Bladder cancer in patients with spinal cord injuries

To evaluate the age-standardized incidence rate of bladder cancer in patients with spinal cord injury (SCI) and the overall risk for this population.

We reviewed 1334 patients with SCI whose dates of SCI, or first attendance at our centre, were between 1940 and 1998. The length of follow-up was calculated for each patient and age-specific incidence rates of bladder cancer calculated using 5-year age bands. This was used to calculate the overall incidence rate, using direct standardization with the European standard population. The cancers were analysed histochemically to characterize the phenotype.

The 1324 patients contributed a total of 12 444 person-years of follow-up. There were four cases of bladder cancer, giving an age-standardized incidence rate of 30.7 per 100 000 person-years. Histochemistry showed areas were positive for cytokeratin 14, which was also positive in the undifferentiated areas. Immunohistochemical staining was positive for cytokeratin 14 and consistently negative for cytokeratin 20, suggesting a pure squamous phenotype.

The age-standardized incidence of invasive bladder cancer in patients in our SCI unit is not statistically different from that of the general population. However, the incidence of invasive bladder cancer in the present study appears to be lower than that reported in other series. Histochemical analysis confirmed a squamous cell phenotype in these tumours.