The value of using urinary red cell volume distribution curve of patients with positive urinary occult blood detected in a mass examination

PURPOSE: We investigated the usefulness of the urinary red blood cell volume distribution curve (RVDC) for screening patients who are positive for asymptomatic urinary occult blood on mass examination. SUBJECTS AND METHODS: The subjects were 200 individuals over 40 years old (44 men with a median age of 53.4 years and 156 women with a median age of 57.2 years) who were positive for urinary occult blood on mass examination between January 1993 and December 1994. The subjects were classified into three groups based on the pattern of their RVDC. Group NG showed a nonglomerular pattern, group M showed a mixed pattern, and group G showed a glomerular pattern. The urological examinations performed included DIP, ultrasound of the kidney and urinary bladder and urethrocystoscopy. To investigate the prognosis, a questionnaire was sent to all subjects in September 1999 in which they were asked about the state of their disease during the period since the initial examination. RESULTS: Group G consisted of 192 patients, or almost all of the subjects (96%). There were five patients (2.5%) who had serious urological diseases, including two with bladder cancer, and all were found in Groups NG and M. During the period from initial examination until the prognosis survey (mean of 5.7 year), one patient in group G developed both bladder and ureteral cancer. The CVDC showed a mixed pattern when this patient was discovered. CONCLUSION: RVDC was useful for screening patients who were found to be positive for urinary occult blood on mass examination. When the RVDC shows a non-glomerular or mixed pattern, detailed urological examination including endoscopy is necessary.