Ras related oncogene protein as a tumor marker in transitional cell carcinoma of the bladder

An oncogene related protein has been detected in the urine of patients with transitional cell carcinoma (TCC). This is a 55 kilodalton protein (p55) which is immunologically related to the ras oncogene product p21. Sixteen patients with TCC (55%) and none of the controls exhibited high level of p55 expression (greater than or equal to 3X the level of background). There were ten cancer patients (35%) who had 2X the level of background and three patients (10%) who had the level of background. In contrast, there were two non-cancer patients with 2X level of expression (9%) and the remainder (91%) had the background level of p55 expression. The expression of the marker (p55) tends to correlate with tumor grade and stage and is elevated in patients with a history of multiple recurrences. The ras oncogene has been identified in the tissues of a wide variety of cancers and is not a marker which is specific for any single cancer. The identification of its related gene product in the urine may be useful as a marker for TCC.