Association of Body Mass Index With Response and Survival in Men With Metastatic Prostate Cancer: Southwest Oncology Group Trials 8894 and 9916

The prognostic impact of BMI in patients with HR+/HER2- advanced breast cancer: a study of the SONABRE registry

PURPOSE

This study determines the prognostic impact of body mass index (BMI) in patients with hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) advanced (i.e., metastatic) breast cancer (ABC).

METHODS

All patients with HR+/HER2- ABC who received endocrine therapy +-a cyclin-dependent kinase 4/6 inhibitor as first-given systemic therapy in 2007-2020 in the Netherlands were identified from the Southeast Netherlands Advanced Breast Cancer (SONABRE) registry (NCT03577197). Patients were categorised as underweight (BMI: < 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), or obese (≥ 30.0 kg/m2). Overall survival (OS) and progression-free survival (PFS) were compared between BMI classes using multivariable Cox regression analyses.

RESULTS

This study included 1456 patients, of whom 35 (2%) were underweight, 580 (40%) normal weight, 479 (33%) overweight, and 362 (25%) obese. No differences in OS were observed between normal weight patients and respectively overweight (HR 0.99; 95% CI 0.85-1.16; p = 0.93) and obese patients (HR 1.04; 95% CI 0.88-1.24; p = 0.62). However, the OS of underweight patients (HR 1.45; 95% CI 0.97-2.15; p = 0.07) tended to be worse than the OS of normal weight patients. When compared with normal weight patients, the PFS was similar in underweight (HR 1.05; 95% CI 0.73-1.51; p = 0.81), overweight (HR 0.90; 95% CI 0.79-1.03; p = 0.14), and obese patients (HR 0.88; 95% CI 0.76-1.02; p = 0.10).

CONCLUSION

In this study among 1456 patients with HR+/HER2- ABC, overweight and obesity were prevalent, whereas underweight was uncommon. When compared with normal weight, overweight and obesity were not associated with either OS or PFS. However, underweight seemed to be an adverse prognostic factor for OS.

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.

Prognostic Impact of Sarcopenia in Patients with Metastatic Hormone-Sensitive Prostate Cancer

The clinical value of sarcopenia has not been determined yet in metastatic hormone-sensitive prostate cancer (mHSPC). We retrospectively evaluated data of 70 consecutive patients with mHSPC receiving treatment with either early docetaxel (n = 42) or abiraterone acetate (n = 28) between July 2018 and April 2021. Skeletal muscle index was calculated from cross-sectional areas of skeletal muscle on baseline computed tomography (CT), defining sarcopenia as a skeletal muscle index of ≤52.4 cm²/m². Failure-free survival (FFS), radiographic progression-free survival, and time to prostate-specific antigen (PSA) progression were estimated using the Kaplan-Meier method, and differences in survival probability were compared using the log-rank test. Cox proportional hazards regression analysis was conducted to identify the predictors of clinical outcomes. Patients with sarcopenia (n = 47) had shorter FFS than those without sarcopenia (n = 23) (median, 20.1 months vs. not reached; log-rank p < 0.001). Sarcopenia was independently associated with shorter FFS (hazard ratio (HR), 6.69; 95% confidence interval (CI), 1.57-28.49; p = 0.010) and time to PSA progression (HR, 12.91; 95% CI, 1.08-153.85; p = 0.043). In conclusion, sarcopenia is an independent prognostic factor for poor FFS and time to PSA progression in patients with mHSPC who receive early docetaxel or abiraterone acetate treatment.

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.

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.

Association of Obesity With Survival Outcomes in Patients With Cancer: A Systematic Review and Meta-analysis

Importance

Obesity, defined as a body mass index (BMI) greater than 30, is associated with a significant increase in the risk of many cancers and in overall mortality. However, various studies have suggested that patients with cancer and no obesity (ie, BMI 20-25) have worse outcomes than patients with obesity.

Objective

To assess the association between obesity and outcomes after a diagnosis of cancer.

Data Sources

PubMed, the Cochrane Library, and EMBASE were searched from inception to January 2020.

Study Selection

Studies reporting prognosis of patients with obesity using standard BMI categories and cancer were included. Studies that used nonstandard BMI categories, that were limited to children, or that were limited to patients with hematological malignant neoplasms were excluded. Screening was performed independently by multiple reviewers. Among 1892 retrieved studies, 203 (17%) met inclusion criteria for initial evaluation.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were reporting guideline was followed. Data were extracted by multiple independent reviewers. Risk of death, cancer-specific mortality, and recurrence were pooled to provide an adjusted hazard ratio (HR) with a 95% CI . A random-effects model was used for the retrospective nature of studies.

Main Outcomes and Measures

The primary outcome of the study was overall survival (OS) in patients with cancer, with and without obesity. Secondary end points were cancer-specific survival (CSS) and progression-free survival (PFS) or disease-free survival (DFS). The risk of events was reported as HRs with 95% CIs, with an HR greater than 1 associated with a worse outcome among patients with obesity vs those without.

Results

A total of 203 studies with 6 320 365 participants evaluated the association of OS, CSS, and/or PFS or DFS with obesity in patients with cancer. Overall, obesity was associated with a reduced OS (HR, 1.14; 95% CI, 1.09-1.19; P < .001) and CSS (HR, 1.17; 95% CI, 1.12-1.23; P < .001). Patients were also at increased risk of recurrence (HR, 1.13; 95% CI, 1.07-1.19; P < .001). Conversely, patients with obesity and lung cancer, renal cell carcinoma, or melanoma had better survival outcomes compared with patients without obesity and the same cancer (lung: HR, 0.86; 95% CI, 0.76-0.98; P = .02; renal cell: HR, 0.74; 95% CI, 0.53-0.89; P = .02; melanoma: HR, 0.74; 95% CI, 0.57-0.96; P < .001).

Conclusions and Relevance

In this study, obesity was associated with greater mortality overall in patients with cancer. However, patients with obesity and lung cancer, renal cell carcinoma, and melanoma had a lower risk of death than patients with the same cancers without obesity. Weight-reducing strategies may represent effective measures for reducing mortality in these patients.

Geriatric Nutritional Risk Index as a Prognostic Marker for Patients With Metastatic Castration-Resistant Prostate Cancer Receiving Docetaxel

Purpose: To investigate the prognostic efficacy of the Geriatric Nutritional Risk Index (GNRI) in patients with metastatic Castration–resistant Prostate Cancer (mCRPC) receiving docetaxel as the first line of treatment.

Methods: We retrospectively reviewed patients with mCRPC and receiving first line docetaxel in Taichung Veterans General Hospital from 2006 to 2012. The GNRI was calculated using serum albumin and body mass index, with a poor nutritional status defined as GNRI <92.0. Multivariate Cox-regression analysis was used to evaluate the risk of survival.

Results: One-hundred seventy patients with mCRPC were included. One-hundred twenty-five patients were of normal nutritional status (GNRI ≥92) and 45 patients were of poor nutritional status (GNRI <92). The cumulative docetaxel dosage was 600 (360–1,185) mg in the normal nutritional status group and 360 (127.5–660) mg in the poor nutritional status group (p < 0.001). The median overall survival from mCRPC was 30.39 months in the good nutritional status group and 11.07 months in the poor nutritional status group (p of log rank <0.001). In a multivariate model, poor nutritional status was an independent risk factor in overall survival (Hazard Ratio [HR] = 5.37, 95% Confidence Interval [CI] 3.27–8.83), together with a high metastatic volume (HR = 4.03, 95% CI 2.16–7.53) and docetaxel cumulative dosage (HR = 0.999, 95% CI 0.999–0.9998).

Conclusion: Poor nutritional status with a GNRI <92 is associated with shorter progression free survival and overall survival in mCRPC patients treated with docetaxel. Metastatic volume and cumulative docetaxel dosage are also independent prognostic factors in overall survival.

Relationship between body composition and hormone sensitivity for androgen deprivation therapy in patients with metastatic prostate cancer

Background

To evaluate the relationship between body composition and the oncological outcome of androgen deprivation therapy (ADT), we investigated whether body composition features including the psoas muscle may be predictive factors of ADT.

Methods

This study enrolled patients with hormone-naïve metastatic prostate cancer who were treated with primary ADT from April 1996 to November 2013 at Kyushu University Hospital and who underwent a computed tomography scan before primary ADT for calculating body fat percentage, psoas muscle ratio (psoas muscle, cm³/height, cm), and body mass index.

Results

Of the 178 patients enrolled, 60 patients died during follow-up. Median follow-up was 32 months, and progression-free survival and overall survival (OS) were 28 and 80 months, respectively. Multivariate analysis revealed that the psoas muscle ratio was correlated with OS (hazard ratio: 0.448; 95% confidence interval = 0.206–0.922; p = 0.028).

Conclusions

This study demonstrated that higher psoas muscle ratio predicts longer OS among patients with nonlocalized prostate cancer treated with primary ADT.

Impact of nutritional status on the prognosis of patients with metastatic hormone-naïve prostate cancer: a multicenter retrospective cohort study in Japan

PURPOSE

To investigate the association between the Geriatric Nutritional Risk Index (GNRI) and prognosis of patients with metastatic hormone-naïve prostate cancer (mHNPC) and to design the optimal risk score predicting for prognosis.

METHODS

We retrospectively reviewed data from the Michinoku Japan Urological Cancer Study Group database, containing information about 656 patients with mHNPC who initially received androgen-deprivation therapy between 2005 and 2017. The baseline GNRI was calculated using serum albumin level and body mass index. Poor nutrition was defined as GNRI < 92.0. The impact of GNRI, CHAARTED criteria, and laboratory parameters on oncological outcomes was investigated using the multivariable Cox regression models. We developed the risk comprising GNRI and laboratory parameters and compared its prognostic performance with the CHAARTED criteria using the receiver operating characteristic curve with the DeLong method.

RESULTS

Of 339 patients with sufficient data, 66 (19%) were diagnosed with poor nutrition. Multivariate analyses showed that GNRI < 92.0 was an independent prognostic factor of cancer-specific survival [hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.04-2.98, P = 0.035] and overall survival (HR 1.80; 95% CI 1.13-2.89, P = 0.013), in addition to hemoglobin (Hb) and lactic dehydrogenase (LDH) levels. We designed the risk score comprising GNRI < 92.0, Hb < 13.0 g/dL, and LDH > 222 IU/L. The predictive value of the risk score was significantly superior to that of the CHAARTED criteria.

CONCLUSIONS

Poor nutrition may predict mortality in patients with mHNPC. Risk factors, such as nutritional status and laboratory parameters, may be useful in decision-making regarding aggressive treatments for patients with mHNPC.

The impact of baseline body mass index on clinical outcomes in metastatic breast cancer: a prospective study

OBJECTIVE

The prognostic value of body mass index (BMI) in metastatic breast cancer (MBC) has not been fully elucidated. In a prospective study to investigate the chemo-sensitizing effect of statins on clinical outcomes in MBC patients who were scheduled to receive palliative chemotherapy (Carboplatin and Vinorelbine), we sought to investigate the relationship between baseline BMI and clinical outcomes; response, overall survival (OS) and progression free survival (PFS), over a median follow-up of 40-months.

RESULTS

Eighty-Two MBC patients were enrolled and categorized using baseline BMI as underweight (BMI, < 18.5 kg/m2, n = 1), normal-weight (BMI, 18.5-24.9 kg/m2, n = 20), overweight (BMI, 25-29.9 kg/m2, n = 34), and obese (BMI, ≥ 30 kg/m2, n = 27). Median OS was 10 months in normal/underweight, 19 months in overweight, and 16 months in obese (P = 0.083). Univariate Cox model revealed that overweight patients were significantly less likely to die of MBC as normal BMI patients (hazard ratio [HR] = 0.54, 95% confidence interval [CI], (0.29-0.98), P = 0.044). Similarly, multivariate Cox model, after adjusting for age, number of metastatic sites, chemotherapy line's grade, HER2 and hormone receptors status, confirmed longer survivorship of overweight in comparison with normal BMI patients (HR = 0.51, 95% CI (0.26-0.99), P = 0.047). Our data suggest that being overweight could improve OS in MBC patients.

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.

Prognostic Factors for Survival in Noncastrate Metastatic Prostate Cancer: Validation of the Glass Model and Development of a Novel Simplified Prognostic Model

BACKGROUND

The Glass model developed in 2003 uses prognostic factors for noncastrate metastatic prostate cancer (NCMPC) to define subgroups with good, intermediate, and poor prognosis.

OBJECTIVE

To validate NCMPC risk groups in a more recently diagnosed population and to develop a more sensitive prognostic model.

DESIGN, SETTING, AND PARTICIPANTS

NCMPC patients were randomized to receive continuous androgen deprivation therapy (ADT) with or without docetaxel in the GETUG-15 phase 3 trial. Potential prognostic factors were recorded: age, performance status, Gleason score, hemoglobin (Hb), prostate-specific antigen, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), metastatic localization, body mass index, and pain.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

These factors were used to develop a new prognostic model using a recursive partitioning method. Before analysis, the data were split into learning and validation sets. The outcome was overall survival (OS).

RESULTS AND LIMITATIONS

For the 385 patients included, those with good (49%), intermediate (29%), and poor (22%) prognosis had median OS of 69.0, 46.5 and 36.6 mo (p=0.001), and 5-yr survival estimates of 60.7%, 39.4%, and 32.1%, respectively (p=0.001). The most discriminatory variables in univariate analysis were ALP, pain intensity, Hb, LDH, and bone metastases. ALP was the strongest prognostic factor in discriminating patients with good or poor prognosis. In the learning set, median OS in patients with normal and abnormal ALP was 69.1 and 33.6 mo, and 5-yr survival estimates were 62.1% and 23.2%, respectively. The hazard ratio for ALP was 3.11 and 3.13 in the learning and validation sets, respectively. The discriminatory ability of ALP (concordance [C] index 0.64, 95% confidence interval [CI] 0.58-0.71) was superior to that of the Glass risk model (C-index 0.59, 95% CI 0.52-0.66). The study limitations include the limited number of patients and low values for the C-index.

CONCLUSION

A new and simple prognostic model was developed for patients with NCMPC, underlying the role of normal or abnormal ALP.

PATIENT SUMMARY

We analyzed clinical and biological factors that could affect overall survival in noncastrate metastatic prostate cancer. We showed that normal or abnormal alkaline phosphatase at baseline might be useful in predicting survival.

Coffee consumption and risk of prostate cancer: a meta-analysis of prospective cohort studies

Observational studies and animal evidence suggest an association between coffee consumption and the risk of prostate cancer. However, the results are inconsistent. We evaluated the association by conducting a meta-analysis of prospective cohort studies. PubMed and Embase were searched through June 2013 to identify studies that met predetermined inclusion criterion. A random-effects model was used to calculate the pooled risk estimates. Ten prospective cohort studies involving 8973 patients with prostate cancer and 206 096 participants were included in this systematic review. Compared with individuals who seldom or never drink coffee, the pooled relative risk of prostate cancer was 0.88 (95% confidence interval: 0.82-0.95) for regular coffee drinkers. Exclusion of any single study did not materially alter the combined risk estimate. Visual inspection of a funnel plot and Begg's and Egger's tests did not indicate evidence of publication bias. In summary, integrated evidence from prospective cohort studies supports the hypothesis that coffee consumption may decrease the risk of prostate cancer.

Predicting response to hormonal therapy and survival in men with hormone sensitive metastatic prostate cancer

Androgen deprivation is the cornerstone of the management of metastatic prostate cancer. Despite several decades of clinical experience with this therapy there are no standard predictive biomarkers for response. Although several candidate genetic, hormonal, inflammatory, biochemical, metabolic biomarkers have been suggested as potential predictors of response and outcome, none has been prospectively validated nor has proven clinical utility to date. There is significant heterogeneity in the depth and duration of hormonal response and in the natural history of advanced disease; therefore to better optimize/individualize therapy and for future development, identification of biomarkers is critical. This review summarizes the current data on the role of several candidate biomarkers that have been evaluated in the advanced/metastatic disease setting.

Influence of obesity and other risk factors on survival outcomes in patients undergoing pancreaticoduodenectomy for pancreatic cancer

OBJECTIVES

Established risk factors for the development of pancreatic cancer include tobacco use, family history of pancreatic cancer, personal history of diabetes, and obesity. The impact of risk factors on prognosis in patients with pancreatic cancer, particularly obesity, has recently become controversial.

METHODS

We conducted a retrospective analysis of patients with pancreatic adenocarcinoma who underwent pancreaticoduodenectomy between 1995 and 2009. Patients were categorized by body mass index (BMI) as normal (18.5-24.9 kg/m), overweight (25-29.9 kg/m), or obese (≥30 kg/m). Univariate analysis was performed to evaluate the association of obesity and other risk factors on overall survival.

RESULTS

Of the 355 patients evaluated, 149 (42.0%) had normal BMI, 131 (36.9%) were overweight, and 75 (21.1%) were obese. Overall survival for normal, overweight, and obese groups was 17.3 months (95% confidence interval [CI], 14.2-20.8 months), 20.0 months (95% CI, 16.6-23.6 months), and 22.1 months (95% CI, 16.5-36.4 months), respectively (P = 0.58). Hazard ratios for tobacco use, family history of pancreatic cancer, and history of diabetes were 1.07, 1.38, and 0.87, respectively.

CONCLUSIONS

Obesity and other risk factors have no impact on overall survival in patients with adenocarcinoma after pancreaticoduodenectomy. Further studies investigating the relationship between risk factors and their prognostic significance in patients with pancreatic cancer are warranted.

Impact of body mass index on outcomes after conformal radiotherapy in patients with prostate cancer

PURPOSE

Several retrospective analyses have suggested that obese men with prostate cancer treated with external beam radiotherapy (EBRT) have outcomes inferior to those of normal-weight men. However, a recently presented analysis for the first time challenged this association between body mass index (BMI) and treatment failure. It is therefore important to provide further data on this issue.

METHODS AND MATERIALS

This was a retrospective analysis of 564 men treated with risk-adapted conformal EBRT at a single institution. Low-risk patients received EBRT alone, and the other patients received EBRT plus endocrine treatment. In addition, high-risk patients were treated to higher EBRT doses (74 Gy). A rectal balloon catheter for internal immobilization, which can be identified on portal images, was used in 261 patients (46%). Thus, localization did not rely on bony landmarks alone in these cases.

RESULTS

The median BMI was 26, and 15% of patients had BMI≥30. Neither univariate nor multivariate analyses detected any significant impact of BMI on biochemical relapse, prostate cancer-specific survival, or overall survival. The 5-year biochemical relapse rate was 21% and prostate cancer-specific survival 96%.

CONCLUSIONS

The present analysis of a large cohort of consecutively treated patients suggests that efforts to reduce prostate movement and geographic miss might result in comparable outcomes in obese and normal-weight patients.

COOPERATIVE GROUP TRIALS - SOUTHWEST ONCOLOGY GROUP (SWOG) INNOVATIONS IN ADVANCED PROSTATE CANCER

The major goals of the SWOG-GU committee in the area of advanced prostate cancer are to improve the survival and quality of life of patients with advanced prostate cancer. SWOG trials have examined the role of combined androgen blockade, intermittent androgen deprivation, and the early application of chemotherapy in castration-naïve disease. In addition, they have contributed to advancing the current chemotherapy standard of docetaxel plus prednisone, and ongoing trials seek to improve upon that standard. Finally, surrogate endpoints have been identified and markers of treatment response or resistance with novel technology are under active investigation. This review highlights findings from recent SWOG clinical trials for advanced prostate cancer, emphasizing the clinical impact and future applications of the data.

Associations between alpha-tocopherol, beta-carotene, and retinol and prostate cancer survival

Previous studies suggest that carotenoids and tocopherols (vitamin E compounds) may be inversely associated with prostate cancer risk, yet little is known about how they affect prostate cancer progression and survival. We investigated whether serum alpha-tocopherol, beta-carotene, and retinol concentrations, or the alpha-tocopherol and beta-carotene trial supplementation, affected survival of men diagnosed with prostate cancer during the alpha-Tocopherol, beta-Carotene Cancer Prevention Study, a randomized, double-blind, placebo-controlled primary prevention trial testing the effects of beta-carotene and alpha-tocopherol supplements on cancer incidence in adult male smokers in southwestern Finland (n = 29,133). Prostate cancer survival was examined using the Kaplan-Meier method with deaths from other causes treated as censoring, and using Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (CI) adjusted for family history of prostate cancer, age at randomization, benign prostatic hyperplasia, age and stage at diagnosis, height, body mass index, and serum cholesterol. As of April 2005, 1,891 men were diagnosed with prostate cancer and 395 died of their disease. Higher serum alpha-tocopherol at baseline was associated with improved prostate cancer survival (HR, 0.67; 95% CI, 0.45-1.00), especially among cases who had received the alpha-tocopherol intervention of the trial and who were in the highest quintile of alpha-tocopherol at baseline (HR, 0.51; 95% CI, 0.20-0.90) or at the 3-year follow-up measurement (HR, 0.26; 95% CI, 0.09-0.71). Serum beta-carotene, serum retinol, and supplemental beta-carotene had no apparent effects on survival. These findings suggest that higher alpha-tocopherol (and not beta-carotene or retinol) status increases overall prostate cancer survival. Further investigations, possibly including randomized studies, are needed to confirm this observation.

The relationship of body mass index and serum testosterone with disease outcomes in men with castration-resistant metastatic prostate cancer

The purpose of this study was to evaluate the relationship of baseline body mass index (BMI) and serum testosterone level with prostate cancer outcomes in men with castration-resistant metastatic prostate cancer (CRPC). BMI and testosterone levels were evaluated for their ability to predict overall survival (OS) and prostate-specific antigen (PSA) declines in the TAX327 clinical trial, an international phase III randomized trial of one of the two schedules of docetaxel and prednisone compared with mitoxantrone and prednisone. In this study of 1006 men with CRPC, the median serum testosterone level was 14.5 ng per 100 ml (range 0-270), the median BMI was 27 kg m(-2) (range 15.7-46.5), and 26% of men were obese or morbidly obese (BMI>or=30). Obesity was associated with younger age, lower PSA and alkaline phosphatase levels, and higher performance status, primary Gleason sum, testosterone and hemoglobin compared to absence of obesity. In multivariate analysis, neither BMI, presence of obesity, nor baseline testosterone was significantly associated with OS or PSA declines. Higher testosterone levels among obese men suggest incomplete gonadal suppression with current therapies, but these differences may not be clinically relevant in men with CRPC. There was evidence of potential hemodilution of PSA and alkaline phosphatase levels in obese men.

Gut hormones and the treatment of disease cachexia

Advances in the understanding of appetite are leading to a refined concept of disease cachexia and point to novel therapeutic strategies based on the manipulation of appetite. The complex social and psychological short-term influences on appetite obscure the fact that over the longer term appetite is tightly regulated by physiological considerations; the homeostatic control of energy balance. Like obesity, which is now viewed as a disorder of homeostasis, cachexia can be seen as an adaptive response to the disease state that becomes harmful when prolonged. Several lines of evidence implicate a disorder of appetite regulation in the pathogenesis of cachexia. As the only known circulating mediator of increased appetite the peptide hormone ghrelin has attracted attention as a potential therapy. Trials in patients with various chronic illnesses, including cancer and kidney failure, have demonstrated short-term increases in energy intake. Trials in patients with emphysema and heart failure have also shown benefits in clinical outcomes such as lean body mass and exercise capacity, and longer-term trials using oral analogues are being undertaken. As well as improving nutrition, ghrelin has a number of other actions that may be useful, including an anti-inflammatory effect; of interest since many cachexias are associated with inappropriate immune activation. The manipulation of appetite, in particular by ghrelin agonism, is emerging as an exciting potential therapy for disease cachexia. Future research should focus on the ascertainment of clinically-relevant outcomes, and further characterisation of the non-nutritional effects of this pathway.