A meta-analysis of the risk of boys with isolated cryptorchidism developing testicular cancer in later life.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational studies (cohort and case-control)
PubMed 23193201 · doi:10.1136/archdischild-2012-302051
What was done
Authors conducted a systematic review and meta-analysis of English-language literature in Medline and Embase from January 1, 1980, to December 31, 2010. Four authors independently screened 735 identified papers for studies evaluating the association between isolated cryptorchidism and the subsequent development of testicular malignancy. Genetic syndromes and other predisposing conditions were excluded. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated from included case-control and cohort studies.
What was found
Twelve studies met inclusion criteria: 9 case-control studies (2,281 cases and 4,811 controls) and 3 cohort studies (2,177,941 boys, 345 testicular cancer cases, and 58,270,679 person-years of follow-up). The pooled RR for developing testicular cancer was 2.90 (95% CI 2.21 to 3.82). Significant heterogeneity was observed across studies (p < 0.00001; I² = 89%).
Why it matters
This study synthesizes decades of observational data to establish a pooled quantitative estimate of testicular cancer risk in isolated cryptorchidism, offering clinicians a baseline threefold risk figure for patient counseling.
Limits
Statistical heterogeneity was extremely high (I² = 89%). The evidence is entirely observational and predominantly case-control in design, introducing susceptibility to confounding and recall bias. The search was limited to English-language publications up to 2010, and the authors note potential publication bias and a lack of high-quality primary studies focusing specifically on isolated cryptorchidism.
Cited by
- supports Cryptorchidism (undescended testicles) is associated with increased risks of male infertility and testicular cancer.