Preanalytical stability of [-2]proPSA in whole blood stored at room temperature before separation of serum and plasma: implications to Phi determination.

Background [-2]proPSA seems to outperform free/total prostate-specific antigen (PSA) ratio in prostate cancer diagnosis. However, [-2]proPSA stability remains an underestimated issue. We examined [-2]proPSA stability over time in whole blood before separation of serum and plasma and its implications for prostate health index (Phi) determination. Total PSA (tPSA) and free PSA (fPSA) stabilities were also assessed. Methods Blood was drawn from 26 patients and separated in two tubes for plasma (K2EDTA and K2EDTA plus protease inhibitors - P100) and one for serum (clot activator plus gel separator). Tubes were stored at room temperature before centrifugation 1, 3 and 5 h for serum and EDTA plasma or 1 and 5 h for P100 plasma. To investigate the influence of gel separator on markers' stability, blood was collected from 10 patients in three types of tubes to obtain serum: tubes with clot activator plus gel separator, with silica particles or glass tubes. Biomarkers were assayed with chemiluminescent immunoassays. Results [-2]proPSA and Phi levels significantly and progressively increased over time in serum (+4.81% and +8.2% at 3 h; +12.03% and +14.91% at 5 h, respectively, vs. 1 h; p<0.001). Conversely, [-2]proPSA levels did not change in plasma (EDTA or P100). tPSA levels did not change over time in serum or plasma, whereas fPSA decreased in serum. All markers were higher in plasma than in serum at any time point. This difference did not seem to be attributable to the use of gel for serum preparation. Conclusions EDTA prevented spurious in vitro modifications in PSA-related isoforms, confirming that a stabilized blood sample is a prerequisite for [-2]proPSA measurement and Phi determination.

Evaluation of cell-free DNA in urine as a marker for bladder cancer diagnosis.

The diagnosis and follow-up of bladder cancer are mainly based on cystoscopy, an invasive method which could be negative in case of flat malignancies such as carcinoma in situ. Other noninvasive diagnostic methods have not yet given satisfactory results. There is a need for a reliable yet noninvasive method for the detection of bladder cancer. Our aim was to investigate whether cell-free DNA quantified in urine (ucf-DNA) could be a useful marker for the diagnosis of bladder cancer. A standard urine test was performed in 150 naturally voided morning urine samples that were processed to obtain a quantitative evaluation of ucf-DNA. Leukocyturia and/or bacteriuria were found in 18 subjects, who were excluded from the study. Statistical analysis was performed on 45 bladder cancer patients and 87 healthy subjects. Ucf-DNA was extracted from urine samples by a spin column-based method and quantified using four different methods: GeneQuant Pro (Amersham Biosciences, Pittsburg, PA, USA), Quant-iT DNA high-sensitivity assay kit (Invitrogen, Carlsbad, CA, USA), Real-Time PCR (Applied Biosystems, Foster City, CA, USA), and NanoDrop 1000 (NanoDrop Technologies, Houston, TX, USA). Median free DNA quantification did not differ statistically between bladder cancer patients and healthy subjects. A receiver-operating characteristic (ROC) curve was developed to evaluate the diagnostic performance of ucf-DNA quantification for each method. The area under the ROC curve was 0.578 for GeneQuant Pro, 0.573 for the Quant-iT DNA high-sensitivity assay kit, 0.507 for Real-Time PCR, and 0.551 for NanoDrop 1000, which indicated that ucf-DNA quantification by these methods is not able to discriminate between the presence and absence of bladder cancer. No association was found between ucf-DNA quantification and tumor size or tumor focality. In conclusion, ucf-DNA isolated by a spin column-based method and quantified by GeneQuant Pro, Quant-iT DNA high-sensitivity assay kit, Real-Time PCR or NanoDrop 1000 does not seem to be a reliable marker for the diagnosis of bladder cancer.

Lessons from 52 patients with leydig cell tumor of the testis: the GUONE (North-Eastern Uro-Oncological Group, Italy) experience.

INTRODUCTION: The goal of the study was to define treatment rules for the uncommon, rarely (10%) malignant and chemorefractory Leydig cell tumors (LCT) of the testis. METHODS: The main clinical data of patients treated in centers affiliated to the GUONE (North-Eastern Uro-Oncological Group, Italy) were reviewed. We considered 52 patients (54 tumors, 2 bilateral) whose ages ranged from 13 to 70 years (mean 36). Of the treatments performed, 52 were orchiectomies and 2 were enucleations (unfavorable pathology in only 2 tumors). There were 5 lymphadenectomies (retroperitoneal lymph node dissections): 2 for suspected stage II disease and 1 each for unfavorable pathology, bilateral disease and associated Sertoli tumor (pathology: pN0 in all cases). The length of follow-up ranged from 15 to 249 months (mean 81). RESULTS: There was no relapse in 51 patients and 1 died as a result of metastatic disease (orchiectomy at the age of 70; unremarkable pathology). CONCLUSIONS: Malignant LCT seems to be, in our experience, less frequent than previously reported. Age and pathology are useful prognostic factors, but their predictive value should never be considered absolute. Enucleation seems justified in young patients with favorable pathology. In clinical stage I LCT, retroperitoneal lymph node dissection should be offered to older patients and/or to patients with unfavorable pathology. A prolonged follow-up is mandatory.

Bladder explosion during transurethral resection of the prostate.

A case of bladder explosion with wide rupture during transurethral resection of the prostate (TURP) is reported. Immediate cystography was performed and the patient was promptly operated; the postoperative course was uneventful. Intravesical explosion is caused by explosive gas formation and the more dangerous combination is the mixture of air and hydrogen; therefore, the introduction of air during TURP is necessary in order to produce a bladder explosion. This unusual complication of a common urological procedure is rare but serious, and should it arise always requires immediate surgical correction.