Urinary excretion of six modified nucleosides by patients with breast carcinoma.

In this preliminary study we investigated the urinary excretion of pseudo-uridine, 1-methyl-adenosine, 1-methyl-inosine, 1-methyl-guanosine, 2-methyl-guanosine and N2,N2-dimethyl-guanosine in 22 patients with breast carcinoma, 16 with metastases. In 88% of the patients with metastatic breast carcinoma, at least one nucleoside level was elevated above the reference range; in 69% of cases at least two nucleoside levels were elevated; whereas three patients had all the six modified nucleosides elevated. Of the six patients without metastases, only one had one modified nucleoside level that was elevated. The others showed no elevated levels. The probability of finding an elevated level of 1-methyladenosine in breast carcinoma is high, when metastasis is present.