[Etiopathology, risk factors, environmental influences and epidemiology of bladder cancer]

The etiology of bladder cancer is well investigated. Bladder carcinogenicity of nitrosamines is proven in animals but not in men, although dimethylnitrosamine in urine of patients with urinary infections or bilharziosis suggest a causative role. Aromatic amines are strong bladder carcinogens. Arsen is proven to be bladder carcinogenic as well as the nitrofurane FANFT. Nitrofurantoin however is not bladder carcinogenic nor are the endogenous metabolites of tryptophan. The influence of papilloma virus on bladder carcinoma induction ist not definitely proven yet. Bilharziosis or chronic urinary infections correlate with bladder carcinomas, nitrosamines being the possible reason. The reason for the increased incidence of bladder carcinomas in balkan nephropathy ist not clear. Arcolein as a metabolite of Cyclophosphamid is a strong bladder carcinogen as well as Phenacetin. Immune suppression and radiotherapy are risk factors, too. About 50% of bladder carcinomas are due to cigaret smoking.

Changes of urodynamic findings after radical retropubic prostatectomy

OBJECTIVES

We wanted to evaluate the urodynamic changes of radical retropubic prostatectomy in patients with localized prostate cancer and identify specific factors that could influence the postoperative continence status.

METHODS

Sixty-six consecutive patients (mean age 68 years) were studied urodynamically within 1 week before surgery, and 44 of them at a mean 7.6 months after radical intervention.

RESULTS

Complete urinary continence was achieved in 37/44 men (84. 1%) after 6 months and in 43/44 patients (97.7%) 1 year after surgery. Stress incontinence of varying degree improved with time. Seven patients demonstrated a moderate incontinence 4 months after radical prostatectomy and 1/7 was still incontinent after 1 year. Mean flow rate, maximum detrusor pressure, maximum urethral closure pressure (at rest and voluntary contraction of the sphincter) and functional urethral length showed significant changes after surgery. Detrusor instability, which was present in 31.8% of the 66 patients preoperatively, was not responsible for any case of postoperative incontinence. The urethral pressure profile was significantly reduced in all patients after surgery.

CONCLUSIONS

The present study indicates that there are no preoperative alterations in bladder function such as detrusor instability to identify patients at risk for postoperative incontinence. Postoperative incontinence seems to depend upon sphincteric deficiency as expressed by the reduced pressures in the sphincteric mechanism.

Management of contralateral adrenal metastasis from renal cell carcinoma: possibility of inferior vena cava tumour thrombus

OBJECTIVE

The contralateral adrenal gland is a rare metastatic site in renal cell carcinoma (RCC). We describe our experiences with this metastasis in a cohort of 610 radical nephrectomy patients analysed. To our knowledge this study is the first to demonstrate an inferior vena cava tumour thrombus from metachronous contralateral adrenal metastasis.

PATIENTS AND METHODS

After radical nephrectomy for RCC, 610 patients treated at our institution from 1985-99 were retrospectively investigated for the incidence of contralateral adrenal metastasis, additional clinical findings, treatment modalities and survival after treatment for contralateral adrenal gland metastasis.

RESULTS

The incidence of contralateral adrenal metastasis was 1.1% (7/610 patients), while the incidence of ipsilateral metastasis was 3.4% (21/610). In 3 of 7 cases the contralateral adrenal metastasis occurred simultaneously with primary RCC in the kidney. The contralateral adrenal gland was affected by distant tumour spread metachronously in 4 of 7 cases (3/4 bilateral adrenal involvement, 1/4 unilateral disease). In 1 case a metachronous contralateral adrenal metastasis caused vena cava tumour thrombus by propagation via the suprarenal venous route. After a mean follow-up of 20 months (range 1-54 months), 4 of 6 patients showed no evidence of disease after contralateral adrenalectomy.

CONCLUSIONS

The probability of contralateral adrenal metastasis from RCC is 1.1%. Adrenalectomy in these cases offers a good chance of cure. In 71% of cases contralateral adrenal metastasis occurs in conjunction with ipsilateral disease, which provides a strong argument for routine ipsilateral adrenalectomy during radical nephrectomy. Care must be taken in preoperative diagnostics, as metachronous adrenal metastasis is capable of causing vena cava tumour thrombus.

Allelic changes at multiple regions of chromosome 5 are associated with progression of urinary bladder cancer

This study has analysed 65 urothelial carcinomas for allelic imbalance at 22 loci of chromosome 5 and has determined three regions of interest. A commonly duplicated region was mapped to chromosome 5p between loci D5S1473 and D5S819, one region of deletion to chromosome 5q22-23 between loci D5S2055 and D5S659, and another to chromosome 5q33-34 between loci D5S1456 and D5S1465. An allelic imbalance was detected in 54% of the cases. Only 10% of grade 1 tumours showed allelic changes at chromosome 5, whereas 60% and 63% of grade 2 and grade 3 cancers, respectively, had alterations of chromosome 5. The frequency of chromosome 5 changes increased from 24% in pTa tumours up to 72% in pT3-4 tumours. Of particular interest, ten out of 12 urothelial carcinomas showing metastatic growth in regional lymph nodes at the time of cystectomy had alterations at chromosome 5. No specific region, but genetic changes in general were associated with the grading and staging of bladder cancers.

Radical nephrectomy for renal cell carcinoma: Is adrenalectomy necessary?

OBJECTIVES

The role of simultaneous adrenalectomy in combination with radical nephrectomy in the treatment for renal cell carcinoma (RCC) remains controversial. With nephron-sparing surgery being commonly applied, the indication for adrenalectomy has to be critically assessed.

PATIENTS AND METHODS

In a retrospective analysis the outcome of 589 patients, who underwent ipsilateral adrenalectomy along with radical nephrectomy in the treatment for RCC between 1985 and 1997 at our institution, was evaluated. The mean follow-up time was 34 months (range 1-95).

RESULTS

Histologically an ipsilateral adrenal metastasis was found in 19/589 patients (3.2%). 16/19 patients had >/= T3, 3/19 had T1 tumours. The average size of the primary tumours with adrenal metastasis was 7.8 cm (range 2.3-13) in diameter with no preferential primary tumour site within the kidney (6/19 upper, 4/19 middle and 9/19 lower third). Only 4/19 patients had suspect adrenal findings in preoperative diagnostics (ultrasound, CT scan). 6/19 (31.5%) patients with adrenal metastasis are alive without evidence of disease at a mean of 41 months (range 11-95) after surgery for RCC.

CONCLUSIONS

The probability of adrenal metastasis correlates with primary tumour stage, but not with its location within the kidney. The preoperative diagnostics are not reliable concerning small adrenal metastases. We thus still recommend simultaneous adrenalectomy in those cases where radical nephrectomy in patients with RCC is indicated.

Intravesical therapy with pertussis toxin before radical cystectomy in patients with bladder cancer: a Phase I study

OBJECTIVES

To ascertain the side effects of intravesical instillation of pertussis toxin (PTX) because it inhibits tumor cell motility in vitro and in vivo and seems to be a promising therapeutic approach against cancer.

METHODS

We initiated a Phase I study and measured the effect of intravesical instillation of PTX before radical cystectomy. Study end points were PTX-related side effects. PTX was instilled at five dose levels, starting with 14 microg and continuing to 72 microg.

RESULTS

Fifteen patients, with a median age of 64 years, were included in the study. Intravesical instillation of PTX was without local or systemic side effects (grade 0, according to National Cancer Institute toxicity criteria).

CONCLUSIONS

Treatment with PTX was safe and well tolerated without any significant local or systemic toxicity in dosages up to 72 microg. Therefore, the influence of PTX on local tumor should be evaluated in a Phase II study.

Surgical treatment of invasive penile cancer--the Heidelberg experience from 1968 to 1994

OBJECTIVES

This study was performed to establish oncological guidelines for the surgical treatment of invasive penile cancer.

MATERIALS AND METHODS

The medical records of 51 patients with invasive penile cancer seen between 1968 and 1994 were reviewed in respect to treatment and long-term outcome.

RESULTS

For stage T1 tumors treated with organ-preserving procedures the local recurrence rats was 56%, whereas no patient experienced a local recurrence after partial amputation. For stage T2 tumors, local recurrence rate was 100% (organ preservation) versus 20% (amputative procedures). There was no significant difference related to regional recurrence between surveillance, inguinal radiation and lymphadenectomy for stage N0 tumors. For N+ stages, survival was related to the extent of inguinal metastasis after dissection (5-year survival rate for N1: 71 vs. 33% for N2/3).

CONCLUSIONS

Organ-preserving procedures include a high risk of local and regional recurrence. Adjuvant regional lymphadenectomy seems beneficial only in patients with solitary metastasis.

[Spontaneous kidney ruptures--a complication of panarteritis nodosa]

Besides renal cell carcinomas and angiomyolipomas panarteritis nodosa (PAN) is a common underlying disorder for spontaneous perirenal hematomas (SPH). Herein we report on 3 cases with PAN associated kidney ruptures where diagnosis of PAN was not known before in 2 instances. The hematoma was identified by computerized tomography (CT) in all patients, nevertheless CT failed to reveal the underlying disorder in any case. In this situation angiography was extremely valuable visualizing multiple renal microaneurysms that are typical for PAN. Operative exploration and drainage of the hematoma was necessary in two patients because of hemodynamic instability. In one patient bleeding could be controlled after an immediate immunosuppressive therapy with prednisone and cyclophosphamide. Due to the high incidence of PAN associated spontaneous perirenal hematomas angiography should be performed in all cases with unclear SPH after CT evaluation. In our opinion an immediate surgical intervention is only indicated in cases with hemodynamic instability. Otherwise a conservative approach including immediate immunosuppression seems justified. Nephrectomy should be avoided whenever possible.

Tumor induction and prophylaxis following different forms of intestinal urinary diversion in a rat model

Eighty Wistar rats were randomized into two groups. In group 1 vesicosigmoidostomy with proximal colostomy was performed, in group 2, vesicosigmoidostomy. The total tumor incidence did not significantly (group 1 10/40, 25%; group 2 13/40, 32.5%). The tumor spectrum differed, with more adenocarcinomas in group 2 (11/40, 27.5% vs 4/40, 10%; P = 0.047) and urothelial carcinomas only in group 1 (5/40, 2.5%). One hundred and ten other Wistar rats were randomized into three groups. Animals in group A received vesicoileosigmoidostomy, group B, two-step vesicosigmoidostomy with initial separation of urine and the urocolonic anastomosis, group C, vesicosigmoidostomy. Significantly fewer adenocarcinomas were observed in group A (2/40, 5%) than in group B (16/40, 40%; P < 0.002) and group C (9/30, 30%; P < 0.007). These results indicate a similar cancer risk in all continent forms of urinary diversion, at least via colon. Ileal interposition seems to be an effective carcinoma prophylaxis following ureterosigmoidostomy. The proliferative instability at the urointestinal anastomosis is crucial for the pathogenesis and prophylaxis of this form of carcinogenesis, whereas urine seems to play only a minor role.

Transurethral incision of the prostate following renal transplantation

Urinary retention in male patients after renal transplantation may cause serious complications in terms of graft function and even patient survival. Only few data concerning the management and outcome of these patients are reported in the literature. Therefore, we retrospectively analyzed the outcome of patients who underwent transurethral incision of the prostate immediately after renal transplantation. Between 1990 and 1993, we performed 259 renal transplantations and 15 patients had symptoms of urinary retention postoperatively. These patients underwent a midline transurethral incision of the prostate from the bladder neck to the verumontanum. Median peak flow preoperatively was 7 ml. per second (range 0 to 11.4) and median residual urine volume was 100 ml. (range 30 to 500). Median prostate volume was 28 ml. (range 12 to 45). After transurethral incision of the prostate a significant improvement (p < 0.001) in peak flow rates (19.6 ml. per second, range 8 to 49) as well as a significant decrease in residual urine volumes (40 ml., range 20 to 80) could be achieved. After a median followup of 19 months the effect was still present.

Laser-induced fluorescence diagnosis and photodynamic therapy of human renal cell carcinoma

Photodynamic therapy (PDT) has recently attracted much attention, especially among urologists, because it appears to be a selective form of cancer treatment which causes minimal damage to normal surrounding tissues. In this study we made use of a new class of photosensitizers for the laser-induced fluorescence diagnosis (LIFD) and photodynamic therapy of human renal cell carcinoma xenotransplanted into nude mice. The purpose of this study was to evaluate the recently developed photosensitizing drug THOPP-MPEG for its efficacy as photosensitizer for LIFD and PDT of renal cell carcinoma. THOPP-MPEG was injected intraperitoneally (0.5 micrograms/g body weight) into the mice 6-8 days after tumor transplantation. On the 18th day after transplantation, the tumors reached a diameter of 3-4 mm. Seven days after administration of the drug the tumor-bearing kidney was irradiated percutaneously with a total light dose of 2 x 60 J/cm2 and a power density in the irradiated area of less than 150 mW/cm2. A continuous-beam argon-pumped dye laser (656 nm) was used. After excitation with laser light (488-514 nm), the vital tumor clusters and the surrounding tissues invaded with tumor cells showed intense red coloration by laser-induced fluorescence. Subsequent to the light exposure (656 nm), a heavy tumor necrosis of up to 3-5 mm resulted. No THOPP-MPEG phototoxicity in normal surrounding tissue at a dose of up to 100 mg/kg body weight was seen. We believe the future role of PDT in the management of tumors of the kidney to be adjuvant within the concept of conservative kidney-preserving surgery.

[Cytokine therapy of superficial bladder carcinoma. Mechanisms of action and results of therapy]

The object of immunotherapy is the elimination of tumor cells mediated by modulation of the immune system. This can be achieved by different mechanisms, i.e. cell-mediated and humorally mediated immune reactions. Immunotherapy can be classified as passive, adoptive, active and non-conventional. Most clinical experience has been gathered with unspecific active immunotherapy. Superficial bladder carcinomas can be treated by intravesical application of Bacillus Calmette-Guérin (BCG) or of different cytokines, i.e., interferons or interleukin-2. Since there has not so far been any standard immunotherapy for superficial bladder carcinoma, the efficacy of therapy with cytokines should be evaluated in clinical studies (phase II/III) only.

[Unconventional therapeutic methods in superficial bladder cancer]

Several unconventional agents or methods are used for recurrence prophylaxis of superficial bladder cancer. In animal experiments KLH (keyhole limpet hemocyanin) has shown an effect comparable to that of BCG on bladder carcinoma, resulting in an increase of natural killer cell activity. The few clinical data dealing with KLH are contradictory. A prospective randomized study with a large number of patients uniform high dosage and early start of instillation has not yet been performed for definitive evaluation of the clinical role of KLH. Whether mistletoe extracts or intravesical antineoplastic iontophoresis can prevent recurrence is not yet known. Vitamin A and megadose multivitamins in combination with intravesical BCG significantly decrease the recurrence rate. The most effective vitamin or the most important combination has not yet been identified, and the precise mechanism of action is also unknown.

[The value of diagnostic imaging in benign prostatic hyperplasia and prostatic cancer]

Diseases of the prostate are of high socioeconomic importance owing to their high incidence and prevalence rates. Benign prostatic hyperplasia (BPH) can be detected in 80% of males over the age of 80. Clinical symptoms do not correlate with organ enlargement. Only 10% of patients with BPH need surgical treatment. The decision for surgical treatment is made as a result of objective findings and the symptoms reported by the patient. Preoperative evaluation of BPH must include digital rectal examination (DRE), measurement of peak flow rate, sonographic estimation of residual urine, transrectal ultrasound (TRUS), urethrocystography and the assessment of subjective complaints using symptom scores. Prostatic carcinoma is the most common malignancy in men. An abnormal DRE, increased PSA level and/or hypoechogenic lesions in TRUS are indications for prostate biopsy. The sensitivity of TRUS is superior to that of CT and MRI. New MRI techniques are promising with regard to local tumour extent. Whereas CT and MRI are not useful in screening of patients, these methods are valuable diagnostic tools in the follow-up of prostate cancer.

[BCG vs interferon A for prevention of recurrence of superficial bladder cancer. A prospective randomized study]

A total of 78 patients with superficial bladder carcinoma were prospectively randomized to two groups following complete transurethral resection (TUR). Each received 12 intravesical instillations of 10(7) units interferon A or 120 mg BCG Connaught for 1 year starting 6 weeks post-TUR. After a mean observation period of 24 (13-31) months in the BCG and 25 (6-32) months in the IFN group 5/32 (15.6%) recurrences in the BCG versus 21/35 (60%) in the IFN group were observed (P = 0.0003). In the IFN group 18.4% of the patients had dysuria and 2.6% fever; in the BCG group 35% had fever, 60% cystitis, 1 patient granulomatous epididimoorchitis and 1 patient pneumonitis with granulomatous prostatitis. With our instillation regimen interferon A had few side effects but also no prophylactic effect, whereas BCG had tolerable-seldom severe--side effects and was very effective in preventing recurrences. Perhaps IFN should be given earlier after TUR and in a higher dosage.

[Screening study for early detection of intestinal tumors after urinary diversion]

The increased risk of colon carcinoma following urinary diversions via colon makes knowledge about preneoplastic changes necessary. In 30 ureterosigmoidostomy patients with a mean observation period of 16 years flexible sigmoidoscopy with biopsies and nitrosamine analysis of the feces/urine mixture have been performed. In the biopsies we found an increased sialomucin concentration at the ureterocolonic anastomosis in 29.2%--sialomucin is supposed to be a preneoplastic change--with no significant difference to the mucosa periureteral and in the rectum. In 58.3% we found chronic inflammation at the anastomosis, in 29.2% periureteral and 4.2% in the rectum. 2/30 patients developed adenocarcinoma, 1 patient an atypia and 1 patient a juvenile polyp. The nitrosamine excretion of the ureterosigmoidostomy patients were significantly increased compared to 20 healthy controls with no correlation to the histology at the anastomosis or the observation time. Because of the multilocular presence--colon carcinomas develop only at the anastomosis--sialomucin and chronic inflammation seem to be no preneoplastic changes in urinary diversions. The nitrosamine analysis is not suitable for routine follow-up as well.

Nitrosamine excretion in patients with continent ileal reservoirs for urinary diversion

Adenocarcinomas are a recognized complication following ureterosigmoidostomy for which the endogenous formation of N-nitroso compounds may be a risk factor. As an alternative means of urinary diversion, the continent ileal reservoir has recently been developed. Microbiological and chemical investigations on the urine of patients with an ileal reservoir showed the presence of bacteria, nitrate, nitrite and N-nitrosamines formed endogenously in the ileal pouch. The role of nitrosamines in carcinogenesis in these patients as a late stage complication resulting from the use of a continent ileal reservoir is discussed.

Secondary amine precursors to nitrosamines in human saliva, gastric juice, blood, urine and faeces

It has been suggested that the endogenous nitrosation of aliphatic, cyclic and heterocyclic secondary amines in the urinary bladder of patients with chronic urinary bacterial infections and in the human stomach may provide an important additional source of exposure to carcinogenic volatile N-nitrosamines. The most commonly occurring nitrosatable secondary amines found in human saliva, gastric juice, blood, urine and faeces are dimethylamine (DMA), pyrrolidine (PYR) and piperidine (PIP). All of 40 analysed samples of gastric juice contained 0.87 +/- 0.89 (SEM) microgram/ml DMA, 39 contained 1.35 +/- 2.53 microgram/ml PIP, 36 contained 0.18 +/- 0.15 microgram/ml PYR and 14 contained 0.05 +/- 0.11 microgram/ml diethylamine. Nitrate (14.0 +/- 15.7 microgram/ml) was present in all samples and 11 of 40 samples contained 0.43 +/- 1.38 microgram/ml nitrite. Only one gastric juice sample with pH less than 4.5 contained nitrite (0.1 microgram/ml). In paraplegics, patients with bladder augmentations and two control groups without bacterial infections of the urinary bladder, a mean daily excretion of 40.5-49.7 mg/day DMA, 19.4-23.8 mg/day PYR and 26.1-31.7 mg/day PIP was found. In both patient groups suffering from chronic bacterial infection of the urinary bladder, the corresponding volatile N-nitrosamines were formed by endogenous nitrosation and excreted in urine.

Tumor induction in a rat model for ureterosigmoidostomy without evidence of nitrosamine formation

Twenty rats were randomized into a vesicosigmoidostomy and an unoperated control group. In both groups the 24 hour excretion of secondary amines, nitrate, nitrite and nitrosamines was measured before and after gavage of proline and nitrate, piperazine and nitrate, N-nitrosoproline, mono-N-nitrosopiperazine. The urinary nitrosamine concentrations were not significantly different between both groups neither before nor after application of the several substances. Thirty rats were randomized into two vesicosigmoidostomy groups with and without antibiotic coverage and an unoperated control group. After ligation of distal rectum and mesosigmoid the rectosigmoids were removed. No significant concentrations of volatile nitrosamines could be measured in the rectosigmoid contents of the three groups. One hundred and twenty rats randomized into three groups following vesicosigmoidostomy received the potential nitrosamine antidotes sodium-2-mercaptoethane sulfonate or sodiumpentosan-polysulfate or acted as controls. 12/118 (10.2%) developed adenomas and 25/118 (21.2%) adenocarcinomas at the vesico-colonic anastomosis with no significant differences between the three groups concerning tumor incidence or mortality. The results show that colon carcinomas occur in a rat model for ureterosigmoidostomy without evidence for thus induced nitrosamine formation. This and the missing effect of nitrosamine antidotes suggest that other factors than nitrosation must be responsible for colon carcinogenesis following urinary diversion via intestine.

Comparative metabolism and urinary excretion of N-mononitrosopiperazine and N,N'-dinitrosopiperazine in the rat

The metabolism of N-mononitrosopiperazine (NPz) and N,N'-dinitrosopiperazine (DNPz) was investigated in Sprague-Dawley rats. When an oral dose of 50 micrograms/rat NPz was administered, 10.5% of the dose was recovered unchanged in urine together with N-nitroso-3-hydroxypyrrolidine (NHPYR, 1.3% of administered NPz dose) and N-nitrosodiethanolamine (NDELA, 0.3%). For DNPz, 7.7% of the administered dose together with NPz (0.04%), NHPYR (2.9%), NDELA (6.7%) and N-nitroso(2-hydroxyethyl)glycine (NHEG, 20.2%) was recovered in urine after 24 h. These results show extensive metabolism of both NPz and DNPz and suggest that both NPz and NHPYR could be analysed in urine as markers for the endogenous nitrosation of piperazine in patients receiving antihelminthic treatment with piperazine.

[Intravesical prevention of recurrence of superficial urinary bladder cancer with BCG and KLH. A prospective randomized study]

In a prospective randomized trial intravesical prophylaxis for recurrence of superficial bladder cancer with BCG versus KLH was performed in 42 patients, 38 of whom were then evaluable. After a mean observation period of 20 +/- 7 months (8-32 months) 41.2% (7/17) of the patients in the KLH and 14.3% (3/21) of the patients in the BCG group developed recurrent bladder tumours. The recurrence rate according to EORTC was 1.95 in the KLH group versus 0.76 in the BCG group. Among the BCG treated patients, 60% (15/25) had cystitis and 28% (7/25) fever, whereas only 1 of 19 (5.3%) patients treated with KLH had cystitis. BCG is a highly effective prophylactic against recurrence of superficial bladder cancer. Intravesical instillation therapy with KLH has only a slight prophylactic effect if treatment is started 6 weeks postoperatively.

Effect of vitamin C on endogenous formation of N-nitrosamines in ureterosigmoidostomy patients

The bacterially catalyzed formation of nitrosamines in the rectosigmoid is a favorite theroy for the increased risk of colon carcinomas following ureterosigmoidostomy. The urine/feces mixtures of 20 ureterosigmoidostomy patients were analyzed for nitrate, nitrite, volatile and nonvolatile nitrosamines prior to, and after, oral administration of vitamin C, a known nitrosation inhibitor. Following a 4-week period of daily ingestion of 2 g vitamin C (1 g in children) there was a slight, but not significant, decrease of volatile and nonvolatile nitrosamines and nitrite, as well as a nonsignificant increase in nitrate in the urine/feces of these patients. No correlation between the vitamin C concentration in serum or urine/feces mixture and the nitrosamine excretion was observed. These results suggest that the administration of vitamin C is not a suitable method for prophylaxis of endogenous nitrosation in ureterosigmoidostomy patients. Clinical and experimental findings implicate that factors other than nitrosamines play an important role in colon carcinogenesis of patients with ureterosigmoidostomies or other forms of urinary diversions using the small or large bowel.

Ureterosigmoidostomy: long-term results, risk of carcinoma and etiological factors for carcinogenesis

We followed postoperatively 75 patients who underwent ureterosigmoidostomy between 1942 and 1987. Of the patients 30 were asked to undergo routine examination, including fiberoptic sigmoidoscopy with biopsy and analysis of a urine-feces slurry for nitrate, nitrite and nitrosamines in comparison to 20 control volunteers. After a mean observation of 14 years 7 months (1 to 46 years) 64.5% of the patients had bilaterally normal kidneys without any previous complications, 77.5% of the renal units being normal. Sigmoidoscopic biopsy revealed 3 carcinomas at the ureterocolonic junction resulting in an 8.5 to 10.5-fold increased risk of colon carcinoma compared to the general population. The excretion of nitrite and N-nitrosamines was increased, and nitrate excretion was decreased compared to healthy control volunteers, suggesting endogenous formation of nitrosamines by bacterially reduced nitrate and endogenous amines. The urological long-term results of ureterosigmoidostomy are similar to those of conduits. However, the increased incidence of colon carcinoma is not yet proved to be higher than in conduits.

[Diagnostic tumor resection in kidney tumors of unclear quality]

From 1985 to June 1989 diagnostic tumour resections have been performed on 37 kidney tumours with unknown dignity following the preoperative imaging techniques. The kidney tumours were completely excised with about 1 cm of adjacent parenchyma outside the pseudocapsule during temporary ischemia. The tumours and biopsies from the resection margins were sent to quick frozen section. In case of benign histology or low grade clear cell carcinomas with exophytic growth and a size of less than 5 cm in diameter the operation was finished without removing of the kidney. In 21 patients with benign and 11/16 with malignant disease the kidneys could be preserved. In 5/16 patients the kidneys were removed after tumour resection and result of the quick frozen section. In our opinion the diagnostic kidney tumour resection in cases of kidney tumours with unknown dignity should be preferred to fine needle biopsies combining diagnostic and therapeutic proceeding in selected cases. On the other hand tumour resections without nephrectomy in patients with renal cell carcinoma and normal contralateral kidney should be done only in low grade tumours of small size.

Pharmacokinetics of technetium-99m-MAG3 in humans

Technetium-99m-mercaptoacetylglycylglycylglycine (99mTc-MAG3) is introduced to replace o-iodohippurate (OIH) for renal function studies. For interpretation of clinical findings, extensive pharmacokinetic studies were performed on patients. These showed that 99mTc-MAG3, compared with OIH, has a higher plasma-protein binding, an essentially higher intravascular concentration, a smaller volume of distribution and, with practically identical biologic half-lives, a correspondingly lower clearance. Simultaneous steady-state measurements resulted in a 1.5-fold higher clearance of OIH than of 99mTc-MAG3 (n = 124). Competitive inhibition of the tubular transport system by p-aminohippurate (PAH) (20 patients) revealed a distinctly higher suppression of the 99mTc-MAG3 clearance than of OIH which indicates a lower affinity of the 99mTc complex to the tubular cell. The plasma extraction efficiencies of both agents, measured during surgery (n = 5), did not indicate an extrarenal elimination of 99mTc-MAG3. This new radiopharmaceutical is a pragmatic alternative to OIH and offers advantages not only for scintigraphic imaging but is also suited for quantitative renal function studies.

[Wilms' tumor in adults]

We report on a 42-year-old patient with a Wilms tumour (nephroblastoma) of the right kidney, which was detected incidentally by sonography. Both radiological examination and intraoperative examination of a quick-frozen section led to a diagnosis of malignant renal tumour. Post-operative histological examination showed a nephroblastoma of predominantly epithelial cell type with no signs of anaplasia. Only about 210 cases of Wilms tumours in adults have been reported in the world literature so far. Because of this low incidence and the frequent lack of any clear distinction from sarcomatoid renal cell carcinoma in terminology and histology, no standardized therapy regimens exist. The prognosis with a 3-year survival rate of 24%-44% is poor compared with that of Wilms tumours in children. In a literature review the current status of knowledge about nephroblastomas in adults is discussed.

The role of nitrate, nitrite and N-nitrosamines in carcinogenesis of colon tumours following ureterosigmoidostomy

Urinary diversion in both a rat model for ureterosigmoidostomy and in ureterosigmoidostomy patients result in an increased incidence of colon tumours. Bacterial and chemical investigations on feces-urine mixtures from both the rat model and ureterosigmoidostomy patients showed the presence of a complex nitrate-reducing bacterial flora in both rats and humans. This bacterial flora actively reduced urinary nitrate to nitrite in humans and increased the endogenous formation of N-nitroso compounds. No evidence of urinary nitrate reduction and increased nitrosamine formation in the rectosigmoid of rats was found. The results support the N-nitrosamine theory of carcinogenesis of the colon following ureterosigmoidostomy in humans, but not in rats. As the rat model induces colon carcinomas, factors other than the increased endogenous formation of N-nitroso compounds in the rectosigmoid may contribute to the initiation of colon carcinomas following ureterosigmoidostomy.

Increased urinary nitrosamine excretion in patients with urinary diversions

Tumor development at the site of ureterointestinal anastomosis is a recognized complication in patients with continent urinary diversions. Aerobic cultures of rectal urine samples from 30 patients with urinary diversions (26 ureterosigmoidostomies, two colon conduits, one ileal conduit and a Gersuny bladder) showed a complex bacterial flora containing nitrate-reducing organisms (Escherichia coli, Proteus and Klebsiella spp.). In comparison to normal bladder urine samples from control volunteers (n = 20), rectal urine samples from ureterosigmoidostomy patients (n = 26) showed a significant decrease (P less than 0.0001) in urinary nitrate (0.93 +/- 0.39 versus 0.27 +/- 0.23 mmol/l), a significant increase (P less than 0.0001) in urinary nitrite (not detected versus 29.24 +/- 39.93 mumol/l) as well as a significant increase (P = 0.013) in urinary N-nitroso compound excretion (57.33 +/- 33.87 versus 93.96 +/- 65.76 nmol/l). Significant increases were also found for the urinary excretion of individual volatile and non-volatile N-nitroso compounds, clearly demonstrating a bacterially mediated in vivo formation of N-nitroso compounds in the 'colon' bladders of patients with urointestinal diversions that may be an important etiological risk factor for colon carcinogenesis in this patient group.