Association of diabetes with prostate cancer risk in the multiethnic cohort

Diabetes Mellitus and Prostate Cancer Risk-A Systematic Review and Meta-Analysis

INTRODUCTION

Prostate cancer is the second most commonly diagnosed malignant tumor worldwide and poses a significant challenge to public health. This systematic review and meta-analysis aims to investigate the association between diabetes mellitus and the risk of developing prostate cancer.

METHODS

We conducted a search of PubMed, Embase, and the Cochrane Library from 1998 to 2024. The risk of bias within the included studies was assessed using the Newcastle-Ottawa Scale. The DerSimonian-Laird random-effect model was employed for the meta-analysis. Heterogeneity was evaluated using a forest plot and statistically assessed via the Q test, I2 index, and p-values.

RESULTS

Forty-three studies involving a total of 3,746,769 patients were included. Both case-control (pOR = 0.68, 95% CI: 0.61-0.97; I2 = 92.24%) and cohort studies (pRR = 0.71, 95% CI: 0.59-0.99; I2 = 85.41%) suggest that diabetes mellitus is associated with a reduced risk of prostate cancer, though with significant heterogeneity (p < 0.05). Subgroup analysis revealed that the risk of developing prostate cancer was significantly higher in patients with a family history of prostate cancer (pRR = 1.25, 95% CI: 1.16-1.35; I2 = 69.51%).

CONCLUSIONS

Our meta-analysis of recent observational studies indicates that diabetes mellitus is associated with a reduced risk of developing prostate cancer.

New findings on the effects of diabetes and anti-diabetic drugs on prostate cancer

Although diabetes mellitus (DM) is known to be related to the risk of many cancers, there are few studies on the risk of prostate cancer (PC) depending on the status of hyperglycemia, such as prediabetes and DM. Thus, the objective of this study was to determine the effect of each status of hyperglycemia on the risk of PC. In a Korean National Health Insurance Service database cohort, a total of 560,413 individuals who were followed until 2018 were analyzed. The risk of PC in patients with impaired fasting glucose (IFG) and new onset DM as well as all DM was determined. Associations of metabolic syndrome (MetS) components with the risk of PC according to glycemic status were evaluated. The association of anti-diabetic drugs with the incidence of PC was also analyzed. The presence of new-onset and all DM showed a significant reduction of the risk of PC in adjusted models. There was a trend that the presence of DM reduced the risk of PC regardless of the presence of MetS components. Regarding associations of anti-diabetic drugs with the incidence of PC, DM patients who were taking less than three drugs of oral hypoglycemic agents including metformin showed a reduced risk of PC compared to patients without using metformin. This study supports an inverse relationship between DM and the risk of PC. However, the risk of PC can be different depending on glycemic status and sorts of anti-diabetic drugs.

Incidence of prostate cancer in Medicaid beneficiaries with and without HIV in 2001-2015 in 14 states

Prostate cancer (PCa) incidence is reportedly lower in men with HIV compared to men without HIV for unknown reasons. We describe PCa incidence by HIV status in Medicaid beneficiaries, allowing for comparison of men with and without HIV who are similar with respect to socioeconomic characteristics and access to healthcare. Men (N = 15,167,636) aged 18-64 with ≥7 months of continuous enrollment during 2001-2015 in 14 US states were retained for analysis. Diagnoses of HIV and PCa were identified using non-drug claims. We estimated cause-specific (csHR) comparing incidence of PCa by HIV status, adjusted for age, race-ethnicity, state of residence, year of enrollment, and comorbid conditions, and stratified by age and race-ethnicity. Hazard of PCa was lower in men with HIV than men without HIV (csHR = 0.89; 95% CI: 0.80, 0.99), but varied by race-ethnicity, with similar observations among non-Hispanic Black (csHR = 0.79; 95% CI: 0.69, 0.91) and Hispanic (csHR = 0.85; 95% CI: 0.67, 1.09), but not non-Hispanic white men (csHR = 1.17; 95% CI: 0.91, 1.50). Findings were similar in models restricted to men aged 50-64 and 40-49, but not in men aged 18-39. Reported deficits in PCa incidence by HIV status may be restricted to specific groups defined by age and race ethnicity.

Incidence of prostate cancer in Medicaid beneficiaries with and without HIV in 2001-2015 in 14 states

Background

Prostate cancer is projected to be the most common cancer among people living with HIV; however, incidence of prostate cancer has been reported to be lower in men with HIV compared to men without HIV with little evidence to explain this difference. We describe prostate cancer incidence by HIV status in Medicaid beneficiaries, allowing for comparison of men with and without HIV who are similar with respect to socioeconomic characteristics and access to healthcare.

Methods

Medicaid beneficiaries (N=15,167,636) aged 18-64 with ≥7 months of continuous enrollment during 2001-2015 in 14 US states were retained for analysis. Diagnoses of HIV and prostate cancer were identified using inpatient and other non-drug claims. We estimated cause-specific (csHR) and sub-distribution hazard ratios comparing incidence of prostate cancer by HIV status, adjusted for age, race-ethnicity, state of residence, year of enrollment, and comorbid conditions. Models were additionally stratified by age and race-ethnicity.

Results

There were 366 cases of prostate cancer observed over 299,976 person-years among beneficiaries with HIV and 17,224 cases over 22,298,914 person-years in beneficiaries without HIV. The hazard of prostate cancer was lower in men with HIV than men without HIV (csHR=0.89; 95% CI: 0.80, 0.99), but varied by race-ethnicity, with similar observations among non-Hispanic Black (csHR=0.79; 95% CI: 0.69, 0.91) and Hispanic (csHR=0.85; 95% CI: 0.67, 1.09), but not non-Hispanic white men (csHR=1.17; 95% CI: 0.91, 1.50). Results were similar in models restricted to ages 50-64 and 40-49, except for a higher hazard of prostate cancer in Hispanic men with HIV in their 40s, while the hazard of prostate cancer was higher in men with HIV across all models for men aged 18-39.

Conclusion

Reported deficits in prostate cancer incidence by HIV status may be restricted to specific groups defined by age and race-ethnicity.

Risk analysis of metformin use in prostate cancer: a national population-based study

INTRODUCTION

Various approaches are required to prevent and treat heterogeneity-based prostate cancer. Here, we analyzed the anticancer effects of metformin, which has a good toxicity profile and is inexpensive.

METHOD

From January 2010 to December 2019, analysis was conducted retrospectively in a cohort from the National Health Insurance Service database. The wash-out period was set for cancer diagnosis in 2010 and 2011, and subjects (105,279) diagnosed with prostate cancer (ICD C61) from 2012 to 2014 were excluded The final subjects (105,216) were defined as the metformin administration group when they took metformin for 180 days or more from January 2012 to December 2019. The non-metformin group was defined as those who took less than 180 days from January 2012 to December 2019. The prevalence of prostate cancer according to metformin administration and the risk according to the cumulative duration of metformin were analyzed.

RESULTS

A total of 105,216 people were included in this study, with 59,844 in the metformin group and 45,372 in the metformin non-administration group. When calculating HRs (Hazard Rate) according to the cumulative period of metformin administration, metformin administration period length was inversely associated with prostate cancer risk (Q2 HR = 0.791 95% CI: 0.773-0.81, Q3 HR = 0.634 95% CI: 0.62-0.649, Q4 HR = 0.571 95% CI: 0.558-0.585). HRs tended to decrease with the cumulative duration of metformin administration.

CONCLUSION

This study confirmed that prostate cancer risk decreased with increasing duration of metformin administration. Metformin should be considered as a new strategy in the treatment and prevention of prostate cancer characterized by heterogeneity.

No Association of Trichomonas vaginalis Seropositivity with Advanced Prostate Cancer Risk in the Multiethnic Cohort: A Nested Case-Control Study

The potential involvement of a sexually transmitted agent has been suggested to contribute to the high number of prostate cancers in the United States and worldwide. We investigated the relationship of Trichomonas vaginalis seropositivity with prostate cancer risk in a nested case-control study within the Multiethnic Cohort in Hawaii and California using blood samples collected prior to cancer diagnoses. Incident cases of advanced prostate cancer (intermediate- to high-grade based on Gleason score ≥ 7 and/or disease spread outside the prostate) were matched to controls by age, ethnicity, and the date of blood collection. T. vaginalis serostatus was measured using an ELISA detecting IgG antibodies against a recombinant T. vaginalis α-actinin protein. Seropositivity to T. vaginalis was observed in 35 of 470 (7.4%) cases and 26 of 470 (5.5%) controls (unadjusted OR = 1.47, 95% CI 0.82-2.64; adjusted OR = 1.31, 95% CI 0.67-2.53). The association was similarly not significant when cases were confined to extraprostatic tumors having regional or distant spread (n = 121) regardless of grade (unadjusted OR = 1.37, 95% CI 0.63-3.01; adjusted OR = 1.20, 95% CI 0.46-3.11). The association of T. vaginalis with prostate cancer risk did not vary by aspirin use. Our findings do not support a role for T. vaginalis in the etiology of advanced prostate cancer.

The impact of diabetes status on total and site-specific cancer risk in the elderly population: A nationwide cohort study

AIMS

We aimed to evaluate the association of prediabetes, diabetes, and diabetes duration with risk of total and site-specific cancer in the Korean population aged 65 years and above.

METHODS

This study included 1,232,173 subjects aged ≥ 65 years who underwent a general health screening program. Diabetes status was categorized as normal glucose tolerance, impaired fasting glucose, new-onset diabetes, diabetes duration of < 5 years, and diabetes duration of ≥ 5 years. Cox proportional hazards models were used to investigate the association of diabetes status with cancer risk.

RESULTS

The risk of total cancer increased as diabetes status worsened, as did the risks of liver, biliary, and pancreatic cancer. Risks of liver, biliary, and pancreatic cancer were significantly higher in subjects aged 65-74 years than in those aged ≥ 75 years. The relationship of diabetes status with overall cancer incidence was found to significantly interact with sex. Among subjects with diabetes, the risks of liver and lung cancer were significantly higher in men than in women regardless of diabetes duration.

CONCLUSIONS

Diabetes status is associated with increased risk of cancer in the elderly. There are age and sex differences in the risk of total and site-specific cancers, including liver, biliary, and pancreatic cancer. This study highlights the importance of cancer screening for elderly subjects with diabetes.

Antitumor Effects and Mechanisms of Metabolic Syndrome Medications on Hepatocellular Carcinoma

Liver cancer has a high incidence and mortality rate worldwide, with hepatocellular carcinoma (HCC) being the most common histological type. With the decrease in the number of newly infected patients and the spread of antiviral therapy, hepatitis virus-negative chronic liver diseases including steatohepatitis are increasingly accounting for a large proportion of HCC, and an important clinical characteristic is the high prevalence of metabolic syndrome including hypertension, type 2 diabetes (T2D), dyslipidemia, and obesity. Since patients with steatohepatitis are less likely to undergo surveillance for early detection of HCC, they may be diagnosed at an advanced stage and have worse prognosis. Therefore, treatment strategies for patients with HCC caused by steatohepatitis, especially in advanced stages, become increasingly important. Further, hypertension, T2D, and dyslipidemia may occur as side effects during systemic treatment, and there will be increasing opportunities to prescribe metabolic syndrome medications, not only for originally comorbid diseases, but also for adverse events during HCC treatment. Interestingly, epidemiological studies have shown that patients taking some metabolic syndrome medications are less likely to develop various types of cancers, including HCC. Basic studies have also shown that these drugs have direct antitumor effects on HCC. In particular, angiotensin II receptor blockers (a drug group for treating hypertension), biguanides (a drug group for treating T2D), and statins (a drug group for treating dyslipidemia) have shown to elucidate antitumor effects against HCC. In this review, we focus on the antitumor effects of metabolic syndrome medications on HCC and their mechanisms based on recent literature. New therapeutic agents are also increasingly being reported. Analysis of the antitumor effects of metabolic syndrome medications on HCC and their mechanisms will be doubly beneficial for HCC patients with metabolic syndrome, and the use of these medications may be a potential strategy against HCC.

Cancer and diabetes co-occurrence: A national study with 44 million person-years of follow-up

The number of new cases of cancer is increasing each year, and rates of diabetes mellitus are also increasing dramatically over time. It is not an unusual occurrence for an individual to have both cancer and diabetes at the same time, given they are both individually common, and that one condition can increase the risk of the other. In this manuscript, we use national-level diabetes (Virtual Diabetes Register) and cancer (New Zealand Cancer Registry) data on nearly five million individuals over 44 million person-years of follow-up to examine the occurrence of cancer amongst a national prevalent cohort of patients with diabetes. We completed this analysis separately by cancer for the 24 most commonly diagnosed cancers in Aotearoa New Zealand, and then compared the occurrence of cancer among those with diabetes to those without diabetes. We found that the rate of cancer was highest amongst those with diabetes for 21 of the 24 most common cancers diagnosed over our study period, with excess risk among those with diabetes ranging between 11% (non-Hodgkin's lymphoma) and 236% (liver cancer). The cancers with the greatest difference in incidence between those with diabetes and those without diabetes tended to be within the endocrine or gastrointestinal system, and/or had a strong relationship with obesity. However, in an absolute sense, due to the volume of breast, colorectal and lung cancers, prevention of the more modest excess cancer risk among those with diabetes (16%, 22% and 48%, respectively) would lead to a substantial overall reduction in the total burden of cancer in the population. Our findings reinforce the fact that diabetes prevention activities are also cancer prevention activities, and must therefore be prioritised and resourced in tandem.

Health Burdens and SES in Alabama: Using Geographic Information System to Examine Prostate Cancer Health Disparity

Socioeconomic disparities influence the risk of many diseases, including cancer. The cancer rate in Alabama is high, and the state has one of the highest rates of prostate cancer in the USA. Alabama's counties are embedded with socioeconomic disparities, politics, race, ethnicity, and oppression, among which social equity and socioeconomic status (SES) been closely associated with prostate cancer. The Geographic Information System (GIS) has become a valuable technology in understanding public health in many applications, including cancer. This study integrates Alabama's county-level prostate cancer incidence and mortality and its association with socioeconomic and health disparities. We conducted robust data mining from several data sources such as the Alabama State Cancer Profile data, Alabama Department of Health, American Cancer Society, Center for Disease Control, and National Cancer Institute. The research method is the Geographic Information System (GIS), and we employed prostate cancer data within GIS to understand Alabama's prostate cancer prevalence regarding SES. The GIS analysis indicated an apparent socioeconomic disparity between the Black Belt and Non-Black Belt counties of Alabama. The Black Belt counties' poverty rate is also remarkably higher than non-Black Belt counties. In addition, we analyzed the median household income by race. Our analysis demonstrates that the Asian background population in the state earned the highest median income compared to non-Hispanic whites and the African American population. Furthermore, the data revealed that the preexisting condition of diabetes and obesity is closely associated with prostate cancer. The GIS analysis suggests that prostate cancer incidence and mortality disparities are strongly related to SES. In addition, the preexisting condition of obesity and diabetes adds to prostate cancer incidences. Poverty also reflects inequalities in education, income, and healthcare facilities, particularly among African Americans, contributing to Alabama's health burden of prostate cancer.

Cancer incidence and stage at diagnosis among people with psychotic disorders: Systematic review and meta-analysis

Research regarding the incidence of cancer among people with psychotic disorders relative to the general population is equivocal, although the evidence suggests that they have more advanced stage cancer at diagnosis. We conducted a systematic review and meta-analysis to examine the incidence and stage at diagnosis of cancer among people with, relative to those without, psychotic disorders. We searched the MEDLINE, EMBASE, PsycINFO, and CINAHL databases. Articles were included if they reported the incidence and/or stage at diagnosis of cancer in people with psychotic disorders. Random effects meta-analyses were used to determine risk of cancer and odds of advanced stage cancer at diagnosis in people with psychosis, relative to those without psychotic disorders. A total of 40 articles were included in the review, of which, 31 were included in the meta-analyses. The pooled age-adjusted risk ratio for all cancers in people with psychotic disorders was 1.08 (95% CI: 1.01-1.15), relative to those without psychotic disorders, with significant heterogeneity by cancer site. People with psychotic disorders had a higher incidence of breast, oesophageal, colorectal, testicular, uterine, and cervical cancer, and a lower incidence of skin, prostate, and thyroid cancer. People with psychotic disorders also had 22% higher (95% CI: 2-46%) odds of metastases at diagnosis, compared to those without psychotic disorders. Our systematic review found a significant difference in overall cancer incidence among people diagnosed with psychotic disorders and people with psychotic disorders were more likely to present with advanced stage cancer at diagnosis. This finding may reflect a need for improved access to and uptake of cancer screening for patients diagnosed with psychotic disorders.

Different effect of obesity and metabolic syndrome on prostate cancer by age group

Substantial evidence supports that metabolic syndrome (MetS) affects the incidence of several cancers, with different effects according to age group. We hypothesized that MetS has an age-specific effect on the occurrence of prostate cancer. We studied a National Health Insurance Service health checkup cohort. A total of 5,370,614 men in the cohort were categorized into three age groups in 2009 (20-39, 40-64, ≥65). Prostate cancer incidence was estimated on a cumulative basis from 2009 to 2018. We tried to identify the correlation of MetS components and prostate cancer by age group using this large retrospective cohort. MetS components included the body mass index (BMI), waist circumference (WC), hypertension, obesity, hyperlipidemia, cardiovascular disease, smoking, drinking, serum glucose, serum total cholesterol, serum triglyceride, serum high-density lipoprotein (HDL)-cholesterol and serum low-density lipoprotein (LDL)-cholesterol. A multivariate Cox proportional hazard model was used for the incidence of prostate cancer according to the MetS component. In the young age (20-39) group, the MetS component was not related to prostate cancer. In the middle-aged (40-64) group, the presence of MetS, WC, HDL cholesterol, and hypertension was significantly associated with an increased prevalence of prostate cancer. In the old age (≥65) group, the presence of MetS, WC, HDL cholesterol, triglycerides, and hypertension were significant factors for the incidence of prostate cancer. This tendency was marked in BMI>30 in the old age group (odds ratio: 1.32; P<0.0001). MetS components were age-specifically associated with an increased incidence of prostate cancer. Because the MetS components were related to prostate cancer from middle age to old age, preventing MetS for these age groups is crucial.

Comparison of the Effects of Allium cepa L. Extract Together with Insulin on Sperm Parameters in Diabetic Rats

Background: In diabetic patients, uncontrolled blood sugar causes disorders in various systems of the body in the long term. The reproductive system is one of these susceptible systems. It is known that diabetes can adversely affect spermatogenesis. The use of medicinal plants in the treatment of various diseases has been discussed by many researchers for a long time. Onion, scientifically known as Allium cepa L., contains antioxidants. Insulin is also a drug used to control blood sugar in diabetic patients. Objectives: This study aimed to evaluate and compare in vivo antidiabetic activities of hydroalcoholic onion seed extract together with insulin in diabetic rats. Methods: In this study, diabetes was induced in rats with streptozotocin (60 mg/kg). Fifty animals were equally divided into five groups: nondiabetic control (group 1); diabetic control (group 2); diabetic rats receiving streptozotocin plus insulin (group 3); and diabetic rats treated with 200 and 400 mg/kg of Allium cepa L. seed extract by gavage for four weeks (groups 4 and 5). At the end of the study, the prostate ventral lobe was removed and processed for histological studies. Next, sperm parameters from the tail of the left epididymis, biochemical parameters, and histopathological changes were analyzed and compared. Results: The sperm parameters of diabetic rats receiving 200 and 400 mg/kg of Allium cepa L. extract showed a significant increase compared to the diabetic control group. Conclusions: Administration of Allium cepa L. extract as a strong antioxidant was adequate to compensate for the toxic effects of streptozotocin and increase the motility of sperms.

Hormonal patterns in men with prediabetes and diabetes in NHANES III: possible links with prostate cancer

PURPOSE

Pathways involving sex hormones and insulin-like growth factors (IGFs) have been proposed to explain, in part, the lower risk of prostate cancer among men with diabetes. To gain insights into potential biological mechanisms we explored differences in serum concentrations of sex hormones and IGFs across the trajectory from normoglycemia to prediabetes to poorly controlled diabetes.

METHODS

Using cross-sectional data from the National Health and Nutrition Examination Survey III we examined differences in levels of circulating sex hormones, sex hormone-binding globulin (SHBG), IGF-1, and IFG-binding protein 3 (IGFBP-3), according to diabetes status: no diabetes [n = 648], prediabetes [n = 578], undiagnosed diabetes [n = 106], well-controlled diabetes [n = 42], and poorly controlled diabetes [n = 56]. Adjusted geometric mean concentrations were derived using multivariable linear regression, adjusted for age, race, and other lifestyle factors.

RESULTS

Total testosterone concentrations were lower among prediabetics (4.89 ng/mL, 95% confidence interval (CI) 4.95-5.21) than men without prediabetes/diabetes (5.29 ng/mL, 95% CI 5.06-5.53) but did not reduce further across diabetes groups. Concentrations of estradiol, estimated free testosterone, SHGB, IGF-1, and IGFBP-3 did not differ. While the ratio of IGF-1 to IGFBP-3 was lower among men with prediabetics and undiagnosed diabetes than men without prediabetes/diabetes, there was no trend across groups. A positive trend for the ratio of estradiol-to-testosterone levels was observed across groups (p trend = 0.045).

CONCLUSION

Our findings do not provide clear support for either an androgen driven or IGF-driven pathway for the inverse association between diabetes and prostate cancer risk.

Clinical research analysis based on prostate cancer screening diagnosis

This study aimed to analyse the clinical characteristics and risk factors of patients with positive prostate biopsy at 4-20 ng/mL of prostate-specific antigen (PSA), construct a new parameter based on this characteristics and assess its diagnostic value for prostate cancer (PCa). Logistic regression analysis was used to clarify the risk factors of PCa, and a new parameter based on the results was constructed. Compare the diagnostic value of various diagnostic parameters for PCa. Logistic multivariate regression analysis revealed that age (OR, 5.269; 95%CI, 2.762-10.050), comorbid diabetes (OR, 2.437; 95%CI, 1.162-5.111), PSA (OR, 2.462; 95%CI, 1.198-5.059) and prostate volume (PV) (OR, 0.227; 95%CI, 0.100-0.516) are risk factors for PCa. The age, PSA and PV of patients were combined to construct a new parameter, that is A-PSAD = (age × total PSA [TPSA])/PV]. The area under the receiver-operating characteristic curve(AUC) of A-PSAD (0.728) for PCa diagnosis was higher than the AUCs of TPSA (0.581), free prostate-specific antigen (0.514), (F/T)PSA (0.535) and PSAD (0.696), with significant differences. Age, history of diabetes, TPSA and PV are risk factors for PCa(PSA:4-20ng/mL); in addition, A-PSAD has a moderate diagnostic value for PCa and may become a new indicator for PCa screening.

Association of Anthropometric Measures With the Risk of Prostate Cancer in the Multiethnic Cohort

In studies of anthropometric measures and prostate cancer risk, conducted primarily in White men, positive associations with advanced disease have been reported. We assessed body size in relation to incident prostate cancer risk in 79,950 men from the Multiethnic Cohort, with 8,819 cases identified over 22 years (1993-2015). Height was associated with increased risk of advanced prostate cancer (≥68 inches (≥ 173 cm) vs. < 66 inches (168 cm); hazard ratio (HR) = 1.24, 95% confidence interval (CI): 1.04, 1.48) and high-grade disease (HR = 1.15, 95% CI: 1.02, 1.31). Compared with men of normal weight, men overweight at baseline were at higher risk of high-grade cancer (HR = 1.15, 95% CI: 1.04, 1.26). Greater weight was positively associated with localized and low-grade disease in Blacks and Native Hawaiians (by race, P for heterogeneity = 0.0002 and 0.008, respectively). Weight change since age 21 years was positively associated with high-grade disease (for ≥ 40 pounds (18 kg) vs. 10 pounds (4.5 kg), HR = 1.20, 95% CI: 1.05, 1.37; P for trend = 0.005). Comparing highest versus lowest quartile, waist-to-hip ratio was associated with a 1.78-fold increase (95% CI: 1.28, 2.46) in the risk of advanced prostate cancer. Positive associations with the majority of anthropometric measures were observed in all 5 racial/ethnic groups, suggesting a general impact of anthropometric measures on risk across populations.

Differences in the relationship between diabetes and prostate cancer among Black and White non-Hispanic men

PURPOSE

Studies finding lower incidence rates of prostate cancer among men with diabetes have been primarily conducted in White non-Hispanic (WNH) populations. The purpose of this analysis is to compare the relationship between diabetes and prostate cancer among Black (BNH) and White non-Hispanic men.

METHODS

We used Surveillance, Epidemiology, and End Results (SEER)-Medicare data from 2011 to 2015 to compare incidence rates and tumor characteristics between BNH and WNH men by diabetes status. Age-adjusted incidence rates and corresponding rate ratios (RR) by diabetes status were calculated overall and by tumor grade, stage, and PSA level separately for BNH and WNH men. We used multivariable logistic regression to compare tumor characteristics among men with prostate cancer in the numerator, both within and across race/ethnic groups.

RESULTS

Overall age-adjusted incidence rates were significantly lower in men with diabetes compared to those without among WNH men [RR = 0.88 95% Confidence Interval (CI) 0.86-0.90] but there was no difference in rates by diabetes status among BNH men (RR = 1.01 95% CI 0.96-1.07). Men with diabetes were less likely to be diagnosed with distant-staged tumors compared to those without diabetes in both race/ethnic groups but the magnitude of difference by diabetes status was greater in BNH [Odds Ratio (OR) = 0.52 95% CI 0.42-0.64] than WNH (OR = 0.88 95% CI 0.81-0.95) men (p-value for interaction < 0.001).

CONCLUSION

The relationship between diabetes and prostate cancer differed between BNH and WNH men. The differences could have implications in evaluating the effectiveness of prostate cancer screening in men with diabetes across racial/ethnic subgroups.

Do the Prostate-Specific Antigen (PSA) Tests That Are Ordered in Clinical Practice Adhere to the Pertinent Guidelines?

Scientific societies have provided guidelines to reduce PSA-specific harms. We studied the potential non-compliance of PSA testing with current guidelines in general practice. A cross-sectional study of a random sample of 1291 patients with a PSA test was performed between January and April 2018 in primary health care. Patients with a previous prostate cancer diagnosis or those who were being followed-up for previous high PSA values were excluded. Two independent researchers classified whether each test was potentially non-compliant with recommendations. We estimated frequencies of potentially non-compliant PSA determinations and calculated prevalence ratios (PR) to assess their relationship with possible explanatory variables. A total of 66% (95% CI: 62-69%) of PSA requests in asymptomatic patients were potentially non-compliant with the current guideline. This was associated with having a previous diagnosis of neoplasm (PR adjusted by age and life expectancy: 1.18; 95% CI: 1.02-1.37) as well as being a current consumer of tobacco, alcohol, or other drugs (PR: 0.80; 95% CI: 0.67-0.97). Real world data shows that patients are still frequently exposed to overdiagnosis risk with a PSA potentially non-compliant with recommendations. Patients diagnosed with another neoplasm or non-consumers of toxic substances were more exposed, probably due to increased contact with doctors or health-seeking behaviour.

Diabetes and Cancer: Metabolic Association, Therapeutic Challenges, and the Role of Natural Products

Cancer is considered the second leading cause of death worldwide and in 2018 it was responsible for approximately 9.6 million deaths. Globally, about one in six deaths are caused by cancer. A strong correlation was found between diabetes mellitus and carcinogenesis with the most evident correlation was with type 2 diabetes mellitus (T2DM). Research has proven that elevated blood glucose levels take part in cell proliferation and cancer cell progression. However, limited studies were conducted to evaluate the efficiency of conventional therapies in diabetic cancer patients. In this review, the correlation between cancer and diabetes will be discussed and the mechanisms by which the two diseases interact with each other, as well as the therapeutics challenges in treating patients with diabetes and cancer with possible solutions to overcome these challenges. Natural products targeting both diseases were discussed with detailed mechanisms of action. This review will provide a solid base for researchers and physicians to test natural products as adjuvant alternative therapies to treat cancer in diabetic patients.

The Roles of ZnT1 and ZnT4 in Glucose-Stimulated Zinc Secretion in Prostate Epithelial Cells

PURPOSE

We have previously demonstrated by MRI that high glucose stimulates efflux of zinc ions from the prostate. To our knowledge, this phenomena had not been reported previously and the mechanism remains unknown. Here, we report some initial observations that provide new insights into zinc processing during glucose-stimulated zinc secretion (GSZS) in the immortalized human prostate epithelial cell line, PNT1A. Additionally, we identified the subtypes of zinc-containing cells in human benign prostatic hyperplasia (BPH) tissue to further identify which cell types are likely responsible for zinc release in vivo.

PROCEDURE

An intracellular fluorescence marker, FluoZin-1-AM, was used to assess the different roles of ZnT1 and ZnT4 in zinc homeostasis in wild type (WT) and mRNA knockdown PNT1A cell lines. Additionally, Bafilomycin A1 (Baf) was used to disrupt lysosomes and assess the role of lysosomal storage during GSZS. ZIMIR, an extracellular zinc-responsive fluorescent marker, was used to assess dynamic zinc efflux of WT and ZnT1 mRNA knockdown cells exposed to high glucose. Electron microscopy was used to assess intracellular zinc storage in response to high glucose and evaluate how Bafilomycin A1 affects zinc trafficking. BPH cells were harvested from transurtheral prostatectomy tissue and stained with fluorescent zinc granule indicator (ZIGIR), an intracellular zinc-responsive fluorescent marker, before being sorted for cell types using flow cytometry.

RESULTS

Fluorescent studies demonstrate that ZnT1 is the major zinc efflux transporter in prostate epithelial cells and that loss of ZnT1 via mRNA knockdown combined with lysosomal storage disruption results in a nearly 4-fold increase in cytosolic zinc. Knockdown of ZnT1 dramatically reduces zinc efflux during GSZS. Electron microscopy (EM) reveals that glucose stimulation significantly increases lysosomal storage of zinc; disruption of lysosomes via Baf or ZnT4 mRNA knockdown increases multi-vesicular body (MVB) formation and cytosolic zinc levels. In human BPH tissue, only the luminal epithelial cells contained significant amounts of zinc storage granules.

CONCLUSIONS

Exposure of prostate epithelial cells to high glucose alters zinc homeostasis by inducing efflux of zinc ions via ZnT1 channels and increasing lysosomal storage via ZnT4. Given that prostate cancer cells undergo profound metabolic changes that result in reduced levels of total zinc, understanding the complex interplay between glucose exposure and zinc homeostasis in the prostate may provide new insights into the development of prostate carcinogenesis.

A powerful method for pleiotropic analysis under composite null hypothesis identifies novel shared loci between Type 2 Diabetes and Prostate Cancer

There is increasing evidence that pleiotropy, the association of multiple traits with the same genetic variants/loci, is a very common phenomenon. Cross-phenotype association tests are often used to jointly analyze multiple traits from a genome-wide association study (GWAS). The underlying methods, however, are often designed to test the global null hypothesis that there is no association of a genetic variant with any of the traits, the rejection of which does not implicate pleiotropy. In this article, we propose a new statistical approach, PLACO, for specifically detecting pleiotropic loci between two traits by considering an underlying composite null hypothesis that a variant is associated with none or only one of the traits. We propose testing the null hypothesis based on the product of the Z-statistics of the genetic variants across two studies and derive a null distribution of the test statistic in the form of a mixture distribution that allows for fractions of variants to be associated with none or only one of the traits. We borrow approaches from the statistical literature on mediation analysis that allow asymptotic approximation of the null distribution avoiding estimation of nuisance parameters related to mixture proportions and variance components. Simulation studies demonstrate that the proposed method can maintain type I error and can achieve major power gain over alternative simpler methods that are typically used for testing pleiotropy. PLACO allows correlation in summary statistics between studies that may arise due to sharing of controls between disease traits. Application of PLACO to publicly available summary data from two large case-control GWAS of Type 2 Diabetes and of Prostate Cancer implicated a number of novel shared genetic regions: 3q23 (ZBTB38), 6q25.3 (RGS17), 9p22.1 (HAUS6), 9p13.3 (UBAP2), 11p11.2 (RAPSN), 14q12 (AKAP6), 15q15 (KNL1) and 18q23 (ZNF236).

We propose a new approach PLACO that uses aggregate-level genotype-phenotype association statistics—commonly referred to as GWAS summary statistics—to identify genetic variants that influence risk of two traits or diseases. It allows correlation in summary statistics between studies that may arise due to sharing of controls between disease traits. We demonstrate that PLACO can achieve major power gain over alternative methods that are typically used. We applied PLACO to Type 2 Diabetes and Prostate Cancer summary data from two large case-control studies. Many previous studies have reported an inverse association of these two chronic diseases suggesting shared risk factors; however, shared genetic mechanisms underlying this association is poorly understood. PLACO identified a number of novel shared genetic regions that are not detected by individual trait analysis. Many of the loci implicated by PLACO increase risk for one disease while decreasing risk for the other. PLACO can similarly be used on other traits to shed light on shared genetic risk factors.

Untangling the association between prostate-specific antigen and diabetes: a systematic review and meta-analysis

Objectives

Several studies have shown an inverse association between diabetes mellitus and prostate cancer (PCa). Some researchers suggest that this relationship is due to reduced PCa detection in diabetics due to lower prostate-specific antigen (PSA) levels compared to non-diabetics. Our objective is to analyze the impact of diabetes on PSA in asymptomatic men without known prostate pathology and without prior prostate intervention.

Methods

We searched Medline (via PubMed), Embase and Scopus. We included studies that reported the relationship between serum PSA levels and diabetes or diabetes treatment in asymptomatic adult men without known prostate pathology, and without prior prostate intervention. Pooled mean differences were compared between diabetics and non-diabetics.

Results

Of 2,392 screened abstracts, thirteen studies met the inclusion criteria and 8 (62%) reported appropriate measures that could be included in a meta-analysis. Eleven (85%) examined the influence of diabetes on PSA levels and 8 (62%) evaluated the influence of diabetes treatments on PSA levels. Overall diabetics had a significantly lower PSA level compared to non-diabetics (mean difference: -0.07 ng/mL; 95% CI -0.10, -0.04).

Conclusions

Diabetes and related factors (such as disease duration, severity and treatment) were significantly associated with lower PSA levels among asymptomatic men, yet differences were small and are unlikely to influence PCa detection in a screening setting.

Cancer Biology and Prevention in Diabetes

The available evidence suggests a complex relationship between diabetes and cancer. Epidemiological data suggest a positive correlation, however, in certain types of cancer, a more complex picture emerges, such as in some site-specific cancers being specific to type I diabetes but not to type II diabetes. Reports share common and differential mechanisms which affect the relationship between diabetes and cancer. We discuss the use of antidiabetic drugs in a wide range of cancer therapy and cancer therapeutics in the development of hyperglycemia, especially antineoplastic drugs which often induce hyperglycemia by targeting insulin/IGF-1 signaling. Similarly, dipeptidyl peptidase 4 (DPP-4), a well-known target in type II diabetes mellitus, has differential effects on cancer types. Past studies suggest a protective role of DPP-4 inhibitors, but recent studies show that DPP-4 inhibition induces cancer metastasis. Moreover, molecular pathological mechanisms of cancer in diabetes are currently largely unclear. The cancer-causing mechanisms in diabetes have been shown to be complex, including excessive ROS-formation, destruction of essential biomolecules, chronic inflammation, and impaired healing phenomena, collectively leading to carcinogenesis in diabetic conditions. Diabetes-associated epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition (EndMT) contribute to cancer-associated fibroblast (CAF) formation in tumors, allowing the epithelium and endothelium to enable tumor cell extravasation. In this review, we discuss the risk of cancer associated with anti-diabetic therapies, including DPP-4 inhibitors and SGLT2 inhibitors, and the role of catechol-o-methyltransferase (COMT), AMPK, and cell-specific glucocorticoid receptors in cancer biology. We explore possible mechanistic links between diabetes and cancer biology and discuss new therapeutic approaches.

The association of diabetes with risk of prostate cancer defined by clinical and molecular features

BACKGROUND

To prospectively examine the association between diabetes and risk of prostate cancer defined by clinical and molecular features.

METHODS

A total of 49,392 men from the Health Professionals Follow-up Study (HPFS) were followed from 1986 to 2014. Data on self-reported diabetes were collected at baseline and updated biennially. Clinical features of prostate cancer included localised, advanced, lethal, low-grade, intermediate-grade, and high-grade. Molecular features included TMPRSS2: ERG and PTEN subtypes. Cox proportional hazards regression models were used to evaluate the association between diabetes and incidence of subtype-specific prostate cancer.

RESULTS

During 28 years of follow-up, we documented 6733 incident prostate cancer cases. Relative to men free from diabetes, men with diabetes had lower risks of total (HR: 0.82, 95% CI: 0.75-0.90), localised (HR: 0.82, 95% CI: 0.74-0.92), low-and intermediate-grade prostate cancer (HR: 0.77, 95% CI: 0.66-0.90; HR: 0.77, 95% CI: 0.65-0.91, respectively). For molecular subtypes, the HRs for ERG-negative and ERG-positive cases were 0.63 (0.42-0.95) and 0.72 (0.46-1.12); and for PTEN-intact and PTEN-loss cases were 0.69 (0.48-0.98) and 0.52 (0.19-1.41), respectively.

CONCLUSION

Besides providing advanced evidence for the inverse association between diabetes and prostate cancer, this study is the first to report associations between diabetes and ERG/PTEN defined prostate cancers.

Systematic review and meta-analysis of the associations between body mass index, prostate cancer, advanced prostate cancer, and prostate-specific antigen

PURPOSE

The relationship between body mass index (BMI) and prostate cancer remains unclear. However, there is an inverse association between BMI and prostate-specific antigen (PSA), used for prostate cancer screening. We conducted this review to estimate the associations between BMI and (1) prostate cancer, (2) advanced prostate cancer, and (3) PSA.

METHODS

We searched PubMed and Embase for studies until 02 October 2017 and obtained individual participant data from four studies. In total, 78 studies were identified for the association between BMI and prostate cancer, 21 for BMI and advanced prostate cancer, and 35 for BMI and PSA. We performed random-effects meta-analysis of linear associations of log-PSA and prostate cancer with BMI and, to examine potential non-linearity, of associations between categories of BMI and each outcome.

RESULTS

In the meta-analyses with continuous BMI, a 5 kg/m2 increase in BMI was associated with a percentage change in PSA of - 5.88% (95% CI - 6.87 to - 4.87). Using BMI categories, compared to normal weight men the PSA levels of overweight men were 3.43% lower (95% CI - 5.57 to - 1.23), and obese men were 12.9% lower (95% CI - 15.2 to - 10.7). Prostate cancer and advanced prostate cancer analyses showed little or no evidence associations.

CONCLUSION

There is little or no evidence of an association between BMI and risk of prostate cancer or advanced prostate cancer, and strong evidence of an inverse and non-linear association between BMI and PSA. The association between BMI and prostate cancer is likely biased if missed diagnoses are not considered.

Association Between Antidiabetic Medications and Prostate-Specific Antigen Levels and Biopsy Results

IMPORTANCE

Diabetic men appear to have a lower risk of prostate cancer. Whether antidiabetic medications are protective or potentially mask prostate cancer by lowering prostate-specific antigen (PSA) levels is unclear.

OBJECTIVE

To examine the associations of antidiabetic medication use with (1) PSA levels, (2) frequency of PSA testing, (3) receipt of biopsy following elevated PSA results, and (4) prostate cancer detection at biopsy.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study using data from the Stockholm PSA and Biopsy Register. Participants were all prostate cancer-free men aged 40 to 79 years residing in Stockholm County, Sweden, between January 1, 2006, and December 31, 2015. Data were analyzed from November 2018 to March 2019.

EXPOSURES

One or more prescription for metformin, sulfonylurea, or insulin, as recorded in Sweden's National Prescribed Drug Register.

MAIN OUTCOMES AND MEASURES

Levels of PSA following first exposure to antidiabetic medications were assessed using multivariable linear regression. Frequency of PSA testing was assessed via multivariable Poisson regression. Biopsy following elevated PSA (≥3.0 ng/mL) and prostate cancer detection at biopsy were assessed via multivariable logistic regression.

RESULTS

The cohort of 564 666 men (median [range] age, 65 [40-79] years) consisted of 4583 men initially exposed to metformin, 1104 exposed to sulfonylurea, and 978 exposed to insulin who were age matched with unexposed men (1:5). Exposed men had lower median (interquartile range) PSA levels before starting antidiabetic medications compared with unexposed men (1.2 [0.7-2.5] vs 1.6 [0.8-3.2] ng/mL). After accounting for baseline differences, PSA levels did not vary from those of unexposed men following exposure to antidiabetic medications. Frequency of PSA testing was higher for those receiving metformin (rate ratio, 1.07; 95% CI, 1.06-1.09) and sulfonylurea (rate ratio, 1.06; 95% CI, 1.03-1.08) but was lower for those receiving insulin (rate ratio, 0.79; 95% CI, 0.77- 0.81). Likelihood of biopsy after elevated PSA was lower among men receiving metformin (odds ratio, 0.87; 95% CI, 0.80-0.96) and insulin (odds ratio, 0.83; 95% CI, 0.74-0.93). There were no differences in prostate cancer detection at biopsy, regardless of PSA levels that triggered the biopsy.

CONCLUSIONS AND RELEVANCE

This study's findings do not support the hypothesis that the inverse association between diabetes and prostate cancer is mediated through antidiabetic medications lowering PSA levels to mask prostate cancer. They do suggest potential detection bias due to fewer biopsies among men receiving antidiabetic medications, which may explain the lower prostate cancer risk in men with diabetes.

Development and Validation of a Multiparameterized Artificial Neural Network for Prostate Cancer Risk Prediction and Stratification

PURPOSE

To develop and validate a multiparameterized artificial neural network (ANN) on the basis of personal health information for prostate cancer risk prediction and stratification.

METHODS

The 1997 to 2015 National Health Interview Survey adult survey data were used to train and validate a multiparameterized ANN, with parameters including age, body mass index, diabetes status, smoking status, emphysema, asthma, race, ethnicity, hypertension, heart disease, exercise habits, and history of stroke. We developed a training set of patients ≥ 45 years of age with a first primary prostate cancer diagnosed within 4 years of the survey. After training, the sensitivity and specificity were obtained as functions of the cutoff values of the continuous output of the ANN. We also evaluated the ANN with the 2016 data set for cancer risk stratification.

RESULTS

We identified 1,672 patients with prostate cancer and 100,033 respondents without cancer in the 1997 to 2015 data sets. The training set had a sensitivity of 21.5% (95% CI, 19.2% to 23.9%), specificity of 91% (95% CI, 90.8% to 91.2%), area under the curve of 0.73 (95% CI, 0.71 to 0.75), and positive predictive value of 28.5% (95% CI, 25.5% to 31.5%). The validation set had a sensitivity of 23.2% (95% CI, 19.5% to 26.9%), specificity of 89.4% (95% CI, 89% to 89.7%), area under the curve of 0.72 (95% CI, 0.70 to 0.75), and positive predictive value of 26.5% (95% CI, 22.4% to 30.6%). For the 2016 data set, the ANN classified all 13,031 patients into low-, medium-, and high-risk subgroups and identified 5% of the cancer population as high risk.

CONCLUSION

A multiparameterized ANN that is based on personal health information could be used for prostate cancer risk prediction with high specificity and low sensitivity. The ANN can further stratify the population into three subgroups that may be helpful in refining prescreening estimates of cancer risk.

Metformin for lung cancer prevention and improved survival: a novel approach

Diabetes mellitus has been associated with increased risk for the development of many types of cancer. Metformin, an oral medication and first-line treatment for type 2 diabetes mellitus, has been suggested to reduce cancer risk and mortality in various types of cancer. This study focuses on assessing metformin association with lung cancer as reported in the literature. Recent studies and reviews investigating metformin effects on lung cancer incidence and patient survival are critically and systematically discussed.

Difference in prostate cancer incidence around sixty years: effects of age and metabolic diseases

We examined the risk of prostate cancer in the Korean population stratified on the basis of age group and risk based on metabolic diseases, using National Health Insurance System (NHIS) data. Of the 51,827,813 people from the NHIS data in 2015, 10,879,591 men without prostate cancer who underwent a health examination were analyzed. The risk of prostate cancer was analyzed with stratification by age. Multivariate-adjusted Cox regression analysis was conducted to examine the association between prostate cancer and metabolic diseases by age groups. The risk of prostate cancer increased continuously with age and 59 years may be a point of inflection. The hazard ratio (HR) of prostate cancer development rose sharply as that age point passed. The population with metabolic diseases was more likely to develop prostate cancer than the population without any of these components. In addition, the incidence rate ratio (IRR) decreased from the youngest age group to the age group comprising 55-59 year olds. Beyond this age group, there was a plateau. The relative risk for prostate cancer associated with metabolic diseases also showed divergent associations with age. The risk of prostate cancer increased continuously with age and the peak Youden index was at 59 years. The relative risk for prostate cancer according to metabolic diseases also showed divergent associations beyond 59 years of age. Therefore, setting the age threshold at 59 years would improve the present clinical risk stratification for prostate cancer in Korea.

Risk of prostate cancer across different racial/ethnic groups in men with diabetes: a retrospective cohort study

AIM

To examine the associations between prostate cancer, diabetes and race/ethnicity.

METHODS

Using administrative data from British Columbia, Canada for the period 1994 to 2012, we identified men aged ≥50 years with and without diabetes. Validated surname algorithms identified men as Chinese, Indian or of other race/ethnicity. Multivariable Cox regression was used to estimate adjusted risks of prostate cancer according to diabetes status and race/ethnicity.

RESULTS

Our cohort of 160 566 men had a mean (sd) age of 64.7 (9.4) years and a median of 9 years' follow-up. The incidence rates of prostate cancer among those with and without diabetes were 177.4 (171.7-183.4) and 216.0 (209.7-222.5) per 1000 person-years, respectively. The incidence among Chinese men was 120.9 (109.2-133.1), among Indian men it was 144.1 (122.8-169.0) and in men of other ethnicity it was 204.8 (200.2-209.5). Diabetes was independently associated with a lower risk of prostate cancer (adjusted hazard ratio 0.82, 95% CI 0.78-0.86), as was Chinese (adjusted hazard ratio 0.54, 95% CI 0.46,0.63) and Indian (adjusted hazard ratio 0.66, 95% CI 0.49,0.89) race/ethnicity; however, there was no statistically significant interaction between diabetes status and race/ethnicity (all P>0.1).

CONCLUSION

Diabetes and Chinese and Indian race/ethnicity were each independently associated with a lower risk of prostate cancer.

Metformin and cancer: An existing drug for cancer prevention and therapy

Metformin is a standard clinical drug used to treat type 2 diabetes mellitus (T2DM) and polycystic ovary syndrome. Recently, epidemiological studies and meta-analyses have revealed that patients with T2DM have a lower incidence of tumor development than healthy controls and that patients diagnosed with cancer have a lower risk of mortality when treated with metformin, demonstrating an association between metformin and tumorigenesis. In vivo and in vitro studies have revealed that metformin has a direct antitumor effect, which may depress tumor proliferation and induce the apoptosis, autophagy and cell cycle arrest of tumor cells. The mechanism underpinning the antitumor effect of metformin has not been well established. Studies have demonstrated that reducing insulin and insulin-like growth factor levels in the peripheral blood circulation may lead to the inhibition of phosphoinositide 3-kinase/Akt/mechanistic target of rapamycin (mTOR) signaling or activation of AMP-activated protein kinase, which inhibits mTOR signaling, a process that may be associated with the antitumor effect of metformin. The present review primarily focuses on the recent progress in understanding the function of metformin in tumor development.

Impact of metformin on serum prostate-specific antigen levels: Data from the national health and nutrition examination survey 2007 to 2008

PURPOSE

A possible association between metformin use and the development of prostate cancer (PCa) has been reported. However, there is limited information on the impact of long-term metformin use on serum prostate-specific antigen (PSA) levels. We investigated the association between exposure to metformin and PSA levels among diabetic patients who were not previously diagnosed with PCa.

METHODS

The analytic sample consisted of 1363 US men aged above 40 in the National Health and Nutrition Examination Survey 2007 to 2008 cycle. Men who had previous diagnoses of PCa or prostatitis and men exposed to manipulations that might have affected PSA levels were excluded. Multivariate logistic regression analyses were used to evaluate the association between PSA levels and metformin use by adjusting for potential confounders.

RESULTS

The mean PSA level of the overall population was 1.8 (standard deviation = 3.1) ng/mL. There were no differences in PSA levels according to the presence of diabetes (P = .517). Among patients with diabetes, metformin users exhibited significantly lower PSA levels compared with nonmetformin users (odds ratio = 0.790; 95% confidence interval 0.666-0.938; P = .007). However, no significant difference was found in PSA levels among men over duration of metformin use when levels were stratified by either 1 year or 5 years by Pearson's coefficient.

CONCLUSION

A negative association between serum PSA levels and metformin use was observed in patients with diabetes. Duration of metformin use did not influence PSA levels. Further studies are warranted to elucidate whether the reduction in PSA level with metformin truly reflects reduced risk of PCa development and progression.

Quantifying the Genetic Correlation between Multiple Cancer Types

Background: Many cancers share specific genetic risk factors, including both rare high-penetrance mutations and common SNPs identified through genome-wide association studies (GWAS). However, little is known about the overall shared heritability across cancers. Quantifying the extent to which two distinct cancers share genetic origin will give insights to shared biological mechanisms underlying cancer and inform design for future genetic association studies.Methods: In this study, we estimated the pair-wise genetic correlation between six cancer types (breast, colorectal, lung, ovarian, pancreatic, and prostate) using cancer-specific GWAS summary statistics data based on 66,958 case and 70,665 control subjects of European ancestry. We also estimated genetic correlations between cancers and 14 noncancer diseases and traits.Results: After adjusting for 15 pair-wise genetic correlation tests between cancers, we found significant (P < 0.003) genetic correlations between pancreatic and colorectal cancer (rg = 0.55, P = 0.003), lung and colorectal cancer (rg = 0.31, P = 0.001). We also found suggestive genetic correlations between lung and breast cancer (rg = 0.27, P = 0.009), and colorectal and breast cancer (rg = 0.22, P = 0.01). In contrast, we found no evidence that prostate cancer shared an appreciable proportion of heritability with other cancers. After adjusting for 84 tests studying genetic correlations between cancer types and other traits (Bonferroni-corrected P value: 0.0006), only the genetic correlation between lung cancer and smoking remained significant (rg = 0.41, P = 1.03 × 10-6). We also observed nominally significant genetic correlations between body mass index and all cancers except ovarian cancer.Conclusions: Our results highlight novel genetic correlations and lend support to previous observational studies that have observed links between cancers and risk factors.Impact: This study demonstrates modest genetic correlations between cancers; in particular, breast, colorectal, and lung cancer share some degree of genetic basis. Cancer Epidemiol Biomarkers Prev; 26(9); 1427-35. ©2017 AACR.

Prospective study of Type 2 diabetes mellitus, anti-diabetic drugs and risk of prostate cancer

Type 2 diabetes mellitus (T2DM) has consistently been associated with decreased risk of prostate cancer; however, if this decrease is related to the use of anti-diabetic drugs is unknown. We prospectively studied men in the comparison cohort in the Prostate Cancer data Base Sweden 3.0, with data on T2DM, use of metformin, sulfonylurea and insulin retrieved from national health care registers and demographic databases. Cox proportional hazards regression models were used to compute hazard ratios (HR) and 95% confidence intervals (CI) of prostate cancer, adjusted for confounders. The study consisted of 612,846 men, mean age 72 years (standard deviation; SD = 9 years), out of whom 25,882 men were diagnosed with prostate cancer during follow up, mean time of 5 years (SD = 3 years). Men with more than 1 year's duration of T2DM had a decreased risk of prostate cancer compared to men without T2DM (HR = 0.85, 95% CI = 0.82-0.88) but among men with T2DM, those on metformin had no decrease (HR = 0.96, 95% CI = 0.77-1.19), whereas men on insulin (89%) or sulfonylurea (11%) had a decreased risk (HR = 0.73, 95% CI = 0.55-0.98), compared to men with T2DM not on anti-diabetic drugs. Men with less than 1 year's duration of T2DM had no decrease in prostate cancer risk (HR = 1.11, 95% CI = 0.95-1.31). Our results gave no support to the hypothesis that metformin protects against prostate cancer as recently proposed. However, our data gave some support to an inverse association between T2DM severity and prostate cancer risk.

Prostate-specific antigen rising in Iranian men in correlation with body mass index, fasting blood sugar and blood lipid profile

Background

Prostate-specific antigen (PSA) is a serine protease that is secreted by prostate cells and it is useful as a tumor marker for prostate cancer.

Objectives

In this study, the relationship between some of metabolic factors and serum PSA level was investigated.

Materials and Methods

In this cross-sectional study, patients with urinary symptoms or for screening of the prostate cancer (after 50 years of age or 40 years with a family history of prostate cancer), were evaluated. Collected data included metabolic syndrome factors such as cholesterol (Chol), triglycerides (TG), fasting blood sugar (FBS), and body mass index (BMI), serum PSA level, prostate volume and age.

Results

481 patients were enrolled to this study with the average age of 60.69 ± 9.72 years and the average PSA level of 1.70 ng/ml. Data analysis showed that there was a significant relationship between serum PSA level with age (P < 0.001, r = 0.30) and prostate volume (P < 0.001, r = 0.29). There were not significant relationship between serum PSA level with TG (P = 0.57, r = 0.026), Chol (P = 0.57, r = -0.025), FBS (P = 0.054, r = 0.088), and BMI (P = 0.89, r = 0.006).

Conclusions

This study showed that, with increasing age and prostate volume, serum PSA level increased, and an increase in the levels of cholesterol, TG, FBS and BMI did not have significant effect on serum PSA level.

The Impact of Diabetes on the Risk of Prostate Cancer Development according to Body Mass Index: A 10-year Nationwide Cohort Study

Purpose: We examined the association between obesity and prostate cancer both with and without diabetic patients included in the analysis using nationally representative data of the Korean population from the National Health Insurance System (NHIS).

Materials and Methods: Of the 424,712 participants who underwent health examinations in 2002-2008, 139,519 men ≥40 years old and without prostate cancer were followed from the beginning of 2002 to the end of 2012. Multivariate adjusted Cox regression analysis was conducted to examine the hazard ratio (HR) and 95% confidence interval (CI) for the association between prostate cancer and body mass index (BMI) both with and without diabetes.

Results: The HR for prostate cancer according to the existence of diabetes was stratified by BMI in both age- and multivariable-adjusted models. In the population without diabetes, the HR for prostate cancer significantly increased as BMI increased beyond the reference range in a model adjusted for age and multiple variables; however, the increase in the HR was small. In the population with diabetes, the HR for prostate cancer significantly increased as BMI increased from < 18.5 kg/m² to within the reference range (18.5 to 22.9) in the multivariable-adjusted model. In addition, a marked decrease in HR in the population with BMI of < 18.5 kg/m² was seen compared to the reference or higher BMI population.

Conclusion: This population-based study shows the evidence of association between obesity and development of prostate cancer, and the risk increases vary according to the change of BMI category and the existence of diabetes.

Metformin for Reducing Racial/Ethnic Difference in Prostate Cancer Incidence for Men with Type II Diabetes

Racial/ethnic disparity in prostate cancer is under studied in men with diabetes who are at a higher risk of aggressive prostate cancer. This study assessed the race/ethnic disparity in prostate cancer incidence for men with type II diabetes (T2D) and whether the impact of metformin on prostate cancer incidence varied by race/ethnicity. We conducted a retrospective study in 76,733 male veterans with T2D during 2003 to 2012. Cox proportional hazards model adjusting for covariates and propensity scores of metformin use and race/ethnic group membership was utilized to compute the HR of prostate cancer incidence associated with race/ethnicity and compare HR associated with metformin use between race/ethnic groups. Mean follow-up was 6.4 ± 2.8 years; 7% were Hispanics; 17% were African Americans (AA); mean age was 67.8 ± 9.8 years; 5.2% developed prostate cancer; and 38.9% used metformin. Among these diabetic men without metformin use, prostate cancer incidence was higher in Hispanics and AA than in non-Hispanic White (NHW). Use of metformin alone or metformin + statins was associated with a greater prostate cancer incidence reduction in Hispanics compared with NHW, but not between AA and NHW. Use of metformin + finasteride was associated with a greater prostate cancer incidence reduction in Hispanics and AA compared with NHW. Our results suggested that metformin treatment could be a potential strategy to reduce prostate cancer incidence in the minority populations who are at high risk for fatal prostate cancer. It will be important to further examine the pleiotropic effects of metformin in multi-race/ethnic prospective studies to better inform clinical management and potentially reduce racial/ethnic disparity in prostate cancer incidence among diabetic men. Cancer Prev Res; 9(10); 779-87. ©2016 AACR.

Association of Family History of Type 2 Diabetes with Prostate Cancer: A National Cohort Study

Background

Personal history of type 2 diabetes mellitus (T2DM) is associated with a lower incidence of prostate cancer, but the underlying mechanisms are largely unknown. We hypothesized that genetic factors that are involved in the development of T2DM might protect against prostate cancer.

Methods

We used a few Swedish registers, including the Swedish Multigeneration Register and the Cancer Register, to examine the risk of prostate cancer among men with a family history of T2DM. Standardized incidence ratios were used to calculate the relative risk.

Results

The overall risk of prostate cancer among men with a familial history of T2DM was 0.87 (95% CI: 0.86–0.89) as compared to matched controls. The risk was even lower for those multiple affected relatives with T2DM, and it was 0.86 for those with two affected relatives and 0.67 for those with three and more affected relatives.

Conclusion

Family history of T2DM was associated with a lower incidence of prostate cancer, and the risk was even lower for those with more than one affected relative. Our study strongly suggests that genetic factors or shared familial factors, such as obesity, that contributed to T2DM may protect against prostate cancer.

Epidemiology of Prostate Cancer

Prostate cancer is the most common malignancy among males worldwide, and is the second leading cause of cancer death among men in United States. According to GLOBOCAN (2012), an estimated 1.1 million new cases and 307,000 deaths were reported in 2012. The reasons for the increase of this disease are not known, but increasing life expectancy and modified diagnostic techniques have been suggested as causes. The established risk factors for this disease are advancing age, race, positive family history of prostate cancer and western diet (use of fat items). Several other risk factors, such as obesity, physical activity, sexual activity, smoking and occupation have been also associated with prostate cancer risk, but their roles in prostate cancer etiology remain uncertain. This mini-review aims to provide risk factors, disease knowledge, prevalence and awareness about prostate cancer.

Cancer incidence in patients with type 2 diabetes mellitus: a population-based cohort study in Shanghai

BACKGROUND

Type 2 diabetes mellitus (T2DM) has been suggested to increase the risk of cancers. The aim of this study was to investigate the risk of common cancers in Chinese patients with T2DM.

METHODS

A population-based retrospective cohort study including 36,379 T2DM patients was conducted in Minhang District of Shanghai, China, during 2004 to 2010. All T2DM patients were enrolled from the standardized management system based on local electronic information system. Newly-diagnosed cancer cases were identified by record-linkage with the Shanghai Cancer Registry. Standardized incidence ratios (SIR) and 95% confidence interval (CI) were used to estimate the risk of cancers among T2DM patients.

RESULTS

Overall crude incidence rate (CIR) of cancers was 955.21 per 105 person-years in men and 829.57 per 105 person-years in women. Increased risk of cancer was found in both gender, with an SIR being 1.28 (95% CI = 1.17-1.38) in men and 1.44 (95% CI =1.32-1.55) in women. Increased risk of colon (SIR = 1.97; 95% CI = 1.49 to 2.46), rectum (1.72; 1.23 to 2.21), prostate (2.87; 2.19 to 3.56), and bladder cancers (1.98, 1.28 to 2.68) were observed in men and elevated risk of colon (1.67; 1.25 to 2.08), breast (1.66; 1.38 to 1.95), and corpus uteri cancers (2.87; 2.03 to 3.71) were observed in women.

CONCLUSIONS

Our results indicate that Chinese patients with T2DM may have an increased risk of some cancers, and the increase may vary by sub-sites of cancers.

Effects of statin use on the response duration to androgen deprivation therapy in metastatic prostate cancer

Purpose

To determine whether statin use delays the development of castration-resistant prostate cancer (CRPC) in patients with metastatic prostate cancer treated with androgen deprivation therapy (ADT).

Materials and Methods

A total of 171 patients with metastatic prostate cancer at the time of diagnosis who were treated with ADT between January 1997 and December 2013 were retrospectively analyzed. The patients were classified into two groups: the nonstatin use group (A group) and the statin use group (B group). Multivariate analysis was performed on statin use and other factors considered likely to have an effect on the time to progression to CRPC.

Results

The mean patient age was 67.1±9.1 years, and the mean follow-up period was 52 months. The mean initial prostate-specific antigen (PSA) level was 537 ng/mL. Of the 171 patients, 125 (73%) were in group A and 46 (27%) were in group B. The time to progression to CRPC was 22.7 months in group A and 30.5 months in group B, and this difference was significant (p=0.032). Blood cholesterol and initial PSA levels did not differ significantly according to the time to progression to CRPC (p=0.288, p=0.198). Multivariate analysis using the Cox regression method showed that not having diabetes (p=0.037) and using a statin (p=0.045) significantly increased the odds ratio of a longer progression to CRPC.

Conclusions

Statin use in metastatic prostate cancer patients appears to delay the progression to CRPC. Large-scale, long-term follow-up studies are needed to validate this finding.

Racial/ethnic differences in lifestyle-related factors and prostate cancer risk: the Multiethnic Cohort Study

PURPOSE

Older age, African ancestry, and family history of prostate cancer are well-established risk factors for prostate cancer, and all are non-modifiable. Various lifestyle factors have been examined in relation to prostate cancer risk, including diet, obesity, and physical activity; however, none of them has been consistently related to risk. In the Multiethnic Cohort Study, we investigated whether lifestyle-related factors are associated with prostate cancer risk and whether such factors explain the racial/ethnic differences in risk.

METHODS

During a mean follow-up of 13.9 years, 7,115 incident cases were identified among 75,216 white, African-American, Native Hawaiian, Japanese American, and Latino men. Cox proportional hazards models were used to calculate relative risks (RRs) and 95 % confidence intervals (95 % CIs) for prostate cancer.

RESULTS

Among selected lifestyle-related factors including body mass index, height, education, physical activity, and intakes of alcohol, calcium, legumes, lycopene, and selenium, only smoking (RR for current (≥20 cigarettes/day) vs. never smoking = 0.72; 95 % CI 0.63-0.83) and history of diabetes (RR for yes vs. no = 0.78; 95 % CI 0.72-0.85) were significantly associated with prostate cancer risk. Compared to whites, the risk of incident prostate cancer was twofold higher in African-Americans and 16 % higher in Latinos. Additional adjustment for a history of PSA testing did not change the results.

CONCLUSIONS

The findings suggest that racial/ethnic differences in prostate cancer risk are not explained by the lifestyle factors examined and that underlying genetic factors may be involved.

Concurrent Diabetes Mellitus may Negatively Influence Clinical Progression and Response to Androgen Deprivation Therapy in Patients with Advanced Prostate Cancer

Objective

To determine if a concurrent diagnosis of diabetes mellitus is associated with worse outcomes in advanced prostate cancer (PC). The effect diabetes may have on the progression of advanced PC is poorly understood.

Methods

Data on 148 advanced PC patients (35 with concurrent diabetes) were collected from an institutional database to obtain diabetic status, data on treatment types and durations, and prostate-specific antigen (PSA) values before, during, and after treatment. Time to castration resistance following the onset of androgen deprivation therapy (ADT) and overall survival (OS) in patients with and without diabetes were compared using univariate Cox regression analyses as the primary endpoints. Differences in PSA response to treatments were compared using chi-squared tests as a secondary endpoint.

Results

With a median follow-up of 29 months, time to castration resistance did not differ significantly between patients with and without diabetes who underwent ADT. However, in a subset of patients who received ADT without radiographic evidence of metastases (N = 47), those with diabetes progressed to castration-resistant disease more quickly than those without DM (hazard ratio for progression with diabetes = 4.58; 95% CI: 1.92–10.94; p = 0.0006). Also, a lower percentage of patients undergoing ADT with diabetes had PSA declines of at least 50% (p = 0.17) and reached a nadir PSA <0.2 ng/mL (p = 0.06). OS did not differ based on diabetic status. No differences were seen in response to first-line therapy for castration-resistant prostate cancer.

Conclusion

Diabetes mellitus may have a detrimental effect on progression of advanced PC, particularly in those patients without radiographic evidence of metastases. Further study is necessary to fully elucidate the effect of diabetes on PC outcomes.

Diabetes mellitus and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition

The current epidemiologic evidence suggests that men with type 2 diabetes mellitus may be at lower risk of developing prostate cancer, but little is known about its association with stage and grade of the disease. The association between self-reported diabetes mellitus at recruitment and risk of prostate cancer was examined in the European Prospective Investigation into Cancer and Nutrition (EPIC). Among 139,131 eligible men, 4,531 were diagnosed with prostate cancer over an average follow-up of 12 years. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models stratified by EPIC-participating center and age at recruitment, and adjusted for education, smoking status, body mass index, waist circumference, and physical activity. In a subset of men without prostate cancer, the cross-sectional association between circulating concentrations of androgens and insulin-like growth factor proteins with diabetes status was also investigated using linear regression models. Compared to men with no diabetes, men with diabetes had a 26% lower risk of prostate cancer (HR, 0.74; 95% CI, 0.63-0.86). There was no evidence that the association differed by stage (p-heterogeneity, 0.19) or grade (p-heterogeneity, 0.48) of the disease, although the numbers were small in some disease subgroups. In a subset of 626 men with hormone measurements, circulating concentrations of androstenedione, total testosterone and insulin-like growth factor binding protein-three were lower in men with diabetes compared to men without diabetes. This large European study has confirmed an inverse association between self-reported diabetes mellitus and subsequent risk of prostate cancer.

Diabetes mellitus and the risk of prostate cancer: an update and cumulative meta-analysis

INTRODUCTION

To provide further insight into the association between type 2 diabetes mellitus (T2DM) and the pathophysiology of prostate cancer, we conducted an updated, detailed meta-analysis of 56 published case-control and cohort studies.

METHODS

MEDLINE and EMBASE were used to identify the literature published in April 2012 related to both diabetes mellitus and prostate cancer. A sensitivity analysis was performed, and potential confounding effects were investigated using a stratified meta-analysis. A cumulative meta-analysis was also carried out to evaluate the cumulative effect estimate over time.

RESULTS

A total of 24 case-control and 32 cohort studies with information on a total of ~8,000,000 subjects and ~140,000 individuals with prostatic cancer showed published estimates of the association between diabetes and prostate cancer malignancy. The pooled effect estimate revealed a relative risk (RR) of 0.88 (95% CI, 0.82-0.93). Interestingly, there was an increased trend for Asians (RR = 1.72, n = 7) but not Americans (RR = 0.82, n = 28) and Europeans (RR = 0.86, n = 21) regarding the association between diabetes mellitus and prostate cancer. The sensitivity analysis, excluding any one study, did not significantly change the pooled RR. The range for the pooled RR when one study was omitted was 0.84-0.89.

DISCUSSION

The findings of our meta-analysis provide strong evidence of an inverse association between diabetes and prostate cancer.

CONCLUSIONS

Further research should focus on limitations in the current literature and re-assess the relationship between diabetes and prostate cancer by analyzing the two different diabetes mellitus types separately.