Bladder cancer and squamous metaplasia in spinal cord injury patients.

The influence of long-term indwelling urethral catheterization was studied by random bladder and urethral biopsies in 62 spinal cord injury patients. Six patients (10 per cent) had diffuse squamous cell bladder carcinoma, 4 of whom had no tumor visible endoscopically. Five of the patients with cancer were among 25 patients (20 per cent) managed with an indwelling urethral catheter for more than 10 years (average 21 years, range 15 to 30 years). The other cancer patient had been free of the catheter for 27 years after suprapubic cystotomy for 4 years. Gross and microscopic hematuria was associated with cancer. Squamous metaplasia of the bladder was significantly greater in patients who had been catheterized for more than 10 years (80 per cent), compared to those catheterized for less than 10 years (42 per cent) and patients without catheters (20 per cent). Urethral squamous metaplasia increased slightly in long-term catheterization patients. Urinary infection was universal and did not distinguish patients with inflammation, metaplasia or cancer. Therefore, the duration of indwelling catheterization seems to be the major factor in squamous changes in these patients.