Is the body mass index a predictor of adverse outcome in prostate cancer after radical prostatectomy in a mid-European study population?

MRI-measured periprostatic to subcutaneous adipose tissue thickness ratio as an independent risk factor in prostate cancer patients undergoing radical prostatectomy

The purpose of this study is to evaluate whether the periprostatic adipose tissue thickness (PPATT) is an independent prognostic factor for prostate cancer patients after laparoscopic radical prostatectomy (LRP). This retrospective cohort study included consecutive prostate cancer patients who underwent LRP treatment at Wuhan Union Hospital from June 2, 2016, to September 7, 2023. PPATT was defined as the thickness of periprostatic fat and was obtained by measuring the shortest vertical distance from the pubic symphysis to the prostate on the midsagittal T2-weighted MR images. Subcutaneous adipose tissue thickness (SATT) was obtained by measuring the shortest vertical distance from the pubic symphysis to the skin at the same slice with PPATT. The primary outcome of the study was biochemical recurrence (BCR), and the secondary outcome was overall survival (OS). Multivariable Cox regression analysis was used to identify independent prognostic factors for prostate cancer survival and prognosis. Based on the optimal cutoff value, 162 patients were divided into a low PPATT/SATT group (n = 82) and a high PPATT/SATT group (n = 80). During the entire follow-up period (median 23.5 months), 26 patients in the high PPATT/SATT group experienced BCR (32.5%), compared to 18 in the low PPATT/SATT group (22.0%). Kaplan-Meier curve analysis indicated that the interval to BCR was significantly shorter in the high PPATT/SATT group (P = 0.037). Multivariable Cox regression analysis revealed that an increase in the PPATT/SATT ratio was associated with BCR (hazard ratio: 1.90, 95% CI, 1.03-3.51; P = 0.040). The PPATT/SATT ratio is a significant independent risk factor for BCR after LRP for prostate cancer patients.

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.

MRI-measured adipose features as predictive factors for detection of prostate cancer in males undergoing systematic prostate biopsy: a retrospective study based on a Chinese population

In this study, we retrospectively evaluated the data of 901 men undergoing ultrasonography-guided systematic prostate biopsy between March 2013 and May 2022. Adipose features, including periprostatic adipose tissue (PPAT) thickness and subcutaneous fat thickness, were measured using MRI before biopsy. Prediction models of all PCa and clinically significant PCa (csPCa) (Gleason score higher than 6) were established based on variables selected by multivariate logistic regression and prediction nomograms were constructed. Patients with PCa had higher PPAT thickness (4.64 [3.65-5.86] vs. 3.54 [2.49-4.51] mm, p < 0.001) and subcutaneous fat thickness (29.19 [23.05-35.95] vs. 27.90 [21.43-33.93] mm, p = 0.013) than those without PCa. Patients with csPCa had higher PPAT thickness (4.78 [3.80-5.88] vs. 4.52 [3.80-5.63] mm, p = 0.041) than those with non-csPCa. Adding adipose features to the prediction models significantly increased the area under the receiver operating characteristics curve for the prediction of all PCa (0.850 vs. 0.819, p < 0.001) and csPCa (0.827 vs. 0.798, p < 0.001). Based on MRI-measured adipose features and clinical parameters, we established two nomograms that were simple to use and could improve patient selection for prostate biopsy in Chinese population.

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.

High body mass index predicts multiple prostate cancer lymph node metastases after radical prostatectomy and extended pelvic lymph node dissection

Our aim is to evaluate the association between body mass index (BMI) and preoperative total testosterone (TT) levels with the risk of single and multiple metastatic lymph node invasion (LNI) in prostate cancer patients undergoing radical prostatectomy and extended pelvic lymph node dissection. Preoperative BMI, basal levels of TT, and prostate-specific antigen (PSA) were evaluated in 361 consecutive patients undergoing radical prostatectomy with extended pelvic lymph node dissection between 2014 and 2017. Patients were grouped into either nonmetastatic, one, or more than one metastatic lymph node invasion groups. The association among clinical factors and LNI was evaluated. LNI was detected in 52 (14.4%) patients: 28 (7.8%) cases had one metastatic node and 24 (6.6%) had more than one metastatic node. In the overall study population, BMI correlated inversely with TT (r = −0.256; P < 0.0001). In patients without metastases, BMI inversely correlated with TT (r = −0.282; P < 0.0001). In patients with metastasis, this correlation was lost. In the overall study population, BMI (odds ratio [OR] = 1.268; P = 0.005) was the only independent clinical factor associated with the risk of multiple metastatic LNI compared to cases with one metastatic node. In the nonmetastatic group, TT was lower in patients with BMI >28 kg m⁻² (P < 0.0001). In patients with any LNI, this association was lost (P = 0.232). The median number of positive nodes was higher in patients with BMI >28 kg m⁻² (P = 0.048). In our study, overweight and obese patients had a higher risk of harboring multiple prostate cancer lymph node metastases and lower TT levels when compared to patients with normal BMI.

Prognostic Value of CT-Attenuation and 18F-Fluorodeoxyglucose Uptake of Periprostatic Adipose Tissue in Patients with Prostate Cancer

This study aimed to assess the prognostic value of computed tomography (CT)-attenuation and ¹⁸F-fluorodeoxyglucose (FDG) uptake of periprostatic adipose tissue (PPAT) for predicting disease progression-free survival (DPFS) in patients with prostate cancer. Seventy-seven patients with prostate cancer who underwent staging FDG positron emission tomography (PET)/CT were retrospectively reviewed. CT-attenuation (HU) and FDG uptake (SUV) of PPAT were measured from the PET/CT images. The relationships between these PPAT parameters and clinical factors were assessed, and a Cox proportional hazard regression test was performed to evaluate the prognostic significance of PPAT HU and SUV. PPAT HU and SUV showed significant positive correlations with tumor stage and serum prostate-specific antigen level (PSA) (p < 0.05). Patients with high PPAT HU and SUV had significantly worse DPFS than those with low PPAT HU and SUV (p < 0.05). In multivariate analysis, PPAT SUV was a significant predictor of DPFS after adjusting for tumor stage, serum PSA, and tumor SUV (p = 0.003; hazard ratio, 1.50; 95% confidence interval, 1.15–1.96). CT-attenuation and FDG uptake of PPAT showed significant association with disease progression in patients with prostate cancer. These imaging findings may be evidence of the role of PPAT in prostate cancer progression.

Predictors of Lymph Node Invasion in Patients with Clinically Localized Prostate Cancer Who Undergo Radical Prostatectomy and Extended Pelvic Lymph Node Dissection: The Role of Obesity

OBJECTIVE

In patients with intermediate- and high-risk localized prostate cancer (PCa), improving the detection of occult lymph node metastases could play a pivotal role for therapeutic counseling and planning. The recent literature shows that several clinical factors may be related to PCa aggressiveness. The aim of this study is to investigate the potential associations between clinical factors and the risk of multiple lymph node invasion (LNI) in patients with intermediate- and high-risk localized PCa (cT1/2, cN0, and ISUP grading group >2 and/or prostate-specific antigen (PSA) >10 ng/mL) who underwent radical prostatectomy (RP) and extended pelvic lymph node dissection (ePLND).

MATERIALS AND METHODS

In a period ranging from January 2014 to December 2018, 880 consecutive patients underwent RP with ePLND for PCa. Among these, 481 met the inclusion criteria and were selected. Data were prospectively collected within an institutional dataset and retrospectively analyzed. Age (years), body mass index (BMI; kg/m2), PSA (ng/mL), prostate volume (mL), and biopsy positive cores (BPC; %) were recorded for each case. BMI and BPC were considered continuous and categorical variables, respectively. The logistic regression models evaluated the association of clinical factors with the risk of nodal metastases.

RESULTS

LNI was detected in 73/418 patients (15.2%) of whom 40/418 (8.3%) harbored multiple LNI (median 2, IQR: 3-4). On multivariate analysis, BMI was independently associated with the risk of multiple LNI in the pathological specimen when compared with patients without LNI (OR = 1.147; p = 0.018), as well as the percentage of biopsy positive cores (OR = 1.028; p < 0.0001) and European Association of Urology high-risk class (OR = 5.486; p < 0.0001). BMI was the only predictor of multiple LNI when compared with patients with 1 positive node (OR = 1.189, p = 0.027).

CONCLUSIONS

In intermediate- and high-risk localized PCa, BMI was an independent predictor of the risk of multiple lymph node metastases. The inclusion of BMI within LNI risk calculators could be helpful, and a detailed counseling in obese patients should be required.

Obesity strongly predicts clinically undetected multiple lymph node metastases in intermediate- and high-risk prostate cancer patients who underwent robot assisted radical prostatectomy and extended lymph node dissection

OBJECTIVE

To evaluate the association between obesity and risk of multiple lymph node metastases in prostate cancer (PCa) patients with clinically localized EAU intermediate and high-risk classes staged by extended pelvic lymph-node dissection (ePLND) during robot assisted radical prostatectomy (RARP).

MATERIALS AND METHODS

373 consecutive PCa intermediate or high-risk patients were treated by RARP and ePLND. According to pathology results, extension of LNI was classified as absent (pN0 status) or present (pN1 status); pN1 was further categorized as one or more than one (multiple LNI) lymph node metastases. A logistic regression model (univariate and multivariate analysis) was used to evaluate the association between significant categorized clinical factors and the risk of multiple lymph nodes metastases.

RESULTS

Overall, after surgery lymph node metastases were detected in 51 patients (13.7%) of whom 22 (5.9%) with more than one metastatic lymph node and 29 (7.8%) with only one positive node. Comparing patients with one positive node to those without, EAU high-risk class only predicted risk of single LNI (OR = 2.872; p = 0.008). The risk of multiple lymph node metastases, when compared to cases without LNI, was independently predicted by BMI ≥ 30 (OR = 6.950; p = 0.002) together with BPC ≥ 50% (OR = 3.910; p = 0.004) and EAU high-risk class (OR = 6.187; p < 0.0001). Among metastatic patients, BMI ≥ 30 was the only factor associated with the risk of multiple LNI (OR = 5.250; p = 0.041).

CONCLUSIONS

In patients with clinically localized EAU intermediate and high-risk classes PCa who underwent RARP and ePLND, obesity was a risk factor of multiple LNI.

Body Mass Index and prostatic-specific antigen are predictors of prostate cancer metastases in patients undergoing robot-assisted radical prostatectomy and extended pelvic lymph node dissection

BACKGROUND

The aim of this study was to investigate the risk factors contributing to multiple lymph node invasion (LNI) in patients with prostate cancer (PCa) undergoing extended pelvic lymph node dissection (ePLND) during robot assisted radical prostatectomy (RARP).

METHODS

A total of 211 patients who underwent RARP and ePNLD from June 2013 to March 2017 were classified according to lymph node status in the surgical specimen (absent, single or multiple). Risk factors of LNI were evaluated by the multinomial logistic regression model. A receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to assess the efficacy of factors and model evaluation.

RESULTS

On multivariate analysis, the risk of multiple LNI, was independently increased by Body Mass Index (BMI) (odds ratio [OR] 1.194; P=0.026) and prostate-specific antigen (PSA) (OR=1.089; P=0.014) when compared to patients without LNI. ROC curves indicated that both BMI (AUC=0.702) and PSA (AUC=0.732) had fair discrimination power. For each unit of increase in PSA, the odds of multiple lymph node invasion increased by 8.9% and for each unit increase of BMI, the odds of multiple LNI increased by 19.4%.

CONCLUSIONS

The risk of multiple LNI was independently predicted by PSA and BMI with fair discrimination power.

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.

Effects of obesity on immune responses to renal tumors

Kidney cancer incidence in the USA has been steadily increasing over the past several decades. The reasons for this are not completely clear, but an increased prevalence of known predisposing factors may be promoting this trend. Several major risk factors for kidney cancer have been identified. Among these, obesity is notable because its incidence has risen dramatically during this same period of time. Here, we will review the relationship between obesity and kidney cancer, and will explore the idea that obesity-mediated alterations in immune function may render immunotherapies for renal tumors ineffective. To support this idea, we will summarize characteristics of endogenous immune responses to renal tumors, as well as existing and developing immune-based therapies for kidney cancer patients. In doing so, we will highlight the ways in which altered immune function in obese individuals may render these therapies ineffective.

Corpulence is the crucial factor: association of testosterone and/or obesity with prostate cancer stage

OBJECTIVES

To evaluate whether low testosterone levels or obesity, or both, are directly associated with tumor stage/grade in patients with clinically localized prostate cancer.

METHODS

Preoperative androgen serum levels (total and free testosterone), sex hormone-binding globulin, body mass index and waist circumference were assessed in 510 consecutive European Caucasian men treated with radical prostatectomy. Hormone levels and body mass index/waist circumference were correlated with patient- and tumor-specific characteristics using multivariable logistic regression analysis.

RESULTS

Even though we confirmed an inverse correlation between bodyweight and testosterone levels, only overweight - but not low testosterone - was associated with advanced disease and poor differentiation of prostate cancer. Using multivariate analyses, both body mass index ≥30 kg/m(2) and waist circumference >110 cm were associated with high-grade disease (Gleason score ≥8). A waist circumference >110 cm also correlated significantly with lymph node metastasis.

CONCLUSIONS

This is the first study showing that obesity, but not low serum testosterone levels, is significantly associated with high grade and metastatic disease in men diagnosed with clinically localized prostate cancer. The present findings suggest that low androgen levels at diagnosis, which used to be held responsible for the development of aggressive prostate cancer, is only an epiphenomenon of obesity rather than the cause of prostate cancer development and/or progression.

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.

Influence of obesity on localized prostate cancer patients treated with radical prostatectomy

This study aimed to investigate the association between different anthropometric measures of obesity and clinicopathological characteristics in Chinese patients with clinically localized prostate cancer (PCa). A total of 734 patients with clinically localized PCa who underwent radical prostatectomy (RP) were included in this study. Clinical and pathological data from each patient were collected. Anthropometric measures of abdominal adiposity were measured from T2-weighted sagittal localisation images from magnetic resonance imaging (MRI) for 413 (56.3%) patients. Patient clinical and pathological characteristics were compared across body mass index (BMI) groups. Univariable and multivariable logistic regression models were used to address the influence of the preoperative total testosterone level and anthropometric measures of obesity on pathological outcomes. In the multivariate analysis, BMI was not significantly associated with any pathological outcomes. However, the percentage of visceral adipose tissue (VAT%) was an independent predictor of a pathological Gleason score ≥8 (P<0.001), extracapsular extension (ECE; P=0.002) and seminal vesicle invasion (SVI; P=0.007). More importantly, we found that the preoperative total testosterone level was significantly correlated with the VAT% (Pearson's correlation coefficient: -0.485, P<0.001) and subcutaneous adipose tissue (SAT; Pearson's correlation coefficient: 0.413, P<0.001). In conclusion, the results of this study suggest that abdominal fat distribution, and particularly VAT%, is associated with a risk of advanced PCa. Moreover, our present study confirms a significant inverse correlation between visceral adiposity and testosterone. Further studies are warranted to elucidate the biological mechanisms underlying the relationship between abdominal adiposity and the aggressiveness of PCa.

Body mass index is not a predictor of biochemical recurrence after radical prostatectomy in Dutch men diagnosed with prostate cancer

PURPOSE

To determine the effect of body mass index (BMI) on clinical and pathological characteristics at time of diagnosis and on risk of biochemical recurrence after radical prostatectomy among Dutch men diagnosed with prostate cancer.

METHODS

In total, 1,116 prostate cancer patients with known BMI, diagnosed between 2003 and 2006, were identified from the population-based cancer registry held by the Comprehensive Cancer Centre East, The Netherlands. Of these, 504 patients underwent a radical prostatectomy. Patients were categorized as normal weight (BMI < 25 kg/m(2)), overweight (BMI 25-30 kg/m(2)), or obese (BMI ≥ 30 kg/m(2)). Multivariable proportional hazards regression models, adjusted for age, prediagnostic PSA levels, and pathological characteristics were used to evaluate BMI as a prognostic factor for biochemical recurrence after radical prostatectomy.

RESULTS

Overall, clinical and biopsy characteristics did not significantly differ among BMI groups. Pathological characteristics after radical prostatectomy did not significantly differ among BMI groups, except for tumor stage, which was highest in obese patients (P = 0.017). For patients treated with radical prostatectomy, 5-year risk (95% Confidence Intervals) of biochemical recurrence was 30% (23-37%) for normal weight, 32% (25-39%) for overweight, and 25% (9-41%) for obese patients (log rank P = 0.810). BMI was not an independent prognostic factor for biochemical recurrence in multivariable proportional hazards regression analyses (HR 0.99 per kg/m(2), 95% CI: 0.93-1.06).

CONCLUSIONS

Compared with non-obese men, pathological tumor stage tended to be higher in obese men. Clinical relevance of this finding is unclear, because BMI was not an independent predictor of biochemical recurrence after radical prostatectomy.

Periprostatic fat correlates with tumour aggressiveness in prostate cancer patients

STUDY TYPE

Prognostic (case series).

LEVEL OF EVIDENCE

4. What's known on the subject? and What does the study add? Nowadays more and more publications have been published about the topic prostate cancer aggressiveness and obesity with mixed results. However, most of the publications used the BMI as a marker for obesity, while the most metabolic active fat is the visceral fat. To learn more about these relations we measured and used the visceral fat in our paper.

OBJECTIVE

To examine if the periprostatic fat measured on computed tomography (CT) correlates with advanced disease we examined patients who received radiotherapy for localized prostate cancer. Several USA reports found a positive association between obesity and prostate cancer aggressiveness. However, in recent European studies these conclusions were not confirmed. Studies concerning this issue have basically relied on body mass index (BMI), as a marker of general obesity. Visceral fat, however, is the most metabolically active and best measured on CT.

PATIENTS AND METHODS

In 932 patients, who were treated with external radiotherapy (N=311) or brachytherapy (N=621) for their T1-3N0M0 prostate cancer, different fat measurements (periprostatic fat, subcutaneous fat thickness) were performed on a CT. Associations between the different fat measurements and risk of having high-risk (according to Ash et al., PSA>20 or Gleason score≥8 or T3) disease was measured.

RESULTS

The median age (IQR) was 67.0 years (62.0-71.0) and median BMI (IQR) was 25.8 (24.2-28.3). Logistic regression analyses, adjusted for age, revealed a significant association between periprostatic fat density (PFD) and risk of having a high risk disease. (Odds ratio [95% CI] 1.06 [1.04-1.08], P<0.001)

CONCLUSION

Patients with a higher PFD had more often aggressive prostate cancer.

Radical prostatectomy in obese patients: Improved surgical outcomes in recent years

OBJECTIVES

Obesity has been proposed as a risk factor for reduced disease-specific survival, increased positive surgical margin (PSM) and biochemical recurrence (BCR) after radical prostatectomy (RP) in patients with prostate cancer. The aim of this study was to clarify the relationship between obesity and surgical outcomes in patients undergoing RP.

METHODS

Medical records of 491 patients who underwent RP from 2004 to 2007 were retrieved from our institutional database. Patients were divided into three groups based on their body mass index (BMI): <25, 25-30 (overweight) and >30 kg/m (obese). Outcomes after RP were compared between the groups in terms of length of stay, perioperative complications, BCR, PSM and Gleason scores.

RESULTS

Age, stage and preoperative prostate-specific antigen were similar between BMI categories. Operating time was prolonged in obese patients (146 vs 135 min, P = 0.01) and blood loss was greater (mean estimated blood loss 640 vs 504 mL, P = 0.02), but did not translate into higher transfusion rates. Early complication rates, PSM rates and Gleason scores were not statistically different between the groups. Significant differences in late outcomes, such as the need for adjunct procedures or BCR (hazard ratio 0.44, 95% CI 0.18-1.09), were not shown.

CONCLUSION

As surgical experience with high BMI patients has developed, RP appears to be a well tolerated procedure in contemporary series, irrespective of BMI. In particular, early outcome parameters, such as PSM and BCR rates, are similar.

Periprostatic fat measured on computed tomography as a marker for prostate cancer aggressiveness

Objective

Several reports found that obesity was associated with prostate cancer (PC) aggressiveness among men treated with radical prostatectomy or radiotherapy. Studies concerning this issue have basically relied on body mass index (BMI), as a marker for general obesity. Because visceral fat is the most metabolic active fat, we sought to evaluate if periprostatic fat measured on a computed tomography (CT) is a better marker than BMI to predict PC aggressiveness in a Dutch population who underwent brachytherapy for localized PC.

Patients and methods

Of the 902 patients who underwent brachytherapy, 725 CT scans were available. Subcutaneous fat thickness (CFT), periprostatic fat area (cm²) and fat-density (%) were determined on the CT scan. Patients were stratified into three groups: <25, 25–75 and >75 percentile of the fat-density. Associations between the three fat-density subgroups and BMI and PC aggressiveness were examined.

Results

237 patients were classified as having normal weight (37.2%), 320 as overweight (50.2%) and 80 as obese (12.6%). There was a strong significant association between BMI and fat-density and CFT. The strongest correlation was seen between BMI and CFT (Pearson r coefficient = 0.71). Logistic regression analysis revealed no statistically significant association between the different fat measurements and the risk of having a high-risk disease.

Conclusions

Periprostatic fat and fat-density as measured with CT were not correlated with PC aggressiveness in patients receiving brachytherapy. However, 31% of the patients with a normal BMI had a fat-density of >75 percentile of the periprostatic fat-density.