Roswitha Siener

Risk Factors for Relapse in Clinical Stage I Nonseminomatous Testicular Germ Cell Tumors: Results of the German Testicular Cancer Study Group Trial

PURPOSE To prospectively assess potential risk factors for relapse in clinical stage I nonseminomatous germ cell tumors of the testis (CS I NSGCT). PATIENTS AND METHODS From September 1996 to May 2002, 200 patients with CS I NSGCT were prospectively assigned to retroperitoneal lymph node dissection (RPLND), and risk factor assessment was performed within a multicenter protocol. One hundred sixty-five patients had an adequate minimum follow-up of 12 months (mean, 34.5 months) or had pathologic stage II. RESULTS Pathologic stage II disease was found in 27.9% of patients. Only 0.6% of patients relapsed in the retroperitoneum after confirmation of pathologic stage I disease. With reference pathology, vascular invasion (VI) was most predictive of stage in multifactorial analysis (accuracy, 65.1%). However, the positive predictive value (PPV) of VI to predict patients who have metastatic disease or relapse during follow-up was only 52.7%. With absent VI, low-risk patients had a negative predictive value (NPV) of 76.9%. With a combination of several risk factors, the PPV increased to 63.6% and the negative predictive value increased to 86.5%. CONCLUSION Even with an optimal combination of prognostic factors and reference pathology, more than one third of patients predicted to have pathologic stage II or relapse during follow-up will not harbor metastatic disease and, therefore, would be overtreated with adjuvant therapy. However, patients at low risk may be predicted at an 86.5% level, and thus, surveillance in highly compliant patients would be a valuable option. For high-risk patients, further reduction of adjuvant treatment is necessary.

Current aspects of epidemiology and nutrition in urinary stone disease

Current examples for the development of urinary stone disease are discussed by means of data from the literature and our own studies. Urinary stone disease has gained increasing significance due to changes in living conditions, i.e., industrialization and malnutrition. Changes in prevalence and incidence, the occurrence of stone types and stone location, and the manner of stone removal are explained. The importance of nutrition in the prevention of calcium oxalate stone disease is discussed in terms of fluid intake, calcium and oxalate metabolism, and dietary fat intake. The results of a study on a standardized mixed diet or an ovo-lactovegetarian diet show that well-balanced nutrition with consecutive high intake of fluids leads to a significant decrease in the risk for urinary stone formation (calculated as relative supersaturation with calcium oxalate by the computer program EQUIL).

Randomized phase III trial of 2nd line gemcitabine and paclitaxel chemotherapy in patients with advanced bladder cancer: short-term versus prolonged treatment [German Association of Urological Oncology (AUO) trial AB 20/99]

BACKGROUND The second-line chemotherapeutic treatment for metastatic urothelial cancer (UC) after failure of cisplatin-based first-line therapy needs to be improved. Based on encouraging phase II data of gemcitabine and paclitaxel (Taxol) (GP), this trial was designed to compare a short-term (arm A) versus a prolonged (arm B) second-line combination chemotherapy of GP. PATIENTS AND METHODS Of 102 randomized patients, 96 were eligible for analysis. Primary end point was overall survival (OS). Secondary end points were progression-free survival (PFS), objective response rates (ORR) and toxicity. RESULTS Neither OS [arm A: 7.8 (95% CI: 4.2-11.4), arm B: 8.0 (95% CI: 4.9-11.1) months] and PFS [arm A: 4.0 (95% CI: 0-8.0), arm B: 3.1 (95% CI: 1.9-4.2) months] nor ORR (arm A: 37.5%, arm B: 41.5%) were significantly different. On prolonged treatment, more patients experienced severe anemia (arm A: 6.7% versus arm B: 26.7% grade III/IV anemia; P = 0.011). In six patients, treatment was stopped during the first cycle due to disease progression or toxicity. Two patients died due to treatment-related toxic effects. CONCLUSION Due to rapid tumor progression and toxicity at this dosage and schedule in a multicenter setting, it was not feasible to deliver a prolonged regimen. However, a high response rate of ∼40% makes GP a promising second-line treatment option for patients with metastatic UC.

The Effect of Different Diets on Urine Composition and the Risk of Calcium Oxalate Crystallisation in Healthy Subjects

OBJECTIVE The aim of the study was to determine the impact of defined diet modifications on urine composition and the risk of calcium oxalate crystallisation. METHODS Ten healthy male volunteers consumed a self-selected diet (SD) for 14 days, and three different standard diets for a period of 5 days each. Whereas the western-type diet (WD) is representative of the usual dietary habits, the normal mixed diet (ND) and the ovo-lacto-vegetarian diet (VD) were calculated according to the requirements. RESULTS The risk of calcium oxalate crystallisation, calculated as relative supersaturation (EQUIL2) from urine composition, was highest during ingestion of diets SD and WD. The intake of diet ND resulted in a significant decrease in relative supersaturation with calcium oxalate by 58% (p<0.05) compared with diet WD, due to a significant decline in urinary calcium and uric acid excretion and a significant increase in urinary volume, pH-value and citrate excretion. In spite of an increase in urinary pH, citrate and magnesium excretion and a decline in calcium excretion, no further significant decrease in the risk of calcium oxalate crystallisation was observed on diet VD, due to a significant increase in urinary oxalate by 30% (p<0.05) on average. CONCLUSIONS The change of usual dietary habits for a normal mixed diet significantly reduces the risk of calcium oxalate crystallisation. With a vegetarian diet a similar decline in urinary supersaturation with calcium oxalate can be achieved compared to a normal mixed diet. Since urinary oxalate excretion increased significantly, a vegetarian diet without adequate intake of calcium may not be recommended to patients with mild hyperoxaluria.

The role of Oxalobacter formigenes colonization in calcium oxalate stone disease

About 75% of urinary stones contain oxalate. As Oxalobacter formigenes is a Gram-negative anaerobic bacterium that degrades oxalate in the intestinal tract, we assessed the role of O. formigenes in oxalate metabolism by evaluating its intestinal absorption, plasma concentration, and urinary excretion. Of 37 calcium oxalate stone formers, 26 tested negative for O. formigenes and were compared with the 11 patients who tested positive. Patients provided 24-h urine samples on both a self-selected and a standardized diet. Urinary oxalate excretion did not differ significantly on the self-selected diet, but was significantly lower in O. formigenes-positive than in O. formigenes-negative patients under controlled, standardized conditions. Intestinal oxalate absorption, measured using [(13)C₂]oxalate, was similar in the patients with or without O. formigenes. Plasma oxalate concentrations were significantly higher in noncolonized (5.79 μmol/l) than in colonized stone formers (1.70 μmol/l). Colonization with O. formigenes was significantly inversely associated with the number of stone episodes. Our findings suggest that O. formigenes lowers the intestinal concentration of oxalate available for absorption at constant rates, resulting in decreased urinary oxalate excretion. Thus, dietary factors have an important role in urinary oxalate excretion. The data indicate that O. formigenes colonization may reduce the risk of stone recurrence.

Impact of dietary habits on stone incidence

Changes in dietary habits and lifestyle are suggested to contribute markedly to the rise in the prevalence and incidence of urolithiasis during the past decades. Insufficient fluid intake and diets rich in animal protein are considered to be important determinants of stone formation. Overweight and associated dietary pattern additionally contribute to the increasing incidence and prevalence of stone disease. Reduction of overweight through extreme fasting or high-protein weight-loss diets, e.g. Atkins diet, also appear to affect stone formation. Although there is evidence that changes in dietary habits can reduce urinary risk factors and the risk of stone formation, further randomized controlled clinical trials are necessary to evaluate long-term effects of dietary interventions on stone disease.

Prospective Study on the Efficacy of a Selective Treatment and Risk Factors for Relapse in Recurrent Calcium Oxalate Stone Patients

OBJECTIVE The present study was performed to examine the efficacy of a selective treatment according to the guidelines for the prevention of recurrence in calcium oxalate stone patients and to assess risk factors for stone recurrence. METHODS To investigate the effect of specific diagnostic and therapeutic measures, 134 recurrent calcium oxalate stone formers participated in a prospective study for two years with regular follow-ups of at least every six months. Depending on the results of analysis of 24-hour urine, nutrition record and metabolic situation, selective recommendations were given concerning diet and medication. RESULTS Throughout the follow-up period, 57 (43%) of the patients experienced relapses. In recurrence-free patients, the significant increase in urinary volume, as well as urinary pH, potassium and citrate excretion, three indexes of compliance with alkalization, resulted in a significant decrease in the calculated risk of calcium oxalate stone formation. In patients with recurrences during follow-up, the relative supersaturation with calcium oxalate increased significantly, mainly due to the significant rise in urinary oxalate excretion exceeding the significant increases in urinary volume, pH, potassium and citrate excretion. Multiple logistic regression analysis revealed previous ESWL treatment and a history of multiple stones as independent predictors of the risk for recurrence. CONCLUSIONS The results indicate that compliance with drinking advice and alkalization therapy was highest among both, patients with and without recurrences, compared with all other therapeutic measures. The increase in oxalate excretion is identified as the major urinary risk factor for relapse during follow-up in recurrent calcium oxalate stone disease.

Prospective Randomized Evaluation of Risk-adapted Prostate-specific Antigen Screening in Young Men: The PROBASE Trial

Department of Urology, University Hospital, Heinrich-Heine-University, Dusseldorf, Germany; Division of Cancer Epidemiology, German Cancer Research Center Heidelberg, Heidelberg, Germany; Department of Urology, University Hospital, Ruprecht-Karls-University, Heidelberg, Germany; Department of Urology, University Hospital, Technical University of Munich, Munich, Germany; Department of Urology, University Hospital, Hannover Medical School, Hannover, Germany; University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany; Department of Pathology, University Hospital, Rheinische Friedrich-Wilhelms-University, Bonn, Germany; Department of Urology, University Hospital, Rheinische Friedrich-Wilhelms-University, Bonn, Germany; Department of Urology, University Hospital, Westfalische Wilhelms-University, Munster, Germany; Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom; Department of Laboratory Medicine, Surgery and Medicine, Memorial Sloan-Kettering Cancer Center, New York, USA; Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, USA; Department of Urology, Erasmus Medical Center Rotterdam, The Netherlands

Effect of n-3 Fatty Acid Supplementation on Urinary Risk Factors for Calcium Oxalate Stone Formation

PURPOSE Findings are inconsistent in a few studies of the effect of n-3 fatty acid supplementation on urinary calcium and oxalate excretion in stone formers. We evaluated the physiological effects of supplementation with eicosapentaenoic acid and docosahexaenoic acid on urinary risk factors for calcium oxalate stone formation under standardized conditions. MATERIALS AND METHODS We studied 15 healthy subjects initially while consuming a standardized diet for 5 days (control phase). During consecutive intervention phases 1-5-day standardized diet, 2-20-day free diet and 3-5-day standardized diet participants received 900 mg eicosapentaenoic acid and 600 mg docosahexaenoic acid daily. While ingesting the standardized diets, daily 24-hour urine samples were collected. RESULTS After short-term supplementation with eicosapentaenoic acid and docosahexaenoic acid in phase 1 we noted no changes in urinary parameters compared to the control phase. After 30-day supplementation with eicosapentaenoic acid and docosahexaenoic acid in phase 3 relative supersaturation with calcium oxalate decreased significantly by 23% from a mean ± SD of 2.01 ± 1.26 to 1.55 ± 0.84 due to significantly decreased urinary oxalate excretion (p = 0.023). Other urinary variables were not affected by supplementation. CONCLUSIONS Results show that 30-day n-3 fatty acid supplementation effectively decreases urinary oxalate excretion and the risk of calcium oxalate crystallization. The mechanism of the physiological effect may be decreased cellular oxalic acid exchange attributable to an altered fatty acid pattern of membrane phospholipids with concomitant changes in oxalate transporter activity. Calcium oxalate stone formers may benefit from long-term n-3 fatty acid supplementation.

Prognostic Factors in Second-Line Treatment of Urothelial Cancers With Gemcitabine and Paclitaxel (German Association of Urological Oncology Trial AB20/99)

BACKGROUND In the treatment of urothelial cancer, identification of patients who are likely to benefit from further therapy after cisplatin failure is crucial for reasonable treatment decisions. OBJECTIVE Validate the prognostic factor model (PFM) for survival developed by Bellmunt et al. in a different patient cohort with a different chemotherapy regimen. DESIGN, SETTING, AND PARTICIPANTS Baseline parameters of 102 patients treated within a randomized phase 3 trial of second-line gemcitabine and paclitaxel (GP) comparing short-term to prolonged chemotherapy (German Association of Urological Oncology trial AB20/99) were analyzed. Patients were stratified according to the PFM based on a score including performance status, presence of hepatic metastases, and hemoglobin levels. MEASUREMENTS The baseline parameters of the GP cohort were compared with those of patients treated in the phase 3 trial of vinflunine versus best supportive care. Univariate and multivariate analyses of baseline parameters with respect to overall survival (OS) and treatment response were performed. OS of patients stratified according to the PFM was compared by log-rank test. RESULTS AND LIMITATIONS The vinflunine and the GP cohorts differed, as patients after perioperative (neoadjuvant or adjuvant) treatment were included in the latter cohort. According to the PFM, prognostic subgroups with significant difference in OS (11.8 mo [95% confidence interval (CI), 6.3-17.3], 8.1 mo [95% CI, 4.8-11.4], 3.2 mo [95% CI, 0.0-7.9]; p=0.007) were identified. The PFM identified risk groups in patients with failed treatment of metastatic disease (14.1 mo [95% CI, 8.9-19.3], 7.3 mo [95% CI, 0.0-17.8], 3.8 mo [95% CI, 0.0-9.0]; p=0.006) but not in patients treated (neo)adjuvantly. Lymph node-only disease was a strong predictor of treatment response that overruled every other single predictive parameter (0.284, p=0.0266). CONCLUSIONS The PFM was successfully validated in the GP and should be used to tailor second-line treatment strategy. Patients with lymph node-only disease may benefit from second-line treatment even if anemia or impaired performance status is present. TRIAL REGISTRATION German Cancer Society 01-09 (www.krebsgesellschaft.de).