Childhood tumor risk after treatment with ovulation-stimulating drugs.
OBJECTIVE
To assess childhood cancer risk among children conceived following the use of ovulation-stimulating drugs.


METHODS
Record linkage study.


METHODS
Infertility patients and their offspring as identified through medical records.


METHODS
Cohort of 30,364 Danish women evaluated for infertility beginning in the early 1960s.


METHODS
Standardized incidence ratios (SIRs) compared cancer incidence in the children to the Danish population. Case-cohort techniques calculated rate ratios (RRs) according to prior maternal drug exposures.


RESULTS
A total of 51 cancers were identified among the study children, resulting in an SIR of 1.14 (95% confidence interval [CI] 0.8-1.5). Usage of any fertility drug was associated with an RR of 0.82 (95% CI 0.4-1.6) and clomiphene citrate with an RR of 0.77 (95% CI 0.4-1.6). Tumors occurring early in life and nonhematopoietic malignancies (including neuroblastomas) were not associated with drug usage. Nonsignificant elevations in the risk of cancers occurring later in life, especially childhood hematopoietic malignancies (RR for use of any ovulation-stimulating drugs of 2.30, 95% CI 0.8-6.6), may have been related to underlying reasons for medication usage.


CONCLUSIONS
Although the findings of this study are reassuring, additional adequately powered studies should continue monitoring the effects of ovulation-stimulating drugs on specific tumors, including hematopoietic malignancies.
Brinton
Louise A
LA
Division of Cancer Epidemiology, National Cancer Institute, Bethesda, Maryland, USA. brinton@nih.gov
Krüger Kjaer
Susanne
S
Thomsen
Birthe L
BL
Sharif
Heidi F
HF
Graubard
Barry I
BI
Olsen
Jørgen H
JH
Bock
Johannes E
JE
D000328:Adult; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005300:Fertility Agents, Female / Q000009:adverse effects*; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy*; D008297:Male; D009369:Neoplasms / Q000139:chemically induced*; D010062:Ovulation Induction / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012306:Risk
D005300:Fertility Agents, Female