Obesity and survival after radical prostatectomy: A 10-year prospective cohort study

Are associations between obesity and prostate cancer outcomes following radical prostatectomy the same in smokers and non-smokers? Results from the SEARCH Cohort

PURPOSE

Obesity and smoking have been associated with poor prostate cancer (PC) outcomes. We investigated associations between obesity and biochemical recurrence (BCR), metastasis, castrate resistant-PC (CRPC), PC-specific mortality (PCSM), and all-cause mortality (ACM) and examined if smoking modified these associations.

METHODS

We analyzed SEARCH Cohort data from men undergoing RP between 1990 and 2020. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between body mass index (BMI) as a continuous variable and weight status classifications (normal: 18.5 ≤ 25 kg/m2; overweight: 25-29.9 kg/m2; obese: ≥ 30 kg/m2) and PC outcomes.

RESULTS

Among 6,241 men, 1,326 (21%) were normal weight, 2,756 (44%) overweight and 2159 (35%) obese; 1,841 (30%) were never-smokers, 2,768 (44%) former and 1,632 (26%) current-smokers. Among all men, obesity was associated with non-significant increased risk of PCSM, adj-HR = 1.71; 0.98-2.98, P = 0.057, while overweight and obesity were inversely associated with ACM, adj-HR = 0.75; 0.66-0.84, P < 0.001 and adj-HR = 0.86; 0.75-0.99, P = 0.033, respectively. Other associations were null. BCR and ACM were stratified for smoking status given evidence for interactions (P = 0.048 and P = 0.054, respectively). Among current-smokers, overweight was associated with an increase in BCR (adj-HR = 1.30; 1.07-1.60, P = 0.011) and a decrease in ACM (adj-HR = 0.70; 0.58-0.84, P < 0.001). Among never-smokers, BMI (continuous) was associated with an increase in ACM (adj-HR = 1.03; 1.00-1.06, P = 0.033).

CONCLUSIONS

While our results are consistent with obesity as a risk factor for PCSM, we present evidence of effect modification by smoking for BCR and ACM highlighting the importance of stratifying by smoking status to better understand associations with body weight.

Association between adiposity after diagnosis of prostate cancer and mortality: systematic review and meta-analysis

Objective

To explore the associations between adiposity indices, assessed at or after a diagnosis of prostate cancer, and mortality.

Design

Systematic review and meta-analysis.

Data sources

PubMed and Embase, from inception to 16 November 2022.

Eligibility criteria for selecting studies

Cohort studies or randomised controlled trials of men with a diagnosis of prostate cancer that investigated the associations between adiposity (body mass index, waist and hip circumference, waist-to-hip ratio, and subcutaneous and visceral adipose tissue) after diagnosis and mortality outcomes. A modified version of the risk of bias for nutrition observational studies tool was used to assess risk of bias.

Results

79 studies were identified that investigated adiposity indices after a diagnosis of prostate cancer in relation to mortality. No randomised controlled trials were found. A non-linear dose-response meta-analysis indicated a J shaped association between body mass index and all cause mortality (33 910 men, 11 095 deaths, 17 studies). The highest rate of all cause mortality was found at the lowest and upper range of the distribution: 11-23% higher rate for a body mass index of 17-21 and 4-43% higher rate for a body mass index of 30-40. The association between body mass index and mortality specific to prostate cancer was flat until body mass index reached 26-27, and then increased linearly by 8-66% for a body mass index of 30-40 (33 137 men, 2947 deaths, 13 studies), but the 95% confidence intervals were wide. These associations did not differ in most predefined subgroups by study design, number of deaths, anthropometric assessment, follow-up time, geographical location, prostate cancer risk group, and adjustment variables. No associations were found in meta-analyses between 10 cm increases in waist circumference and all cause mortality or mortality specific to prostate cancer, but only three studies were available. The few studies with data on change in weight, waist-to-hip ratio, and subcutaneous and visceral adipose tissue reported conflicting results.

Conclusions

This review suggests that patients with prostate cancer might benefit from maintaining a healthy weight and avoiding obesity. Future studies should investigate adiposity across different stages of cancer survivorship and use various parameters for distribution of adipose tissue.

Systematic review registration

Open Science Framework https://osf.io/qp3c4.

Adipose Tissue Distribution and Body Mass Index (BMI) Correlation With Daily Image-Guided Radiotherapy (IGRT) Shifts of Abdominal Radiation Therapy Patients

Purpose There are several studies suggesting a correlation between image-guided radiotherapy (IGRT) setup errors and body mass index (BMI). However, abdominal fat content has visceral and subcutaneous components, which may affect setup errors differently. This study aims to analyze a potential workflow for characterizing adipose content and distribution in the region of the target that would allow a quickly calculated metric of abdominal fat content to stratify these patients. Methods IGRT shift data was retrospectively tabulated from daily fan-beam CT-on-rails pre-treatment alignment for 50 abdominal radiation therapy (RT) patients, and systematic and random errors in the daily setup were characterized by tabulating average and standard deviations of shift data for each patient and looking at differences for different distributions of adipose content. Visceral and subcutaneous fat content were defined by visceral fat area (VFA) and subcutaneous fat area (SFA) using a region-growing algorithm to contour adipose tissue on CT simulation scans. All contours were created for a single slice at the treatment isocenter, on which the VFA and SFA were calculated. A log-rank test was used to test trends in shifts over quartiles of adiposity. Results VFA ranged from 1.9-342.8c m², and SFA from 11.8-756.0 cm². The standard definition (SD) of random error (σ) in the lateral axis for Q1 vs. Q4 VFA was 0.10cm vs. 0.29cm, 0.12cm vs. 0.28cm for SFA, and 0.12cm vs. 0.31cm for BMI. The percentage of longitudinal shifts greater than 10mm for Q1 vs. Q4 VFA was 0% vs. 9%, 2% vs. 19% for SFA, and 0% vs. 20% for BMI. Statistically significant trends in shifts vs. the BMI quartile were seen for both pitch and the longitudinal direction, as well as for pitch corrections vs. the VFA quartile. Conclusion Within this dataset, abdominal cancer patients showed statistically significant trends in shift probability vs. BMI and VFA. Also, patients in the upper quartiles of all adiposity metrics showed an increased SD of σ in the lateral direction and increased shifts over 10 mm in the longitudinal direction. However, despite these relationships, neither VFA nor SFA offered discernible advantages in their relationship to shift uncertainty relative to BMI.

Targeting lipid metabolism in metastatic prostate cancer

Despite key advances in the treatment of prostate cancer (PCa), a proportion of men have de novo resistance, and all will develop resistance to current therapeutics over time. Aberrant lipid metabolism has long been associated with prostate carcinogenesis and progression, but more recently there has been an explosion of preclinical and clinical data which is informing new clinical trials. This review explores the epidemiological links between obesity and metabolic syndrome and PCa, the evidence for altered circulating lipids in PCa and their potential role as biomarkers, as well as novel therapeutic strategies for targeting lipids in men with PCa, including therapies widely used in cardiovascular disease such as statins, metformin and lifestyle modification, as well as novel targeted agents such as sphingosine kinase inhibitors, DES1 inhibitors and agents targeting FASN and beta oxidation.

Antidepressant medication use and prostate cancer recurrence in men with depressive disorders

Purpose

Whether treating prostate cancer survivors with a depressive disorder with antidepressants can affect their cancer outcomes is unknown. We evaluated the association between antidepressant use and prostate cancer recurrence, in survivors with comorbid depressive disorders.

Methods

We conducted a longitudinal cohort study of 10,017 men with prostate cancer (stages I–II) diagnosed who also had a comorbid depressive disorder followed a maximum of 22 years, and examined rates of biochemical recurrence by antidepressant medication use. We conducted multivariable Cox models based on time-dependent antidepressant drug use status, and examined the risk of biochemical recurrence by cumulative duration of antidepressant use.

Results

Of these 10,017 survivors, 1842 (18%) experienced biochemical recurrence over 69,500 person-years of follow-up. The prostate cancer biochemical recurrence rate was greater with antidepressant non-use (31.3/1000 person-years) compared to antidepressant use (23.5/1000 person-years). In Cox proportional hazards multivariable adjusted models, non-use of antidepressants was associated with a 34% increased risk of biochemical recurrence compared to antidepressant use (HR = 1.34, 95% CI: 1.24–1.44). Longer use of antidepressants was associated with a lower biochemical recurrence risk (P trend test < 0.001).

Conclusion

Untreated depressive disorders in prostate cancer patients may be associated with an increased risk of biochemical recurrence.

Obesity and biochemical recurrence in clinically localised prostate cancer: a systematic review and meta-analysis of 86,490 patients

BACKGROUND

The association of obesity with biochemical recurrence (BCR) after treatment of clinically localised prostate cancer (PC) shows inconsistent results. Our aim was to systematically review all evidence evaluating obesity as a prognostic factor for BCR.

METHODS

We searched PubMed, Web of Science and Scopus, from inception to June 1, 2021. Cohort studies reporting BCR among PC patients stratified by body mass index (BMI) were included. To assess the quality of the selected studies, we used the Newcastle-Ottawa scale (NOS). Risk of BCR among obese patients (BMI ≥ 30 kg/m²) was compared with normal weight (BMI < 25), pooling individual hazard ratios (HR) in random-effect meta-analysis. Associations for continuous BMI per 5 kg/m² were also calculated. Subgroup analyses were conducted to assess reasons for heterogeneity and causal criteria were formally evaluated.

RESULTS

We identified 46 cohort studies including 86,490 PC patients. A total of 14,719 (17.1%) patients developed BCR. There was no consistent definition of BCR. Obesity was associated with BCR (HR: 1.25, 95% CI: 1.11-1.39, I²: 70.3%), and there was a 10% increase (95% CI: 4-15%, I²: 66.3%) in BCR per 5 kg/m² increase in BMI. The heterogeneity was high but decreased in the subgroup of highest-quality NOS score and when the BMI was measured by the researchers (I²: 0.0%). The association was consistent in patients receiving radical prostatectomy but not in patients receiving other therapies.

CONCLUSIONS

Obesity showed a moderate, consistent relationship with biochemical recurrence after radical prostatectomy. Measurement of BMI and BCR was variable, highlighting the need for standardised clinical guidelines. Preventive weight control programs may have a role in reducing BCR for clinically localised PC patients.

Obesity as a Risk Factor for Prostate Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of 280,199 Patients

Simple Summary

Results from individual studies on the association between obesity and prostate cancer mortality remain inconclusive; additionally, several large cohort studies have recently been conducted. We aimed to systematically review all available evidence and synthetize it using meta-analytic techniques. The results of our study showed that obesity was associated with prostate cancer specific mortality and all-cause mortality. The temporal association was consistent with a dose-response relationship. Our results demonstrated that obesity, a potentially modifiable prognostic factor, was associated with higher prostate cancer mortality. This study improved the evidence regarding the potential impact of lifestyle on improving prostate cancer prognosis. Strategies aimed at maintaining normal, or reducing abnormal, body mass index in diagnosed prostate cancer patients might improve survival. These results should guide urologists, oncologists, patients, policy-makers and primary care providers with respect to evidence-based practice and counselling concerning lifestyle changes after prostate cancer diagnosis.

Abstract

The aim of this study was to systematically review all evidence evaluating obesity as a prognostic factor for PC mortality. Cohort and case-control studies reporting mortality among PC patients stratified by body mass index (BMI) were included. The risk of mortality among obese patients (BMI ≥ 30) was compared with the risk for normal weight (BMI < 25) patients, pooling individual hazard ratios (HR) in random-effects meta-analyses. Reasons for heterogeneity were assessed in subgroup analyses. Dose-response associations for BMI per 5 kg/m² change were assessed. Among 7278 citations, 59 studies (280,199 patients) met inclusion criteria. Obesity was associated with increased PC-specific mortality (HR: 1.19, 95% CI: 1.10–1.28, I²: 44.4%) and all-cause mortality (HR: 1.09, 95% CI: 1.00–1.18, I²: 43.9%). There was a 9% increase (95% CI: 5–12%, I²: 39.4%) in PC-specific mortality and 3% increase (95% CI: 1–5%, I²: 24.3%) in all-cause mortality per 5 kg/m² increase in BMI. In analyses restricted to the higher quality subgroup (NOS ≥ 8), obesity was associated with increased PC-specific mortality (HR: 1.24, 95% CI: 1.14–1.35, I²: 0.0%) and maintained the dose-response relationship (HR: 1.11 per 5 kg/m² increase in BMI, 95% CI: 1.07–1.15, I²: 26.6%). Obesity had a moderate, consistent, temporal, and dose-response association with PC mortality. Weight control programs may have a role in improving PC survival.

Effect of pre-operative internal obturator muscle mass index in MRI on biochemical recurrence of prostate cancer patients after radical prostatectomy: a multi-center study

Background

Recent reports show that the pre-operative or post-operative skeletal mass index (sarcopenia) affects survival rates for various cancers; however, the link between prostate cancer survival and sarcopenia is unclear. Therefore, this study examined the effect of the pre-operative internal obturator muscle (IOM) mass index on biochemical recurrence (BCR) of prostate cancer (PCa) patients who underwent radical prostatectomy.

Methods

In total, 222 patients, who underwent open, laparoscopic, or robot-assisted radical prostatectomy at seven centers in 2011 and were followed up for 5 years, were enrolled. BCR was examined in the context of pre-operative IOM mass index and BMI.

Results

The mean age of the patients was 67.82 ± 6.23 years, and the mean pre-operative prostate-specific antigen (PSA) level was 11.61 ± 13.22 ng/ml. There was no significant difference in baseline characteristics between the low and high IOM mass index groups (p > 0.05). Age, pre-op PSA level, ECE, and T-stage were associated with BCR (p = 0.049, p < 0.001, p = 0.001, p = 0.004, respectively). BMI, prostate volume, Gleason score, resection margin, N-stage, M-stage and IOM mass index was not associated with BCR (p > 0.05).

Conclusions

Pre-operative IOM mass index was not associated with BCR; however, long-term follow-up is necessary to evaluate cancer-specific and overall survival of PCa patients.

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.

Preoperative Nutritional Risk Index Predicts Recurrence of Oligometastatic Prostate Cancer in Patients Undergoing Cytoreductive Radical Prostatectomy

This study aims to investigate the specific predictive role of the preoperative Nutritional Risk Index (NRI) in oligometastatic prostate cancer (OM-PC) patients, who have undergone cytoreductive radical prostatectomy (cRP), and explored its prognostic index values. A total 89 OM-PC patients, who were identified between 2013 and 2019, were included in the present study. The Kaplan-Meier method and Cox regression analysis were used to separately assess the prostate specific antigen (PSA) progression-free survival (PFS). Overall accuracy was determined by analyzing the area under the receiver operating characteristic curve (AUC). The analysis of patients in these three different groups indicated that patients with lower NRI values were significantly associated with a higher Gleason score and more neoadjuvant androgen deprivation therapy (P < 0.05). In addition, the Kaplan-Meier curve analysis revealed that OM-PC patients in the preoperative high-risk group had shorter PSA-PFS (P < 0.001). Furthermore, the multivariate analysis further predicted that the high-risk NRI value is a common independent prognostic factor for shorter PSA-PFS (P < 0.001). Moreover, it was also observed that the AUC value of the NRI score was higher than other conventional nutritional indicators. The present study suggests that NRI can potentially be used as a new prognostic indicator for PSA-PFS for patients with OM-PC after cRP.

Postdiagnosis Body Mass Index, Weight Change, and Mortality From Prostate Cancer, Cardiovascular Disease, and All Causes Among Survivors of Nonmetastatic Prostate Cancer

PURPOSE

To investigate the association of postdiagnosis body mass index (BMI) and weight change with prostate cancer-specific mortality (PCSM), cardiovascular disease-related mortality (CVDM), and all-cause mortality among survivors of nonmetastatic prostate cancer.

METHODS

Men in the Cancer Prevention Study II Nutrition Cohort diagnosed with nonmetastatic prostate cancer between 1992 and 2013 were followed for mortality through December 2016. Current weight was self-reported on follow-up questionnaires approximately every 2 years. Postdiagnosis BMI was obtained from the first survey completed 1 to < 6 years after diagnosis. Weight change was the difference in weight between the first and second postdiagnosis surveys. Deaths occurring within 4 years of the follow-up were excluded to reduce bias from reverse causation. Analyses of BMI and weight change included 8,330 and 6,942 participants, respectively.

RESULTS

Postdiagnosis BMI analyses included 3,855 deaths from all causes (PCSM, n = 500; CVDM, n = 1,155). Using Cox proportional hazards models, hazard ratios (HRs) associated with postdiagnosis obesity (BMI ≥ 30 kg/m2) compared with healthy weight (BMI 18.5 to < 25.0 kg/m2) were 1.28 for PCSM (95% CI, 0.96 to 1.67), 1.24 for CVDM (95% CI, 1.03 to 1.49), and 1.23 for all-cause mortality (95% CI, 1.11 to 1.35). Weight gain analyses included 2,973 deaths (PCSM, n = 375; CVDM, n = 881). Postdiagnosis weight gain (> 5% of body weight), compared with stable weight (± < 3%), was associated with a higher risk of PCSM (HR, 1.65; 95% CI, 1.21 to 2.25) and all-cause mortality (HR, 1.27; 95% CI, 1.12 to 1.45) but not CVDM.

CONCLUSION

Results suggest that among survivors of nonmetastatic prostate cancer with largely localized disease, postdiagnosis obesity is associated with higher CVDM and all-cause mortality, and possibly higher PCSM, and that postdiagnosis weight gain may be associated with a higher mortality as a result of all causes and prostate cancer.

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 (ORobese = 1.5; ORvery obese = 1.7) and upward reclassification of disease between biopsy and surgery, driven by change in tumor stage (ORobese = 1.3; ORvery obese = 1.6). We observed an association between BMI and recurrence with adjustment for disease severity using diagnostic factors (HRvery 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.

Obesity, risk of biochemical recurrence, and prostate-specific antigen doubling time after radical prostatectomy: results from the SEARCH database

OBJECTIVES

To examine the association between body mass index (BMI) and aggressive biochemical recurrence (BCR) using the Shared Equal Access Regional Cancer Hospital (SEARCH) database.

MATERIAL AND METHODS

We identified 4123 men with complete data treated by radical prostatectomy between 1988 and 2015. We tested the association between BMI and BCR using Cox models, and among men with BCR, prostate-specific antigen doubling time (PSADT) was compared across BMI categories using linear regression. Models were adjusted for age, race, prostate-specific antigen, biopsy Gleason score, clinical stage, year and surgical centre.

RESULTS

Overall, 922 men (22%) were of normal weight (BMI <25 kg/m² ), 1863 (45%) were overweight (BMI 25-29.9 kg/m² ), 968 (24%) were obese (BMI 30-34.9 kg/m² ), and 370 (9%) were moderately or severely obese (BMI ≥35 kg/m² ). After adjustment for multiple clinical characteristics, higher BMI was significantly associated with higher risk of BCR (P = 0.008). Among men with BCR, men in the four BMI categories had similar multivariable-adjusted PSADT values (increasing BMI categories: 20.9 vs 21.3 vs 21.0 vs 14.9 months; P = 0.48).

CONCLUSION

While we confirmed that higher BMI was associated with BCR, we found no link between BMI and PSADT at the time of recurrence. Our data suggest obese men do not have more aggressive recurrences. Future studies are needed to test whether obesity predicts response to salvage therapies.

Exploring positive surgical margins after minimally invasive radical prostatectomy: Does body habitus really make a difference ?

BACKGROUND

Positive surgical margins (PSMs) at radical prostatectomy (RP) are generally recognized as a surrogate of poor or difficult dissection of the prostatic gland. In open RP cohorts, obesity seems to be associated to an increased risk of PSMs, probably due to the technical challenge that obese men pose to surgical access. Minimally invasive RP has been claimed to possibly reduce PSM rate. Aim of the study was to explore the impact of obesity and body habitus on PSM risk and their localisation during laparoscopic and robotic-assisted RP.

MATERIALS AND METHODS

We reviewed 539 prospectively enrolled patients undergoing laparoscopic and robotic-assisted RP with pT2 prostate cancer. The outcome measured was rate of PSM according to the BMI and surgical approach (laparoscopic vs robotic-assisted). Patients were categorized in BMI<25kg/m², BMI 25-29.9kg/m² and BMI >30kg/m² groups respectively and compared using Kruskall-Wallis or χ² test, as appropriate. Uni- and multivariate logistic regression models were constructed to assess the impact of BMI and surgical technique on PSM risk.

RESULTS

Overall, 127 (24%) of men had PSMs detected at final specimen evaluation. Mean PSM length was 3.9±3.4mm, and 30 (6%) men presented significant margins ≥4mm. Analysing the rate of PSMs across BMI categories, no significant association between increased BMI and PSM was detected (all P>0.48). On uni- and multivariate logistic regression BMI was not a statistically significant risk factor for PSM (P=0.14), nor was the minimally invasive technique (laparoscopic vs robotic-assisted) (P=0.54).

CONCLUSIONS

In this study obese men do not appear to have a significant increase in risk of PSMs at RP compared to lean and overweight men when operated by a minimally invasive approach. The magnified vision and increased access to the pelvis allowed by a laparoscopic and robotic-assisted approach may be accountable for our findings. Larger studies are needed to validate our results.

LEVEL OF PROOF

4.

Obese patients with castration-resistant prostate cancer may be at a lower risk of all-cause mortality: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database

OBJECTIVE

To assess whether obesity is associated with progression to metastasis, prostate cancer-specific mortality (PCSM), and all-cause mortality (ACM), in patients with non-metastatic castration-resistant prostate cancer (non-mCRPC). At the population level, obesity is associated with prostate cancer mortality; however, some studies have found that higher body mass index (BMI) is associated with better long-term prostate cancer outcomes amongst men with mCRPC.

PATIENTS AND METHODS

We identified 1 192 patients with non-mCRPC from the Shared Equal Access Regional Cancer Hospital (SEARCH) database. BMI was calculated from height and weight abstracted from the medical records at the time closest to but prior to CRPC diagnosis and categorised as underweight (<21 kg/m² ), normal weight (21-24.9 kg/m² ), overweight (25-29.9 kg/m² ), and obese (≥30 kg/m² ). Competing risks regression and Cox models were used to test associations between obesity and progression to metastasis, PCSM, and ACM, accounting for confounders.

RESULTS

Overall, 51 (4%) men were underweight, 239 (25%) were normal weight, 464 (39%) were overweight, and 438 (37%) were obese. In adjusted analysis, higher BMI was significantly associated with reduced ACM (hazard ratio [HR] 0.98, P = 0.012) but not PCSM (HR 1.00, P = 0.737) or metastases (HR 0.99, P = 0.225). Likewise, when BMI was treated as a categorical variable in adjusted models, obesity was not associated with PCSM (HR 1.11, P = 0.436) or metastases (HR 1.06, P = 0.647), but was associated with decreased ACM (HR 0.79, P = 0.016) compared to normal weight. No data were available on treatments received after CRPC diagnosis.

CONCLUSIONS

Amongst patients with non-mCRPC obesity was associated with better overall survival. Although this result mirrors evidence from men with mCRPC, obesity was not associated with prostate cancer outcomes. Larger studies are needed to confirm these findings.

Examining the association between adiposity and biochemical recurrence after radical prostatectomy

INTRODUCTION

Herein, we examined the association between adiposity, as measured by computed tomography (CT), and biochemical recurrence (BCR) after radical prostatectomy (RP).

METHODS

Using axial CT images, preoperative fat mass index (FMI) was calculated for 698 men who underwent RP from 2007-2010 by using measurements of total surface area of adipose tissue at the L3 level. Obesity was classified according to National Health and Nutrition Examination Survey (NHANES) standards for obesity (FMI >9 kg/m²). The associations between obesity and the distribution of adiposity (visceral vs. subcutaneous) with BCR were examined using the Kaplan-Meier method and Cox proportional hazards regression analyses.

RESULTS

Obese men were older than non-obese men (63.0 vs. 60.7 years; p<0.001), but were similar with regards to all other clinical and pathological characteristics. With a median followup of six years, 152 patients were diagnosed with BCR. Five-year BCR-free survival was similar between obese and non-obese patients (80.6% vs. 82.1%; p=0.27). Furthermore, in multivariable analyses, obesity was not independently associated with the risk of BCR (hazard ratio [HR] 1.02; 95% confidence interval [CI] 0.73-1.43). Similar results were obtained when analyzing FMI as a continuous variable (HR 1.02; 95% CI 0.94-1.09 for each 1 kg/m² increase in FMI). Additionally, neither visceral adiposity, subcutaneous adiposity, or visceral-to-subcutaneous adiposity ratio were associated with BCR (all p>0.05) in multivariable analyses.

CONCLUSIONS

Neither total abdominal adiposity nor the distribution of adiposity were independently associated with BCR after RP in this study. As such, the presence of obesity may not be a marker of increased oncological risk after RP.

The Association Between Sarcopenia and Oncologic Outcomes After Radical Prostatectomy

PURPOSE

Sarcopenia is associated with inferior perioperative and oncologic outcomes in patients undergoing surgery for multiple malignancies. The purpose of this study was to evaluate the association between sarcopenia and outcomes after radical prostatectomy (RP) for men with prostate cancer.

PATIENTS AND METHODS

Using a representative computed tomographic image from the L3 level, preoperative skeletal muscle indices (SMI) calculated for 698 patients who underwent RP between 2007 and 2010. Patients were classified as sarcopenic if they had a SMI < 55 cm²/kg² according to international consensus. The associations between sarcopenia and biochemical recurrence (BCR), systemic progression (SP), and all-cause mortality (ACM) were investigated by Cox proportional hazards regression.

RESULTS

Sarcopenic patients were older than nonsarcopenic patients (mean age, 63.0 vs. 60.4 years, P < .001) but were otherwise similar with regard to clinical and pathologic characteristics. There was no significant difference in the perioperative complication rate after RP between sarcopenic and nonsarcopenic patients (16.5% vs. 17.4%, P = .82). At a median follow-up after surgery of 6.0 years, 152 patients were diagnosed with BCR, patients were diagnosed with SP, and 50 patients died. In multivariable analysis, the presence of sarcopenia was not significantly associated with the risks of BCR, SP, or ACM. Similar results were obtained when analyzing SMI as a continuous variable.

CONCLUSION

Sarcopenia was not found to be independently associated with perioperative complications or oncologic outcomes after RP. As such, the presence of sarcopenia may not be prognostic marker for inferior outcomes among men with localized prostate cancer undergoing RP.

BMI and serum lipid parameters predict increasing risk and aggressive prostate cancer in Chinese people

OBJECTIVES

To determine if obesity and serum lipid parameters are associated with increased risk and more aggressive prostate cancer in Chinese population.

MATERIALS AND METHODS

We conducted a retrospective cohort analysis including 3102 patients. Kruskal-Wallis test for continuous variables and the chi-squared tests for categorical variables were used for univariate comparison of the differences in patient characteristics across BMI categories between different groups. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for the association between prostate cancer and the various patient characteristics. Multivariable Cox proportional hazards regression was performed to assess the risk of prostate cancer recurrence.

RESULTS

974 consecutive men were diagnosed as prostate cancer and 700 patients subsequently received radical prostatectomy immediately, and 1031 patients were pathologically diagnosed as biopsy negative. The level of low-density-lipoprotein cholesterol (LDL-c) and total cholesterol was significantly higher and the high-density-lipoprotein cholesterol (HDL-c) level is much lower in prostate cancer patients. Patients with low level of HDL-c, who subsequently received radical prostatectomy, had increased risk of high risk disease. In addition, patients with normal weight were less likely to develop a biochemical recurrence. Combined analysis revealed that obese patients had significantly higher rates of PSA recurrence over time than nonobese patients.

CONCLUSIONS

In our study, lipid parameters are supposed to be associated with prostate cancer risk and aggressiveness. Obese men are at increased risk of PSA recurrence after radical prostatectomy.

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.

Association between preoperative serum total cholesterol level and biochemical recurrence in prostate cancer patients who underwent radical prostatectomy

The aim of this study was to investigate the association between serum total cholesterol (TC) level and biochemical recurrence (BCR) following radical prostatectomy (RP). The study included 562 patients with T1-3N0M0 prostate cancer, who underwent RP at our institution between 2002 and 2010. No patients received neoadjuvant and/or adjuvant therapy. The associations between preoperative TC level, clinicopathological factors and BCR were assessed using univariate and multivariate analyses. During follow-up (mean, 54.0 months), 168 patients (168/562, 29.9%) experienced BCR, with a 5-year BCR-free rate of 67.2%. Of the clinicopathological characteristics investigated, statin use and lymphovascular invasion (LVI) status were associated with lower TC level (P=0.003 and P=0.014, respectively). In the univariate analysis, a higher serum prostate-specific antigen (PSA) level at diagnosis, extracapsular extension, positive surgical margin, seminal vesicle invasion, LVI, perineural invasion, higher Gleason score (GS ≥8) based on the RP specimen, increased body mass index, and low preoperative TC level, were significantly associated with BCR. In the multivariate analysis, the TC level was an independent predictor of BCR (hazard ratio = 0.925 per 10 mg/dl; 95% confidence interval: 0.879-0.973; P=0.003), as was the serum PSA level, extracapsular extension, positive surgical margin and the GS. Low preoperative serum TC levels were associated with an increased risk of BCR among prostate cancer patients who underwent RP. Our findings suggest that the preoperative serum TC level may provide important clinical information that may prove to be useful in patient counseling.

Body mass index and mortality in prostate cancer patients: a dose-response meta-analysis

BACKGROUND

Previous studies concerning the association between body mass index (BMI) and mortality in prostate cancer yielded mixed results. We investigated the association by performing a meta-analysis of all available studies.

METHODS

Relevant studies were identified by searching PubMed and EMBASE to August 2015. We calculated the summary hazard ratio (HR) and 95% confidence interval (CI) using random-effects models. We estimated combined HRs associated with defined increments of BMI, using random-effects meta-analysis and dose-response meta-regression models.

RESULTS

Thirty-seven cohort studies and one case-control study involving 27 38 000 patients of prostate cancer were selected for meta-analysis. The summary results indicated higher prediagnosis BMI but not postdiagnosis BMI was associated with increased risk of death from prostate cancer. An increment of every 5 kg/m(2) in prediagnosis BMI was associated with a 15% higher prostate cancer-specific mortality (HR=1.15, 95% CI: 1.07-1.23, P<0.01). Prediagnosis or postdiagnosis BMI showed no effect on all-cause mortality in prostate cancer patients.

CONCLUSIONS

In conclusion, higher prediagnosis BMI is associated with a higher risk of death from prostate cancer. Considering the significant heterogeneity among included studies, these findings require confirmation in future studies.

Impact of body mass index on clinico-pathological parameters and outcome in patients with metastatic prostate cancer

BACKGROUND

This study evaluates the correlation between body mass index (BMI) and clinicopathological parameters of metastatic prostate cancer (MPC) and its impact on survival.

METHOD

During the study period, 71 MPC patients were eligible. Patients with BMI<25.0kg/m(2) were categorized as level I and patients with BMI⩾25.0kg/m(2) were categorized as level II. Demographic features and survival rates were evaluated by the Kaplan-Meier method and Cox proportional models.

RESULTS

31 patients belonged to level I while the rest belonged to level II with insignificant higher median follow-up duration in level II; p=0.5. In terms of age, metastasis, serum level of albumin, prostatic specific antigen, alkaline phosphatase (AKP) and Gleason score, there was no significant difference between the two levels. The cumulative survival probability in the 12th, 24th and 36th month in level I vs; level II was; 86.7%, 68.7%, 64.1% vs; 74.4%, 67.7%, 55.1%, respectively with 7 patients dead in level I compared to 14 patients dead in level II denoting a higher PC-specific death rate in the level II group. In univariate and multivariate analysis, poor prognosis was associated with increasing AKP (HR=1.0005, 95% CI, p=0.03; HR=1.001, 95% CI, p=0.03) respectively, while better prognosis was associated with no visceral metastasis (HR=0.09, 95% CI, p=0.000; HR=0.04, 95% CI, p=0.000) and increasing albumin levels (HR=0.17, 95% CI, p=0.000; HR=0.15, 95% CI, p=0.000) respectively. In multivariate analysis only, patients belonging to level I were associated with better prognosis (HR=0.17, 95% CI, p=0.02).

CONCLUSION

BMI is dependent on prognostic factors in patients with MPC.

Impact of pelvic biometric measurements, visceral and subcutaneous adipose tissue areas on trifecta outcome and surgical margin status after open radical retropubic prostatectomy

OBJECTIVE

There is no sufficient evidence to demonstrate whether more challenging pelvic anatomy affects the functional and oncological outcomes of radical retropubic prostatectomy (RP). The aim of this study was to investigate the impact of pelvic biometric measurements, visceral and subcutaneous adipose tissue areas on trifecta outcome (cancer control, continence and potency) and surgical margin status after open RP.

MATERIALS AND METHODS

A retrospective study was performed on 270 patients who were diagnosed with clinically localized prostate cancer between 2005 and 2011 and underwent computed tomography imaging before RP. Pelvic bony and soft-tissue measurements, and visceral and subcutaneous adipose tissue area calculations were performed. Patients were evaluated for trifecta outcome and surgical margin status on univariate and multivariate analyses. Subgroup analysis was performed for prostate volume, body mass index (BMI) and D'Amico risk classification.

RESULTS

Univariate analysis revealed that patients with trifecta were younger, and had lower prostate-specific antigen (PSA) levels, wider symphysis angle, and narrower prostate width and soft-tissue width (p < 0.05). Patients with positive surgical margins were older, and had higher PSA levels, lower prostate volume and narrower prostate width (p < 0.05). Visceral adipose tissue area was lower in patients with trifecta when BMI was below 25 kg/cm² (p < 0.05). In multivariate analysis, PSA level and symphysis angle were statistically significant for trifecta while PSA level was the only statistically significant variable for positive surgical margins (p < 0.05). Interfemoral index was significant in the low-risk group of D'Amico classification for trifecta outcome.

CONCLUSION

Pelvic biometric measurements and adipose tissue area calculations may help in preoperative planning and the management of RP.

Role of p73 Dinucleotide Polymorphism in Prostate Cancer and p73 Protein Isoform Balance

Background. Molecular markers for prostate cancer (PCa) risks are currently lacking. Here we address the potential association of a dinucleotide polymorphism (DNP) in exon 2 of the p73 gene with PCa risk/progression and discern any disruption of p73 protein isoforms levels in cells harboring a p73 DNP allele. Methods. We investigated the association between p73 DNP genotype and PCa risk/aggressiveness and survival by fitting logistic regression models in 1,292 incident cases and 682 controls. Results. Although we detected no association between p73 DNP and PCa risk, a significant inverse relationship between p73 DNP and PCa aggressiveness (AT/AT + GC/AT versus GC/GC, OR = 0.55, 95%Cl = 0.31–0.99) was detected. Also, p73 DNP is marginally associated with overall death (dominant model, HR = 0.76, 95%Cl = 0.57–1.00, P = 0.053) as well as PCa specific death (HR = 0.69, 95%Cl = 0.45–1.06, P = 0.09). Western blot analyses for p73 protein isoforms indicate that cells heterozygous for the p73 DNP have lower levels of ∆Np73 relative to TAp73 (P < 0.001). Conclusions. Our findings are consistent with an association between p73 DNP and low risk for PCa aggressiveness by increasing the expressed TAp73/∆Np73 protein isoform ratio.

A combined index to classify prognostic comorbidity in candidates for radical prostatectomy

BACKGROUND

In patients with early prostate cancer, stratification by comorbidity could be of importance in clinical decision making as well as in characterizing patients enrolled into clinical trials. In this study, we investigated several comorbidity classifications as predictors of overall mortality after radical prostatectomy, searching for measures providing complementary prognostic information which could be combined into a single score.

METHODS

The study sample consisted of 2205 consecutive patients selected for radical prostatectomy with a mean age of 64 years and a mean follow-up of 9.2 years (median: 8.6). Seventy-four patients with incomplete tumor-related data were excluded. In addition to age and tumor-related parameters, six comorbidity classifications and the body mass index were assessed as possible predictors of overall mortality. Kaplan-Meier curves and Mantel-Haenszel hazard ratios were used for univariate analysis. The impact of different causes of death was analyzed by competing risk analysis. Cox proportional hazard models were calculated to analyze combined effects of variables.

RESULTS

Age, Gleason score, tumor stage, Charlson score, American Society of Anesthesiologists (ASA) physical status class and body mass index were identified a significant predictors of overall mortality in the multivariate analysis regardless whether two-sided and three-sided stratifications were used. Competing risk analysis revealed that the excess mortality in patients with a body mass index of 30 kg/m2 or higher was attributable to competing mortality including second cancers, but not to prostate cancer mortality.

CONCLUSION

Stratifying patients by a combined consideration of the comorbidity measures Charlson score, ASA classification and body mass index may assist clinical decision making in elderly candidates for radical prostatectomy.

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.

The effect of BMI on clinicopathologic and functional outcomes after open radical prostatectomy

OBJECTIVES

To analyze the effect of body mass index (BMI) on pathologic and functional outcomes after open radical retropubic prostatectomy.

PATIENTS AND METHODS

We retrospectively analyzed 2,471 patients who underwent RP. Clinicopathologic and patient characteristics were compared with respect to patients' BMI (normal weight: BMI < 25 kg/m(2) [n = 795], overweight: BMI ≥ 25 kg/m(2) and < 30 kg/m(2) [n = 1305], and obese: BMI ≥ 30 kg/m(2) [n = 371]). Multivariable logistic and linear regression models were used to quantify the effect of BMI on pathologic and functional outcomes.

RESULTS

Compared with normal weight patients, overweight and obese patients demonstrated higher pathologic Gleason grade and higher pathologic T stage, without any difference in preoperative prostate-specific antigen levels. Overweight and obese men were less likely to have a negative surgical margin (odds ratio (OR) 0.74 [confidence interval (CI) 0.65-0.84, P<0.001] for overweight men and OR 0.66 [CI 0.49-0.89, P<0.01] for obese men) and had a lower rate of postoperative erectile function (OR 0.60 [CI 0.48-0.76, P<0.001] for overweight patients and OR 0.34 [CI 0.27-0.44, P<0.001] for obese patients). Moreover, duration of surgery and intraoperative blood loss increased significantly with an increase in BMI. When using BMI as a continuous variable, the same trends were demonstrated. However, a lower rate of continence was not evident for overweight or obese men.

CONCLUSIONS

In contrast to many other studies, in this cohort of patients with prostate cancer, BMI was an independent risk factor for most analyzed pathologic and functional outcomes after radical prostatectomy, including negative surgical margin, potency, duration of surgery, and intraoperative blood loss.

Laparoscopic and robotic radical prostatectomy outcomes in obese and extremely obese men

OBJECTIVE

To evaluate the operative and pathologic outcomes of laparoscopic radical prostatectomy and robot-assisted radical prostatectomy in men with progressive changes in body mass index (BMI) category.

MATERIALS AND METHODS

A single-surgeon series of 1023 laparoscopic radical prostatectomy and robot-assisted radical prostatectomy (mostly extraperitoneal) patients was considered. Of these patients, 987 were evaluable. Results were stratified by the World Health Organization BMI category. Multivariate linear and logistic regression analysis was used to model the operating time, length of stay, positive surgical margins, and noncurable cancer.

RESULTS

Of the 987 patients, 563 (57%) were overweight and 193 (19.6%) were obese. Of the 193 obese patients, 152 (15.4%) had a BMI of 30 to <35 kg/m(2) (class I obesity), 28 (2.8%) a BMI of 35 to <40 kg/m(2) (class II), and 13 (1.3%) a BMI of ≥40 kg/m(2) (class III). No differences were found in the estimated blood loss, complications, PSM, pathologic stage, or biochemical recurrence across the BMI categories (6-month median follow-up). However, pelvic lymph node dissection was more commonly omitted and the nerve-sparing score was inferior in the obese men. On multivariate analysis, a higher BMI was a significant predictor of a longer operating time.

CONCLUSION

Obese men can safely undergo laparoscopic radical prostatectomy or robot-assisted radical prostatectomy, although the ability to perform excellent nerve sparing appears to decrease with increasing obesity. Nevertheless, obese men can expect perioperative and early oncologic outcomes comparable to those of normal weight men without an increased risk of perioperative complications.

A study of caloric restriction versus standard diet in overweight men with newly diagnosed prostate cancer: a randomized controlled trial

INTRODUCTION

Obese men have an increased risk of prostate cancer (PCa)-specific mortality. Potential mechanisms include insulin and related proteins. We investigate whether a short-term caloric restriction diet in overweight/obese men with newly diagnosed PCa can lead to measurable changes in patient anthropometrics and insulin-related proteins.

METHODS

Overweight and obese PCa patients choosing active surveillance or radical prostatectomy were randomized to a 6-week, caloric-restricted diet or to continue their current diet. Changes from baseline to end of study in anthropometrics, dietary constituents and serum proteins (insulin, c-peptide, IGF-1, adiponectin, IGF-BP3) were compared between the intervention and control groups using a Generalized Estimating Equation model.

RESULTS

Nineteen patients were randomized to the intervention (N = 10) or control (N = 9) group. Men in the intervention group had a 1.7% (3.7 lbs) mean decline in weight versus 1.0% (2.0 lbs) in controls (P < 0.05), and a reduced intake of calories, total and saturated fat, protein and starch (all P < 0.1 compared to controls). There was a significant difference (P = 0.002) in mean serum IGFBP-3 between the intervention (+2.8%) and control group (-6.9%). Other biomarkers changed with the diet intervention to a degree similar to previous weight loss studies but were not statistically significant compared with controls.

CONCLUSION

In this small pilot study, a 6-week caloric restricted diet in men with newly diagnosed PCa produced changes in weight, diet and serum proteins possibly related to prognosis. These results support larger-scale trials testing longer-term weight loss effects on potential PCa progression biomarkers.

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.

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.

miR-21, miR-221 and miR-222 expression and prostate cancer recurrence among obese and non-obese cases

Recent evidence shows that certain microRNAs (miRNAs) play a role in both obesity and prostate cancer recurrence, but the association between the expression of these miRNAs and obesity in prostate cancer recurrence is unknown. In this study, we examined the effect of the interaction between obesity and miR-21, miR-221 or miR-222 expression on prostate cancer recurrence among 28 recurrent and 37 non-recurrent prostate cancer cases. miRNA expression was determined using quantitative real-time polymerase chain reaction. Cox proportional hazard models adjusting for age at diagnosis, clinical stage and Gleason score were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for recurrence free survival. A significantly (P=0.014) higher proportion of recurrent cases (78.6%) than non-recurrent cases (48.6%) had a low expression of miR-21 and the difference was more prominent in obese than non-obese patients. Multivariate analysis showed that the expression of miR-21 was an independent risk factor for recurrence in obese (HR=6.15, 95% CI=1.04-36.48, P=0.045), but not in non-obese (HR=1.28, 95% CI=0.30-5.49, P=0.74) cases. A significant association with recurrence was not observed for the expression of miR-221 and miR-222. In summary, our findings show that miR-21 is associated with prostate cancer recurrence after radical prostatectomy and suggest that the differential expression of miR-21 is more prominent in obese than in non-obese cases. Future larger studies are warranted to confirm these initial findings and to elucidate the mechanisms involved.

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.

Obesity in cancer survival

Although obesity is a well-known risk factor for several cancers, its role on cancer survival is poorly understood. We conducted a systematic literature review to assess the current evidence evaluating the impact of body adiposity on the prognosis of the three most common obesity-related cancers: prostate, colorectal, and breast. We included 33 studies of breast cancer, six studies of prostate cancer, and eight studies of colo-rectal cancer. We note that the evidence overrepresents breast cancer survivorship research and is sparse for prostate and colorectal cancers. Overall, most studies support a relationship between body adiposity and site-specific mortality or cancer progression. However, most of the research was not specifically designed to study these outcomes and, therefore, several methodological issues should be considered before integrating their results to draw conclusions. Further research is urgently warranted to assess the long-term impact of obesity among the growing population of cancer survivors.

Does body mass index "dilute" the predictive property of prostate-specific antigen for tumor volume at radical prostatectomy?

OBJECTIVE

To evaluate the effect of the body mass index (BMI) as it relates to the predictive value of the preoperative prostate-specific antigen (PSA) level regarding the tumor volume at radical prostatectomy. Stage migration with the widespread use of PSA screening is well documented; however, the association between the PSA level and tumor volume is less defined. Additionally, the effect of obesity on the serum PSA level might cause relative hemodilution and account for the decreased predictive ability of the PSA level to determine the tumor volume in the modern era.

METHODS

We identified 14 293 patients who had undergone radical prostatectomy for prostate cancer from 1987 to 2007 and had a documented BMI. Using the clinicopathologic variables, we examined the relationship among the BMI, preoperative PSA level, and tumor volume at radical prostatectomy using multiple linear regression analysis.

RESULTS

An elevated BMI was associated with an increased pathologic Gleason score (P < .0001), increased tumor volume (P < .0001), and increased prostate size (P < .0001). The preoperative PSA level correlated significantly with the tumor volume (P < .0001). No significant correlation was found between the BMI and preoperative PSA level (P = .39). On multivariate analysis, controlling for the BMI, the preoperative PSA level remained a significant predictor of the tumor volume (P < .0001). The interaction between the preoperative PSA level and BMI in the prediction of the tumor volume was not statistically significant (P = .56), suggesting that the BMI does not affect the association between the PSA level and tumor volume.

CONCLUSION

Our results have shown that the predictive ability of the PSA level for tumor volume is not affected by the BMI. There does not appear to be a need to correct the serum PSA level in relation to the BMI when used in preoperative prediction models of the tumor volume.

The interaction of body mass index and race in predicting biochemical failure after radical prostatectomy

STUDY TYPE

Therapy (case series).

LEVEL OF EVIDENCE

4

OBJECTIVE

To examine the interaction of body mass index (BMI) and race in predicting biochemical failure (BCF) after radical prostatectomy (RP). The relative contribution of BMI and race to BCF after RP has not been well characterized.

PATIENTS AND METHODS

From 1988 to 2008, 969 white and black men underwent RP and BMI data were available. In all, 168 (17.3%) were black and 801 (82.7%) were white men. BCF was defined as a post-surgery PSA level≥0.2 ng/mL on ≥2 measurements. Cox regression methods were used to model the relationship between race, BMI and BCF.

RESULTS

The 969 men had a mean age of 59.8±7.2 years. There was no significant difference in BMI between black and white men (P=0.32). The 5-year disease-free survival for black obese men was the lowest at 48%, compared with non-obese black (73%), obese white (82%) and non-obese white men (83%, P<0.001). BMI did not have a significant impact on BCF. In a multivariate analysis, black race remained an independent predictor of BCF [hazard ratio (HR)=1.76, P=0.01]. BMI does not affect the risk of BCF in black men differently than white men (P value for interaction 0.93).

CONCLUSIONS

Black race is an independent predictor of biochemical failure after adjusting for pathological factors. The impact of BMI on BCF did not vary among different races. These findings suggest that elevated BMI does not affect the BCF rates of black men more than in other races, and that other factors may influence the racial variability in disease-free survival and BCF risk.

Does body mass index have an impact on the rate and location of positive surgical margins following robot assisted radical prostatectomy?

OBJECTIVE

Obesity has been shown to be associated with more aggressive prostate cancer. We sought to determine whether body mass index (BMI) has an impact on the rate and location of positive surgical margins (PSM) in robot-assisted laparoscopic radical prostatectomy (RLRP).

METHODS

Records of patients undergoing RLRP between the years 2003 and 2009 were retrospectively reviewed. We collected data regarding clinicopathologic data (i.e., age, BMI, PSA levels, Gleason score, pathologic stage, surgical margins status, and location). BMI was categorized as <25, 25-30, and >30 Kg/m(2). The rates of overall apical, peripheral, and prostate base (PB) PSM were compared across BMI groups.

RESULTS

Overall, 577 records were analyzed. Median age, PSA levels, and BMI were 60.1, 5.3, and 28.2, respectively. Percentage of Gleason score 4, 5, 6, 7, 8, 9 in the entire series was 0.2, 2.1, 40.7, 53, 2.3, and 1.7, respectively. Four hundred eighty-four (81.8%) cases were pathologically organ-confined. The overall incidence of PSM was 23.1% (n = 133) of those 10.2% apical, 3.6% PB and 14.2% peripheral. There were no statistically significant differences found in the rate of PSM by location between BMI groups; however, in the obese group there was a tendency toward slightly higher involvement of the PB with tumor in all stages and greater involvement of all anatomic areas in the T3 pathologic stage.

CONCLUSIONS

Although obesity has been associated with more aggressive prostate cancer, BMI does not appear to have statistically significant influence on the rate and location of PSM in RLRP. Larger studies are required to confirm these findings.