Steroid hormone concentrations in relation to patient prognosis and prostate tumour grade

Low serum testosterone levels are predictive of prostate cancer

PURPOSE

Although hormones play fundamental roles in prostate growth, their clinical significance is not completely clear. Aims of present study were to assess whether testosterone and serum sex hormone levels are predictors of benign prostatic hyperplasia (BPH) or prostate cancer (PC) and to verify whether prostate cancer is associated with low testosterone levels, and to test association between testosterone levels and known prognostic factors in prostate cancer.

METHODS

In 206 consecutive patients with benign prostatic hyperplasia or prostate cancer testosterone, follicle-stimulating hormone, luteinizing hormone and prolactin levels were tested and correlated with disease. In patients with prostate cancer, hormone levels were also correlated with known prognostic factors. Predictive value was assessed for age, prostate-specific antigen (PSA), PSA ratio, PSA density, prostate volume and serum sex hormone levels using multiple logistic regression analysis and receiver operating characteristic curves.

RESULTS

Considering sex hormones, only testosterone levels were significantly lower in patients with prostate cancer than those with BPH; testosterone levels appear to be independent predictor of prostate cancer, enhancing predictive accuracy for BPH and PC. Testosterone levels do not seem to be associated with known clinical prognostic factors.

CONCLUSIONS

This study supports experimental findings that testosterone levels are predictor of prostate cancer and that prostate cancer is frequently associated with low testosterone levels. In the diagnostic work-up for prostate cancer, adding testosterone determination to PSA test may improve predictive accuracy.

Correlation between CD8+ T cells specific for prostate-specific antigen and level of disease in patients with prostate cancer

Modest work has been performed to improve the sensitivity of residual disease detection or investigate the contribution that the immune system makes in controlling metastatic tumor growth, in particular, the frequency and biological actions of peptide-specific CD8+ T lymphocytes in limiting metastatic disease and/or maintaining remission. Fifty-three peripheral blood samples from 32 prostate cancer (PC) patients were investigated for the presence of circulating prostate-specific antigen (PSA)-expressing cells (CPECs) using a highly sensitive and specific assay combining immunomagnetic epithelial cell enrichment with nested RT-PCR of PSA mRNA. Using HLA-A2 tetramer complexes, frequency of CD8+ T cells specific for PSA-derived peptides was determined. Additionally, serum concentrations of PSA and testosterone were measured. CPECs were detected in 26% of peripheral blood samples from PC patients. CD8+ T cells specific for PSA-derived peptides were detected at low frequency in HLA-A2-positive PC patients. The correlation between these PSA-specific CD8+ T cells and residual prostate tumor cells and clinical measures was investigated. Our data suggest that frequency of PSA-specific CD8+ T cells is correlated to CPECs, but not to serum PSA level.

LOW SERUM TESTOSTERONE LEVELS ARE ASSOCIATED WITH POSITIVE SURGICAL MARGINS IN RADICAL RETROPUBIC PROSTATECTOMY: HYPOGONADISM REPRESENTS BAD PROGNOSIS IN PROSTATE CANCER

PURPOSE

It has been reported that more aggressive prostate cancer (PC) can be associated with low serum testosterone levels. The relationship between serum androgens and PC is still not completely understood. In this study we examined the association of prognostic factors in men who underwent radical retropubic (RRP) prostatectomy with low or normal total testosterone.

MATERIALS AND METHODS

We retrospectively evaluated 64 consecutive patients with localized PC treated with RRP between July 2002 and November 2003. PC was diagnosed by transrectal ultrasonography guided biopsy performed for either a suspicious digital rectal examination or serum prostate specific antigen greater than 4.0 ng/ml. Gleason score was determined in prostatic biopsies. Pathological TNM staging (1997), capsular perforation, seminal vesicle involvement and surgical margin status were determined in all surgical specimens. The threshold for serum total testosterone was 270 ng/dl. In all analyses p <0.05 was considered statistically significant.

RESULTS

There were no statistically significant differences among prostate specific antigen, Gleason score (biopsy or specimen), pathological stage, capsular perforation and seminal vesicle involvement. However, patients with low total testosterone had increased positive surgical margins (p = 0.026).

CONCLUSIONS

Patients with low total testosterone more frequently present with positive surgical margins in RRP specimens. The true association between low testosterone and poor clinical outcome in the long term needs validation in large prospective studies.

Activation of signal transducer and activator of transcription 5 in human prostate cancer is associated with high histological grade

We have recently identified signal transducer and activator of transcription 5 (Stat5) as a critical survival factor for prostate cancer cells. We now report that activation of Stat5 is associated with high histological grade of human prostate cancer. Specifically, immunohistochemical analysis demonstrated a strong positive correlation with activation of Stat5 and high Gleason score in 114 human prostate cancers. To investigate the mechanisms underlying constitutive activation of Stat5 in prostate cancer, a dominant-negative mutant of Janus kinase 2 (Jak2) was delivered by adenovirus to CWR22Rv cells. Dominant-negative-Jak2 effectively blocked the activation of Stat5 whereas wild-type Jak2 enhanced activation, indicating that Jak2 is the main kinase that phosphorylates Stat5 in human prostate cancer cells. A ligand-induced mechanism for activation of Stat5 in prostate cancer was suggested by the ability of prolactin (Prl) to stimulate activation of both Jak2 and Stat5 in CWR22Rv human prostate cancer cells and in CWR22Rv xenograft tumors. In addition, Prl restored constitutive activation of Stat5 in five of six human prostate cancer specimens in ex vivo long-term organ cultures. Finally, Prl protein was locally expressed in the epithelium of 54% of 80 human prostate cancer specimens with positive correlation with high Gleason scores and activation of Stat5. In conclusion, our data indicate that increased activation of Stat5 was associated with more biologically aggressive behavior of prostate cancer. The results further suggest that Jak2 is the principal Stat5 tyrosine kinase in human prostate cancer, possibly activated by autocrine/paracrine Prl.

A multivariate approach to the description of patient populations. An example of the analysis of the hormone profiles of patients with advanced prostate cancer

In view of the multifactorial nature of the endocrine dysfunctions that may develop during prostate cancer and the unsuitability of the most widely used statistical methods to study such dysfunction, we have in the present study examined the relationships among 17 biological variables in 26 patients with advanced prostate cancer by two complementary multivariate methods, correspondence factorial analysis (CFA) and a hierarchical automatic classification procedure. The 17 variables included 14 hormones, their precursors or metabolites [LH, FSH, estradiol (E2), testosterone, dihydrotestosterone (DHT), androstenedione (A), androstenediol (Ediol), dehydroepiandrosterone (DHA), DHA-sulphate (DS), cortisol (CORT), 17 alpha-hydroxyprogesterone (17-OH-PROG), pregnenolone (PREG), 17 alpha-hydroxypregnenolone (17-OH-PREG), and androstanediol glucuronide (ADG)], one plasma binding protein, namely, sex-hormone-binding protein (SHBG) and two tumour markers, prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA). The originality of these multivariate methods is that they do not preselect a dependent variable nor perform two-by-two correlations as in stepwise multiple regression analysis but describe the patient population by extracting layers of correlations (from strong to weak) from amid confounding variables. Compared to principal component analysis which is based on covariance, CFA, based on the chi 2-metric, enables the licit representation of both tests and patients on the same factorial maps. From an examination of proximity among variables, it is possible to deduce which tests are related, which groups of patients have similar hormone profiles, and which tests vary most in which patients. The most discriminant factors in this particular population of patients were PSA and PAP levels, which were, however, not strongly correlated and were apparently selectively associated with certain hormones. PAP seemed the more pathological marker; PSA was somewhat anticorrelated to the adrenal androgen (DHA and DS) and PREG levels. The hormones with the lowest variance were A, Ediol and CORT reflecting their key roles in metabolism. A number of patients were hypogonadic. SHBG levels were not closely related to total T levels but anticorrelated with ADG suggesting that, in the patients concerned, SHBG decreases the bioavailable T fraction. There was no correlation between ADG and precursor hormones (PREG, DHA, DS) but a slight anticorrelation between these precursors and DHT. Therefore the source of ADG in these patients does not seem to be increased levels of precursor hormones nor of DHT but increased peripheral tissue metabolism of androgens. In future, descriptive multivariate analyses of large patient cohorts should help to define subpopulations with distinctive hormone profiles for prospective clinical studies.

Analysis of prognostic factors in men with metastatic prostate cancer. Uro-Oncology Group of Northern Alberta

We determined the influence of the extent of disease on bone scan, serum testosterone, patient age, performance status, method of initial diagnosis, Gleason grade, clinical stage at diagnosis, serum acid phosphatase, serum prostate specific antigen (PSA) and primary hormonal treatment on survival. The clinical and hormonal data were obtained when the presence of metastatic disease was established and treatment was to be initiated in 162 men with metastatic prostate cancer. Mean followup was 16 months (range 1 to 105 months). A total of 70 men (43.2%) died of the metastatic disease during the evaluation period. Log rank analysis revealed that only serum testosterone (p = 0.035) and extent of disease on bone scan (p = 0.003) significantly affected over-all survival. A trend (p = 0.068) towards decreased survival was observed with increasing values of PSA. Increasing values of acid phosphatase positively correlated with extent of disease on bone scan but was not a significant independent prognostic factor. Patient age, performance status, clinical stage, method of initial diagnosis, Gleason grade and type of hormonal treatment did not significantly influence survival. Upon using multivariate Cox analysis, only extent of disease on bone scan was significantly correlated with over-all survival (p less than 0.014). PSA may also be influential but longer duration of followup will be necessary. We conclude that extent of disease on bone scan is the most important prognosticator of the analyzed factors and that serum testosterone may be of value.

A randomized double-blind study evaluating Anandron associated with orchiectomy in stage D prostate cancer

A randomized double-blind study with a 3-yr follow-up comparing the two arms "orchiectomy + Anandron (300 mg)" vs "orchiectomy + placebo" in 125 patients with stage D prostate cancer has confirmed the beneficial effects of the combined Anandron therapy on subjective parameters and on the best objective response (NPCP criteria), although these effects were not statistically significant, but failed to detect any improvement in time-to-disease progression or survival. Comparison with the results of other trials emphasizes the urgent need to establish suitable prognostic factors by further clinical research before evaluating the benefits of individual drugs.

Estradiol and testosterone metabolism and production in men with prostatic cancer

We recently observed a familial influence on the plasma concentration of sex-steroids and the metabolic clearance in men with prostatic cancer. We have now determined, by isotope dilution techniques, the blood estradiol and testosterone production and clearance rates in men with prostatic cancer and in unrelated controls. Thirty-eight men had a diagnosis of prostatic cancer before the age of 63, and 22 controls matched for age were randomly selected from the general population. None of the patients or controls had received endocrine therapy. The plasma content of testosterone, dihydrotestosterone, estrone, estradiol, 3 alpha-androstanediol glucuronide, dehydroepiandrosterone sulfate, sex-hormone binding globulin, apparent free testosterone concentration, follicle stimulating hormone and luteinizing hormone were not significantly different between the groups. The metabolic clearance and production rates of testosterone were significantly (P = 0.008 and P = 0.013, respectively) higher in patients [447 +/- 26 L/day/body surface area(m2) and 2.21 +/- 0.17 mg/day/m2, n = 38] than in controls [346 +/- 20 L/day/m2 and 1.70 +/- 0.11 mg/day/m2, n = 22]. The PR and MCR of estradiol were not significantly different between patients with prostatic cancer (n = 19) and controls (n = 12). These results indicate that men with prostatic cancer have elevated clearance and production rates of testosterone without an alteration of estradiol production or clearance.