**6. Aggressive prostate cancer**

It is also assumed that PCa in overweight people is more aggressive. Usually it was stated that Pca with Gleason score > 7 was significantly more frequent in obese patients. Not all authors agree with that hypothesis (Chyou et al., 1994; Major et al., 2011; Nilsen et al., 1999; Rodriguez et al., 2007; Schuurman et al., 2000; Snowdon et al., 1984).

Authors emphasize that central obesity as the outcome of excessive fat accumulation results in glucose intolerance, high blood pressure, atherosclerosis, cardiovascular disease, insulin resistance, altered metabolic profile, metabolic syndrome, and obesity-related lipid

The Influence of Obesity on Prostate Cancer Diagnosis and Treatment 25

in plasma volume which is mainly dependant on the obesity extent. This led some authors to explore new markers independent of hemodilution (Bryniarski et al., 2011). PSA mass meets these criteria, but further studies are needed to demonstrate its superiority over

Hereby we present our work on hemodilution (Bryniarski et al., 2011). The aim of our study was to prove the superiority of PSA mass over standard PSA concentration in predicting

From 1994 until the end of 2007 206 radical retropubic prostatectomies in Caucasian men suffering from prostate cancer were carried out in the Department of Urology in Zabrze, Medical University of Silesia in Katowice. The patients who underwent preoperative antiandrogen therapy, chemotherapy or radiotherapy were excluded from the research (29

177 patients were qualified for the research. In our group two types of data were subject to analysis. Preoperative data, such as: age, height, weight, BMI, PSA concentration (immunoenzymatic Elecsys test; Cobas 6000 Hitachi) and postoperative data: the extent of histopathologic differentiation of prostate tissue in Gleason score, extracapsular extension (pT3), the presence of lymph nodes metastases and the presence of positive surgical

Patients are under constant control in the Hospital Outpatient Clinic, thanks to which data concerning progression (biochemical recurrence, local recurrence, death) were also collected and the cancer-specific survival time was determined. The total volume of plasma and the PSA mass were calculated on the basis of the formulas (Table 1) (Boer, 1984; Du Bois & Du

(EBS) Plasma volume [liters] (PV) PSA mass [µg]

1. BMI – into 3 groups: I – 45 patients with normal weight (BMI < 25), II – 95 overweight

2. Preoperative PSA concentration – into 3 groups: I – 79 patients with PSA < 10 ng/ml, II – 66 patients with PSA 10 – 19,9 ng/ml, III – 32 patients with PSA ≥ 20 ng/ml. 3. Preoperative PSA mass – into 3 groups: I – 71 patients with PSA < 40 µg, II – 78 patients

0,007184 EBS x 1,670 PV x PSA concentration

standard PSA concentration.

**9. Author's contribution** 

**9.1 Material and methods** 

patients).

margins.

Bois, 1916).

Estimated Body Surface

(weight)0,425 x (height)0,72 x

Table 1. The formulas to estimate plasma volume and PSA mass.

patients (BMI – 25 – 29,9), III – 37 obese patients (BMI ≥ 30).

with PSA 40 – 69,9 µg and III – 28 patients with PSA ≥ 70 µg.

The characteristics of each group is shown in tables 2 and 3.

The group of 177 patients was divided according to:

biochemical recurrence after radical prostatectomy.

disorders (Hsing et al., 2007). Especially insulin resistance, higher IGF-1 and leptin levels are recognized responsible for such aggressiveness (Hedlund et al., 1994; Prabhat et al., 2010). IGF-1 is involved in angiogenesis, responsible for bone metastases and developing androgen-independent progression of Pca. Leptin is responsible for cell migration and growth factor expression in hormone-resistant cells of Pca.

It is not proven that worse treatment outcomes in obese patients are due to unfavorable features of prostate cancer itself. In one of the studies it was reported that obesity was positively correlated with clinical progression independently of prostate cancer grade, stage and primary treatment (Gong et al., 2007).

Higher rate of cancer progression is also due to unfavorable features of obese men after radical prostatectomy. It was proven that increased BMI is associated with high grade disease, positive surgical margins, extraprostatic extension of the disease and lymph node metastases. Biochemical recurrence after radical prostatectomy is also more frequent in obese patients compared to non-obese men (Freedland et al., 2005).
