Clinical application of a novel urinary cytology detection system for bladder cancer / 现代泌尿外科杂志

【Objective】 To investigate the diagnostic efficacy of a novel bladder cancer detection system utilizing a urine cell processing kit for urine sample preservation and detection. 【Methods】 Patients with primary persistent gross hematuria and high recurrence risk of bladder cancer after transurethral resection of bladder tumor were prospectively enrolled between Dec.2021 and Mar.2022. Urine specimens were either added to (experimental group) or not added to (control group) the urine cell processing kit and were fixed on Day 0, Day 3 and Day 7. The sensitivity and specificity of the two groups were compared after the cells were fixed, produced, stained and read with body fluid cytology total staining technique. 【Results】 The sensitivity and specificity of the experimental group on Day 0 were 82.50% (33/40) and 87.50% (14/16), respectively; those of the control group were 79.49% (31/39) and 82.35% (14/17), respectively. On Day 3, the sensitivity and specificity of the experimental group were 76.32% (29/38)and 81.25% (13/16), respectively; those of the control group were 52.78% (19/36) and 78.57% (11/14), respectively. On Day 7, the sensitivity and specificity of the experimental group were 71.43% (25/35) and 72.22% (13/18), respectively; those of the control group were 35.71% (10/28) and 60.00% (9/15), respectively. The sensitivity of the experimental group on Day 3 and Day 7 was significantly higher than that of the control group (P<0.05). 【Conclusion】 This bladder cancer urine cytology detection system provides clear diagnostic advantages and can be used as an auxiliary examination before cystoscopy for patients with hematuria and those at high risk of bladder cancer recurrence. It can also be used as a bladder cancer screening tool for pre-screening a large sample of people in order to achieve early diagnosis and treatment of bladder cancer.

Clinical value of NMP22 and cytology in bladder cancer / 国际外科学杂志

Objective To investigate the clinical applications of nuclear matrix protein 22 (NMP22) and urine cytology in early diagnosis,monitoringrecurrence and determining prognosis of bladder cancer.Methods Ninty-six urine specimens,including 45 cases before the resection of bladder cancer (pathologically confirmed),20 cases after the resection of bladder cancer and 31 cases with benign urinary tract condition,were both selected in detecting NMP22 by enzyme-linked i mmunosorbent assay (ELISA),and the results were compared with urinary cytology by x2 test.Results The NMP22 content of 45 cases before the resection of bladder cancer was 9.3 to 112.5 U/mL,the median was 48.7 U/mL.The NMP22 content of 31 cases with benign urinary tract condition was from 2.1 to 14.7 U/mL,the median was 7.9 U/mL.The NMP22 content of 20 cases after the resection of bladder cancer was from 4.3 to 18.7 U/mL,the median was 8.9 U/mL.The median of NMP22 before the resection of bladder cancer was significantly higher than the median in patients with benign urinary,the difference was statistically significant (P ＜0.05).Considering NMP22 ≥ 10 U/mL as the critical value,the sensitivity of the NMP22 in diagnosing bladder cancer was 82.2％ and the specificity was 70.9％.And the sensitivity of urine cytology was 31.1％ and the specificity was 100％.The recurrence of 9 cases was confirmed by cystoscopy in 20 cases after the resection of bladder cancer.Conclusion The NMP22 can be a effective biomarker in the early screeningand postoperative follow-up of bladder cancer.

Evaluation of Urine Cytology in Urothelial Carcinoma Patients: A Comparison of CellprepPlus(R) Liquid-Based Cytology and Conventional Smear

BACKGROUND: Urine cytology is an important test in the screening of urothlelial neoplasms. The conventional smear (CS) method of testing urine samples has a low sensitivity, approximately 50% result accuracy for detecting urothelial carcinomas, while liquid-based cytology (LBC) has much improved diagnostic accuracy, sensitivity, and specificity. The aim of this study was to compare the morphologic features and diagnostic efficacy of CellprepPlus(R) LBC with those of CS for urine cytology. METHODS: A total of 713 cases of urine specimens collected from November 2009 to September 2010 were included. All specimens were divided equally for the preparation of CellprepPlus(R) LBC and CS for each case. RESULTS: CellprepPlus(R) revealed more cellularity, a cleaner background and better cytomorphologic features, but it showed a less intact architectural pattern compared to that of CS. Of the 88 histologically confirmed cases, the diagnostic sensitivity for CellprepPlus(R) was 50% and higher than the 37.5% for CS. The specificity of both preparations was 100%. CONCLUSIONS: The CellprepPlus(R) showed an improved quality of slides and provided better diagnostic accuracy, thus CellprepPlus(R) could be a first-line screening tool in urinary tract cytology.

Utility of fluorescence in situ hybridization for the diagnosis of bladder urothelial carcinoma / 中华泌尿外科杂志

Objective To evaluate the clinical value of fluorescence in situ hybridization (FISH) method for diagnosis of bladder urothelial carcinoma.Methods Urine samples from 81 patients suspected of having bladder urothelial carcinoma were collected for immediate urine cytology and FISH analysis.All patients underwent cystoscopy for identification of bladder lesions.Urine samples from 8 patients with benign disease of urinary system werealso analyzed by means of FISH and cytology.The sensitivity and specificity of FISH were compared with cytology.Results 81 subjects of bladder urothelial carcinoma were verified with pathology,which included 34 non-muscle invasive carcinoma,14 cases with muscle invasive carcinoma,42 cases with high-grade carcinoma,and 24 cases with low-grade carcinoma.Residual cases included 12 verified benign disease of urinary system,and to serve as controls with 8 patients with benign disease of urinary system.The sensitivities of FISH,cytology and cystoscopy were 72.8％,27.2％ and 97.5％.The sensitivity of FISH was superior to cytology,but inferior to cystoscopy.The specificity and diagnostic concordance rate of FISH and cytology were 85.0％,100.0％ and 75.2％,41.6％,respectively.Conclusion FISH analysis as a non-invasive method has good sensitivity and specificity for diagnosing bladder urothelial carcinoma.

Diagnosis of Bladder Cancer Using Fluorescence in Situ Hybridization Technique / 中国综合临床

Objective To evaluate the value of using fluorescence in situ hybridization (FISH)technique for the detection of chromosome aberration of urine exfoliated cells for the diagnosis of bladder tumor.MethodsFISH technique were used to detect the abnormalities of chromosome 3,7,17 and 9p16 site from 20 normal people, and to establish the threshold.The morning's first urinations were available from 75 patients with bladder cancer and 25 patients without urothelial tumor, then were detected using FISH technique and urine cytology respectively.The sample was considered positive if two or more probes results higher than the criteria,or one probe has two or more abnormal results.Results The sensitivity of single using were 73.3％ (55/75),76.0％ (57/75),62.7％ (47/75) and 62.7％ (47/75) for the 4 probes (3,7, 17 and 9p16)respectively.The sensitivity of combined detection was 85.3％ (64/75) and specificity was 96.0％ (24/25) The sensitivity and specificity of urine cytology examination was 9.3％ (7/75) and 100％ (25/25) .The sensitivity of FISH examination was significantly higher than that of urine cytology examination (85.3％ vs 9.3％ ,x2 = 57.00, P ＜ 0.001) .Sensitivity of FISH examination was not correlated with cancer pathologic grading(low vs high : 84.2％ vs 86.5％, x2 = 0.08, P ＞ 0.05)and clinical stage (ta-tl : 82.9％, t2-t4 :87.5％, x2 = 0.32 ,P ＞ 0.05) .ConclusionFISH technique is a non-invasive and effective method for the early diagnosis of bladder tumor and is more sensitive than urine cytology.Furthermore, FISH technique can be used to predict the tumor's biological behavivor and prognosis.

Decoy cells in the urine cytology of a renal transplant recipient: An immunohistochemical study.

Human polyoma virus causes renal dysfunction and graft loss as a result of tubulo-interstial nephritis in renal transplant recipients after reactivation of latent virus in renal epithelium. The infected cells in the urinary sediments are characterized by large homogenous inclusions, which may cause diagnostic error in urine cytology. The epithelial cells with polyoma viral inclusions in urine cytology specimens are termed Decoy cells to caution pathologists not to misdiagnose these cells as cancer cells. We present a case of polyoma viral changes detected the first time in our laboratory in the urine of a 46year old male who underwent renal transplantation six months back and followed by immunotherapy. Urine cytological examination showed decoy cells and subsequently revealed on histopathology. Immunoperoxidase staining for SV-40 LT antigen (LT ag), expression of proliferating cell nuclear antigen (PCNA), p53 and Rb genes were also studied in the tissue sections for further observation. The expression of SV40 LT ag was negative, while PCNA showed strong positivity; p53 and Rb were expressed moderately in the nuclei of cells in the tubules. The report of a case of decoy cells in the urine of a patient with renal transplantation focuses the importance of cytologic analysis of urine as a diagnostic tool for screening renal transplant recipients at risk of polyoma viral infection.

Comparison of Detecting Methods of BK Virus Infection in Patients with Renal Allograft Recipients

BACKGROUND: BK virus nephropathy (BKVN) is an emerging problem as a consequence of the use of potent immunosuppressive agents. Because optimal detection methods for the diagnosis of BKVN are required clinically, we compared the results of renal allograft biopsy, urine cytology, and urine and blood viral loads. METHODS: Four hundred sixty two case notes from 2004 to 2009 at Seoul St. Mary's Hospital were reviewed. During that period, 286 cases of urine cytology for decoy cells, 938 cases of urine BKV reverse transcription-polymerase chain reaction (RT-PCR), and 1,029 cases of blood BKV RT-PCR were performed. All diagnostic methods were performed in 85 cases. RESULTS: A histological diagnosis of BKVN was made in 2.4% of cases (11/462). Urine cytology for decoy cells was positive in 26.2% (75/286). BKV RT-PCR revealed viruria in positivity of 22.1% (207/938) and viremia in 5.2% (54/1,029). In cases of BKVN, the sensitivities of urine and blood BKV RT-PCR were all 100% and the specificities were 69% and 94.5%, respectively. In cases with positive urine decoy cells, the sensitivities of urine and blood BKV RT-PCR were 50% and 27.7%, with specificities of 77.7% and 100%, respectively. CONCLUSIONS: BKV screening by RT-PCR assays may be a clinically useful noninvasive test to identify renal recipients with concurrent BKVN.

Fluorescence in situ hybridization for detection of bladder cancer / 国际外科学杂志

Fluorescence in situ hybridization (FISH) is a kind of technique that uses fluoreseently la-beled DNA probes to assess cells for genetic alterations. UroVysion is a technique that uses FISH to detect bladder cancer in the voided urine by four fluorescently labeled DNA probes to the pericentromeric regions of chromosomes 3 ( CEP3 ) ,7 (CEPT), and 17 (CEP17) and to the 9p21 locus ( LSI 9p21 ) location of the p16 tumor suppressor gene. It is reported that sensitivity of FISH was higher than cytology for the detection of all stages and grades of bladder cancer. FDA has approved UroVysion for the detection of recurrent bladder cancer in voided urine specimens from patients with a history of bladder cancer in the year 2001 and from pa-tients with gross or microscopic hematuria but no previous history of bladder cancer in the year 2005. Fur-thermore, UroVysion can benefit the assessment of bladder cancer patients receiving BCG treatment.

Detecting Malignant Urothelial Cells by Morphometric Analysis of ThinPrep(R) Liquid-based Urine Cytology Specimens / 대한세포병리학회지

Urothelial carcinoma accounts for 90% of all the cases of bladder cancer. Although many cases can be easily managed by local excision, urothelial carcinoma rather frequently recurs, tends to progress to muscle invasion, and requires regular follow-ups. Urine cytology is a main approach for the follow-up of bladder tumors. It is noninvasive, but it has low sensitivity of around 50% with using the conventional cytospin preparation. Liquid-based cytology (LBC) has been developed as a replacement for the conventional technique. We compared the cytomorphometric parameters of ThinPrep(R) and cytospin preparation urine cytology to see whether there are definite differences between the two methods and which technique allows malignant cells to be more effectively discriminated from benign cells. The nuclear-to-cytoplasmic ratio value, as measured by digital image analysis, was efficient for differentiating malignant and benign urothelial cells, and this was irrespective of the preparation method and the tumor grade. Neither the ThinPrep(R) nor the conventional preparation cytology was definitely superior for distinguishing malignant cells from benign cells by cytomorphometric analysis of the adequately preserved cells. However, the ThinPrep(R) preparation showed significant advantages when considering the better preservation and cellularity with a clear background.

Comparision of Effectiveness between the ThinPrep(R) and the Cytospin Preparations of the Repeated Urine Cytology / 대한세포병리학회지

Once diagnosed as "cell paucity" or "atypia" by the cytospin (CS) preparation, this CS preparation does not secure a precise diagnosis by repeated testing alone. Although the ThinPrep(R) (TP) preparation is acknowledged to show increased cellularity, performing the screening tests for the cases that have enough cellularity, according to CS, raises issues for the cost-effectiveness. To obtain a more precise diagnosis through increasing the cellularity by performing TP, we selected the cases that were diagnosed as "cell paucity" or "atypia" by CS, but they required a more precise diagnosis, and the samples were processed via both CS and TP to compare the results. 11 patients diagnosed as "cell paucity" and 22 patients diagnosed as "atypia" by CS participated in this study. When the detection rate of atypical cells in both preparations with repeated urine cytology was compared, the overall detection rate of TP (16cases, 48.5%) was superior than that of CS (11cases, 33.3%), with statistical significance. The cellularity of both preparations was compared on repeated urine cytology; the general cellularity of TP (29cases, 87.9%) was higher than that of CS (20cases, 60.6%), but there was no statistical significance. Particularly, we repeated the TP for the 1 case that was diagnosed as "atypia" and we performed polyoma virus immunohistochemical staining, which confirmed polyoma virus. In conclusion, we can avoid obtaining negative diagnosis from cases with uncertain "atypia" or "cell paucity" by performing repeated TP testing.

BK Virus Induced Interstitial Nephritis in Renal Transplants: Diagnosis, Treatment and Prognosis / 대한이식학회지

PURPOSE: It is difficult to differentiate BKV nephritis (BKVN) from acute rejection. We diagnosed 8 cases of BKVN in renal transplantation recipients. Herein, we report the clinical nature of BKVN in terms of diagnosis, treatment and prognosis. METHODS: Between June 1998 and September 2002, 8 cases of BKVN were confirmed by H and E stain, immunohistochemical study against SV40, and electron microscopy in renal allograft biopsy samples. Additionally, between April and September 2002, we obtained urine sample for urine cytology from 49 potential donors, 40 end-stage renal failure patients awaiting renal transplantation, and 140 renal transplant recipients who were hospitalized with variable causes and 32 renal transplants as a routine follow-up. RESULTS: In 7 male and 1 female patients, BKVN was diagnosed mean of 20.4 months after transplantation. The kind of immunosuppression they had been on were mycophenolate mofetil (6/8), azathioprine (1/8), cyclosporin (4/8), tacrolimus (4/8). Range of whole blood levels of cyclosporine and tacrolimus at the time of diagnosis of BKVN were 187.5~252.5 ng/ml and 11~16.5 ng/ml, respectively. Four patients had treated acute rejection episode, and in 6 patients, pathologically proven acute rejection was found concomitantly with BKVN. After reduction of net immunosuppression (discontinuation of MMF and AZA, dose reduction of cyclosporine or tacrolimus, and switch from tacrolimus to cyclosporine), renal function of 3 patients was fully recovered. However, 4 patients with delayed diagnosis lost grafts. In urine cytologic examination, 15 patients (one in end-stage renal failure patient, 10 in renal transplant recipients with elevated serum creatinine, 2 in patients with other infection, and 2 in other situation) were found to secrete decoy cell through urine. CONCLUSION: BKVN should be considered in the differential diagnosis of renal allograft dysfunction. Early diagnosis of BKVN and reduction of net immunosuppression can rescue the grafts. Monitoring of decoy cell in the urine cytology is a simple diagnostic tool both for screening of graft with dysfunction and follow-up of grafts after diagnosis and treatment of BKVN.

Urinary Cytologic Findings of Small Cell Neuroendocrine Carcinoma: A Case Report / 대한세포병리학회지

We report the cytologic features of a case of primary small cell carcinoma of the urinary bladder with high grade transitional cell and signet ring cell carcinomatous components. A 64-year-old male presented with gross hematuria for one week. Computed tomography revealed an ill-defined mass in the left lateral wall of the urinary bladder. Urinary cytology showed hypercellularity with predominantly isolated single cells and clustered cells. They have scanty cytoplasm and naked hyperchromatic nuclei with finely granular nuclear chromatin and rare nucleoli. The tumor cells occurred predominantly singe cells, but a few in clusters. Nuclear molding was prominent. No glandular formation or nesting was noted. The second tumor cells had high nuclear/cytoplasmic ratio, irregular nuclear membrane, and coarse granular chromatin. The background was inflamed and necrotic. The histologic findings of transurethral resection were mainly composed of small cell carcinoma, and partly transitional cell and signet ring cell carcinomatous components. Small cell neuroendocrine carcinoma have distinctive cytologic features to make a proper diagnosis.

Comparison between nuclear matrix protein 22 (NMP 22) test and voided urine cytology for detection of bladder cancer / 中华泌尿外科杂志

Objective To compare the sensitivity and specificity of NMP 22 test with voided urine cytology in detection of bladder cancer and to evaluate their clinical values. Methods For 155 patients suspected with bladder cancer NMP 22 and cytology were conducted in the same voided urine samples.Of them 95 patients with bladder transitional cell carcinoma were confirmed histologically.The sensitivity and specificity of NMP 22 and urine cytology were analyzed.60 patients without bladder cancer were selected as control. Results The overall sensitivity and specificity of NMP 22 test were 65.3% and 70.0%,respectively,those of urine cytology were 43.2% and 83.3%,respectively.There was no significant difference between the specificity of urine cytology and that of NMP 22 test;however,NMP 22 was significantly more sensitive than urine cytology in detection of any stages and grades of bladder cancer(P

Comparison between urinary cytokeratin test and voided urine cytology for detection of bladder cancer / 中国癌症杂志

Purpose:To compare the sensitivity and specificity of urinary cytokeratin test with voided urine cytology in detection of bladder cancer and to evaluate their clinical values. Methods:For 136 patients suspected to have bladder cancer urinary concentrations cytokeratin 8 and 18 and cytology were conducted in the same voided urine samples. Of them 87 patients with bladder transitional cell carcinoma were confirmed histologically The sensitivity and specificity of urinary cytokeratin and urine cytology were analyzed. 49 patients without bladder cancer were selected as control.Results:The overall sensitivity and specificity of urinary cytokeratin test were 70.1% and 73.3%,respctively ,those of urine cytology were (42.5%) and 83.7%, respectively, there was no significant difference between the specificity of urine cytology and that of urinary cytokeratin test ;however, urinary cytokeratin was significantly more sensitive than urine cytology in detection of any stages and grades of bladder cancer (P

Urinary NMP22 and BTA tests as screening markers for bladder transitional cell carcinoma / 대한임상병리학회지

BACKGROUND: Urinary bladder cancer has been diagnosed by urine cytology and cystoscopy with biopsy. Recently, in vitro noninvasive diagnostic tests, measuring urinary nuclear matrix protein22(NMP22) and bladder tumor antigen(BTA), were introduced. We analyzed the usefulness of the NMP22 and BTA tests for diagnosing bladder cancer and compared those with voided urine cytology. MATERIALS AND METHODS: Single voided urine specimens were obtained from 27 patients with bladder cancer and 23 healthy volunteers. The urine specimens were assayed by enzyme immunoassay(NMP22, Matrietech(R), Newton, MA.) and latex immunoassay(BTA, Bard, USA). Urine cytology was performed in patients with bladder cancer. RESULTS: Mean urinary NMP22 level of patients with bladder cancer(144.6 U/mL) was significantly higher than those of normal controls(2.9 U/mL, P<0.01). The sensitivities were 89% and 74% for NMP22 and BTA tests, respectively, compared with 41% for voided urine cytology. The sensitivities of NMP22 and BTA tests were 88%, 63% at grade 1(G1), 82%, 73% at G2, and 100%, 88% at G3, respectively(P<0.01; NMP22, P=0.580; BTA). According to tumor stage, the sensitivities of NMP22 and BTA tests were both 79% at superficial, and 100% and 69% at invasive cancer, respectively(P=0.110; NMP22, P=0.678; BTA). The sensitivities of urine NMP22 and BTA tests combined with urine cytology were both 96%. In following of transitional cell carcinoma patients, agreement between urine cytology and BTA test was 75%(24/32). Among the various urologic disease, false positive rate for BTA test was 17%(8/47). CONCLUSION: Urinary NMP22 and BTA tests were more sensitive than voided urine cytology regardless of tumor grade and stage, so these noninvasive and simple tests can be used as screening tests for urinary bladder transitional cell carcinoma.

Urinary Cytologic Findings of Plasmacytoid Transitional Cell Carcinoma of the Urinary Bladder: A Case Report / 대한세포병리학회지

We report a case of 53-year-old man with plasmacytoid transitional cell carcinoma of the urinary bladder, which may be confused with plasmacytoma. The patient initially presented with gross hematuria and dysuria for two months. Cystoscopy and radiologic studies revealed multiple intraluminal protruding masses on the urinary bladder invading perivesical fat tissue. After urinary cytologic examination and cystoscopic biopsy, radical cystectomy and pelvic lymph node dissections were done. Urine cytology showed single cells and poorly cohesive cells with round eccentric nuclei, bi-or multi-nucleation, indistinct nucleoli, coarse chromatin, and abundant basophilic cytoplasm within relatively clear background. The cytologic findings of tumor cells were similar to the plasma cells seen in plasmacytoma. The tumor of the bladder was composed of discohesive, individual cancer cells with diffuse pattern that simulated lymphoma or plasmacytoma. Immunohistochemical and electron microscopic studies clearly established the epithelial nature of the neoplasm. Recognition of this plasmacytoid type of transitional cell carcinoma of the urinary bladder can avoid the misdiagnosis.

Tract Infection in Acute Febrile Children

Peripheral neuroepithelioma (PNE) of soft tissue is a malignant neuroectodermal tumor arising from peripheral (nonautonomic) nerve. It may occur in both children and adults, and are highly aggressive neoplasms that rapidly give rise to metastatic disease and death. We exprienced a case of peripheral neuroepithelioma of soft tissue in the upper arm in a 18-year-old female. Cytologic features revealed small round cells with scanty cytoplasm occurring both singly and in clusters. The clusters frequently tended to form Homer-Wright rosettes. The cells had a round to oval nucleus with fine chromatin and in- conspicuous nucleoli in a hemorrhagic background.

Evaluation of urinary NMP_(22) in the detection of transitional cell carcinoma of bladder / 中国癌症杂志

0. 05) . The sensitivity and specificity of NMP-,2 in diagnosing transitional cell carcinoma of bladder were 85. 7% and 60% when the cut-off was set 10 u/ml, In contrast, the sensitivity and specificity of urinec cytology were 32. 1% and 100%. Conclusions: Urinary NMP22 can be used to screen and follow up transitional cell carcinomas of bladder with high sensitivity and high specificity.

Hematuria among Benzidine Dye Industry Workers / 예방의학회지

Benzidine Industry in Korea has started after Japan has banned its production in early 1970's. and it has been in operation in Korea for over 20 years. However, it is not known yet whether any bladder cancer has developed from benzidine exposure. This study was done to screen benzidine-exposed workers for bladder cancer, and to examine the feasibility of employing screening test at the workplace. All the workplaces that manufacture or use benzidine for more than 20 years in Korea have been covered in this study, and they include 2 benzidine manufacturing factories, 5 benzidine using factories, as well as 2 benzidine free factories as an outside control. In total, 516 workers were screened with urine stick test and urine cytology test for the evidence of hematuria and abnormal urothelial cells. Each worker was also asked about risk factors and symptoms of bladder cancer including past medical history, smoking, medication and occupational history. Benzidine in the air was measured by personal and area sampling. Out of 516 screened workers, 84(16.3%)workers showed positive hematuria in urine stick test, and 7(1.4%)workers showed degenerative cells in urine cytology tests. Those workers with abnormal urine test results who have been exposed to benzidine for more than 10 years were further screened, and, in total. 23 workers were examined with intra-venous pyelography and cystoscopy. None of those screened had any evidence of bladder cancer. When workers with only past hematuria history were included in the positive hematuria group, 96(18.5%) had positive hematuria. On the multiple logistic regression analysis, positive hematuria was significantly associated with benzidine exposure history of other occupations with elevated bladder cancer risk, pyuria and glycosuria. The association got stronger as direct benzidine exposure was accounted through individual task analysis, and as exposure duration was accounted with tenure analysis. For those with benzidine exposure with more than 10 years of tenure, the odds of having positive hematuria was elevated 2.14(95%C.I is 1.08 to 4.25) times more than for those without exposure. Even though bladder cancer was not detected for several limitations including short observation period, majority of studied workers with short latency, healthy worker effect, and low sensitivity of single screening test in a cross-sectional study, the study results suggest that hematuria screening is a feasible and very useful test for bladder cancer screening among benzidine exposed workers.