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Urology

Volume 9, No 1 - Winter 2007

Volume 9, No 1 - Winter 2007

Table of Contents

Recent Progress in the Treatment of Advanced Prostate Cancer With Intermittent Dose-Intense Calcitriol (DN-101) Treatment Update
Docetaxel is becoming standard therapy for androgen-independent prostate cancer (AIPC), and investigational agents are being added to docetaxel to assess potential additive effects and synergy. Although one of these agents, calcitriol, has repeatedly demonstrated antiproliferative properties against cancer of the prostate, breast, colon, and lung, the antineoplastic activity of calcitriol requires superphysiologic levels. Unfortunately, chronic exposure to superphysiologic levels of calcitriol causes hypercalcemia and resulting toxicity. Therefore, a host of analogues of calcitriol have been investigated for antineoplastic function, including intermittent dose-intense calcitriol, or DN-101. Because of encouraging results from phase II studies of DN-101 combined with docetaxel, the ASCENT (AIPC Study of Calcitriol Enhancement of Taxotere) phase II trial investigated docetaxel plus DN-101 versus docetaxel plus placebo in 250 men with metastatic AIPC and an abnormal baseline prostate-specific antigen (PSA) level. Although the ASCENT trial did not achieve its primary endpoint for increased PSA response, there was a significant trend in PSA response rate in the DN-101 arm. DN-101 in combination with docetaxel seems to improve overall survival and, interestingly, has a favorable safety profile compared with docetaxel alone. The DN-101/docetaxel combination is currently being studied in a much larger international trial, ASCENT-2. [Rev Urol. 2007;9(1):1-8]
Diagnosis of Interstitial Cystitis/ Painful Bladder Syndrome in Patients With Overactive Bladder Symptoms Diagnosis Update
Overactive bladder (OAB) and interstitial cystitis (IC) have similar symptoms, including urinary urgency/frequency and nocturia, making them difficult to differentiate on the basis of clinical presentation alone. Both conditions may represent a clinical manifestation of a hypersensitive bladder and should be included in the differential diagnosis for patients who present with urgency/ frequency. It is especially important that IC be considered in patients with OAB that is refractory to treatment. The proposed diagnostic framework may be useful for differentiating IC from OAB and for facilitating appropriate treatment. [Rev Urol. 2007;9(1):9-16]
Uric Acid Nephrolithiasis: Recent Progress and Future Directions Management Update
The prevalence of urolithiasis has been increasing for the past few decades in industrialized nations. Uric acid calculi account for a significant percentage of urinary stones. Certain risk factors may be involved in the pathogenesis of uric acid nephrolithiasis, including hyperuricosuria, low urinary volume, and persistently low urinary pH. Patients with medical conditions that promote profound hyperuricosuria are at high risk of developing uric acid calculi. These conditions include chronic diarrheal states; myeloproliferative disorders; insulin resistance, including diabetes mellitus; and monogenic metabolic disorders, such as Lesch-Nyhan syndrome. Computed tomography can provide a definitive diagnosis. Except in cases in which there is severe obstruction, progressive azotemia, serious infection, or unremitting pain, the initial treatment of patients with uric acid nephrolithiasis should be medical dissolution therapy because this approach is successful in the majority of cases. A thorough review of the epidemiology and pathophysiology of uric acid nephrolithiasis is crucial for the diagnosis, treatment, and prevention of stones in patients with this condition. [Rev Urol. 2007;9(1):17-27]
Is the Testis a Chemo-Privileged Site? Is There a Blood–Testis Barrier? Point-Counterpoint
The incidence of testicular cancer, primarily seminoma, has been increasing in many countries, including the United States. The testis is often the site of residual cancer after adequate treatment with systemic chemotherapy. The blood-testis barrier is commonly cited as the explanation for residual tumor within the gonad after chemotherapy and as the indication for delayed orchiectomy. Conversely, complete eradication of viable tumor from the primary site is common and argues against the testis as a “tumor sanctuary.” Residual tumor is also demonstrated within metastatic foci, and the disparity between the histopathologic response of the primary tumor and metastatic sites may be best explained by tumor heterogeneity and multiple tumor clones. Regardless of the scientific and academic arguments, delayed radical orchiectomy remains an important part of treatment for patients undergoing primary chemotherapy. [Rev Urol. 2007;9(1):28-32]
Updates in Pediatric Urology Meeting Review
Highlights of the American Academy of Pediatrics Section on Urology Annual Meeting October 7-9, 2006, Atlanta, GA [Rev Urol. 2007;9(1):33-35]
Solitary Fibrous Tumor of the Kidney: A Case Report and Review of the Literature Case Review
A solitary fibrous tumor (SFT) is an unusual spindle cell neoplasm that usually occurs in the pleura but has recently been described in diverse extrapleural sites. Urogenital localization is rare, and only 19 cases of SFT of the kidney have been described. We report a case of a large SFT clinically thought to be renal cell carcinoma arising in the kidney of a 70-year-old man. The tumor was well circumscribed and composed of a mixture of spindle cells and dense collagenous bands, with areas of necrosis or cystic changes noted macroscopically and microscopically. Immunohistochemical studies revealed reactivity for CD34, CD99, and Bcl-2 protein, with no staining for keratin, S-100 protein, or muscle markers, confirming the diagnosis of SFT. This tumor is benign in up to 90% of cases. The immunohistochemical study is the key to diagnosis. [Rev Urol. 2007;9(1):36-40]