Systematic review of bladder cancer outcomes in patients with spina bifida

In patients with congenital bladder anomalies, bladder augmentation is used as a last resort to reduce intravesical pressure, but concerns about malignant transformation in augmented patients were first raised in the 1980s. The best evidence to date indicates that augmentation does not appear to increase the risk of bladder cancer in spina bifida patients. To date, oncologic outcomes from patients with spina bifida with and without augmentation have only been available in small case reports.

To systematically evaluate factors in myelomeningocele patients with bladder cancer, including bladder augmentation, that contribute to overall survival (OS).

A systematic review using PubMed was conducted by cross referencing terms 'myelomeningocele,' 'cystoplasty,' 'bladder cancer' and respective synonyms according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Inclusion criteria were studies with patients with an underlying diagnosis of myelomeningocele and bladder cancer with data on age, stage, and mortality status. Studies were excluded for spinal cord injury, history of tuberculosis or schistosomiasis, or prior ureterosigmoidostomy.

Fifty-two patients were identified from 28 studies with a median age at bladder cancer diagnosis of 41 years (range 13-73); 37 (71%) presented with stage III or IV bladder cancer. Overall survival at 1 year and 2 years was 48.5% and 31.5%, respectively. Overall survival was different between those with and without augmentation (P = 0.009) by log-rank analysis. No between-group differences in OS were seen based on age, management with indwelling catheter, diversion with ileal conduit or being on a surveillance program. Only stage remained a significant predictor of OS on multivariate analysis (HR 2.011, 95% CI 1.063-3.804, P = 0.032). Secondary analysis was performed after removing patients with gastric augmentation (n = 8), and no difference in OS was seen between patients with (n = 8) and without augmentation (n = 36, P = 0.112). Of augmented patients, latency to development of bladder cancer was variable (Summary Figure).

Bladder cancer is a deadly diagnosis in patients with congenital bladder anomalies like spina bifida, and while overall prevalence of the two conditions occurring together is low, bladder cancer will go on to affect 2-4% of spina bifida patients. The present study examined overall survival, and further characterized outcomes in these patients. Presence of a bladder augment did not appear to worsen overall survival.

Patients with myelomeningocele who developed bladder cancer had aggressive disease. Augmentation did not worsen OS, based on cases reported in the literature. Risk of bladder cancer should be discussed with all myelomeningocele patients.