Relationship between serum prostate-specific antigen and calculated epithelial volume

Metabolite interactions in prostatic fluid mimics assessed by 1H NMR

INTRODUCTION

Molecular interactions in prostatic fluid are of biological interest and may affect MRI and MRS of the prostate. We investigated the existence of interactions between the major components of this fluid: spermine, citrate and myoinositol, metal ions, including zinc, and proteins.

MATERIALS AND METHODS

Solutions of 90 mM citrate, 18 mM spermine and 6 mM myo-inositol, mimicking expressed prostatic fluid, were investigated by 1H NMR using changes in T2 relaxation and chemical shift as markers for interactions.

RESULTS AND DISCUSSION

Adding to this metabolite mixture the ions Na⁺ , K⁺, Ca⁺⁺, Mg⁺⁺ and Zn⁺⁺, decreased the T2 relaxation times of citrate and spermine protons by factors of 3 and 2, respectively, with Zn++ causing the largest effect, indicating ion-metabolite interactions. The T2 of 18 mM spermine dropped by a factor of 2 upon addition with 90 mM citrate, but no effect on T2 was seen with myo-inositol pointing to a specific citrate-spermine interaction. Moreover, the T2 of citrate in the presence of spermine decreased by adding metal ions and increasing amounts of Zn⁺⁺, indicating complexation of citrate and spermine with metal ions, particularly with Zn. The addition of bovine serum albumin (BSA), as an index protein, substantially further decreased the T2 of spermine and citrate implying the formation of a transient spermine-metal ion-citrate-BSA complex. Finally, we found that the T2 of citrate in extracellular fluid of prostate cancer cells, as a mimic of fluid in cancerous prostates, decreased by adding fetal calf serum, indicating protein binding.

Between-subject variations of transition zone epithelial volume and serum PSA levels in men with benign prostatic hyperplasia

PURPOSE

We verified if the measure of transition zone epithelial volume (TZepiV) could be a valid predictor of serum PSA value in men with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Between January 2005 and July 2008, a total of 90 patients undergoing transvesical suprapubic adenomectomy for sintomatic BPH were enrolled. In case of an elevated PSA level (above 4 ng/ml) or abnormal digital rectal examination, systematic multisite biopsies were performed preoperatively to rule out prostate cancer. We have examined PSA levels before and after open surgery, TZ weight as measured by the pathologist and TZepiV by multiplying percentage of epithelium of a single biopsy core with the weight of adenoma. Means, Spearman correlation coefficients and percent change were calculated for all variables and intervals.

RESULTS

The mean serum PSA decreased from 4.8 ng/ml preoperatively to 0.5 ng/ml postoperatively. The mean decrease in PSA was 90% (range 70-99%).The mean weight of enucleated adenoma was 67 gr.(range 18-201) and the TZepiV was 7.7 ml (0.3-28.4). Overall, both TZ volume and TZepiV were correlated to PSA value with TZepiV representing the most predictive variable for PSA (r = 0.54 P = 0.002 vs. r = 0.26 P = 0.02). When we analyzed different ranges of PSA values, only TZepiV was always significantly proportional to PSA.

CONCLUSIONS

Ninety percentage of serum PSA level comes from TZ in range of 0.01-0.17 ng/ml/gr. In presence of equal BPH volumes, the amount of epithelium can be different and it is the main determinant in PSA increase. Thus, TZ epithelial volume could represent a new useful clinical tool able to increase the specificity of PSA in the diagnosis of prostate cancer.

Prostate-specific antigen 'bounce' after permanent 125I-implant brachytherapy in Japanese men: a multi-institutional pooled analysis

OBJECTIVE

To examine the incidence, timing, and magnitude of the prostate-specific antigen (PSA) level 'bounce' after permanent prostate brachytherapy (BT) and correlate the PSA bounce with clinical and dosimetric factors in Japanese patients with prostate cancer.

PATIENTS AND METHODS

A multi-institutional pooled analysis was carried out in 388 consecutive patients with T1-T2N0M0 prostate cancer treated with (125)I-seed implant BT with no hormonal therapy or external beam radiotherapy. All patients had >or=1 year of follow-up and at least three follow-up PSA level measurements. Three definitions of PSA bounce were used: definition A, a PSA level rise of 0.1 ng/mL; definition B, a PSA level rise of 0.4 ng/mL; and definition C, a PSA level rise of 35% over the previous value, followed by a subsequent fall.

RESULTS

The actuarial likelihood of having PSA bounce at 24 months was 50.8% for definition A, 23.5% for definition B, and 19.4% for definition C. The median time to develop PSA bounce was 12 months for definition A, 18 months for definition B, and 18 months for definition C. There was a PSA bounce magnitude of 2 ng/mL in 5.3% of patients, and 95.3% of PSA bounce occurred within 24 months after (125)I-BT. Among the before and after (125)I-BT factors, clinical stage, initial PSA level, and Gleason score did not predict for PSA bounce using any definition; only being younger predicted for PSA bounce on multivariate analysis (P < 0.001).

CONCLUSIONS

PSA bounce is a common phenomenon after (125)I-BT and occurred at a rate of 19-51% in the Japanese men who underwent (125)I-BT, depending on the definition used. It is more common in younger patients, and early PSA bounce should be considered when assessing a patient with a rising PSA level after (125)I-BT, before implementing salvage interventions. Furthermore, PSA bounce magnitude might be lower in Japanese than in Caucasian patients.

A paradigm for the treatment of prostate cancer bone metastases based on an understanding of tumor cell-microenvironment interactions

The pliability of cancer cells to mutate into several different phenotypes in an attempt to find one that will survive and colonize at the metastatic site is a tremendous "hurdle" to overcome in designing novel cancer therapeutics. New targets of therapy are essential if we are to effectively overcome the evasiveness of cancer. The interaction between the tumor cell and the surrounding microenvironment creates a vicious cycle that perpetuates disease survival and progression. The future of cancer therapy resides in the ability to focus on the recruited and exploited relationships of the cancer cell with the host environment. These therapies target cancer cell growth early and interrupt the vicious cycle that is created by the tumor cells interacting with bone components by inhibiting osteoclasts, osteoblasts, stromal cells, and endothelial cells. They alter the bone microenvironment, creating a hostile "soil" that prevents the "seed" from developing into bone metastases and represent a potential new platform for the development of prostate cancer therapeutics.

Natural history of human prostate gland: Morphometric and histopathological analysis of Japanese men

BACKGROUND

To clarify the pathology of the development of prostatic disorders such as inflammation, cancer, and hyperplasia, we compared histopathological findings of the prostate according to age group.

METHODS

Whole-mount sections of prostates were used to assess the relationship between age and prostate weight (n=962), prostate histological composition in the transition zone (TZ) and in the peripheral zone (PZ) (n=68), prostate histopathological findings by zone (n=102), and comparison of latent tumor development by age group (n=1,815).

RESULTS

A rapid increase in prostate weight from birth to the 20s was followed by a slow rise thereafter. Volume increases (P<0.01) were observed in all components of glandular epithelium, glandular lumen, and stroma in the TZ from the 40s to 70s inclusive. In the PZ, the epithelial and stromal volumes tended to decrease in an age-dependent manner (P<0.05). Calculi and lymphocyte infiltration were detected at a relatively early age, with a tendency towards an age-dependent increase. Glandular dilation and nodular hyperplasia were noted first in the 30s group, also with a tendency towards age-dependent increase. Latent tumors were first detected in the 30s group (5.6%), and slowly increased thereafter.

CONCLUSIONS

There was an age-dependent trend towards prostate glandular dilation and prostate enlargement with inflammation. It was demonstrated that tumor and hyperplasia have a long natural history, usually starting in the fourth decade of life, accompanied by dynamic changes with age in glandular tissue composition as well as cell proliferation activity.