Urological oncology

Abstract

Purpose: High fluid intake has been associated with a decreased risk of bladder cancer development in men. We evaluated whether higher fluid intake can impact tumor recurrence rates in patients with superficial bladder cancer.Materials and Methods: We conducted a prospective single institution analysis of fluid intake in 267 consecutive patients with superficial bladder cancer undergoing routine bladder cancer surveillance between January 1998 and December 2001. Fluid intake questionnaires, urine cytology and physical examination were routinely performed at each surveillance cystoscopy. Cytological and histological recurrences were recorded. All patients had a minimum followup of 2 years.Results: No relationship between fluid intake and tumor recurrence was demonstrated. Average daily fluid intake was 2,654 ml daily, which was well within the highest protective level (more than 2,531 ml) previously reported. However, multivariate analysis failed to show a protective effect against recurrence at any level of fluid intake. Increasing age correlated with decreased fluid intake (Pearson's correlation coefficient -0.19, p = 0.0015), but did not increase the risk of recurrence (p = 0.59). Single fluid intake data correlated with the average of additional fluid intakes (median 5 per patient) in the same patient (Pearson's correlation coefficient, 0.45, p < 0.0001). Of the study population 123 patients (46%) experienced 1 or more tumor recurrences (range 0 to 11) within a median followup of 2.6 years.Conclusions: Our prospective study of fluid intake in patients with superficial bladder cancer at risk for recurrence did not find any association between daily fluid intake levels and tumor recurrence. Editorial CommentAfter having diagnosed and treated his superficial bladder cancer appropriately, the urologist used to urge the patient to "drink a lot". However, under scientific conditions, this advice did not prove to be well founded. The authors conducted a prospective study in 267 consecutive patients, and their results told that fluid intake was not correlated with tumor recurrences. However when looking into the data given in this paper, the difference between all the patients with regard to fluid intake was not high, the overall 24-hour fluid intake being 2.5 L. Fluid intake of those with no recurrences was 2,550 mL and those with recurrences was 2,640 mL. These data in mind it is highly unlikely, even if fluid intake had an impact on tumor recurrences, that a difference of 100 mL per day might be the relevant quantity to have such enormous impact.