Impact of obesity on prostate cancer recurrence after radical prostatectomy: data from CaPSURE

Dual contribution of the mTOR pathway and of the metabolism of amino acids in prostate cancer

BACKGROUND

Prostate cancer is the leading cause of cancer in men, and its incidence increases with age. Among other risk factors, pre-existing metabolic diseases have been recently linked with prostate cancer, and our current knowledge recognizes prostate cancer as a condition with important metabolic anomalies as well. In malignancies, metabolic disorders are commonly associated with aberrations in mTOR, which is the master regulator of protein synthesis and energetic homeostasis. Although there are reports demonstrating the high dependency of prostate cancer cells for lipid derivatives and even for carbohydrates, the understanding regarding amino acids, and the relationship with the mTOR pathway ultimately resulting in metabolic aberrations, is still scarce.

CONCLUSIONS AND PERSPECTIVES

In this review, we briefly provide evidence supporting prostate cancer as a metabolic disease, and discuss what is known about mTOR signaling and prostate cancer. Next, we emphasized on the amino acids glutamine, leucine, serine, glycine, sarcosine, proline and arginine, commonly related to prostate cancer, to explore the alterations in their regulatory pathways and to link them with the associated metabolic reprogramming events seen in prostate cancer. Finally, we display potential therapeutic strategies for targeting mTOR and the referred amino acids, as experimental approaches to selectively attack prostate cancer cells.

Alteration in Plasma Metabolome in High-Fat Diet-Fed Monocyte Chemotactic Protein-1 Knockout Mice Bearing Pulmonary Metastases of Lewis Lung Carcinoma

Both clinical and laboratory studies have shown that monocyte chemotactic protein-1 (MCP-1) is involved in cancer spread. To understand the role of MCP-1 in metabolism in the presence of metastasis, we conducted an untargeted metabolomic analysis of primary metabolism on plasma collected from a study showing that MCP-1 deficiency reduces spontaneous metastasis of Lewis lung carcinoma (LLC) to the lungs in mice fed a high-fat diet (HFD). In a 2 × 2 design, wild-type (WT) or Mcp-1 knockout (Mcp-1 ^-/-) mice maintained on the AIN93G standard diet or HFD were subcutaneously injected with LLC cells to induce lung metastasis. We identified 87 metabolites for metabolomic analysis from this study. Amino acid metabolism was altered considerably in the presence of LLC metastases with the aminoacyl-tRNA biosynthesis pathways as the leading pathway altered. The HFD modified lipid and energy metabolism, evidenced by lower contents of arachidonic acid, cholesterol, and long-chain saturated fatty acids and higher contents of glucose and pyruvic acid in mice fed the HFD. These findings were supported by network analysis showing alterations in fatty acid synthesis and glycolysis/gluconeogenesis pathways between the 2 diets. Furthermore, elevations of the citrate cycle intermediates (citric acid, fumaric acid, isocitric acid, and succinic acid) and glyceric acid in Mcp-1 ^-/- mice, regardless of diet, suggest the involvement of MCP-1 in mitochondrial energy metabolism during LLC metastasis. The present study demonstrates that MCP-1 deficiency and the HFD altered plasma metabolome in mice bearing LLC metastases. These findings can be useful in understanding the impact of obesity on prevention and treatment of cancer metastasis.

Interactions Between Obesity and One-Carbon Metabolism Genes in Predicting Prostate Cancer Outcomes Among White and Black Patients

BACKGROUND

One-carbon metabolism genes are linked to several cancers, but the association with prostate cancer (PCa) is less clear. Studies examining the relationship have not accounted for obesity, a risk factor for advanced PCa and altered methylation patterns. We hypothesized that obesity could moderate the association between one-carbon metabolism genes and PCa outcomes.

METHODS

We conducted secondary data analyses of the Study of Clinical Outcomes, Risk and Ethnicity. Obesity was included as a primary exposure and modifier (interacting with genetic polymorphisms) in the analytic models. We used logistic regression to determine associations of common one-carbon metabolism genotypes with odds of high stage (T3/T4) and high grade (Gleason score ≥ 7). We used Cox regression to examine associations of genotypes with biochemical recurrence.

RESULTS

There were 808 patients (632 White and 176 Black.) Among White men, we observed associations of TCN2_R259P with increased odds of high stage (OR = 0.64, 95% CI = 0.41-1.00), but no significant interactions with obesity. Among Black men, the SCL19A1_61bpdel and CBS_68bpINS variants were associated with high grade (OR = 2.61, 95% CI = 1.39-4.89 and OR = 0.29, 95% CI = 0.09-0.91, respectively.) Both the CBS_68bpINS and MTHFR_E429A variants interacted with obesity in Black men, where the highest risk for biochemical failure and odds of high grade, respectively, occurred among obese patients with variants.

CONCLUSIONS

We observed associations of one-carbon metabolism genes with different associations by race. We also observed interactions with obesity related to PCa outcomes in Black men only. Therefore, the involvement of one-carbon metabolism on PCa was dependent upon obesity status for Black men. These novel results could help identify patients that might benefit from effective weight management targeting one-carbon metabolism effects.

The effect of medical and urologic disorders on the survival of patients with metastatic castration resistant prostate cancer treated with abiraterone or enzalutamide

Introduction:

Androgenic deprivation therapies have been linked to the development of metabolic syndrome (MS) and cardiovascular diseases, which may lead to a poorer survival in patients with metastatic Castration-Resistant Prostate Cancer (mCRPC). We aimed to analyze whether some cardiovascular or neurological disorders, together with other medical and urological complications, may have an effect on survival outcomes, at baseline and during treatment from patients treated with androgen pathway inhibitors (API).

Material and Methods:

A retrospective study of a consecutive series of patients diagnosed with mCRPC between 2010 and 2018 treated with API in the first line setting in a single center.

Results:

Seventy-three patients met the inclusion criteria. Baseline prognostic factors associated with worse survival were diabetes mellitus (DM) with insulin needs compared to patients without DM [hazard ratio (HR) = 0.19, p = 0.025], hypertension (HTN) (HR = 0.46, p = 0.035), and a history of stroke (HR = 0.16, p < 0.001). However, previous history of hypercholesterolemia, arrythmias, and cognitive disorders did not result in a significant worsening on survival. During treatment, patients who developed de novo HTN had the best progression free survival (PFS) (HR = 0.38, p = 0.048) and overall survival (OS) (HR 0.08, p = 0.012) compared with patients with previous HTN. Other factors related to worse outcomes included the presence of heart failure (HR = 0.31, p = 0.001), the requirement for major opioids for pain relief (HR = 0.33, p = 0.023), and the presence of bilateral ureterohydronephrosis (HR = 0.12, p = 0.008).

Conclusions:

Some comorbidities may be strongly involved in patient outcomes when receiving API for mCRPC. In this sense, collaborative networking between specialists and caregivers treating prostate cancer (PC) patients should be recommended, focusing on MS features, cardiovascular and neurological disorders in order to anticipate medical and surgical complications.

Tenesmus: An Unusual Presentation of Delayed Prostate Adenocarcinoma Recurrence

We describe a case of prostate cancer recurrence 25 years after radical prostatectomy. Our patient is a 77-year-old male with past medical history pertinent for obesity and coronary artery disease. The patient’s initial presentation in 1994 was for persistent lower urinary tract symptoms. He was subsequently diagnosed with high-grade prostate adenocarcinoma and underwent radical prostatectomy. The patient was followed up postoperatively for 16 years and deemed to be in clinical and biochemical remission with undetectable prostate-specific antigen (PSA).

Twenty-five years post-operatively, the patient was evaluated with an investigatory colonoscopy for tenesmus, constipation, and change in stool caliber. Colonoscopy revealed significant anal canal stenosis. Biopsy of the lesion showed prostate adenocarcinoma recurrence.

Prostate cancer recurrence presenting with only gastrointestinal symptoms is highly unusual, especially in a patient who never received radiotherapy and had been in remission for 25 years.

Metabolomics in cancer research and emerging applications in clinical oncology

Cancer has myriad effects on metabolism that include both rewiring of intracellular metabolism to enable cancer cells to proliferate inappropriately and adapt to the tumor microenvironment, and changes in normal tissue metabolism. With the recognition that fluorodeoxyglucose-positron emission tomography imaging is an important tool for the management of many cancers, other metabolites in biological samples have been in the spotlight for cancer diagnosis, monitoring, and therapy. Metabolomics is the global analysis of small molecule metabolites that like other -omics technologies can provide critical information about the cancer state that are otherwise not apparent. Here, the authors review how cancer and cancer therapies interact with metabolism at the cellular and systemic levels. An overview of metabolomics is provided with a focus on currently available technologies and how they have been applied in the clinical and translational research setting. The authors also discuss how metabolomics could be further leveraged in the future to improve the management of patients with cancer.

Post-Diagnostic Dietary and Lifestyle Factors and Prostate Cancer Recurrence, Progression, and Mortality

PURPOSE OF REVIEW

This study aimed to summarize evidence published between 1999 and June 2020 examining diet and lifestyle after prostate cancer (PC) diagnosis in relation to risk of biochemical recurrence, PC progression, and PC-specific mortality.

RECENT FINDINGS

Secondary prevention is an important research area in cancer survivorship. A growing number of studies have reported associations between post-diagnostic modifiable behaviors and risk of PC outcomes. Evidence on modifiable lifestyle factors and PC remains limited. Where multiple studies exist, findings are often mixed. However, studies consistently suggest that smoking and consumption of whole milk/high-fat dairy are associated with higher risk of PC recurrence and mortality. In addition, physical activity and ½ to 1 glass of red wine/day have been associated with lower risk of recurrence and PC-specific mortality. Greater inclusion of racially/ethnically diverse groups in future research is necessary to understand these relationships in populations most impacted by adverse PC outcomes.

Caprylic acid (C8:0) promotes bone metastasis of prostate cancer by dysregulated adipo-osteogenic balance in bone marrow

Prostate cancer (PCa) continues to be the most common, noncutaneous cancer in men. Bone is the most frequent site of PCa metastases, and up to 90% of patients with advanced PCa develop bone metastases. An altered bone marrow microenvironment, induced by obesity, is a significant mediator for the bone tropism of PCa. However, the specific molecular mechanisms by which obesity causes changes in the bone marrow microenvironment, leading to PCa bone metastasis, are not fully understood. Our results demonstrate that a high‐fat diet (HFD) leads to dyslipidemia and changes in bone marrow of nude mice: an increase in the area and number of adipocytes and a reduction in the area and number of osteoblasts. Moreover, a HFD promoted cyclooxygenase 2 (COX2) expression and inhibited osteoprotegerin (OPG) expression in the bone microenvironment. Additionally, the total level of free fatty acids (FFAs) and caprylic acid (C8:0) was significantly higher in PCa patients with bone metastases. In vitro, caprylic acid (C8:0) promoted bone mesenchymal stem cell (MSC)‐derived adipocytic differentiation, COX2 expression, and prostaglandin E2 (PGE2) secretion, whereas osteoblastic differentiation and OPG expression were reduced. Furthermore, caprylic acid (C8:0)‐treated adipocytes promoted the invasion and migration of PCa cells. Taken together, our findings suggest caprylic acid (C8:0) promotes bone metastasis of PCa by dysregulated adipo‐osteogenic balance of bone marrow.

The effect of neighborhood social environment on prostate cancer development in black and white men at high risk for prostate cancer

INTRODUCTION

Neighborhood socioeconomic (nSES) factors have been implicated in prostate cancer (PCa) disparities. In line with the Precision Medicine Initiative that suggests clinical and socioenvironmental factors can impact PCa outcomes, we determined whether nSES variables are associated with time to PCa diagnosis and could inform PCa clinical risk assessment.

MATERIALS AND METHODS

The study sample included 358 high risk men (PCa family history and/or Black race), aged 35-69 years, enrolled in an early detection program. Patient variables were linked to 78 nSES variables (employment, income, etc.) from previous literature via geocoding. Patient-level models, including baseline age, prostate specific antigen (PSA), digital rectal exam, as well as combined models (patient plus nSES variables) by race/PCa family history subgroups were built after variable reduction methods using Cox regression and LASSO machine-learning. Model fit of patient and combined models (AIC) were compared; p-values<0.05 were significant. Model-based high/low nSES exposure scores were calculated and the 5-year predicted probability of PCa was plotted against PSA by high/low neighborhood score to preliminarily assess clinical relevance.

RESULTS

In combined models, nSES variables were significantly associated with time to PCa diagnosis. Workers mode of transportation and low income were significant in White men with a PCa family history. Homeownership (%owner-occupied houses with >3 bedrooms) and unemployment were significant in Black men with and without a PCa family history, respectively. The 5-year predicted probability of PCa was higher in men with a high neighborhood score (weighted combination of significant nSES variables) compared to a low score (e.g., Baseline PSA level of 4ng/mL for men with PCa family history: White-26.7% vs 7.7%; Black-56.2% vs 29.7%).

DISCUSSION

Utilizing neighborhood data during patient risk assessment may be useful for high risk men affected by disparities. However, future studies with larger samples and validation/replication steps are needed.

Obesity at Diagnosis and Prostate Cancer Prognosis and Recurrence Risk Following Primary Treatment by Radical Prostatectomy

BACKGROUND

The association of obesity at diagnosis with prostate cancer progression is uncertain. This study aimed to examine the relationship between body mass index (BMI; 18.5-<25, 25-<30, 30-<35, ≥35 kg/m²) and prognostic risk at diagnosis, compare the concordance between prognostic risk assessed at diagnostic biopsy versus pathologic risk assessed at surgery across BMI categories, and investigate the association between obesity and prostate cancer recurrence and all-cause death.

METHODS

We examined men enrolled in CaPSURE who underwent radical prostatectomy between 1995 and 2017. Multiple imputation methods were used to handle missing data and reported along with complete case findings.

RESULTS

Participants (n = 5,200) were followed for a median of 4.5 years; 685 experienced recurrence. Obesity was associated with higher prognostic risk at time of diagnosis (OR_obese = 1.5; OR_{very obese} = 1.7) and upward reclassification of disease between biopsy and surgery, driven by change in tumor stage (OR_obese = 1.3; OR_{very obese} = 1.6). We observed an association between BMI and recurrence with adjustment for disease severity using diagnostic factors (HR_{very obese} = 1.7); this association disappeared when adjusting for disease severity factors obtained at surgery.

CONCLUSIONS

Our findings suggest that residual confounding may partially explain the conflicting evidence regarding obesity's influence on prostate cancer progression. Assessing T-stage via digital rectal exam may be complicated in larger men, potentially affecting clinical treatment decisions. A strong association with all-cause mortality demonstrates healthier BMI at diagnosis may still improve overall survival.

IMPACT

Patients with greater BMI are prone to more advanced disease at diagnosis and may be more likely to have their tumor stage underestimated at diagnosis.

A high-sucrose diet does not enhance spontaneous metastasis of Lewis lung carcinoma in mice

A high energy intake contributes to obesity, a risk factor for cancer. We previously reported that an excessive intake of dietary fat enhances malignant spread in mice. This study tested the hypothesis that consumption of a diet with an excessive amount of sucrose enhances metastasis. In a spontaneous metastasis model of Lewis lung carcinoma (LLC), male C57BL/6 mice were maintained on an AIN93G, a high-fat, or a high-sucrose diet for the duration of the study. Pulmonary metastases from a primary tumor, established by a subcutaneous injection of LLC cells, were quantified. There were no differences in energy intake among the 3 groups. The percent body fat mass of the high-sucrose group, while higher than that of the AIN93G group, was lower than that of the high-fat group. The number and size of lung metastases were significantly higher in the high-fat group than in the AIN93G group; these measurements in the high-sucrose group remained similar to those in the AIN93G group. Hepatic concentrations of triacylglycerols and plasma concentrations of insulin, proinflammatory cytokines (leptin, plasminogen activator inhibitor-1, and monocyte chemotactic protein-1) and angiogenic factors (vascular endothelial growth factor and tissue inhibitor of metalloproteinase-1) in the high-sucrose group were significantly lower than those in the high-fat group. In conclusion, the high-sucrose diet does not enhance spontaneous metastasis of LLC. This null effect may be due to the inadequate production of tumorigenic proinflammatory cytokines and angiogenic factors by the high-sucrose diet compared to the high-fat diet.

The association of weight change in young adulthood and smoking status with risk of prostate cancer recurrence

The decades before prostate cancer diagnosis represent an etiologically relevant time period for prostate cancer carcinogenesis. However, the association of weight gain in young adulthood with subsequent biochemical recurrence among men with prostate cancer is not well studied, particularly among smokers. We conducted a prospective cohort study of 1,082 men with prostate cancer and treated with either radical prostatectomy or radiation between 2003 and 2010. The association of weight at age 20, weight at age 50 and weight change from age 20 to age 50 with biochemical recurrence was assessed using Cox Proportional Hazards with adjustment for confounders. Stratum-specific hazard ratio (HR) estimates by smoking status were evaluated. In the overall cohort, weight at age 20 (HR per 30 kg: 1.56, 95% confidence interval (CI): 1.02, 2.38, p-trend: 0.039), weight at age 50 (HR per 30 kg: 1.80, 95% CI: 1.32, 2.47, p-trend: <0.001) and weight change from age 20 to age 50 (HR per 30 kg: 1.84, 95% CI: 1.24, 2.74, p-trend: 0.003) were associated with biochemical recurrence. In stratified analyses, weight change from age 20 to age 50 was significantly associated with biochemical recurrence only in former smokers (HR per 30 kg: 3.87, 95% CI: 1.88, 8.00, p-trend: <0.001) and ever smokers (HR per 30 kg: 2.38, 95% CI: 1.27, 4.45, p-trend: 0.007). No significant association was observed between weight gain in young adulthood and biochemical recurrence in never smokers. Our study adds further evidence that weight gain during early adult years conveys long-term risk for adverse cancer outcomes.

Lipidomic Impacts of an Obesogenic Diet Upon Lewis Lung Carcinoma in Mice

Metabolic reprogramming of lipid metabolism is a hallmark of cancer. Consumption of a high-fat obesogenic diet enhances spontaneous metastasis using a Lewis lung carcinoma (LLC) model. In order to gain further insights into the mechanisms by which dietary fats impact cancer progression, we conducted a lipidomic analysis of primary tumors originated from LLC from mice fed with a standard AIN93G diet or a soybean oil-based high-fat diet (HFD). Hierarchical clustering heatmap analysis of phosphatidylcholine (PC) lipids and phosphatidylethanolamine (PE) lipids demonstrated an increase in polyunsaturated fatty acids (PUFA)-containing phospholipids and a decrease in monounsaturated fatty acids (MUFA)-containing lipids in tumors from mice fed the HFD. The quantities of 51 PC and 24 PE lipids differed in primary tumors of LLC from mice fed the control diet and the HFD. Analysis of triacylglycerol (TAG) lipids identified differences in 32 TAG (by brutto structure) between the two groups; TAG analysis by neutral loss identified 46 PUFA-containing TAG species that were higher in mice fed with the HFD than in the controls. Intake of the HFD did not alter the expression of the de novo lipogenesis enzymes (fatty acid synthase, acetyl-CoA carboxylase-1, and stearoyl-CoA desaturase-1). Our results demonstrate that the dietary fatty acid composition of the HFD is reflected in the higher order lipidomic composition of primary tumors. Subsequent studies are needed to investigate how these lipidomic changes may be used for targeted dietary intervention to reduce tumor growth and malignant progression.

Dietary energy restriction reduces high-fat diet-enhanced metastasis of Lewis lung carcinoma in mice

The objective of this study was to determine whether a reduction in energy intake ameliorated the high-fat diet-enhanced spontaneous metastasis of Lewis lung carcinoma in mice. Male C57BL/6 mice were fed the AIN93G diet, a high-fat diet or a high-fat diet with a 5% restriction of the intake. Energy restriction reduced body adiposity and body weight, but maintained growth similar to mice fed the AIN93G diet. The high-fat diet significantly increased the number and size (cross-sectional area and volume) of metastases formed in lungs. Restricted feeding reduced the number of metastases by 23%, metastatic cross-sectional area by 32% and volume by 45% compared to the high-fat diet. The high-fat diet elevated plasma concentrations of proinflammatory cytokines (monocyte chemotactic protein-1, plasminogen activator inhibitor-1, leptin), angiogenic factors (vascular endothelial growth factor, tissue inhibitor of metalloproteinase-1) and insulin. Restricted feeding significantly reduced the high-fat diet-induced elevations in plasma concentrations of proinflammatory cytokines, angiogenic factors and insulin. These results demonstrated that a reduction in diet intake by 5% reduced high-fat diet-enhanced metastasis, which may be associated with the mitigation of adiposity and down-regulation of cancer-promoting proinflammatory cytokines and angiogenic factors.

Bone marrow adipocytes promote the Warburg phenotype in metastatic prostate tumors via HIF-1α activation

Metabolic adaptation is increasingly recognized as a key factor in tumor progression, yet its involvement in metastatic bone disease is not understood. Bone is as an adipocyte-rich organ, and a major site of metastasis from prostate cancer. Bone marrow adipocytes are metabolically active cells capable of shaping tumor metabolism via lipolysis and lipid transfer. In this study, using in vitro and in vivo models of marrow adiposity, we demonstrate that marrow fat cells promote Warburg phenotype in metastatic prostate cancer cells. We show increased expression of glycolytic enzymes, increased lactate production, and decreased mitochondrial oxidative phosphorylation in tumor cells exposed to adipocytes that require paracrine signaling between the two cell types. We also reveal that prostate cancer cells are capable of inducing adipocyte lipolysis as a postulated mechanism of sustenance. We provide evidence that adipocytes drive metabolic reprogramming of tumor cells via oxygen-independent mechanism of HIF-1α activation that can be reversed by HIF-1α downregulation. Importantly, we also demonstrate that the observed metabolic signature in tumor cells exposed to adipocytes mimics the expression patterns seen in patients with metastatic disease. Together, our data provide evidence for a functional relationship between marrow adipocytes and tumor cells in bone that has likely implications for tumor growth and survival within the metastatic niche.

Monocyte chemotactic protein-1 deficiency reduces spontaneous metastasis of Lewis lung carcinoma in mice fed a high-fat diet

Adipose-produced pro-inflammatory cytokines contribute to obesity and cancer. This 2×2 experiment was designed to investigate effects of monocyte chemotactic protein-1 (MCP-1) deficiency on pulmonary metastasis of Lewis lung carcinoma (LLC) in MCP-1 deficient and wild-type mice fed a modified AIN93G diet containing 16% and 45% of energy from corn oil, respectively. The high-fat diet significantly increased the number and size (cross-sectional area and volume) of lung metastases compared to the AIN93G control diet. Deficiency in MCP-1 reduced lung metastases by 37% in high-fat diet-fed mice; it reduced metastatic cross-sectional area by 46% and volume by 69% compared to wild-type mice. Adipose and plasma concentrations of MCP-1 were significantly higher in high-fat diet-fed wild-type mice than in their AIN93G-fed counterparts; they were not detectable in MCP-1 deficient mice regardless of diet. Plasma concentrations of plasminogen activator inhibitor-1, tumor necrosis factor-α, vascular endothelial growth factor and tissue inhibitor of metalloproteinase-1 were significantly higher in MCP-1 deficient mice compared to wild-type mice. We conclude that adipose-produced MCP-1 contributes to high-fat diet-enhanced metastasis. While MCP-1 deficiency reduces metastasis, the elevation of pro-inflammatory cytokines and angiogenic factors in the absence of MCP-1 may support the metastatic development and growth of LLC in MCP-1 deficient mice.

Monocyte chemotactic protein-1 deficiency attenuates and high-fat diet exacerbates bone loss in mice with Lewis lung carcinoma

Bone loss occurs in obesity and cancer-associated complications including wasting. This study determined whether a high-fat diet and a deficiency in monocyte chemotactic protein-1 (MCP-1) altered bone structural defects in male C57BL/6 mice with Lewis lung carcinoma (LLC) metastases in lungs. Compared to non-tumor-bearing mice, LLC reduced bone volume fraction, connectivity density, trabecular number, trabecular thickness and bone mineral density and increased trabecular separation in femurs. Similar changes occurred in vertebrae. The high-fat diet compared to the AIN93G diet exacerbated LLC-induced detrimental structural changes; the exacerbation was greater in femurs than in vertebrae. Mice deficient in MCP-1 compared to wild-type mice exhibited increases in bone volume fraction, connectivity density, trabecular number and decreases in trabecular separation in both femurs and vertebrae, and increases in trabecular thickness and bone mineral density and a decrease in structure model index in vertebrae. Lewis lung carcinoma significantly decreased osteocalcin but increased tartrate-resistant acid phosphatase 5b (TRAP 5b) in plasma. In LLC-bearing mice, the high-fat diet increased and MCP-1 deficiency decreased plasma TRAP 5b; neither the high-fat diet nor MCP-1 deficiency resulted in significant changes in plasma concentration of osteocalcin. In conclusion, pulmonary metastasis of LLC is accompanied by detrimental bone structural changes; MCP-1 deficiency attenuates and high-fat diet exacerbates the metastasis-associated bone wasting.

Race and risk of metastases and survival after radical prostatectomy: Results from the SEARCH database

BACKGROUND

Black race is associated with prostate cancer (PC) diagnosis and poor outcome. Previously, the authors reported that black men undergoing radical prostatectomy (RP) in equal-access hospitals had an increased risk of biochemical disease recurrence (BCR), but recurrences were equally aggressive as those occurring in white men. The authors examined the association between race and long-term outcomes after RP.

METHODS

Data regarding 1665 black men (37%) and 2791 white men (63%) undergoing RP were analyzed. Using Cox models, the authors tested the association between race and BCR, BCR with a prostate-specific antigen (PSA) doubling time <9 months (aggressive disease recurrence), metastases, PC-specific death, and overall death.

RESULTS

At a median follow-up of 102 months, 1566 men (35%) developed BCR, 217 men (5%) experienced aggressive disease recurrence, 193 men (4%) developed metastases, and 1207 men (27%) had died, 107 of whom (2%) died of PC. White men were older and had a lower preoperative PSA level, a lower biopsy and pathological grade group, and more capsular penetration but less seminal vesicle invasion and positive surgical margins versus black men (all P<.05). Black men were found to have a more recent surgery year (P<.001). On univariable analysis, black race was associated with increased BCR (P = .003) and reduced overall death (P = .017). On multivariable analysis, black race was not found to be associated with BCR (hazard ratio [HR], 1.07; P = .26), aggressive recurrence (HR, 1.14; P = .42), metastasis (HR, 1.24; P = .21), PC-specific death (HR, 1.03; P = .91), or overall death (HR, 1.03; P = .67).

CONCLUSIONS

Among men undergoing RP at equal-access centers, although black men were found to have an increased risk of BCR, they had similar risks of aggressive disease recurrence, metastasis, and PC-specific death compared with white men, and the risk of BCR was found to be similar after controlling for risk parameters. Longer follow-up is needed to confirm these findings. Cancer 2017;123:4199-4206. © 2017 American Cancer Society.

Weight change, obesity and risk of prostate cancer progression among men with clinically localized prostate cancer

Obesity is associated with an increased risk of fatal prostate cancer. We aimed to elucidate the importance and relevant timing of obesity and weight change for prostate cancer progression. We identified 5,158 men diagnosed with localized prostate cancer (clinical stage T1/T2) from 1986 to 2012 in the Health Professionals Follow-up Study. Men were followed for biochemical recurrence and lethal prostate cancer (development of distant metastasis or prostate cancer-specific mortality) until 2012. Cox regression estimated hazard ratios (HRs) for body mass index (BMI) at age 21, BMI at diagnosis, "long-term" weight change from age 21 to diagnosis and "short-term" weight change over spans of 4 and 8 years preceding diagnosis. Because weight, weight change and mortality are strongly associated with smoking, we repeated analyses among never smokers only (N = 2,559). Among all patients, neither weight change nor BMI (at age 21 or at diagnosis) was associated with lethal prostate cancer. Among never smokers, long-term weight gain was associated with an increased risk of lethal disease (HR for gaining >30 pounds vs. stable weight [±10 pounds] 1.59, 95% CI, 1.01-2.50, p-trend = 0.06). Associations between weight change, BMI and lethal prostate cancer were stronger for men with BMI ≥ 25 at age 21 compared to those with BMI < 25. Weight change and obesity were not associated with an increased risk of biochemical recurrence. Our findings among never smoker men diagnosed with localized prostate cancer suggest a positive association between long-term weight gain and risk of lethal prostate cancer. Metabolic changes associated with weight gain may promote prostate cancer progression.

The Association of Diabetes and Obesity With Prostate Cancer Progression: HCaP-NC

BACKGROUND

The role of race in modifying the association among diabetes, obesity, and prostate cancer (CaP) progression is not well studied. We evaluated diabetes and obesity in association with time to CaP progression in White Americans (Whites) and Black Americans (Blacks).

METHODS

Our study sample consisted of 363 White and 284 Black research participants from the Health Care Access and CaP Treatment in North Carolina (HCaP-NC) cohort. The association between self-reported diabetes or obesity and CaP progression (mean follow-up time approximately 5 years) was assessed using Cox proportional hazards modeling, with adjustment for potential confounders. Stratum-specific hazard ratio (HR) estimates for Whites and Blacks were evaluated.

RESULTS

Self-reported diabetes was not associated with CaP progression in the cohort as a whole (HR: 0.86, 95%CI: 0.54, 1.35), or among racially defined groups (Whites, HR: 1.03, 95%CI: 0.50, 2.13 or Blacks, HR: 0.77, 95%CI: 0.43, 1.39). Obesity was positively associated with CaP progression among Whites, in models including (HR: 1.79, 95%CI: 1.08, 2.97), and excluding (HR: 1.80, 95%CI: 1.09, 2.96) diabetes as a covariate. No association was observed between obesity and CaP progression in Blacks or the cohort as whole.

CONCLUSIONS

Self-reported diabetes was not associated with CaP progression In HCaP-NC. Obesity was associated with CaP progression only among White research participants. Prostate 77:878-887, 2017. © 2017 Wiley Periodicals, Inc.

Obesity and Other Cancers

Purpose

Evidence on overweight, obesity, and an increased risk of cancer continues to accumulate and was updated in the 2016 handbook on weight control from the International Agency for Research on Cancer (IARC). The underlying primary data, together with dose-response meta-analysis and, finally, pooled analysis of individual participant data, add insight into the relation between obesity and cancer risk and prognosis. We summarize the evidence for mortality from prostate cancer, hematologic malignancies, and kidney cancer.

Methods

We reviewed pooled analysis of rare end points across cohorts, regardless of primary results reported from the individual studies, further reducing risk of publication bias. Of these cancer sites, only kidney cancer was included in the IARC 2002 report, although mortality from prostate cancer and hematologic malignancies was noted in the American Cancer Society prospective cohort study in 2003. The 2016 update from the IARC added details for prostate and hematologic malignancies, classifying the evidence as sufficient to conclude that avoiding excess body fatness lowers the risk of multiple myeloma but found that the evidence for it lowering the risk of prostate cancer mortality or diffuse large B-cell lymphoma was limited.

Results

A higher body mass index is associated with an increased risk of advanced prostate cancer and prostate cancer mortality and is associated with worse survival in most subtypes of hematologic malignancies, in a dose-response fashion. Evidence for kidney cancer is built mostly on retrospective data, which supports an obesity paradox in patients with the clear cell variant; however, population-based cohort data indicate that a higher cohort-entry body mass index is associated with worse kidney cancer–specific survival.

Conclusion

Together, these data add support to the evidence for a growing cancer burden caused by adiposity in both early adult and later adult life, yet leave open the question of the means of weight management after diagnosis as a strategy to improve survival.

Omentum and bone marrow: how adipocyte-rich organs create tumour microenvironments conducive for metastatic progression

A number of clinical studies have linked adiposity with increased cancer incidence, progression and metastasis, and adipose tissue is now being credited with both systemic and local effects on tumour development and survival. Adipocytes, a major component of benign adipose tissue, represent a significant source of lipids, cytokines and adipokines, and their presence in the tumour microenvironment substantially affects cellular trafficking, signalling and metabolism. Cancers that have a high predisposition to metastasize to the adipocyte-rich host organs are likely to be particularly affected by the presence of adipocytes. Although our understanding of how adipocytes influence tumour progression has grown significantly over the last several years, the mechanisms by which adipocytes regulate the metastatic niche are not well-understood. In this review, we focus on the omentum, a visceral white adipose tissue depot, and the bone, a depot for marrow adipose tissue, as two distinct adipocyte-rich organs that share common characteristic: they are both sites of significant metastatic growth. We highlight major differences in origin and function of each of these adipose depots and reveal potential common characteristics that make them environments that are attractive and conducive to secondary tumour growth. Special attention is given to how omental and marrow adipocytes modulate the tumour microenvironment by promoting angiogenesis, affecting immune cells and altering metabolism to support growth and survival of metastatic cancer cells.

Obesity and prostate cancer-specific mortality after radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database

Background:

At the population level, obesity is associated with prostate cancer (PC) mortality. However, few studies analyzed the associations between obesity and long-term PC-specific outcomes after initial treatment.

Methods:

We conducted a retrospective analysis of 4268 radical prostatectomy patients within the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Cox models accounting for known risk factors were used to examine the associations between body mass index (BMI) and PC-specific mortality (PCSM; primary outcome). Secondary outcomes included biochemical recurrence (BCR) and castration-resistant PC (CRPC). BMI was used as a continuous and categorical variable (normal <25 kg/m², overweight 25–29.9 kg/m² and obese ⩾30 kg/m²). Median follow-up among all men who were alive at last follow-up was 6.8 years (interquartile range=3.5–11.0). During this time, 1384 men developed BCR, 117 developed CRPC and 84 died from PC. Hazard ratios were analyzed using competing-risks regression analysis accounting for non-PC death as a competing risk.

Results:

On crude analysis, higher BMI was not associated with risk of PCSM (P=0.112), BCR (0.259) and CRPC (P=0.277). However, when BMI was categorized, overweight (hazard ratio (HR) 1.99, P=0.034) and obesity (HR 1.97, P=0.048) were significantly associated with PCSM. Obesity and overweight were not associated with BCR or CRPC (all P⩾0.189). On multivariable analysis adjusting for both clinical and pathological features, results were little changed in that obesity (HR=2.05, P=0.039) and overweight (HR=1.88, P=0.061) were associated with higher risk of PCSM, but not with BCR or CRPC (all P⩾0.114) with the exception that the association for overweight was no longer statistical significant.

Conclusions:

Overweight and obesity were associated with increased risk of PCSM after radical prostatectomy. If validated in larger studies with longer follow-up, obesity may be established as a potentially modifiable risk factor for PCSM.

Socioeconomic and Other Demographic Disparities Predicting Survival among Head and Neck Cancer Patients

BACKGROUND

The Institute of Medicine (IOM) report, "Unequal Treatment," which defines disparities as racially based, indicates that disparities in cancer diagnosis and treatment are less clear. While a number of studies have acknowledged cancer disparities, they have limitations of retrospective nature, small sample sizes, inability to control for covariates, and measurement errors.

OBJECTIVE

The purpose of this study was to examine disparities as predictors of survival among newly diagnosed head and neck cancer patients recruited from 3 hospitals in Michigan, USA, while controlling for a number of covariates (health behaviors, medical comorbidities, and treatment modality).

METHODS

Longitudinal data were collected from newly diagnosed head and neck cancer patients (N = 634). The independent variables were median household income, education, race, age, sex, and marital status. The outcome variables were overall, cancer-specific, and disease-free survival censored at 5 years. Kaplan-Meier curves and univariate and multivariate Cox proportional hazards models were performed to examine demographic disparities in relation to survival.

RESULTS

Five-year overall, cancer-specific, and disease-free survival were 65.4% (407/622), 76.4% (487/622), and 67.0% (427/622), respectively. Lower income (HR, 1.5; 95% CI, 1.1-2.0 for overall survival; HR, 1.4; 95% CI, 1.0-1.9 for cancer-specific survival), high school education or less (HR, 1.4; 95% CI, 1.1-1.9 for overall survival; HR, 1.4; 95% CI, 1.1-1.9 for cancer-specific survival), and older age in decades (HR, 1.4; 95% CI, 1.2-1.7 for overall survival; HR, 1.2; 95% CI, 1.1-1.4 for cancer-specific survival) decreased both overall and disease-free survival rates. A high school education or less (HR, 1.4; 95% CI, 1.0-2.1) and advanced age (HR, 1.3; 95% CI, 1.1-1.6) were significant independent predictors of poor cancer-specific survival.

CONCLUSION

Low income, low education, and advanced age predicted poor survival while controlling for a number of covariates (health behaviors, medical comorbidities, and treatment modality). Recommendations from the Institute of Medicine's Report to reduce disparities need to be implemented in treating head and neck cancer patients.

Increased body mass index as a risk factor in localized prostate cancer treated by radical prostatectomy

BACKGROUND

The association between obesity and aggressive forms of prostate cancer is controversial. We compared preoperative body mass index (BMI) and prostate-specific antigen (PSA) levels as predictive risk factors for increased prostate weight and disease aggressiveness.

MATERIALS AND METHODS

This retrospective review of 464 patients with localized prostate cancer who underwent radical prostatectomy between March 1999 and October 2006 examined relationships among clinicopathological variables (BMI, preoperative serum PSA, biopsy and pathologic Gleason score [GS], and whole prostate weight) using linear and multinomial logistic regression analysis. We used multivariate regression modeling adjusting for age, year of surgery, PSA or BMI, pathologic stage, and GS.

RESULTS

Median age of patients (51% cT1c, 69% pT2) was 61 years (41-76), mean BMI 26.50kg/m(2) (standard deviation = 4.82), mean PSA 6.8ng/ml (0.67-27.2), median prostate weight 51g (12-200), median biopsy GS 6 (3-9), and median pathologic GS 7 (4-10). GS was upgraded in 227 patients (49%) from median GS 6 to 7 (P<0.00001). Mean prostate weight was 47±13.7g for BMI<25kg/m(2) (n = 170), 47±15g for BMI 25 to 30kg/m(2) (n = 224), and 59±26g for BMI>30kg/m(2) (n = 69) (P<0.00184). Mean prostate weight was significantly higher for BMI>30 than BMI<25 (47±13g vs. 59±25g, P<0.00015). Mean PSA was significantly higher for BMI>30 than for all other patients combined (8.56 [95% CI: 6.94-10.18] vs. 8.34 [7.23-9.45]; P = 0.001). PSA was positively associated with high biopsy GS for BMI≥25 (P = 0.048) and BMI≥30 (P = 0.009) but not for BMI≤25 (P = 0.151). BMI≥30 was associated with higher pT stage (odd ratio = 1.279 [1.5-1.56]; P = 0.015). In multivariate analyses, higher BMI was associated with higher prostate weight (P = 0.036) and pT stage (P = 0.008), and higher PSA with higher biopsy GS (P = 0.002). Neither BMI nor PSA was associated with GS upgrading.

CONCLUSIONS

Higher BMI was associated with higher prostate weight and PSA, as well as with higher pT stage and pathologic GS in men undergoing radical prostatectomy, providing further evidence that obese men are more likely to have aggressive cancer. BMI thus constitutes an additional risk factor besides PSA.

Abnormal body mass index at diagnosis in patients with Ewing sarcoma is associated with inferior tumor necrosis

BACKGROUND

Abnormal body mass index (BMI) in cancer patients at diagnosis has been associated with lower survival rates. The degree of tumor necrosis after induction chemotherapy in Ewing sarcoma (EWS) is highly associated with treatment failure. We analyzed the effect of BMI on tumor necrosis in children and young adults undergoing induction treatment for EWS.

PROCEDURE

Retrospective review of BMI and tumor necrosis in children and young adults with EWS. Patients were grouped into normal and abnormal BMI groups. Multivariate logistic regression and multivariate Cox regression were used to evaluate the impact of BMI on tumor necrosis, recurrence of disease, and survival.

RESULTS

Fifty patients who underwent resection of the tumor were eligible. Of them, 32 (64%) and 18 (36%) had normal and abnormal BMI, respectively. Poor histologic response (PR), defined as tumor necrosis of less than 90%, was achieved in 35 (70%) patients. When comparing abnormal to normal BMI, there were more cases of PR [9 (50%) vs. 6 (19%) (P = 0.025)], more relapses [8 (44%) vs. 8 (25%) (P = 0.164)], and more deaths [10 (57%) vs. 7 (22%) (P = 0.040)], respectively. Abnormal BMI was independently associated with PR (OR 4.33, 95% CI 1.12-19.14 P = 0.034) and worse overall survival (HR 2.76, 95% CI 1.19-9.99 P = 0.022), while it had no impact on event free survival.

CONCLUSIONS

The association between abnormal BMI and lower survival in EWS is presumed to be due to PR to chemotherapy. These findings stress the significance of BMI on treatment response in malignant diseases.

Associations of body mass index, smoking, and alcohol consumption with prostate cancer mortality in the Asia Cohort Consortium

Many potentially modifiable risk factors for prostate cancer are also associated with prostate cancer screening, which may induce a bias in epidemiologic studies. We investigated the associations of body mass index (weight (kg)/height (m)(2)), smoking, and alcohol consumption with risk of fatal prostate cancer in Asian countries where prostate cancer screening is not widely utilized. Analysis included 18 prospective cohort studies conducted during 1963-2006 across 6 countries in southern and eastern Asia that are part of the Asia Cohort Consortium. Body mass index, smoking, and alcohol intake were determined by questionnaire at baseline, and cause of death was ascertained through death certificates. Analysis included 522,736 men aged 54 years, on average, at baseline. During 4.8 million person-years of follow-up, there were 634 prostate cancer deaths (367 prostate cancer deaths across the 11 cohorts with alcohol data). In Cox proportional hazards analyses of all cohorts in the Asia Cohort Consortium, prostate cancer mortality was not significantly associated with obesity (body mass index >25: hazard ratio (HR) = 1.08, 95% confidence interval (CI): 0.85, 1.36), ever smoking (HR = 1.00, 95% CI: 0.84, 1.21), or heavy alcohol intake (HR = 1.00, 95% CI: 0.74, 1.35). Differences in prostate cancer screening and detection probably contribute to differences in the association of obesity, smoking, or alcohol intake with prostate cancer risk and mortality between Asian and Western populations and thus require further investigation.

Metabolic syndrome in castration-resistant prostate cancer patients treated with abiraterone

BACKGROUND

Metabolic syndrome (MS) has not yet been studied in castration-resistant prostate cancer (CRPC) men treated with novel hormonal therapies. The study aims to assess the impact of MS on outcome from time starting abiraterone.

PATIENTS AND METHODS

We retrospectively evaluated a consecutive series of metastatic CRPC patients treated with abiraterone after docetaxel failure. MS, as defined by modified Adult Treatment Panel (ATP) III criteria, was assessed at the time of initiation of abiraterone, during treatment and follow-up.

RESULTS

Sixty-seven of 178 patients evaluated (37.6%) met MS criteria at baseline, before abiraterone initiation, whereas for 11 (9.9%) without MS before treatment with abiraterone this occurred during treatment. Median PFS was equal to 4.7 months for patients with MS versus 9 months for those without MS. Patients with MS had an increased risk of 71% of progression or death for all causes than patients without MS (HR = 1.7, 95% CI [1.2-2.4], P = 0.03). Median OS was 14.7 months and 22.3 months in patients with and without MS, respectively. After adjusting for covariates, MS resulted not significantly associated to OS (HR = 1.42, 95% CI [0.91-2.22], P = 0.073).

CONCLUSIONS

The presence of MS is a significant risk factor for shorter PFS in CRPC patients treated with abiraterone, even if it does not show a significant impact on OS. A prospective evaluation is warranted.

The impact of obesity on prostate cancer recurrence observed after exclusion of diabetics

PURPOSE

Although overall there is a positive association between obesity and risk of prostate cancer (PrCa) recurrence, results of individual studies are somewhat inconsistent. We investigated whether the failure to exclude diabetics in prior studies could have increased the likelihood of conflicting results.

METHODS

A total of 610 PrCa patients who underwent radical prostatectomy between 2005 and 2012 were followed for recurrence, defined as a rise in serum PSA ≥ 0.2 ng/ml following surgery. Body mass index (BMI) and history of type 2 diabetes were documented prior to PrCa surgery. The analysis was conducted using Cox proportional hazard models.

RESULTS

Obesity (25.6 %) and diabetes (18.7 %) were common in this cohort. There were 87 (14.3 %) recurrence events during a median follow-up of 30.8 months after surgery among the 610 patients. When analyzed among all PrCa patients, no association was observed between BMI/obesity and PrCa recurrence. However, when analysis was limited to non-diabetics, obese men had a 2.27-fold increased risk (95 % CI 1.17-4.41) of PrCa recurrence relative to normal weight men, after adjusting for age and clinical/pathological tumor characteristics.

CONCLUSIONS

This study found a greater than twofold association between obesity/BMI and PrCa recurrence in non-diabetics. We anticipated these results because the relationship between BMI/obesity and the biologic factors that may underlie the PrCa recurrence-BMI/obesity association, such as insulin, may be altered by the use of anti-diabetes medication or diminished beta-cell insulin production in advanced diabetes. Studies to further assess the molecular factors that explain the BMI/obesity-PrCa recurrence relationship are warranted.

Effects of a high-fat diet on spontaneous metastasis of Lewis lung carcinoma in plasminogen activator inhibitor-1 deficient and wild-type mice

This study investigated the effects of a high-fat diet on spontaneous metastasis of Lewis lung carcinoma (LLC) in plasminogen activator inhibitor-1 deficient (PAI-1^−/−) and wild-type mice. The high-fat diet increased the number of pulmonary metastases by 60% (p<0.01), tumor cross-sectional area by 82% (p<0.05) and tumor volume by 130% (p<0.05) compared to the AIN93G diet. Deficiency in PAI-1 reduced the number of metastases by 35% (p<0.01) compared to wild-type mice. In mice fed the high-fat diet, PAI-1 deficiency reduced tumor cross-sectional area by 52% (p<0.05) and tumor volume by 61% (p<0.05) compared to their wild-type counterparts; however, PAI-1 deficiency affected neither area nor volume in mice fed the AIN93G diet. Adipose and plasma concentrations of PAI-1 were significantly higher in high-fat fed wild-type mice than in their AIN93G-fed counterparts. Adipose and plasma PAI-1 were not detectable in PAI-1^−/− mice regardless of the diet. Mice deficient in PAI-1 showed significantly greater plasma concentrations of monocyte chemotactic protein-1, tumor necrosis factor-α, leptin, vascular endothelial growth factor, tissue inhibitor of metalloproteinase-1 and insulin compared to wild-type mice, indicating a compensatory overproduction of inflammatory cytokines, angiogenic factors and insulin in the absence of PAI-1. We conclude that PAI-1 produced by the host, including that by adipose tissue, promotes high-fat enhanced metastasis of LLC.

Bone marrow adipocytes promote tumor growth in bone via FABP4-dependent mechanisms

Incidence of skeletal metastases and death from prostate cancer greatly increases with age and obesity, conditions which increase marrow adiposity. Bone marrow adipocytes are metabolically active components of bone metastatic niche that modulate the function of neighboring cells; yet the mechanisms of their involvement in tumor behavior in bone have not been explored. In this study, using experimental models of intraosseous tumor growth and diet-induced obesity, we demonstrate the promoting effects of marrow fat on growth and progression of skeletal prostate tumors. We reveal that exposure to lipids supplied by marrow adipocytes induces expression of lipid chaperone FABP4, pro-inflammatory interleukin IL-1β, and oxidative stress protein HMOX-1 in metastatic tumor cells and stimulates their growth and invasiveness. We show that FABP4 is highly overexpressed in prostate skeletal tumors from obese mice and in bone metastasis samples from prostate cancer patients. In addition, we provide results suggestive of bi-directional interaction between FABP4 and PPARγ pathways that may be driving aggressive tumor cell behavior in bone. Together, our data provide evidence for functional relationship between bone marrow adiposity and metastatic prostate cancers and unravel the FABP4/IL-1β axis as a potential therapeutic target for this presently incurable disease.

Bone marrow fat: linking adipocyte-induced inflammation with skeletal metastases

Adipocytes are important but underappreciated components of bone marrow microenvironment, and their numbers greatly increase with age, obesity, and associated metabolic pathologies. Age and obesity are also significant risk factors for development of metastatic prostate cancer. Adipocytes are metabolically active cells that secrete adipokines, growth factors, and inflammatory mediators; influence behavior and function of neighboring cells; and have a potential to disturb local milleu and dysregulate normal bone homeostasis. Increased marrow adiposity has been linked to bone marrow inflammation and osteoporosis of the bone, but its effects on growth and progression of prostate tumors that have metastasized to the skeleton are currently not known. This review focuses on fat-bone relationship in a context of normal bone homeostasis and metastatic tumor growth in bone. We discuss effects of marrow fat cells on bone metabolism, hematopoiesis, and inflammation. Special attention is given to CCL2- and COX-2-driven pathways and their potential as therapeutic targets for bone metastatic disease.

Low body mass index is associated with adverse oncological outcomes following radical prostatectomy in Korean prostate cancer patients

PURPOSE

The purpose of this study was to determine the impact of obesity on clinicopathological features and biochemical recurrence (BCR) following radical prostatectomy (RP) in Korean prostate cancer (PCa) patients.

METHODS

A single-institutional retrospective analysis was performed on 880 PCa patients treated by RP without neoadjuvant therapy between July 2005 and December 2011. Patients were stratified according to body mass index (BMI) standards for Asian populations: obese (BMI ≥25 kg/m(2)), overweight (BMI 23-24.9 kg/m(2)), or normal weight (BMI <23 kg/m(2)). For analysis, overweight and obese patients were combined (n = 592, BMI ≥23 kg/m(2)) and compared with normal weight patients (n = 288, BMI <23 kg/m(2)). BCR was defined as prostate-specific antigen (PSA) ≥0.2 ng/ml following RP.

RESULTS

Normal weight patients tended to be classified into the higher D'Amico risk category with smaller prostate volumes compared with obese and overweight patients. Normal weight patients had higher pathological Gleason scores and were at higher risk of BCR during the mean follow-up of 58.2 months. This translated to a higher 5-year BCR-free survival rate for obese and overweight patients compared with normal weight patients (77.8 vs. 70.3 %; p = 0.017). On multiple Cox-proportional hazards regression analysis incorporating variables of BMI category, PSA, positive surgical margins, pathological T stage, and Gleason score, higher BMI category remained a significant predictor of a lower risk of BCR (HR = 0.634, p = 0.028).

CONCLUSIONS

Obese and overweight Korean PCa patients have lower Gleason scores and a reduced risk of BCR compared with normal weight patients. These findings suggest that body fat influences pathological features and oncologic outcomes of PCa.

Obesity has multifaceted impact on biochemical recurrence of prostate cancer: a dose-response meta-analysis of 36,927 patients

Obesity is inconsistently related to biochemical recurrence (BCR) of prostate cancer (PCa) in different epidemiological studies. We conducted a systematic review and dose-response meta-analysis of published studies from MEDLINE and EMBASE in order to determine the relationship between body mass index (BMI) and BCR of PCa. We identified a total of 26 studies including 36,927 individuals. Pooled estimates of relative risk (RR) and confidence interval (CI) were computed, and dose-response meta-analysis was subsequently performed. Based on the random-effects approach, a 5 kg/m(2) increase in BMI was associated with 16 % (RR 1.16, 95 % CI 1.08-1.24) higher risk of BCR for entire set of 26 studies. Significantly higher rates of BCR were also observed in radical prostatectomy series (RR 1.17, 95 % CI 1.07-1.28) and external beam radiation therapy series (RR 1.19, 95 % CI 1.10-1.28), while no significant correlation was observed in brachytherapy series (RR 0.91, 95 % CI 0.64-1.28). Different BCR outcomes came out for studies held in USA (RR 1.18, 95 % CI 1.10-1.28), Europe (RR 1.04 95 % CI 0.91-1.17) and Asia (RR 1.83 95 % CI 0.85-3.97), respectively. There was limited evidence of a nonlinear association between BMI and BCR, which showed a critical point of 33 in BMI. The findings from meta-analysis showed that excess BMI was positively correlated with BCR of PCa multifacetedly, indicating good weight control and detailed attention to treating obese patients might improve the prognosis of PCa.

Association of body mass index and prostate cancer mortality

OBJECTIVES

Inconsistent evidence exists on whether obesity is associated with an increased risk of prostate cancer death post-radical prostatectomy. We examined data from three large health plans to evaluate if an increased body mass index (BMI) at prostate cancer diagnosis is related to prostate cancer mortality

SUBJECTS AND METHODS

This population-based case-control study included 751 men with prostate cancer who underwent radical prostatectomy. Cases were men who died due to prostate cancer (N=323) and matched controls (N=428). We used multivariable logistic regression models to assess the association between BMI at diagnosis and prostate cancer mortality, adjusted for Gleason score, PSA, tumour characteristics, and matching factors.

RESULTS

Study subjects were classified into the following BMI (kg/m2) categories: healthy (18.5-24.9), overweight (25-29.9) and obese (≥30). Nearly 43% of the participants had a BMI ≥25 at diagnosis. A higher fraction of cases (30%) were obese compared to controls (22%). Overall, obese men had more than a 50% increase in prostate cancer mortality (adjusted odds ratio=1.50 [95% CI, 1.03-2.19]) when compared to men with healthy BMI. After stratifying by Gleason score, the odds of mortality generally rose with increasing BMI. The strongest effect was observed in the Gleason score 8+ category (2.37, 95% CI: 1.11-5.09). These associations persisted after adjusting for PSA at diagnosis and other tumour characteristics.

CONCLUSIONS

These results suggest that BMI at diagnosis is strongly correlated with prostate cancer mortality, and that men with aggressive disease have a markedly greater odds of death if they are overweight or obese.

Impact of body mass index on clinicopathological outcome and biochemical recurrence after radical prostatectomy

BACKGROUND

Accumulating evidence suggests that obesity is associated with tumor progression in prostate cancer (PCa) patients after radical prostatectomy (RP). We conducted a retrospective multicenter study to determine the effect of body mass index (BMI) on the clinicopathological characteristics and biochemical recurrence of PCa in Japanese men who underwent RP.

METHODS

The medical records of 1257 men with PCa treated by RP without neoadjuvant therapy at four medical institutes between 2001 and 2009 were retrospectively reviewed. Patients were categorized into four groups using the World Health Organization (WHO) BMI classification and BMI quartiles. Associations of the various BMI categories with clinicopathological characteristics and biochemical recurrences were statistically evaluated. Biochemical recurrence was defined as a PSA level of >0.2 ng ml(-1).

RESULTS

Of the 1257 patients, 230 (18.3%) experienced biochemical recurrence during the median follow-up period of 49 months. The median BMI was 23.8 kg m(-2), and 1.4% patients were underweight, 65.4% were of normal weight, 30.9% were overweight and 2.4% were obese (WHO classification). Preoperative PSA levels and PSA density (PSAD) tended to decrease as BMI increased. Pathological characteristics did not differ significantly among BMI categories. As per the WHO classification and quartile categories, biochemical recurrence rate was comparable among the BMI groups. After adjusting for other pre- and postoperative covariables, multivariate Cox proportional hazards analysis revealed that a high BMI did not have an independent impact on biochemical recurrence-free survival.

CONCLUSIONS

Underweight Japanese PCa patients treated by RP had higher preoperative PSA levels and PSAD. High BMI was not associated with adverse pathological findings or increased biochemical recurrence rate in Japanese PCa patients treated with RP. Racial differences may exist in the relationship between obesity and outcomes of RP in PCa patients.

Metabolic syndrome as a peculiar target for management of prostate cancer patients

An interesting and reciprocal association between the metabolic syndrome and prostate cancer has been identified. Metabolic alterations, such as hyperinsulinemia, increased levels of insulin growth factor-1, and insulin resistance could be on the basis of development and progression of many tumors, including prostate cancer, and changes in body composition, in turn, can represent some side effects of androgen deprivation therapy and novel drugs, such as mammalian target of rapamycin inhibitors. This review evaluates this interrelation between metabolic syndrome and prostate tumor scanning in many clinical and preclinical epidemiological studies and describes possible pathogenetic biological mechanisms. Finally, this article discusses feasible clinical implications for the management, prevention, diagnosis, prognosis, and treatment of patients affected by metabolic syndrome and prostate cancer, with particular attention to the metformin action.

Obesity is not associated with aggressive pathologic features or biochemical recurrence after radical prostatectomy

OBJECTIVE

To determine whether obesity is associated with adverse pathologic characteristics, positive surgical margins, greater biochemical recurrence rates, and interval to death after primary treatment with radical prostatectomy (RP).

MATERIALS AND METHODS

A 12-year, retrospective, single-institution analysis of patients treated with RP was performed. Patients were categorized by their body mass index (BMI) as normal weight (n = 533), overweight (n = 1342), obese (n = 603), and morbidly obese (n = 22). The associations among the BMI, clinicopathologic characteristics, and biochemical recurrence rates were assessed.

RESULTS

After adjusting for multiple clinical preoperative characteristics, the BMI category was not associated with positive surgical margins (P = .66), organ-confined disease (P = .10), Gleason score (P = .22), extracapsular extension (P = .09), seminal vesicle invasion (P = .15), percentage of cancer in the prostate gland (P = .67), largest tumor nodule (P = .13), or lymph node metastasis (P = .39). Gleason score 4+3 (P <.001), Gleason score 9 and 10 (P <.001), and an increasing prostate-specific antigen level (P <.001) were associated with biochemical recurrence. At a mean overall follow-up of 55.6 months, 276 patients (11.0%) had developed biochemical recurrence (normal weight 11.3%, overweight 10.5%, obese 12.3%, and morbid obesity 4.5%). After multivariate adjustment for age, ethnicity, risk group, clinical stage, Gleason score, preoperative prostate-specific antigen level, and year of surgery, no association was found between the BMI and biochemical recurrence (P = .87).

CONCLUSION

In men undergoing RP for clinically localized prostate adenocarcinoma, obesity was not associated with adverse pathologic features, positive surgical margins, or biochemical recurrence. These data provide evidence that obese men undergoing RP are not more likely to have aggressive prostate cancer.

Neck circumference correlates with tumor size and lateral lymph node metastasis in men with small papillary thyroid carcinoma

BACKGROUND/AIMS

Obesity is correlated with numerous diseases, including thyroid cancer, but the clinical significance of obesity with regard to the clinical characteristics of thyroid cancer remains unclear. Neck circumference is an index of upper-body adipose tissue distribution.

METHODS

In total, 401 patients with papillary thyroid carcinoma (PTC) measuring ≤ 2 cm were included. Neck circumference was measured horizontally at the level just below the thyroid cartilage on preoperative neck computed tomographic images.

RESULTS

Neck circumference correlated significantly with tumor size in men (p = 0.001) but not in women (p = 0.930). Body mass index (BMI) did not significantly correlate with tumor size in either sex. Neck circumference was significantly larger in men with lateral lymph node (LN) metastasis than in those without (p = 0.004). Neck circumference and BMI did not differ significantly in women according to other factors such as tumor size, multifocality, extrathyroid extension, and LN metastasis. Tumor size and the prevalence of lateral LN metastasis in men tended to increase in the middle/large neck circumference subgroup compared with those in the low neck circumference subgroup. Multivariate logistic regression analysis revealed that neck circumference (p = 0.009) was a predictor for the presence of lateral LN metastasis in men. BMI was not a predictive factor for lateral LN involvement in either sex.

CONCLUSIONS

Neck circumference, an indicator of central or visceral obesity but not BMI, may be associated with some prognostic factors in men with small PTC.

Association between biomarkers of obesity and risk of high-grade prostatic intraepithelial neoplasia and prostate cancer--evidence of effect modification by prostate size

Prostate enlargement is common with aging and obesity. We investigated the association between obesity and prostate cancer controlling for differential detection related to prostate enlargement. In an analysis of 500 men, we found body mass index, waist-hip ratio, and blood leptin levels were significantly associated with high-grade PC, but only among men without prostate enlargement. Leptin was also significantly associated with high-grade prostatic intraepithelial neoplasia (HGPIN) in the absence of prostate enlargement. Our results suggest obesity advances prostate carcinogenesis, and that detection biases at prostate biopsy may explain past inconsistencies in the association between obesity and PC.

A longitudinal study on engagement with dieting information as a predictor of dieting behavior among adults diagnosed with cancer

OBJECTIVE

This study explores cancer survivors' engagement with information about dieting to control weight from doctors, interpersonal, and media sources and examines whether engagement from these sources impacts subsequent dieting behavior.

METHODS

A total of 1128 respondents diagnosed with colorectal, breast, or prostate cancers were surveyed over three years following their cancer diagnoses. Using weighted logistic regression analyses, the authors predicted the odds of dieting based on earlier information engagement with sources, controlling for dieting in the previous year and confounders.

RESULTS

Participants reported talking with doctors more frequently (37%) than seeking or scanning from interpersonal and media sources about dieting (15-22%). Seeking from interpersonal and media sources, and discussion with physicians, significantly predicted dieting behavior. In addition, discussions with physicians increased the odds of subsequent dieting behavior by 2.32 times (95% CI: 1.50-3.61; p=.002), over and above the effects of other information engagement.

CONCLUSION

Cancer survivors reported engaging with a variety of information sources about dieting. Engagement with doctors and information-seeking from interpersonal or media sources predicted cancer survivors' dieting behavior a year later.

PRACTICE IMPLICATIONS

The results may inform strategies to encourage and empower cancer survivors to engage with information about healthy lifestyle changes for promoting long-term health.

Effect of body mass index on intrafraction prostate displacement monitored by real-time electromagnetic tracking

PURPOSE

To evaluate, using real-time monitoring of implanted radiofrequency transponders, the intrafraction prostate displacement of patients as a function of body mass index (BMI).

METHODS AND MATERIALS

The motions of Beacon radiofrequency transponders (Calypso Medical Technologies, Seattle, WA) implanted in the prostate glands of 66 men were monitored throughout the course of intensity modulated radiation therapy. Data were acquired at 10 Hz from setup to the end of treatment, but only the 1.7 million data points with a "beam on" tag were used in the analysis. There were 21 obese patients, with BMI ≥ 30 and 45 nonobese patients in the study.

RESULTS

Mean displacements were least in the left-right lateral direction (0.56 ± 0.24 mm) and approximately twice that magnitude in the superior-inferior and anterior-posterior directions. The net vector displacement was larger still, 1.95 ± 0.47 mm. Stratified by BMI cohort, the mean displacements per patient in the 3 Cartesian axes as well as the net vector for patients with BMI ≥ 30 were slightly less (<0.2 mm) but not significantly different than the corresponding values for patients with lower BMIs. As a surrogate for the magnitude of oscillatory noise, the standard deviation for displacements in all measured planes showed no significant differences in the prostate positional variability between the lower and higher BMI groups. Histograms of prostate displacements showed a lower frequency of large displacements in obese patients, and there were no significant differences in short-term and long-term velocity distributions.

CONCLUSIONS

After patients were positioned accurately using implanted radiofrequency transponders, the intrafractional displacements in the lateral, superior-inferior, and anterior-posterior directions as well as the net vector displacements were smaller, but not significantly so, for obese men than for those with lower BMI.

Health behaviors of cancer survivors of different sexual orientations

OBJECTIVE

This study identifies differences by sexual orientation in health behaviors of cancer survivors.

METHODS

We pooled data from the 2001, 2003, and 2005 California health interview survey to compare cancer survivors' alcohol use, smoking, exercise, fruit and vegetable consumption, weight, and physician visits by sexual orientation.

RESULTS

Female bisexual cancer survivors were 2.2 times more likely to report being a current smoker and were 0.39 times less likely to report physical inactivity compared with female heterosexual cancer survivors. Lesbian cancer survivors were 7.4 times more likely to have visited a physician during the past year than female heterosexual cancer survivors. Among male cancer survivors, both gay and bisexual men had significantly lower odds (OR = 0.4) of being overweight or obese, and bisexual men were 3.0 times more likely to engage in vigorous activity and 7.8 times more likely to visit physicians compared with heterosexual men.

CONCLUSIONS

This study's prevalence estimates of behavioral risk factors of gay, lesbian, and bisexual cancer survivors suggest considerable need for promotion of healthy lifestyle behaviors. We discuss the need for future studies with lesbian, gay, and bisexual cancer survivors.

Relationship of obesity, androgen receptor genotypes and biochemical failure after radical prostatectomy

BACKGROUND

Obesity and androgen metabolism have been implicated in the progression of prostate cancer. Obesity has been associated with increased risk for advanced disease and biochemical failure after treatment. This association may be the result of changes in androgen metabolism that occur with obesity and are mediated by the androgen receptor (AR).

METHODS

To evaluate the effects of obesity and AR polymorphisms on biochemical failure, we conducted a study of 536 Caucasian prostate cancer cases. We determined the relationship between time to biochemical failure and obesity stratified by short and long AR-CAG and AR-GGN repeat sequence. The AR repeat groups were dichotomized at the median number of repeats for each polymorphism.

RESULTS

An association was found for obesity in the short CAG group (HR = 3.45, 95% CI = 1.00-11.96). Among obese patients diagnosed with localized disease (T1/T2), the risk of biochemical failure was significantly higher (HR = 7.05, 95% CI = 1.55-32.06). No difference was observed for high stage (T3/T4) obese patients. Additionally, no differences in biochemical failure were observed in obese and non-obese men grouped by number of AR-GGN repeats.

CONCLUSIONS

Obesity is significantly associated with increased risk of biochemical failure in men with the high-risk short CAG sequence on the AR gene. This effect is not observed in men with long CAG repeats. Therefore, it appears that the relationship between biochemical failure and obesity may be modified by the AR-CAG repeat pattern. The short AR-CAG genotype may be more responsive to an altered hormonal milieu created by obesity.

Effect of Roux-en-Y gastric bypass on testosterone and prostate-specific antigen

Background

Obese men have lower serum levels of testosterone, dehydroepiandrosterone (DHEA) and prostate-specific antigen (PSA), but an increased risk of dying from prostate cancer. The aim of this study was to examine the effect of surgically induced weight loss on serum testosterone, DHEA and PSA levels in obese men.

Methods

Consecutive men undergoing Roux-en-Y gastric bypass (RYGB) participated in a prospective, longitudinal study. Main outcomes were changes were body mass index (BMI), percentage excess weight loss, serum levels of testosterone, DHEA and PSA, PSA mass and plasma volume, measured before operation and 3, 6 and 12 months later.

Results

In 64 patients, mean BMI fell from 48·2 kg/m2 before operation to 39·2, 35·6 and 32·4 kg/m2 at 3, 6 and 12 months after RYGB. Testosterone levels rose significantly from 259 ng/dl to 386, 452 and 520 ng/dl respectively. Serum PSA levels increased significantly from 0·51 ng/ml to 0·67 ng/ml at 12 months. There were no significant changes in DHEA or PSA mass.

Conclusion

RYGB normalizes the serum testosterone level. PSA levels increase with weight loss and may be inversely correlated with changes in plasma volume, indicating that PSA levels may be artificially low in obese men owing to haemodilution.

Obesity is associated with castration-resistant disease and metastasis in men treated with androgen deprivation therapy after radical prostatectomy: results from the SEARCH database

Study Type - Prognosis (cohort series). Level of Evidence 2a. What's known on the subject? and What does the study add? The incidence and prevalence of obesity in the USA and Europe is increasing. Higher body mass index is associated with a lower risk of overall prostate cancer diagnosis but also with an increased risk of high grade prostate cancer. Obese men undergoing primary therapy with radical prostatectomy or external beam radiation are more likely to experience a biochemical recurrence after treatment compared with normal weight men. Finally, obesity is associated with increased prostate-cancer-specific mortality. We hypothesized that obese men on androgen deprivation therapy may be at increased risk for prostate cancer progression. Previous studies have shown that obese men have lower levels of testosterone compared with normal weight men. Additionally, one previous study found that obese men have higher levels of testosterone on androgen deprivation therapy. Men with higher levels of testosterone on androgen deprivation therapy are at increased risk of prostate cancer progression. We found that men with higher body mass index were at increased risk of progression to castration-resistant prostate cancer, development of metastases and prostate-cancer-specific mortality. When we adjusted for various clinicopathological characteristics, obese men were at increased risk of progression to castration-resistant prostate cancer and development of metastases. The results of our study help generate hypotheses for further study regarding the mechanisms between obesity and aggressive prostate cancer.

OBJECTIVE

• To investigate whether obesity predicts poor outcomes in men starting androgen deprivation therapy (ADT) before metastasis, since previous studies found worse outcomes after surgery and radiation for obese men.

METHODS

• A retrospective review was carried out of 287 men in the SEARCH database treated with radical prostatectomy between 1988 and 2009. • Body mass index (BMI) was categorized to <25, 25-29.9 and ≥ 30 kg/m2. • Proportional hazards models were used to test the association between BMI and time to castration-resistant prostate cancer (PC), metastases and PC-specific mortality adjusting for demographic and clinicopathological data.

RESULTS

• During a median 73-month follow-up after radical prostatectomy, 403 men (14%) received early ADT. • Among 287 men with complete data, median BMI was 28.3 kg/m2. • Median follow-up from the start of ADT was 52 months during which 44 men developed castration-resistant PC, 34 developed metastases and 24 died from PC. • In multivariate analysis, higher BMI was associated with a trend for greater risk of progression to castration-resistant PC (P= 0.063), a more than threefold increased risk of developing metastases (P= 0.027) and a trend toward worse PC-specific mortality (P= 0.119). • Prognostic biomarkers did not differ between BMI groups.

CONCLUSIONS

• Among men treated with early ADT, our results suggest that obese men may have increased risk of PC progression. • These data support the general hypothesis that obesity is associated with aggressive PC, although validation of these findings and further study of the mechanisms linking obesity and poor PC outcomes are required.

Preoperative weight change and risk of adverse outcome following radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital database

BACKGROUND

We examined the relationship between weight change in the year before radical prostatectomy (RP) and biochemical recurrence (BCR) and adverse pathology.

METHODS

We abstracted data from 359 men undergoing RP in the SEARCH (Shared Equal Access Regional Cancer Hospital) database between 2001-2007. Logistic regression and Cox proportional hazards models were used to test the association between weight change in the year before surgery and adverse pathology and BCR, respectively.

RESULTS

In all, 152 (42%) men gained weight, 193 (54%) lost weight and 14 (4%) had the same weight. Among weight gainers, median gain was 2.4 kg and among weight losers, median loss was 2.7 kg. As a continuous variable, weight change was not associated with adverse pathology or BCR (all P>0.05). In secondary analysis, on multivariate analysis, men gaining ≥ 2.5 kg were at higher BCR risk (hazards ratio=1.65, 95% confidence interval (CI): 1.03-2.64, P=0.04) while weight loss ≥ 2.5 kg was not associated with BCR (hazards ratio=0.83, 95% CI: 0.54-1.29, P=0.41).

CONCLUSIONS

As a continuous variable, weight change was not associated with outcome. In secondary hypothesis-generating analyses, weight gain ≥ 2.5 kg in the year before surgery, regardless of final body mass index, was associated with increased BCR following RP. If validated, these data suggest weight gain ≥ 2.5 kg may promote prostate cancer progression.