IJE Advance Access published online on September 23, 2009
International Journal of Epidemiology, doi:10.1093/ije/dyp287
A systematic review and meta-analysis of perinatal variables in relation to the risk of testicular cancer—experiences of the mother
1 Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.
2 Karolinska Institutet, Karolinska Sjukhuset, Stockholm, Sweden.
3 Cancer Epidemiology Group, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds, UK.
4 Cancer Epidemiology Unit, Department of Human Oncology and Biomedical Sciences, University of Turin, Torino, Italy.
* Corresponding author. Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 6120 Executive Blvd, EPS/Suite 550/Room 5012, Bethesda, MD 20852-7234, USA. E-mail: michael.cook{at}nih.gov
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Abstract |
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Background We undertook a systematic review and meta-analysis of perinatal variables in relation to testicular cancer risk, with a specific focus upon characteristics of the mother.
Methods EMBASE, PubMed, Scopus and Web of Science databases were searched using sensitive search strategies. Meta-analysis was undertaken using STATA 10.
Results A total of 5865 references were retrieved, of which 67 met the inclusion criteria and contributed data to at least one perinatal analysis. Random effects meta-analysis found maternal bleeding during pregnancy [odds ratio (OR) 1.33, 95% confidence interval (CI) 1.02–1.73], birth order (primiparous vs not, 1.08, 95% CI 1.01–1.16; second vs first, OR 0.94, 95% CI 0.88–0.99; third vs first, OR 0.91, 95% CI 0.83–1.01; fourth vs first, OR 0.80, 95% CI 0.69–0.94) and sibship size (2 vs 1, OR 0.93, 95% CI 0.75–1.15; 3 vs 1, OR 0.89, 95% CI 0.74–1.07; 4 vs 1, OR 0.75, 95% CI 0.62–0.90) to be associated with testicular cancer risk. Meta-analyses that produced summary estimates which indicated no association included maternal age, maternal nausea, maternal hypertension, pre-eclampsia, breech delivery and caesarean section. Meta-regression provided evidence that continent of study is important in the relationship between caesarean section and testicular cancer (P = 0.035), and a meta-analysis restricted to the three studies from the USA was suggestive of association (OR 1.67, 95% CI 1.07–2.56).
Conclusions This systematic review and meta-analysis has found evidence for associations of maternal bleeding, birth order, sibship size and possibly caesarean section with risk of testicular cancer.
Keywords Epidemiology, meta-analysis, pregnancy, review, systematic, testicular neoplasms
Accepted 28 July 2009