of disability, tumor grade, diabetes, prolonged dexamethasone use, or subsequent treatment modalities. Increased glucose control is warranted in this patient population and may contribute to improved outcomes in the treatment of malignant brain astrocytomas.

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.