Urinary pseudouridine and beta-aminoisobutyric acid in patients with low grade urothelial tumours. Relations between excretion and tumour recurrence.

The simultaneous 24 hours excretion of pseudouridine and beta-aminoisobutyric acid in the urine from patients treated for low grade urothelial tumours has been determined and related to tumour recurrence inside of 6 months after the determinations. The results of 53 assays in 39 patients without clinical signs of recurrence at the time of the detrmination showed a high excretion of pseudouridine in 53% and of beta-aminoisobutyric acid in 28.5% of the assays. Recurrences appeared more often after a high urinary pseudouridine (53.5%) than after a low, but the difference was not statistically significant (p more than 0.05) and more often after a low urinary beta-aminoisobutyric acid (52.5%) than after a high (p less than 0.01). The highest incidence of recurrence was in patients with a simultaneously high urinary pseudouridine and a low urinary beta-aminoisobutyric acid. Seventy per cent of these excretion patterns were from patients, who developed a recurrence before 6 months (p less than 0.002).