Meta-analysis of studies analyzing the relationship between bladder cancer and infection by human papillomavirus

Studies have been done of the possibility that infection by human papillomavirus is a risk factor contributing to bladder cancer but no definite conclusions have yet been drawn. We performed a meta-analysis of observational studies published until July 2005 to ascertain the degree of association between bladder cancer and human papillomavirus infection.

The MEDLINE database was searched using the key words bladder cancer and virus. Strict criteria were applied to select studies revealing the prevalence in serum of human papillomavirus infection or its direct detection in patients. A total of 44 articles with these methodological criteria were chosen.

In 39 studies the investigators determined the presence of human papillomavirus DNA, and found a prevalence of between 0% and 100% and significant homogeneity analysis (p <0.001). Pooled estimation of the presence of the infection was 16.0% (95% CI 12.8 to 19.1). Pooled OR estimation was 2.3 (95% CI 1.3 to 4.1) with no significant publication bias. In 7 studies human papillomavirus infection was studied by detecting the antigen or antibodies and a prevalence of between 14% and 60% was found with significant homogeneity analysis (p <0.001). Pooled estimation of the prevalence of infection was 32.4% (95% CI 17.0 to 47.8). Pooled OR estimation was 2.9 (95% CI 1.7 to 5.3).

Finding a relationship between bladder cancer and human papillomavirus depends on the method used. In the literature examined there are insufficient cases and samples compared to controls and studies rely on a combination of various microbiological techniques in the same patient and sample, making it difficult to draw any definite conclusion.