Micro RNA expression and prognosis in low-grade non-invasive urothelial carcinoma

Purpose To analyze a possible correlation between a miRNA expression profile and important prognostic factors for pTa urothelial carcinomas (UC), including tumor size, multiplicity and episodes of recurrence. Materials and Methods Thirty low-grade non-invasive pTa bladder UC from patients submitted to transurethral resection were studied, in a mean follow-up of 17.7 months. As controls, we used normal bladder tissue from five patients submitted to retropubic prostatectomy to treat benign prostatic hyperplasia. Extraction, cDNA and amplification were performed for 14 miRNAs (miR-100, -10a, -21, -205, -let7c, -143, -145, -221, -223, -15a, -16, -199a and -452) using specific kits, and RNU-43 and -48 were used as endogenous controls. Statistical tests were used to compare tumor size, multiplicity and episodes of recurrence with miRNAs expression profiles. Results There was a marginal correlation between multiplicity and miR-let7c over-expression. For all others miRNA no correlation between their expression and prognostic factors was found. Conclusion We did not find differences for miRNAs expression profiles associated with prognostic factors in tumor group studied. The majority of miRNAs are down-regulated, except miR-10a, over-expressed in most of cases, seeming to have increased levels in tumor with more unfavorable prognostic factors. More studies are needed in order to find a miRNA profile able to provide prognosis in pTa UC to be used in clinical practice. .

Undergrading and understaging in patients with clinically insignificant prostate cancer who underwent radical prostatectomy

PURPOSE: The aim of our study is to evaluate the undergrading and understaging rates in patients with clinically localized insignificant prostate cancer who underwent radical prostatectomy. MATERIALS AND METHODS: Between July 2005 and July 2008, 406 patients underwent radical prostatectomy for clinical localized prostate cancer in our hospital. Based on preoperative data, 93 of these patients fulfilled our criteria of non-significance: Gleason score < 7, stage T1c, PSA < 10 ng/mL and percentage of affected fragments less than 25 percent. The pathologic stage and Gleason score were compared to preoperative data to evaluate the rate of understaging and undergrading. The biochemical recurrence free survival of these operated insignificant cancers were also evaluated. RESULTS: On surgical specimen analysis 74.7 percent of patients had Gleason score of 6 or less and 25.3 percent had Gleason 7 or greater. Furthermore 8.3 percent of cases showed extracapsular extension. After 36 months of follow-up 3.4 percent had biochemical recurrence, defined by a PSA above 0.4 ng/mL. CONCLUSIONS: Despite the limited number of cases, we have found considerable rates of undergrading and understaging in patients with prostate cancer whose current definitions classified them as candidates for active surveillance. According to our results the current definition seems inadequate as up to a third of patients had higher grade or cancer outside the prostate.

Tumor banks: the cornerstone of basic research in urology

PURPOSE: Tumor banks have the primary responsibility for collecting, cataloging, storing and disseminating samples of tissues, cells and fluids, which are used by researchers to identify diagnostic molecular markers, prognostic indicators and therapeutic targets. The objective of this review was to describe a simple, reliable and reproducible protocol for obtaining and storing samples of urological tumors. MATERIALS AND METHODS: Urogenital tumor tissues were collected by the surgeons from the Urology Division of University of Sao Paulo Medical School. The obtained surgical specimens were immediately placed in liquid nitrogen, dry ice or in a tube containing RNAlater ®, and then stored by cryopreservation (-80°C). A mirror fragment was fixed in 10 percent formalin processed routinely and embedded in Paraplast®. RESULTS: We developed a protocol for the collection, cataloging, storage, conservation and use of tumor samples. During a period of one year the Urological Tumor Bank of the Urology Division stored 274 samples of prostate, bladder, kidney, penis and testicle tumors of different histological types, 74 urine and 271 serum samples. CONCLUSIONS: Having biological materials characterized and available along with the clinical patient information provides an integrated portrait of the patients and their diseases facilitating advances in molecular biology. It also promotes the development of translational research improving methods of diagnosis and cancer treatment.