Obesity-Related Plasma Hemodilution and PSA Concentration Among Men With Prostate Cancer

126

Obesity is associated with increased risk of positive surgical margins and prostate specific antigen (PSA) recurrence among men undergoing radical prostatectomy. To what degree positive margins contribute to poorer outcome is unclear. Thus, we sought to examine the association between body mass index (BMI) and more objective measures of tumor aggressiveness, tumor grade and size. We carried out a retrospective analysis of 2302 patients treated with radical prostatectomy at the Duke Prostate Center from 1988-2007. Tumor volume was calculated by multiplying prostate weight by percent of specimen involved with cancer. Associations between BMI and tumor volume and highgrade disease (GleasonX4 þ 3) independent of pre-operative clinical characteristics of age, race, PSA, clinical stage, biopsy Gleason sum, and year of surgery were assessed using linear and logistic regression, respectively. Mean and median BMI among all subjects was 28.1 and 27.6 kg m -2 , respectively. Increased BMI was significantly associated with younger age (Po0.001), black race (Po0.001), more recent year of surgery (Po0.001), and positive surgical margins (Po0.001). After adjusting for multiple clinical pre-operative characteristics, higher BMI was associated with a greater percent of the prostate involved with cancer (P ¼ 0.003), increased tumor volume (Po0.001), and high-grade disease (P ¼ 0.007). Men with a BMI X35 kg m 2 had nearly 40% larger mean tumor volumes than normal weight men (5.1 versus 3.7 cc), after adjustment for multiple clinical characteristics. In this study, obese men undergoing radical prostatectomy had higher-grade and larger tumors, providing further evidence that obese men undergoing radical prostatectomy have more aggressive prostate cancers.

Section: Discussionmentioning

confidence: 99%

Obese men have higher-grade and larger tumors: an analysis of the duke prostate center database

Freedland

Bañez

Sun

et al. 2009

126

“…11 This explanation was validated by Branz and co-workers study on prostate cancer patients. [12][13][14] The main aim of this study was to find a useful clinically applied equation based on the already established PSA-BMI correlation, as well as to test our hypothesis based on this equation, we applied this equation in randomly selected previously biopsied cases, comparing our data with Oesterling et al 5 We are not referring to the use of any of TRUS data (that is, volume and density). This is based on two reasons; first is the subjective error that could be countered during measurements; and second is our aim itself, which is supplying an equation before any invasive maneuver (TRUS).…”

Section: Discussionmentioning

confidence: 99%

Obesity–PSA relationship: a new formula

Hekal

Ibrahiem

2009

To clinically apply the inverse PSA-body mass index (BMI) correlation and enhance PSA sensitivity in obese cases, a new formula is warranted. An innovated BMI-PSA equation is designed. PSA-BMI adjusted formula (named Hekal's equation): measured total PSA (ng ml À1 ) multiplied by age (years) and divided by BMI of the patient. The formula is applied over a randomly chosen 1000 cases of different PSA, BMI, age and trans-rectal ultrasound biopsy results, the yield of new PSA is correlated with pathology and age-specific PSA adjustment values. Among the 988 cases with complete data, obesity (BMI: 30-35 kg m À2 ) in 236 cases (23.8%) and 79 cases (7.9%) have BMI435 kg m À2 . Mean PSA was 5.8 ng ml À1 (s.d.±8.4 ng ml À1 ). Cases stratified based on their age (every 10 years). The new equation was applied. Obesity is detected in 33.5 and 43.6% of fifth and sixth decade of life respectively (P ¼ 0.02), with low measured PSA values (2.1, 3.8 ng ml À1 , respectively). By such PSA measurement biopsy may be omitted, missing 53.3% of malignant cases. In contrast, PSA adjusted were 4 and 9.3 ng ml À1 within the same group of patients. With such values, the decision of a biopsy could not be missed for the targeted groups. Specificity and sensitivity of adjusted PSA values at cutoff point 4 ng ml À1 was 41.7 and 70%, respectively. Based on our results, the new PSA-BMI adjusted formula is reproducible, easy applied formula. With such a formula the higher sensitivity of PSA in obese patients could be achieved. The misleading low PSA in obese cases in the fifth and sixth decade will be corrected.

“…3,4 In addition, obesity correlates with a number of clinical variables, including serum PSA level and prostate volume, in patients with prostatic disease. [5][6][7] Several studies from western countries have shown that obesity predisposes to recurrent PCa with more aggressive pathological features and/or higher biochemical recurrence rates after radical prostatectomy (RP). [8][9][10][11][12][13][14] In addition, obese men were reported to be at greater risk of developing higher-grade tumors after surgery in low-risk PCa matched the criteria of active surveillance programs.…”

Section: Introductionmentioning

confidence: 99%

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

Narita

Mitsuzuka

Yoneyama

et al. 2013

BACKGROUND: Accumulating evidence suggests that obesity is associated with tumor progression in prostate cancer (PCa) patients after radical prostatectomy (RP). We conducted a retrospective multicenter study to determine the effect of body mass index (BMI) on the clinicopathological characteristics and biochemical recurrence of PCa in Japanese men who underwent RP. METHODS: The medical records of 1257 men with PCa treated by RP without neoadjuvant therapy at four medical institutes between 2001 and 2009 were retrospectively reviewed. Patients were categorized into four groups using the World Health Organization (WHO) BMI classification and BMI quartiles. Associations of the various BMI categories with clinicopathological characteristics and biochemical recurrences were statistically evaluated. Biochemical recurrence was defined as a PSA level of 40.2 ng ml -1 . RESULTS: Of the 1257 patients, 230 (18.3%) experienced biochemical recurrence during the median follow-up period of 49 months. The median BMI was 23.8 kg m -2 , and 1.4% patients were underweight, 65.4% were of normal weight, 30.9% were overweight and 2.4% were obese (WHO classification). Preoperative PSA levels and PSA density (PSAD) tended to decrease as BMI increased. Pathological characteristics did not differ significantly among BMI categories. As per the WHO classification and quartile categories, biochemical recurrence rate was comparable among the BMI groups. After adjusting for other pre-and postoperative covariables, multivariate Cox proportional hazards analysis revealed that a high BMI did not have an independent impact on biochemical recurrence-free survival. CONCLUSIONS: Underweight Japanese PCa patients treated by RP had higher preoperative PSA levels and PSAD. High BMI was not associated with adverse pathological findings or increased biochemical recurrence rate in Japanese PCa patients treated with RP. Racial differences may exist in the relationship between obesity and outcomes of RP in PCa patients.