The efficacy of urine cytology in diagnosis of urinary bladder tumors at Muhimbili National Hospital Dar Es Salaam, Tanzania

Abstract

Background: Bladder tumors are among the common cancers in the African population with an average prevalence of 30% in most regions. In Sub Sahara Africa the annual adjusted mortality rate is 2.8 whereas that of East Africa is 2.6. Currently bladder cystoscopy and biopsy are the gold standard for diagnosing bladder cancer, while urine cytology is used infrequently. Majority of patients in Tanzania cannot access cystoscopy and biopsy services timely, and the services are costly. Urine cytology therefore provides a convenient initial tool in the algorithm for early detection and diagnosing urinary bladder tumors as well as follow up for recurrences. Most patients with bladder cancer present late with advanced disease because of poor accessibility and expensive cystoscopy and biopsy as diagnostic tools because majority of patients in Africa live in rural areas where there are no cystoscopy and biopsy services. Urine cytology allows early tumour detection and can be employed in screening programs and post management follow-up. Additionally, urine cytology is a non-invasive, cost efficient procedure, which can be used at all levels of the health care system. Broad Objective: To determine the efficacy of urine cytology in diagnosing urinary bladder tumors at Muhimbili National Hospital (MNH), Tanzania. Materials and Methods: A hospital based prospective study was conducted from June to December 2018, among patients attending the urology department at MNH, Dar es Salaam, Tanzania. A structured data-collecting instrument was used for collection of data. Urine samples collected from patients were processed and smeared on glass slides for cytological studies. Biopsies were collected and processed for histology. Bladder cystoscopy results were collected from patients’ files. The obtained information was summarized using SPSS database version 23.0, followed by data analysis. Results: Of 127 patients, only 88 patients were eligible for analysis. Urine cytology revealed a sensitivity of 90.5% and specificity of 92.0%. The positive and negative predictive values were 96.6% and 79.3% respectively (p<0.05). There was a moderate agreement between urine cytology results and their corresponding histological diagnosis, with Kappa coefficient () of 0.78. Conclusion: Urine cytology has an important role in early diagnosis of bladder tumors especially high-gradeones, in which it has good sensitivity. However, it is not meant to replace other techniques for bladder tumor diagnosis, but it remains one of the best ways to diagnose a variety of bladder tumors, especially high-grade ones.