A systematic review and meta-analysis of perinatal variables in relation to the risk of testicular cancer--experiences of the mother.
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.
Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20852-7234, USA. michael.cook@nih.gov
Michael B
MB
Cook
Olof
O
Akre
David
D
Forman
M Patricia
MP
Madigan
Lorenzo
L
Richiardi
Katherine A
KA
McGlynn
D001722:Birth Order; D002585:Cesarean Section / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008423:Maternal Age; D018743:Perinatal Care; D011247:Pregnancy; D011248:Pregnancy Complications; D012307:Risk Factors; D035781:Siblings; D013736:Testicular Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D014592:Uterine Hemorrhage / Q000150:complications