Pathologic variables and recurrence rates as related to obesity and race in men with prostate cancer undergoing radical prostatectomy

Impact of prediagnosis smoking, alcohol, obesity, and insulin resistance on survival in male cancer patients: National Health Insurance Corporation Study

PURPOSE

Although many studies have demonstrated that smoking, alcohol, obesity, and insulin resistance are risk factors for cancer, the role of those factors on cancer survival has been less studied.

PATIENTS AND METHODS

The study participants were 14,578 men with a first cancer derived from a cohort of 901,979 male government employees and teachers who participated in a national health examination program in 1996. We obtained mortality data for those years from the Korean Statistical Office. We used a standard Poisson regression model to estimate the hazard ratio (HR) for survival in relation to smoking, alcohol, obesity, and insulin resistance before diagnosis.

RESULTS

Poor survival of all cancer combined (HR, 1.24; 95% CI, 1.16 to 1.33), cancer of the lung (HR, 1.45; 95% CI, 1.15 to 1.82), and cancer of the liver (HR, 1.36; 95% CI, 1.21 to 1.53) were significantly associated with smoking. Compared with the nondrinker, heavy drinkers had worse outcomes for head and neck (HR, 1.85; 95% CI, 1.23 to 2.79) and liver (HR, 1.25; 95% CI, 1.11 to 1.41) cancer, with dose-dependent relationships. Patients with a fasting serum glucose level above 126 mg/dL had a higher mortality rate for stomach (HR, 1.52; 95% CI, 1.25 to 1.84) and lung (HR, 1.48; 95% CI, 1.18 to 1.87) cancer. Higher body mass index was significantly associated with longer survival in head and neck (HR, 0.54; 95% CI, 0.39 to 0.74) and esophagus (HR, 0.44; 95% CI, 0.28 to 0.68) cancer.

CONCLUSION

Prediagnosis risk factors for cancer development (smoking, alcohol consumption, obesity, and insulin resistance) had a statistically significant effect on survival among male cancer patients.

Greater body mass index is associated with better pathologic features and improved outcome among patients treated surgically for clear cell renal cell carcinoma

OBJECTIVES

Obesity increases the risk of developing renal cell carcinoma (RCC); however, it remains unclear whether obesity is associated with RCC aggressiveness and survival. We used data from a large cohort of patients treated surgically for clear cell RCC to evaluate the association of obesity with the pathologic features of tumor aggressiveness and cancer-specific outcomes.

METHODS

From 1988 to 2002, 970 patients underwent nephrectomy at Mayo Clinic Rochester for clear cell RCC and had body mass index (BMI) data available. To evaluate the association of BMI at surgery with the tumor pathologic features, we used the chi-square and Fisher's exact tests. We then analyzed the association of BMI with cancer-specific survival using Kaplan-Meier curves and Cox regression models.

RESULTS

Overweight (BMI 25 to less than 30 kg/m2) and obese (BMI 30 kg/m2 or more) patients were more likely to present with less-aggressive tumors compared with normal-weight patients (BMI less than 25 kg/m2). The 5-year cancer-specific survival rate was 62.3%, 76.9%, and 81.7% for the normal, overweight, and obese patients, respectively. The overweight (hazard ratio 0.64, 95% confidence interval 0.49 to 0.84) and obese (hazard ratio 0.48, 95% confidence interval 0.36 to 0.66) patients were at a reduced risk of RCC death compared with patients with a BMI in the normal range. The inverse association of BMI with survival was attenuated after adjustment for well-known pathologic predictors of tumor aggressiveness.

CONCLUSIONS

BMI offers little additional prognostic information beyond the accepted prognostic features; however, the association of an increased BMI with a less-aggressive disease profile at presentation warrants further exploration.

The older cancer survivor

Cancer is an age-related disease, and has increased in prevalence as the population has grown older. Improvements in screening and the availability of better therapeutic options contribute to burgeoning numbers of cancer survivors, who number more than 24 million worldwide. Sixty-one percent of these survivors are at least 65 years old. This review is an attempt to consolidate some of the data available in the area of cancer survivorship, with emphasis on the elderly. Our aim is to provide a better description of the population, elucidate specific physical and psychosocial sequelae secondary to cancer and it's treatment, and better understand how comorbid conditions, functional status, body-weight, and other issues contribute to quality of life, and overall health. This paper also suggests some surveillance guidelines for following elderly cancer survivors and identifies areas that require further research.

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

BACKGROUND

Obesity and prostate cancer are among the most common health problems affecting American men today. The authors' goal was to assess the impact of obesity on clinical and pathologic features of prostate cancer and long-term outcomes.

METHODS

The authors performed a prospective cohort study on 5313 men who underwent radical prostatectomy between 1990 and 1999. Patient height and weight were measured at the time of surgery to calculate the body mass index (BMI). The patients were separated into 3 BMI groups: BMI <25, 25-29.9, and > or =30 kg/m2. The associations between BMI and age, prostate-specific antigen (PSA) level, and Gleason score were assessed with the Spearman rank correlation test. The associations between BMI and pathologic features were assessed with the Mantel-Haenszel chi 2 test. Fifteen-year biochemical progression-free survival, systemic progression-free survival, cancer-specific survival, and overall survival were estimated using the Kaplan-Meier method and evaluated using Cox models. RESULTS.: The median length of follow-up for the entire cohort was 10.1 years. Clinical and pathologic features appear worse in patients with a higher BMI. On univariate and multivariate analyses, it was found that BMI had no impact on biochemical progression, systemic progression, prostate cancer survival, or overall survival.

CONCLUSIONS

Obese patients appear to have worse pathologic features at the time of prostatectomy. Despite these features, long-term oncologic outcomes, including cancer-specific survival, remain the same regardless of BMI. BMI appears to influence prostate cancer outcomes at the time of prostatectomy, as evidenced by more aggressive pathologic features. However, after prostatectomy, BMI does not appear to be an independent predictor of recurrence or survival.

Influence of obesity on biochemical and clinical failure after external-beam radiotherapy for localized prostate cancer

BACKGROUND

Several reports have shown that obesity is associated with increased risk of biochemical failure after radical prostatectomy. However, limited information is available regarding the impact of obesity on prostate cancer progression after radiotherapy. The current study sought to determine whether obesity was an independent predictor of biochemical failure (BF) and clinical recurrence (CF) among patients treated with external-beam radiotherapy (EBRT).

METHODS

A retrospective analysis was performed on 873 patients receiving EBRT as the sole treatment for localized prostate cancer between 1988 and 2001. The Kaplan-Meier method, log-rank test, and Cox proportional hazards analyses were performed.

RESULTS

Of the 873 patients, 18% were mildly obese and 5% were moderately to severely obese. Obesity was related to younger age at diagnosis (P < .001), more recent year of diagnosis (P = .03), and race (P = .03), with African-American men having the highest obesity rates. During a mean follow-up of 96 months, 295 patients experienced BF and 127 had CF. On multivariate analysis, controlling for clinical and treatment characteristics, increased body mass index (BMI) significantly predicted BF (hazards ratio [HR] = 1.04; 95% confidence interval [95% CI], 1.02-1.07) with a positive trend by BMI category (P = .001). Similar results were found when the outcome was CF; BMI remained an independent predictor of progression (HR = 1.05; 95% CI, 1.01-1.09), with a statistically significant trend by increased BMI category (P = .03).

CONCLUSIONS

The current findings validate the important role of obesity, not only on BF but also on CF, and suggest a link to the biologic basis of tumor progression that can be therapeutically exploited.

Obesity and prostate cancer screening among African-American and Caucasian men

BACKGROUND

Differential prostate-specific antigen (PSA) testing practices according to obesity-related comorbid conditions may contribute to inconsistent results in studies of obesity and prostate cancer. We investigated the relationship between obesity and PSA testing, and evaluated the role of prior diagnoses and disease screening on PSA testing patterns.

METHODS

Men, 40 and 79 years old and without prior prostate cancer were recruited from 25 health centers in the Southern US (n = 11,558, 85% African-American). An extensive in-person interview measured medical and other characteristics of study participants, including PSA test histories, weight, height, demographics, and disease history. Odds ratios (OR) and (95% confidence intervals) from logistic regression summarized the body mass index (BMI) and PSA test association while adjusting for socio-economic status (SES).

RESULTS

BMI between 25 and 40 was significantly associated with recent PSA testing (past 12 months) (OR(25.0-29.9) = 1.23 (1.09, 1.39); OR(30-34.9) = 1.36 (1.18, 1.57); OR(35.0-39.9) = 1.44 (1.18, 1.76); OR(> or =40) = 1.15 (0.87, 1.51)). Prior severe disease diagnoses, such as heart disease, did not influence the obesity and PSA test association. However, adjustment for prior high blood pressure or high cholesterol diagnoses reduced the BMI-PSA testing associations. Physician PSA test recommendations were not associated with BMI, and results did not appreciably vary by race.

CONCLUSIONS

Overweight and obese men were preferentially PSA tested within the past 12 months. BMI was not associated with physician screening recommendations. Data suggest that clinical diagnoses related to obesity increase clinical encounters that lead to preferential selection of obese men for prostate cancer diagnosis. This detection effect may bias epidemiologic investigations of obesity and prostate cancer incidence.

Black race does not independently predict adverse outcome following radical retropubic prostatectomy at a tertiary referral center

PURPOSE

There is controversy in the literature as to whether black race is associated with poorer oncological outcomes among men undergoing radical prostatectomy for clinically localized prostate cancer. To address this issue we examined the outcomes of a cohort of black and white men treated by multiple surgeons at our institution.

MATERIALS AND METHODS

The study population consisted of 4,962 white and 326 black men treated with anatomical radical retropubic prostatectomy between 1988 and 2004 by 10 different surgeons at the Johns Hopkins Hospital, a tertiary care referral center. We evaluated the association between race and adverse pathological features, and biochemical progression.

RESULTS

Black men had significantly higher preoperative serum prostate specific antigen (mean 7.2 vs 6.0 ng/ml, p <0.001), body mass index (median 27.4 vs 26.3 kg/m, p <0.001) and incidence of higher grade disease (Gleason sum 4 + 3 or greater) on prostate biopsy (17% vs 14%, p = 0.011). After adjustment for multiple clinical variables there was no statistically significant association between race and the adverse pathological characteristics of high grade disease, positive surgical margins, extraprostatic extension or seminal vesicle invasion. Black race was associated with a significantly increased risk of biochemical progression on univariate analysis (HR 1.52, 95% CI 1.16-2.00, p = 0.002). However, after adjusting for clinical and pathological characteristics, black race was not an independent predictor of biochemical progression (HR 1.09, 95% CI 0.81-1.45, p = 0.578).

CONCLUSIONS

Black men were more likely to be obese and present with adverse preoperative clinical features at a younger age, and have a higher rate of biochemical progression. However, on multivariate analysis black race was not an independent predictor of adverse pathological outcome or biochemical recurrence. Further efforts are needed to detect prostate cancer earlier among black men.

African-American men with nonpalpable prostate cancer exhibit greater tumor volume than matched white men

BACKGROUND

Although prostate cancer (PC) mortality disproportionately affects African-American (AA) men, limited data exist comparing the pathologic characteristics of white and AA patients with nonpalpable PC (clinical stage T1c).

METHODS

The authors reviewed the radical prostatectomy (RP) specimens from 37 consecutive AA men with clinical stage T1c PC and 35 white men who were matched for age, clinical stage, serum prostate-specific antigen (PSA) level, year of surgery, prostate weight, and prostate biopsy strategy. Pathologic characteristics were compared after mapping tumor foci and calculating tumor volumes by using computer software.

RESULTS

For AA men, the median age (57.7 years), mean serum PSA level (9.3 ng/mL), mean prostate weight (43 g), and biopsy strategy (73% sextant) were matched with the cohort of 35 white men (median age, 57.1 years; mean PSA, 9.3 ng/mL;, mean prostate weight, 43 g; biopsy strategy, 66% sextant). Despite similar biopsy characteristics between the 2 groups (Gleason score > or =7 in 43% of AA men vs. 37% of white men), AA men exhibited significantly higher prostatectomy Gleason scores (> or =7 in 76% of AA men vs. 34% of white men; P = .01). AA men also had a higher mean tumor volume (1.82 cm3 vs. 0.72 cm3; P = .001) and had 2.8 times more tumor per ng/mL of serum PSA (0.22 cm3 per ng/mL vs. 0.079 cm3 per ng/mL; P = .001).

CONCLUSIONS

Compared with a cohort of white men with similar clinical features at the time of biopsy, AA men with nonpalpable PC had higher prostatectomy Gleason scores, greater cancer volume, and greater tumor volume per ng/mL of serum PSA. These data provide additional support for the concept of early PC detection using a serum PSA threshold of 2.5 ng/mL for biopsy among AA men.

Obesity adversely affects health related quality of life before and after radical retropubic prostatectomy

PURPOSE

Obesity adversely affects surgical procedures and outcomes. We used a validated health related quality of life measure to examine the effects of obesity on disease specific health related quality of life before and following radical retropubic prostatectomy.

MATERIALS AND METHODS

From June 2000 to April 2003, 575 consecutive patients with prostate cancer were approached to participate in a prospective, health related quality of life study. Health related quality of life was assessed before surgery, and 1, 4, 12, 24 and 36 months postoperatively. Repeated measures mixed models were constructed to determine the independent effects of body mass index on health related quality of life.

RESULTS

Of 472 consenting subjects 376 (80%) completed a baseline and at least 1 followup survey. Higher body mass index was associated with worse preoperative hormonal/vitality function (p = 0.0009) and bother (p = 0.02), and delayed recovery of bowel function (p = 0.01) and bother (p = 0.01) health related quality of life. There were no measurable differences postoperatively in hormonal/vitality, urinary or sexual health related quality of life associated with higher body mass index. Increased body mass index was associated with prostate specific antigen recurrence (p = 0.05) and adjuvant treatment (p = 0.02). Adjuvant treatment was independently associated with worse bowel function (p = 0.01) and bother (p = 0.01) health related quality of life in obese patients. At 24 months bowel health related quality of life in obese patients no longer significantly differed from that in nonobese patients.

CONCLUSIONS

Obesity is associated with worse preoperative hormonal/vitality health related quality of life, slower recovery of bowel function and bother health related quality of life after radical retropubic prostatectomy, and prostate specific antigen recurrence. Impaired health related quality of life recovery in obese patients is influenced by disease recurrence and resultant adjuvant therapies. Despite these findings obese patients should not be dissuaded from considering prostatectomy as definitive treatment for localized prostate cancer.

Update on outcomes research databases in prostate cancer 2006

PURPOSE OF REVIEW

The purpose of this review is to summarize single-institution prostate-cancer-outcomes databases (which are most commonly derived from large academic medical centers, Veterans Affairs medical centers, and military hospitals) to summarize the design and development of three well characterized outcomes databases that combine data from multiple sites (Carcinoma of the Prostate Strategic Urological Research Endeavor, Center for Prostate Disease Research, and the Shared Equal Access Regional Cancer Hospital database) and to use the examples of obesity and prostate-specific antigen changes over time to highlight the importance of these databases in prostate-cancer outcomes.

RECENT FINDINGS

Multiple databases have demonstrated that obese men are at greater risk of biochemical progression following radical prostatectomy. In addition, objective data have shown that it is more difficult to operate on obese men leading to greater risk of positive surgical margins, which may contribute to poorer outcomes. Several databases have shown that a rapidly increasing prostate-specific antigen, measured either before diagnosis or after failed primary therapy, is associated with increased risk of prostate-cancer-specific mortality.

SUMMARY

Outcomes databases are extremely useful tools. They have lead to dramatic improvements of our understanding of prostate cancer. The challenge is to use this information from past patients to help us better manage our current and future patients.

The link between obesity and prostate cancer: the leptin pathway and therapeutic perspectives

Obesity-associated prostate cancer (PCa) remains controversial, although most studies rely on body mass index evaluation, which is an indirect measure of fatness. Studies using body fat measurement and disease stratification according to PCa stage found stronger associations between obesity and PCa. Leptin is a pleiotrophic hormone mainly synthesized by adipocytes that acts in peripheral organs such as the prostate. This article reviews obesity-associated leptin's pathophysiological role in PCa progression. PCa development results from some known risk factors. Currently, there is enough evidence suggesting that leptin is an additional factor involved in advanced PCa occurrence, and obesity association with high-grade disease. Life-long exposure to genetic and/or environmental susceptibility factors that predispose to obesity and higher leptin levels may increase the risk for advanced PCa.

Angiogenic factors are elevated in overweight and obese individuals

BACKGROUND

Adipose tissue produces both vascular growth factors and inhibitors. Since obesity is associated with expansion of the capillary bed in regional adipose depots the balance between these factors may favor angiogenesis.

OBJECTIVE

To investigate the relationship between body mass index and serum concentrations of vascular growth factors in human subjects.

METHODS

Vascular endothelial growth factor (VEGF), VEGF-C, VEGF-D, soluble VEGF receptor-2 (sVEGFr2), hepatocyte growth factor (HGF), angiopoietin-2, angiogenin and endostatin concentrations were measured in serum collected from 58 lean (24 males, 34 female, mean BMI, 22.2+/-0.3) and 42 overweight and obese (16 males and 26 females, mean BMI, 33.5+/-1.2) subjects after an overnight fast.

RESULTS

Sexual dimorphism was apparent in the serum concentrations of VEGF-C, VEFG-D and angiopoietin-2 with significantly higher levels in female compared to male subject. VEGF, VEGF-C, VEGF-D, soluble VEGF receptor-2, angiopoietin-2, angiogenin and endostatin but not HGF were significantly elevated in overweight and obese subjects. Positive correlations between BMI and the serum concentrations of VEGF-C, VEGF-D, sVEGF-R2, angiopoietin-2, angiogenin and endostatin were observed even after adjustment for gender and age.

CONCLUSIONS

Increased levels of vascular growth factors as well as the angiogenesis inhibitor endostatin are present in overweight and obese subjects and may contribute to previously documented increased risk of metastatic disease in obese subjects with cancer.

Are Findings from Studies of Obesity and Prostate Cancer Really in Conflict?

Recent studies on the association between obesity and prostate cancer appear to be in conflict. A recent prospective cohort study reported that the incidence of prostate cancer was lower among obese men under the age of 60 years and among those men with a family history of prostate cancer. Similarly, a case-control study found obesity was inversely associated with prostate cancer risk in men aged 40-64 years. However, several prospective cohort studies found that obese men are more likely to die from prostate cancer than non-obese men. Finally, two recent studies found that among men with prostate cancer, obese men were more likely to have a biochemical progression after surgery. We postulate that by closely examining the comparison groups used in these studies, these findings may, in fact, be in agreement. Specifically, this paradox within the literature may result from the possibility that obesity influences the development of aggressive (i.e., higher stage, higher grade, recurrence, death) and non-aggressive disease differently. We suggest that obesity may reduce the risk of non-aggressive disease but simultaneously increase the risk of aggressive disease. Finally, additional methodological issues are discussed that investigators need to be aware of to be able to draw inferences across studies of obesity and prostate cancer outcomes.

Differences between latent and clinical prostate carcinomas: lower cell proliferation activity in latent cases

BACKGROUND

Biological significance of prostate latent cancers as early phase of clinical cancers has been controversial. The characterization of the latent cancer may be important to investigate differences between latent and clinical prostate cancers.

METHODS

Latent cancers of the prostate, discovered at autopsy in men with no prior treatment for prostate disease and clinical prostate cancers, were compared for cell proliferation activities with parameters such as markers Ag-nucleolar organizer regions (AgNOR), topoisomerase II-alpha, and Ki-67. We also immunohistochemically studied alpha-methylacyl-CoA racemase (AMACR) expression that was recently identified as a possible positive marker of the prostate cancers. We analyzed 50 latent cancers and 50 clinical cancers, and samples were analyzed with Gleason grades or tumor volume.

RESULTS

In the latent cancers, Gleason grades 1-4 were observed, but in the clinical cancers Gleason grades 2-5 were recognized. Cell proliferation activities were significantly lower in the latent cancers in Gleason grade 3, and similar results were obtained but without statistical significance in Gleason grades 2 and 4. When analysis was performed according to the tumor size, it was shown that the growth activities of the tumor of the clinical cancer were higher than the latent cancer.

CONCLUSIONS

These results indicate that proliferation activities of the latent cancers were lower than the clinical cancers at the same Gleason grades. The data also suggest that latent cancers are just of preclinical stage and there is a possibility to progress to clinical ones by changing life style and longer life expectancy.

Treatment effects, disease recurrence, and survival in obese women with early endometrial carcinoma

BACKGROUND

The objective was to examine whether rates of disease recurrence, treatment-related adverse effects, and survival differed between obese or morbidly obese and nonobese patients.

METHODS

Data from patients who participated in a randomized trial of surgery with or without adjuvant radiation therapy were retrospectively reviewed. RESULTS.: Body mass index (BMI) data were available for 380 patients, of whom 24% were overweight (BMI, 25-29.9), 41% were obese (BMI, 30-39.9), and 12% were morbidly obese (BMI, > or =40). BMI did not significantly differ based on age, performance status, histology, tumor grade, myometrial invasion, or lymphovascular-space involvement. BMI > 30 was more common in African Americans (73%) than non-African Americans (50%). Patients with a BMI > or = 40 compared with BMI < 30 (hazards ratio [HR], 0.42; 95% confidence interval [CI], 0.09-1.84; P = .246) did not have lower recurrence rates. Compared with BMI < 30, there was no significant difference in survival in patients with BMI 30-39.9 (HR, 1.48; 95% CI, 0.82-2.70; P = .196); however, there was evidence for decreased survival in patients with BMI > or = 40 (HR, 2.77; 95% CI, 1.21-6.36; P = .016). Unadjusted and adjusted BMI hazards ratios for African Americans versus non-African Americans in the current study differed, thus suggesting a confounding effect of BMI on race. Eight (67%) of 12 deaths among 45 morbidly obese patients were from noncancerous causes. For patients who received adjuvant radiation therapy, increased BMI was significantly associated with less gastrointestinal (R, -0.22; P = .003) and more cutaneous (R, 0.17; P = .019) toxicities.

CONCLUSIONS

In the current study, obesity was associated with higher mortality from causes other than endometrial cancer but not disease recurrence. Increased BMI was also associated with more cutaneous and less gastrointestinal toxicity in patients who received adjuvant radiation therapy. Future recommendations include lifestyle intervention trials to improve survival in obese endometrial cancer patients.

The changing face of prostate cancer

Prostate cancer remains the most common noncutaneous human malignancy, and the second most lethal tumor among men. However, the natural history of the disease is often prolonged, and the survival benefits of local therapy for men with low-risk tumors may not be realized for a decade or more, as is increasingly well demonstrated in long-term observational cohorts in both the United States and Europe. A significant proportion of men with prostate cancer may be overdiagnosed, in the sense that diagnosis may not improve their lifespan or quality of life. However, the extent to which overdiagnosis represents a true problem relates to the consistency with which diagnosis leads invariably to active treatment. Prostate cancer is diagnosed at progressively earlier stages and with lower risk features; despite these trends, patients are less likely now than a decade ago to undergo a trial of active surveillance. Rates of brachytherapy and hormonal therapy use, in particular, have risen markedly. Important progress has been made in recent years in prostate cancer risk assessment. These advances, in combination with biomarkers in later stages of development, should be expected in the coming years to yield further improvements in clinicians' ability to diagnose prostate cancer early, and guide appropriately selected patients toward increasingly tailored treatment.

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

OBJECTIVES

To determine the association between obesity and prostate cancer recurrence after primary treatment with radical prostatectomy.

METHODS

Data were abstracted from CaPSURE, a disease registry of 10,018 men with prostate cancer. We included 2131 men who had undergone radical prostatectomy between 1989 and 2003 and had body mass index (BMI) information available. Recurrence was defined as two consecutive prostate-specific antigen (PSA) levels of 0.2 ng/mL or greater or any second treatment. Patients were risk stratified using the PSA level, Gleason grade, and clinical T stage.

RESULTS

Patients were followed up for a median of 23 months. Of the 2131 patients, 251 (12%) developed recurrence at a median of 13 months (range 1 to 107); 183 (9%) of these men had PSA failure and 68 (3%) received a second treatment. After adjusting for risk group, ethnicity, age, and comorbidities, a significant association was found between an increasing BMI and disease recurrence (P = 0.028). Very obese patients (BMI 35 kg/m2 or more) were 1.69 times more likely to have recurrence relative to men of normal weight (BMI less than 25.0 kg/m2; 95% confidence interval [CI] 1.01 to 2.84). An increasing PSA level (P <0.0001) and Gleason grade (P <0.0001) were also associated with recurrence. Ethnicity was not significantly associated with either BMI or PSA recurrence (P = 0.685 and P = 0.068, respectively).

CONCLUSIONS

The results of our study have shown that obesity is an independent predictor of prostate cancer recurrence. Because of the increased comorbidities and greater rates of recurrence, obese individuals undergoing radical prostatectomy need vigilant follow-up care.

Prostate cancer and adiponectin

OBJECTIVES

To search for any relation between plasma adiponectin levels and the cellular differentiation or progression of prostate cancer (PCa). PCa is becoming an increasingly important public health problem, particularly for those countries with a trend toward an aging population. Because insulin resistance in the setting of obesity is associated with the development of PCa, we hypothesized that decreased adiponectin levels might underlie the association between PCa and obesity/insulin resistance.

METHODS

In this study, we investigated plasma adiponectin levels in 30 patients with PCa, 41 subjects with benign prostatic obstruction, and 36 healthy individuals. The body mass index and age of the groups were similar. Patients with PCa were stratified into two groups according to the spread of the disease as organ-confined and advanced disease and into three groups according to grade (low, intermediate, and high grade determined by a Gleason sum of less than 5, between 5 and 7, and more than 7, respectively).

RESULTS

Plasma adiponectin levels were significantly lower in the PCa group than in the benign prostatic obstruction group or controls (P < 0.001 for both). Additionally, the plasma adiponectin levels were significantly lower in the advanced disease group than in the organ-confined PCa group (P = 0.012). Significant negative associations were found between plasma adiponectin levels and prostate-specific antigen levels or biopsy Gleason scores in the PCa group. The plasma adiponectin levels of those with high-grade PCa were also significantly lower than those for both the low-grade and intermediate-grade groups (P < 0.001 for both).

CONCLUSIONS

The results of the present study imply that plasma adiponectin levels are not only lower in patients with PCa but are also negatively associated with the histologic grade and disease stage. Future prospective studies are recommended to establish any causal relation between PCa and plasma adiponectin levels.

Obesity does not adversely affect health-related quality-of-life outcomes after anatomic retropubic radical prostatectomy

OBJECTIVES

To study the impact of obesity on the health-related quality-of-life (HRQOL) outcomes after radical prostatectomy (RP).

METHODS

Patient-reported sexual and urinary HRQOL was assessed at baseline and 3, 6, 12, and 24 months after anatomic retropubic RP using the University of California, Los Angeles, Prostate Cancer Index among a cohort of 340 men. Linear regression analysis was used to compare the longitudinal HRQOL scores by body mass index (BMI) adjusting for age, baseline HRQOL, and nerve-sparing status (non-nerve sparing versus unilateral versus bilateral).

RESULTS

At baseline, the sexual and urinary function and bother scores were similar between normal-weight (BMI less than 25 kg/m2), overweight (BMI 25.0 to 29.9 kg/m2), and obese (BMI 30 kg/m2 or greater) men. Obese men were as likely to undergo bilateral nerve-sparing surgery as men with a lower BMI. After adjustment for age, baseline HRQOL, and nerve-sparing status, no statistically significant differences were found in any HRQOL score at any point among the BMI groups, except for a lower urinary function score at 24 months among overweight men (P = 0.02).

CONCLUSIONS

In a select group of men undergoing RP at a tertiary care referral center, BMI was, in general, unrelated to the baseline and longitudinal postoperative HRQOL scores. Obese men (BMI 30 to 35 kg/m2) should not be selectively discouraged against RP because of concerns about HRQOL. Additional studies are needed to assess the HRQOL outcomes among men with very high BMI values (greater than 35 kg/m2).

Observed effect of age and body mass index on total and complexed PSA: analysis from a national screening program

OBJECTIVES

To assess the effect of aging and body mass index (BMI) on both serum total prostate-specific antigen (tPSA) and complexed PSA (cPSA) from the results of the 2003 Prostate Cancer Awareness Week national screening database.

METHODS

A total of 12,943 men were screened for prostate cancer. Of these, 4458 men had simultaneous measurements of tPSA and cPSA. Height and weight were used to calculate the BMI. The subjects were grouped by decade of age and categorized as either obese or nonobese with a cutoff BMI of 30 kg/m2. The rates of increase in mean tPSA and cPSA between consecutive decades were compared. The relationship among BMI, PSA, and cPSA was also analyzed using multivariate regression analysis.

RESULTS

The median age of those screened was 60 years. The median PSA and cPSA was 1.10 and 0.69 ng/dL, respectively. Both serum tPSA and cPSA levels showed an exponential increase with advancing age. The ratio of cPSA/tPSA remained relatively constant at 0.6. Compared with the nonobese cohort, men with a BMI of 30 kg/m2 or more had significantly lower tPSA and cPSA levels across all age groups (P <0.01). The overall odds ratio for all age groups was 1.8 (95% confidence interval 1.2 to 2.3).

CONCLUSIONS

Both tPSA and cPSA levels increased with age. Across age groups, men with a greater BMI had significantly lower cPSA and tPSA levels. The clinical significance of age-adjusted cutoff levels for PSA in obese men for the diagnosis of prostate cancer should be explored further in future prospective clinical trials.

2-[18F]fluoro-2-deoxyglucose positron emission tomography for the detection of disease in patients with prostate-specific antigen relapse after radical prostatectomy

EXPERIMENTAL DESIGN

Retrospective cohort study in 91 patients with prostate-specific antigen (PSA) relapse following prostatectomy, imaged with 2-[18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) in a tertiary care cancer center between February 1997 and March 2003. Comparison was made with magnetic resonance imaging (n = 64), bone scan (n = 56), and computed tomography (n = 37). The standard of reference included biopsy or clinical and imaging follow-up. We calculated sensitivity and specificity of PET and correlated PET findings with PSA values, other clinical parameters, and conventional imaging, when available.

RESULTS

PET was true positive in 28 of 91 (31%) patients, showing isolated disease in the prostate bed (n = 3) or metastatic disease with (n = 2) or without (n = 23) simultaneous disease in the prostate bed. In detail, PET identified lesions in the prostate bed (n = 5, all true positives), bones (n = 22; 20 true positives, 2 false positives), lymph nodes (n = 7; 6 true positives, 1 likely false positive), and one liver metastasis. Mean PSA was higher in PET-positive than in PET-negative patients (9.5 +/- 2.2 versus 2.1 +/- 3.3 ng/mL). PSA of 2.4 ng/mL and PSA velocity of 1.3 ng/mL/y provided the best tradeoff between sensitivity (80%; 71%) and specificity (73%; 77%) of PET in a receiver operating curve analysis. Combination with other clinical parameters in a multivariate analysis did not improve disease prediction. There were only two patients in whom other imaging studies showed isolated local recurrence or metastatic disease.

CONCLUSIONS

FDG-PET detected local or systemic disease in 31% of patients with PSA relapse referred for this test. There is a link to tumor burden and tumor biology in that the probability for disease detection increased with PSA levels.

OBESITY AND CAPSULAR INCISION AT THE TIME OF OPEN RETROPUBIC RADICAL PROSTATECTOMY

PURPOSE

The goal of radical prostatectomy (RP) is complete removal of the intact prostate. Obese men can represent a technical challenge. However, to our knowledge objective data linking obesity with technically inferior surgery are lacking. Therefore, we examined the association between body mass index (BMI) and capsular incision at RP as a surrogate of a poor technical operation in men treated for prostate cancer by several high volume surgeons at a center of excellence.

MATERIALS AND METHODS

The study population consisted of 7,027 men treated with anatomical retropubic RP between 1996 and 2004 by 7 high volume surgeons. We evaluated the association between BMI and capsular incision using logistic regression, adjusting for clinical and pathological variables, and for the surgeon.

RESULTS

Overall capsular incision was noted in 4.6% of all RP specimens. After adjustment for preoperative prostate specific antigen, patient race, height, year of surgery, clinical stage, pathological Gleason sum, prostate weight, extraprostatic extension and seminal vesicle invasion increased BMI was associated with increased odds of capsular incision (p trend = 0.005). After further adjustment for surgeon mild obesity was associated with 30% increased odds of capsular incision (OR 1.30, 95% CI 0.92 to 1.83), while moderate and severe obesity was associated with 57% increased odds of capsular incision (OR 1.57, 95% CI 0.82 to 3.00) relative to normal weight men (p trend = 0.06).

CONCLUSIONS

In a study of more than 7,000 men treated by 7 experienced surgeons BMI was positively related to capsular incision. This suggests that open retropubic RP is technically more difficult in obese men, which results in a greater likelihood of a less than technically ideal operation. Although this may be predicted to have a negative impact on disease-free survival outcomes in obese men, it is unlikely to alone explain the worse outcomes in obese men noted in previous RP series.

Health ramifications of the obesity epidemic

For the first time in human history, the numbers of overweight and underweight individuals are about the same, at 2.1 billion each. Along with the current worldwide obesity epidemic is the explosion of obesity- and overweight-related health problems, including diabetes and the metabolic syndrome, musculoskeletal disorders,cardiovascular disease, pulmonary disorders, and certain forms of cancer. Obesity and overweight account for a significant percentage of overall health care costs and contribute significantly to morbidity and mortality in the United States and around the world.

Association between serum adiponectin, and pathological stage and grade in men undergoing radical prostatectomy

PURPOSE

Adiponectin is a polypeptide hormone produced by adipocytes that has anti-angiogenic properties. Circulating adiponectin is lower in obese men. Obesity has been associated with advanced stage and a higher risk of biochemical progression following radical prostatectomy (RP) in several series. We examined whether serum adiponectin is associated with advanced disease stage at RP.

MATERIALS AND METHODS

Adiponectin was measured by enzyme-linked immunosorbent assay in the preoperative serum of 236 men treated with RP between 1998 and 1999. The odds ratio (OR) of advanced stage (pT3a or greater) and high grade disease (pathological Gleason sum 7 or greater) associated with quartiles of adiponectin were estimated using multivariate logistic regression models.

RESULTS

Serum adiponectin weakly correlated inversely with body mass index (Spearman r = -0.22, p = 0.01). Serum adiponectin was not associated with cancer stage or grade. However, in normal weight men adiponectin was positively associated with high stage disease (OR 1.14, 95% CI 1.02 to 1.29, p = 0.03), although there was no statistically significant association with high grade disease (OR 1.05, 95% CI 0.94 to 1.18, p = 0.38). In overweight and obese men adiponectin was inversely associated with high grade disease (OR 0.94, 95% CI 0.87 to 1.01, p = 0.09), although there was no statistically significant association with high stage disease (OR 0.97, 95% CI 0.91 to 1.04, p = 0.43). Further adjustments for body mass index had little impact on any ORs.

CONCLUSIONS

These data provide evidence to suggest that adiponectin may be related to prostate cancer aggressiveness, although the direction of the associations may depend on the extent of adiposity and on cancer grade.

Obesity, weight gain, and risk of biochemical failure among prostate cancer patients following prostatectomy

PURPOSE

Several lines of evidence suggest that diet and weight gain may be important environmental factors implicated in prostate carcinogenesis, especially in tumor progression. The purpose of this study was to evaluate obesity at different ages in a well-characterized cohort of prostate cancer patients treated with prostatectomy and to develop a prognostic model that incorporates body mass index (BMI) as a measure of obesity.

EXPERIMENTAL DESIGN

We carried out a prospective study of 526 patients registered at the M.D. Anderson Cancer Center from 1992 to 2001. Kaplan-Meier and Cox proportional hazard analyses were done.

RESULTS

During an average follow-up of 54 months, 97 (18%) post-prostatectomy patients experienced biochemical failure. Patients who were obese (BMI > or = 30 kg/m2) at diagnosis had a higher rate of biochemical failure than nonobese men (P = 0.07). Those obese at 40 years had an even greater rate of biochemical failure (P = 0.001). Higher BMI at diagnosis [hazard ratio (HR), 1.07; P = 0.01] and Gleason score = 7(4 + 3) and > or =8 (HR, 3.9; P = 0.03 and HR, 10.0; P < or = 0.001, respectively) remained significant independent predictors of biochemical failure in multivariate analysis. Men who gained weight at the greatest rate (>1.5 kg/y) between 25 years and diagnosis progressed significantly sooner (mean time, 17 months) than those who exhibited a slower weight gain (mean time, 39 months; P(trend) = 0.005). The inclusion of obesity to the clinical nomogram improved performance.

CONCLUSIONS

Our findings validate the importance for a role of obesity in prostate cancer progression and suggest a link to the biological basis of prostate cancer progression that can be therapeutically exploited.

Influence of body mass index on biochemical outcome after permanent prostate brachytherapy

OBJECTIVES

To evaluate the impact of body mass index (BMI) on the 8-year biochemical outcome after permanent prostate brachytherapy with or without the addition of supplemental external beam radiotherapy and/or androgen deprivation therapy (ADT).

METHODS

From April 1995 through February 2001, 686 consecutive patients underwent brachytherapy using either palladium-103 or iodine-125 for clinical Stage T1b-T3aNxM0 (2002 American Joint Committee on Cancer) prostate cancer. No patient underwent seminal vesicle biopsy or pathologic lymph node staging. The median follow-up was 59.5 months. The evaluated BMI subgroups were less than 25, 25.0 to 29.9, 30.0 to 34.9, and 35 or more kg/m2. Biochemical progression-free survival was defined by a prostate-specific antigen (PSA) level of 0.4 ng/mL or less after a nadir. The clinical, treatment, and dosimetric parameters evaluated for biochemical progression-free survival included BMI, patient age, clinical T stage, Gleason score, preimplant PSA level, risk group, percentage of positive biopsies, isotope, use of supplemental external beam radiotherapy, use of ADT, prostate volume, planning volume, percentage of target volume receiving 100%, 150%, and 200% of the prescribed dose, minimal percentage of dose covering 90% of the target volume, tobacco use, and the presence of hypertension and diabetes.

RESULTS

For the entire group, the actuarial 8-year biochemical progression-free survival rate was 95.8%, 95.6%, 94.1%, and 100% for patients in BMI categories less than 25, 25.0 to 29.9, 30.0 to 34.9, and 35 or more kg/m2, respectively. In hormone-naive and hormone-manipulated patients free of biochemical progression, the median post-treatment PSA level was less than 0.1 ng/mL. When integrated across risk groups and ADT use, BMI had no statistically significant impact on biochemical progression-free survival. At last follow-up, 5 patients (0.7%) had died of metastatic prostate cancer. In multivariate Cox regression analysis, pretreatment PSA level, Gleason score, clinical stage, percentage of positive biopsies, ADT use, and tobacco status, but not BMI, were statistically significant predictors of 8-year biochemical progression-free survival.

CONCLUSIONS

Prostate brachytherapy results in a high probability of 8-year biochemical progression-free survival for low, intermediate, and high-risk patients. When integrated across risk groups and hormonal status, BMI had no statistically significant influence on biochemical progression-free survival.

Progress in detection and treatment of prostate cancer

PURPOSE OF REVIEW

The purpose of this review is to highlight the most important developments in the diagnosis, prevention, and management of prostate cancer reported in the past year that have been published in the medical literature.

RECENT FINDINGS

Recent research has shown that clinically meaningful prostate cancer can develop in patients with a PSA value <4 ng/dL and has suggested that 'watchful waiting' approaches may not be appropriate for young patients or those with a life expectancy of greater than 15 years. The contribution of obesity to high-grade disease and a higher rate of relapse has also been described. There is now randomized data suggesting that adjuvant hormonal therapy for as little as six month's time confers a survival benefit for those receiving radiation therapy. Secondary hormonal manipulation with ketoconazole is now supported by randomized phase III data. Most importantly, this year the results of two randomized phase III clinical trials of chemotherapy in hormone refractory prostate cancer have shown that survival can be increased by 20% with the use of docetaxel.

SUMMARY

Recent data reported in the past year have significant implications for those involved in the management of prostate cancer. The results of the chemotherapy trials have resulted in new standards of care for this disease.

An investigation of the effects of late-onset dietary restriction on prostate cancer development in the TRAMP mouse

In our previous work we showed that dietary restriction initiated at puberty reduced prostate cancer development in the TRAMP mouse model. The current study was conducted to ascertain whether a dietary restriction regime would similarly reduce lesion development if imposed once tumor development was well established. Male TRAMP mice were maintained on an ad libitum diet until 20 weeks of age when proliferative prostate lesions are clearly evident. Mice were then subjected to a 20% restriction in dietary calories compared to matched controls, which were continued on ad libitum feeding. Mice were sacrificed at 20, 24, 32, and 39 weeks of age and proliferative epithelial lesions of the prostate were assessed using an established grading scheme. In this study, although dietary restriction reduced mean sex pluck weight (prostate and seminal vesicles), and mean grade of epithelial proliferative lesions in the dorsal and lateral lobes of the prostate, the effect was not as pronounced as was the case with dietary restriction from puberty. There was no relationship between serum insulin like growth factor (IGF-1) and prostate lesion grade. Additionally, we also report the relationship between lobe specific lesion development and SV40 immunostaining and, the occurance of neuroendocrine tumors (NETs) in the ventral prostate and urethra of the TRAMP mouse. NETs stained with high specificity and sensitivity for the neuroendocrine markers, synaptophysin and neuron-specific enolase (NSE), less for serotonin, but not for chromogranin A. NETs did not stain for cyclo-oxygenase-2 (COX-2) nor androgen receptor (AR). SV40 positive tubulo-acinar tumors seen occasionally in the kidney, did not stain for synaptophysin nor NSE.

Body mass index is weakly associated with, and not a helpful predictor of, disease progression in men with clinically localized prostate carcinoma treated with radical prostatectomy

BACKGROUND

Several studies have recently suggested an association between body mass index (BMI) and disease progression after radical prostatectomy. In the current study, the authors examined this association and that between the reciprocal of BMI (INVBMI, 1/BMI) and progression-free probability in men treated with radical retropubic prostatectomy (RRP) for clinically localized prostate carcinoma.

METHODS

The authors retrospectively studied 2210 patients who underwent RRP at Memorial Sloan-Kettering Cancer Center between September 1986 and May 2003. Clinicopathologic variables analyzed included BMI (kg/m2), preoperative serum prostate-specific antigen level (ng/mL), clinical T classification, year of surgery, race, biopsy-derived primary and secondary Gleason grades, and INVBMI, known to better correlate with percent body fat than BMI. Cox regression analysis was used to examine the possible association between BMI or its reciprocal with disease progression after controlling for the effects of common prognostic factors. The areas under the receiver operating curve (AUC) for models with and without INVBMI were calculated.

RESULTS

Of the 2210 patients analyzed, 251 experienced disease progression in a median follow-up time of 25.9 months (range, 0-143 months). After adjusting for all clinical variables, both BMI (P = 0.071; hazards ratio [HR] = 1.027) and INVBMI (P = 0.041; HR < 0.001) were associated with disease progression. However, the areas under AUC for models with and without INVBMI were similar (range, 0.794-0.798).

CONCLUSIONS

Although conflicting evidence has been reported regarding the link between obesity and an increased risk of developing prostate carcinoma, as well as an increased risk of developing aggressive disease and prostate carcinoma-related mortality, the authors found weak associations with disease progression for both BMI and INVBMI. These variables were of negligible prognostic value in men who received surgery. Studies with longer follow-up, that examine alternative end points, and that follow treatment(s) besides surgery are needed.

RADICAL PERINEAL PROSTATECTOMY FOR THE TREATMENT OF LOCALIZED PROSTATE CANCER IN MORBIDLY OBESE PATIENTS

PURPOSE

We assessed the feasibility of radical perineal prostatectomy (RPP) in morbidly obese patients with clinically organ confined prostate cancer.

MATERIALS AND METHODS

Of 1,265 consecutive patients who underwent RPP at our institution from 1992 to 2003 we identified 18 with a body mass index (BMI) of 40 kg/m or greater. Demographic and clinical patient characteristics were obtained from the medical records, which were further reviewed to identify the perioperative incidence of surgical and anesthesia related complications.

RESULTS

Median BMI was 41.7 kg/m (range 40.2 to 62.6). Five patients had a BMI of 45.0 kg/m or greater. No intraoperative or anesthesia related complication occurred. Mean operative time +/- SD was 188 +/- 32 minutes and estimated blood loss was 573 +/- 285 ml. None of the 18 patients received blood transfusions. During the immediate postoperative period 4 complications occurred in the form of lower extremity neuropraxia in 2 patients, local skin bleeding in 1 and early sepsis in 1 requiring rehospitalization for intravenous antibiotics. Mean operative time and estimated blood loss were significantly lower when surgery was performed by a highly experienced surgeon compared with experienced surgeons (174 +/- 21 vs 235 +/- 10 minutes and 485 +/- 258 vs 838 +/- 197 ml, p = 0.001 and 0.027, respectively).

CONCLUSIONS

RPP in morbidly obese patients is feasible and it is associated with acceptable perioperative morbidity. The perineal approach should be considered in morbidly obese patients seeking surgical treatment for clinically localized prostate cancer.

Body mass index as a predictor of prostate cancer: Development versus detection on biopsy

OBJECTIVES

To determine whether obesity is biologically associated with an increased risk of prostate cancer development, especially aggressive disease and to explore whether a bias may exist in our ability to detect these cancers in obese patients.

METHODS

We evaluated the association of body mass index (BMI) with prostate cancer, biopsy Gleason sum, and amount of cancer using logistic and linear regression analyses adjusting for age at biopsy, race, prostate-specific antigen level, digital rectal examination findings, and prostate volume among 787 consecutive men undergoing prostate biopsy between 1998 and 2002 at an equal-access medical center.

RESULTS

Men with a higher BMI were younger (P < 0.001), had lower prostate-specific antigen concentrations (P = 0.02), fewer abnormal digital rectal examination findings (P = 0.02), and larger prostate volumes (P < 0.001). After adjusting for age, no overall association was found between BMI and the odds of being diagnosed with cancer (P trend = 0.89), although overweight and mild obesity were inversely associated with the diagnosis of cancer. After multivariable adjustment, a higher BMI was associated with an increased odds of being diagnosed with prostate cancer (P trend = 0.007). Among men diagnosed with cancer, and after multivariable adjustment, a higher BMI was associated with a similar percentage of biopsy tissue with cancer (P trend = 0.23), but with greater odds of a high Gleason sum (P trend = 0.004).

CONCLUSIONS

After taking into account the clinical characteristics that influence the likelihood of finding an existent cancer, a higher BMI was positively associated with being diagnosed with prostate cancer. Also, among the men with cancer, a higher BMI increased the odds of high-grade disease. These findings suggest that obesity may be biologically associated with prostate cancer development and, in particular, with high-grade disease.

Minority issues in prostate disease

This article has discussed the increased incidence and disproportionately increased mortality of prostate cancer among African American men.Although the exact reasons are unknown, genetics may play a role, in addition to health care practices. Morbidity from other disease states, such as diabetes, obesity, or hypertension, may influence the overall survival of patients with prostate cancer. Current research tools will continue to explore biologic differences between the races; however, socioeconomic status and access to health care must not be overlooked. Several studies have demonstrated that similar disease stages and equal access to health care will result in similar outcomes. It is recognized that screening for prostate cancer will remain a controversial topic. Several influential professional societies recommend against screening and other professional societies endorse screening. Large-scale trials are currently underway hoping to answer this critical question. Since the advent of current screening tools, however, it seems that the overall mortality for prostate cancer has decreased and this cannot be ignored. Certainly, screening programs and clinical trials have traditionally had difficulty in recruiting minority participants, although more recent trials seem to be finding success. A primary care physician who is viewed as competent by their patients can certainly have a positive impact on their African American patients' willingness to participate in studies and screening programs. Most importantly, on the individual level, primary care physicians can provide a great service to their minority patients by offering educational materials on prostate cancer and by offering screening to qualified patients. The current American Urologic Association and National Cancer Institute guidelines recommend offering screening to all men age 50 and above. African American men or men with a first-degree relative with prostate cancer should be offered screening beginning at age 40. Proper screening consists of both a digital rectal examination to assess for asymmetry or nodules of the prostate and a serum PSA. Current recommendations are that individuals with a serum PSA greater than 4 ng/mL ora prostate nodule or asymmetric prostate should be referred to an urologist,where a biopsy can be performed easily in the office setting.The PSA cutoff of 4 has recently been questioned. A study by Thompson et al [31] evaluated 2950 men with a PSA of 4 or less with prostate biopsy.They found that the risk of prostate cancer in men with a PSA between 3.1 and 4 was 26.9% and that 25% of these men with prostate cancer had high-grade disease. All men found to have cancer had T1 disease. The clinical relevance of this surprisingly high rate of prostate cancer in men with a normal PSA is yet to be determined and is pending in studies on the ultimate effect of screening on mortality from prostate cancer. This information is not intended to confuse the issue, but intended to provide the most up-to-date information and allow for the best clinical decision making by the primary care physician. What can currently be recommended is if a patient is concerned about his possibility of having prostate cancer despite a normal PSA, a referral to an urologist to at least further discuss the issue may be in order. This may be especially true if the patient is African American or has a family history of prostate cancer at an early age.

Physical exercise in cancer patients during and after medical treatment: a systematic review of randomized and controlled clinical trials

PURPOSE

To systematically review the methodologic quality of, and summarize the evidence from trials examining the effectiveness of physical exercise in improving the level of physical functioning and psychological well-being of cancer patients during and after medical treatment.

METHODS

Thirty-four randomized clinical trials (RCTs) and controlled clinical trials were identified, reviewed for substantive results, and assessed for methodologic quality.

RESULTS

Four of 34 trials met all (seven of seven) methodologic criteria on the Delphi criteria list. Failure to conceal the sequencing of treatment allocation before patient recruitment, failure to blind the outcome assessor, and failure to employ an intention-to-treat analysis strategy were the most prevalent methodologic shortcomings. Various exercise modalities have been applied, differing in content, frequency, intensity, and duration. Positive results have been observed for a diverse set of outcomes, including physiologic measures, objective performance indicators, self-reported functioning and symptoms, psychological well-being, and overall health-related quality of life.

CONCLUSION

The trials reviewed were of moderate methodologic quality. Together they suggest that cancer patients may benefit from physical exercise both during and after treatment. However, the specific beneficial effects of physical exercise may vary as a function of the stage of disease, the nature of the medical treatment, and the current lifestyle of the patient. Future RCTs should use larger samples, use appropriate comparison groups to rule out the possibility of an attention-placebo effect, use a comparable set of outcome measures, pay greater attention to issues of motivation and adherence of patients participating in exercise programs, and examine the effect of exercise on cancer survival.

Relationship between obesity and prostate cancer

PURPOSE OF REVIEW

This review examines the relationship between obesity and prostate cancer, with an update of recent research in this field.

RECENT FINDINGS

A recent report of the Cancer Prevention Study II showed a direct relationship between increasing body mass index and prostate cancer mortality. However, the US Health Professionals Followup Study reported an inverse association between obesity and the risk of developing prostate cancer in men under 60 years of age or in those with a family history of prostate cancer. These studies illustrate the contradictory evidence linking obesity to prostate cancer risk and mortality. Body mass does not appear to affect the performance of prostate-specific antigen as a diagnostic test, and on prostate biopsy a lower body mass is associated with a higher cancer detection rate and a higher cancer volume as measured by core length involvement. In two recent radical prostatectomy series, obesity was associated with worse pathological features and higher biochemical recurrence rates. The higher risk of recurrence persisted in patients with organ-confined disease and negative surgical margins, implying that this risk is not related to surgical technique. Several potential biological mechanisms have been proposed to explain this link including hormonal alterations, hyperinsulinemia, glucose intolerance, and elevated insulin-like growth factor and leptin levels.

SUMMARY

Recent literature provides evidence that obesity may promote the development of a more aggressive form of prostate cancer, resulting in higher recurrence rates after primary therapy and higher cancer mortality rates overall. The mechanism to explain the association between obesity and prostate cancer is unclear.

Stronger Association between Obesity and Biochemical Progression after Radical Prostatectomy among Men Treated in the Last 10 Years

BACKGROUND

Prior prospective cohort studies found that obesity was associated with increased risk of prostate cancer death. However, in the last 20 years dramatic changes in both the extent of obesity and prostate cancer screening and treatment have occurred. Whether the association between obesity and aggressive disease has changed as a result of these temporal changes is unclear.

METHODS

The study population consisted of 2,832 men treated by anatomic radical retropubic prostatectomy between 1985 and 2004 by a single surgeon. We evaluated the associations of obesity (body mass index > or =30 kg/m(2))with tumor stage and grade using logistic regression and with biochemical progression using Cox proportional hazards regression. We examined whether these associations have changed over the last 20 years.

RESULTS

On multivariable analysis, the strength of the positive association between obesity and high-grade disease increased over time whereas the strength of the positive association between obesity and positive surgical margins decreased over time. The strength of the positive association between obesity and extraprostatic extension fluctuated over time, although the strongest and only statistically significant association was among men treated since 2000. The association between obesity and biochemical progression was strongest among men treated since 1995 (relative risk, 1.90; 95% confidence interval, 1.09-3.30; P = 0.02).

CONCLUSIONS

In the current study, with the exception of positive surgical margins, the positive association between obesity and high-grade disease, advanced stage, and biochemical progression after radical retropubic prostatectomy was in general strongest among men treated in the last 10 years. The reasons for these findings are not clear, although factors possibly related to prostate-specific antigen-based screening and/or other temporal changes in prostate cancer diagnosis and treatment may play a role.

Impact of obesity on clinical outcomes in robotic prostatectomy

OBJECTIVES

To assess the preoperative parameters and clinical outcomes of patients undergoing robotic laparoscopic radical prostatectomy with specific attention to the body mass index (BMI). Little is known about the impact of obesity (BMI greater than 30) on the clinical outcomes of patients undergoing radical prostatectomy.

METHODS

The data of 100 men undergoing robotic laparoscopic radical prostatectomy between June 2002 and October 2003 were prospectively entered into a database. The standard clinical characteristics (eg, prostate-specific antigen, Gleason score) and perioperative and postoperative parameters were evaluated. Additionally, all were assessed preoperatively and postoperatively for American Urological Association symptom and bother scores, uroflowmetry, postvoid residual urine volume, and sexual function.

RESULTS

Nineteen men were obese (BMI greater than 30) and 81 were not (BMI less than 30). The two groups had a similar need for transfusion, length of stay, and pathologic outcome. However, the obese men had poorer baseline urinary function (peak flow rate 13.9 versus 18.3 mL/s; voided volume 306 versus 454 mL; P < or =0.05) and sexual function (Sexual Health Inventory of Men score 14.1 versus 18.2; P < or =0.05). Obese men had significantly more complications (26.3% versus 4.9%; P = 0.01) and required more time to return to baseline activities (7 versus 4.3 weeks; P = 0.09) and urinary function. Finally, at 6 months, only 47% of obese patients versus 91.4% of nonobese patients had achieved pad-free urinary continence (P < or =0.001).

CONCLUSIONS

In this study, obese patients had significantly worse baseline urinary and sexual function, had complications, and did not recover urinary function as quickly or as well as nonobese patients. Obese patients also demonstrated a strong trend toward a delay in recovery time.

The association of body mass index and prostate-specific antigen in a population-based study

BACKGROUND

Recent studies of men with prostate carcinoma suggest that obesity may be associated with more advanced-stage disease and lower overall survival rates. One possible link between body mass index (BMI) and prostate carcinoma prognosis may be disease ascertainment. Prostate-specific antigen (PSA) is widely used to screen for prostate carcinoma.

METHODS

The authors examined the association between BMI and PSA in a population-based study of 2779 men without prostate carcinoma. Between 2001 and 2004, these men were enrolled in a study sponsored by the San Antonio Center of Biomarkers of Risk, a clinical and epidemiologic center of the Early Detection Research Network of the National Cancer Institute.

RESULTS

The mean PSA value decreased in a linear fashion with an increase in BMI category, from 1.01 ng/mL in normal weight men to 0.69 ng/mL in obese (Class III) men, after adjusting for race/ethnicity and age.

CONCLUSIONS

Lower levels of PSA in obese and overweight men could mask biologically consequential prostate carcinoma.

SERUM LEPTIN AND PATHOLOGICAL FINDINGS AT THE TIME OF RADICAL PROSTATECTOMY

PURPOSE

Obesity has been associated with a higher risk of progression following radical prostatectomy (RP). Obese men have higher serum leptin, a hormone produced by adipocytes, which has also been shown to be an in vitro prostate cancer growth factor. We examined whether serum leptin correlates with advanced pathological findings at RP.

MATERIALS AND METHODS

Preoperative serum from 225 men treated with RP between 1998 and 1999 was examined for serum leptin. Multivariate logistic regression analysis was used to determine whether serum leptin was predictive of extraprostatic extension (pT3a).

RESULTS

Serum leptin highly correlated with body mass index (Spearman r = 0.602, p <0.001). Serum leptin was not associated with total or percent free prostate specific antigen (PSA), biopsy or prostatectomy Gleason score, age or height. On multivariate analysis with total and percent free PSA, clinical stage, age, biopsy Gleason score, body mass index, serum leptin, and height as variables considered for entry into the model, serum PSA (p = 0.009), clinical stage (p = 0.019) and serum percent free PSA (p = 0.041) were the only variables predictive of extraprostatic extension. Serum leptin was not significantly associated with pathological stage (pT3a).

CONCLUSIONS

In the current study of predominantly white men with mainly low risk disease there was no statistically significant association between serum leptin and pathological stage (pT3a) at RP. In this cohort serum leptin was not a good biomarker for predicting advanced stage at RP.

OBESITY AND PROSTATE CANCER CLINICAL RISK FACTORS AT PRESENTATION: DATA FROM CaPSURE

PURPOSE

We investigated the association of obesity with prostate cancer case demographics and clinical disease features at presentation.

MATERIALS AND METHODS

Data were abstracted from CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor), a disease registry of 10,018 men with prostate cancer. A total of 2,952 men were included who were treated between 1989 and 2002, and had complete body mass index (BMI) information. BMI classes were defined as normal (less than 25 kg/m), overweight (25 to 29.9 kg/m), obese (30 to 34.9 kg/m) or very obese (35 kg/m or greater). Patients were categorized as having low, intermediate or high risk disease based on the D'Amico classification. Associations among BMI, risk and demographics were analyzed using univariate and multivariate models.

RESULTS

Of the patients 29% had a normal BMI, 51% were overweight, 16% were obese and 5% were very obese. Patients who were overweight or obese were more likely to be young, have hypertension and diabetes, and have a lower education level. The overweight group had a lower serum prostate specific antigen (p = 0.010) and lower stage disease (p = 0.030) at diagnosis, but there was no association between Gleason score and obesity (p = 0.57). However, among men with a BMI of 25 kg/m or greater there was a positive correlation between increasing BMI and risk of being in a worse prognostic group at diagnosis (p = 0.018).

CONCLUSIONS

Overweight and obese patients are more likely to be young at diagnosis and have multiple comorbidities. Men in the overweight and obese groups presented with lower risk prostate cancer at diagnosis. This may be due to earlier disease detection secondary to more frequent interaction with the medical community. Among overweight and obese patients increased obesity is associated with a slightly increased chance of having high risk prostate cancer at diagnosis.

Leptin and prostate: implications for cancer prevention--overview of genetics and molecular interactions

Leptin's relation with obesity has been clearly demonstrated while its role in oncobiology is still largely unknown. Epidemiological studies on serum leptin provide valuable though controversial data, while in vitro studies consistently show leptin's angiogenic and proliferative potential in cancer. Leptin's activity is mediated by tissue-specific receptors, differentially expressed in organs such as the prostate. The molecular cascades triggered by leptin result in prostatic cell proliferation and angiogenic activity, thus linking the hormone mainly to prostate cancer prognosis. This review also addresses leptin's metabolic interactions with cytokines, growth factors or hormones, establishing perceptive pathways leading to carcinogenesis or prostate cancer progression and metastasis. Better understanding of these mechanisms may help in the development of new and more effective treatments for prostate cancer. The consolidation of leptin molecular genetics profile in prostate cancer patients may help to create susceptibility groups in normal individuals, facilitating a preventive dietary intervention or strategies for chemoprevention. We hypothesize that the balance between androgen and leptin levels may facilitate the increase in the ratio of androgen-independent prostate cancer cells to androgen-dependent cells in the tumour.

Obesity and prostate cancer

PURPOSE OF REVIEW

This review provides an update on research into the association between obesity and prostate cancer.

RECENT FINDINGS

The US Health Professional Study reported an inverse relationship between risk for prostate cancer and obesity in men under the age of 60 or in those with a positive family history for prostate cancer. Others found no association between obesity and risk for the disease. Regarding detection, obesity does not impact upon measurement of prostate specific antigen as a method of detecting prostate cancer; however, in a referral population there was an inverse association between detection rate and obesity. In three radical prostatectomy series, obesity was associated with worse pathological features and higher biochemical relapse rates. Possible mechanisms for the association between obesity and prostate cancer include the impact on serum testosterone, leptin, insulin-like growth factor I, and interleukin-6 levels.

SUMMARY

A growing body of evidence suggests that obesity may impact upon risk, detection and outcome with regard to prostate cancer.

The association between obesity and the progression of prostate and renal cell carcinoma

Obesity has been linked to the incidence and mortality of several malignancies, including prostate and renal cancer. Increased body mass appears to have a more consistent association with prostate cancer mortality than incidence and recent studies suggest that it may be related to higher recurrence rates after radical prostatectomy. Obesity has an even stronger association with the development and progression of renal cancer, particularly in women. Since obesity is one of few modifiable risk factors that may impact the clinical course of these cancers, lifestyle and dietary changes to limit obesity should be recommended.

OBESITY AND BIOCHEMICAL OUTCOME FOLLOWING RADICAL PROSTATECTOMY FOR ORGAN CONFINED DISEASE WITH NEGATIVE SURGICAL MARGINS

PURPOSE

We have previously shown that men with a body mass index (BMI) greater than 35 kg/m2 had higher rates of positive surgical margins and significantly higher biochemical recurrence rates following radical prostatectomy (RP). To determine whether the higher prostate specific antigen (PSA) recurrence rates were due solely to the higher positive margin rate, we examined whether obesity was an independent predictor of biochemical failure among men with negative surgical margins.

MATERIALS AND METHODS

We examined data from 1,250 men treated with RP between 1988 and 2003 at 5 equal access medical centers, of whom 731 had pathologically organ confined disease and negative surgical margins. Multivariate Cox proportional hazards analysis was used to determine if BMI was a significant independent predictor of biochemical recurrence.

RESULTS

Mean BMI significantly increased over time (p = 0.010). Black men were significantly more likely to be obese than white or nonwhite-nonblack men. After controlling for all preoperative characteristics, body mass index was a significant predictor of biochemical failure with moderately and severely obese men (BMI 35 kg/m2 or greater) having greater than a 4-fold increased risk of PSA failure (p = 0.035). After controlling for the higher pathological Gleason grades among obese men, body mass index remained a significant predictor of biochemical failure with moderately and severely obese men (BMI 35 kg/m2 or greater) having nearly a 4-fold increased risk for PSA failure (p = 0.036).

CONCLUSIONS

BMI 35 kg/m2 or greater was associated with higher grade tumors and worse outcome following RP in a cohort of men with favorable pathological findings. Thus, surgical technique (margin status) cannot fully explain the worse outcomes among obese men, suggesting that obesity may be associated with a biologically more aggressive form of prostate cancer.

Prostate cancer and coronary heart disease: correlation or coincidence?

A few past clinical and recent case-control studies of statin use, for example, in patients with and without prostate cancer have not demonstrated its potential for reducing or preventing the risk for this disease, and the potential for benefit may have been a confounding coincidence. Data from larger continuing and future studies will be needed to resolve this issue, but the recent data on cholesterol or dyslipidemia and risk increase or reduction with treatment are interesting, especially because of other potential improvements with therapy in nonprostate cancers. In addition, the finding that some available cancer treatments improve some parameters of the lipid profile is fascinating, and some cancer drugs are being used in a specific cardiovascular disease treatment setting to improve outcome. Even if CHD, dyslipidemia, and the treatment of these conditions has no role in preventing prostate cancer or its progression, what has been lost? CVD is still the leading cause of death of men, and a heart-healthy program for the patient concerned about prostate disease would reduce this primary cause of death. Patients would take a step forward in improving all-cause mortality. Recent data from surveys, however, continue to demonstrate that men have an inadequate understanding of cholesterol and heart disease. Crisis creates opportunity, and individuals working in urology have ample reasons not only to discuss the overall benefits of reducing lipid markers, but to improve cholesterol and CHD awareness as much as health professionals working in other fields of medicine. The marriage between general preventive medicine and urology seems to be inevitable, and in the authors' opinion, this merger will provide the foundation for novel research that could affect patients' lives dramatically.