Urinary calreticulin in the diagnosis of bladder urothelial carcinoma

Objectives: To evaluate the potential suitability of calreticulin (CRT) as a urinary marker for bladder cancer. Methods: Urine specimens were collected from patients with histologically confirmed bladder urothelial carcinoma (Group 1; n = 109), urological patients without urothelial carcinoma (Group 2; n = 60), and non‐urological patients (Group 3; n = 40). We developed an enzyme‐linked immunosorbent assay (ELISA) procedure using commercially available anti‐CRT mono/polyclonal antibodies, and then measured the concentration of urinary CRT. Results: Urinary CRT concentration of group 1 was significantly higher than group 2 and 3 (Mann–Whitney U‐test, P