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.
Cook
Michael B
MB
Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20852-7234, USA. michael.cook@nih.gov
Akre
Olof
O
Forman
David
D
Madigan
M Patricia
MP
Richiardi
Lorenzo
L
McGlynn
Katherine A
KA
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