Melanoma, thyroid, cervical, and colon cancer risk after use of fertility drugs.
OBJECTIVE
This study was undertaken to evaluate melanoma, thyroid, colon, and cervical cancer risks after clomiphene or gonadotropins.


METHODS
Retrospective cohort of 8422 women (155,527 women-years) evaluated for infertility (1965-1988). Through 1999, cancers were ascertained by questionnaire, cancer and death registries. Poisson regression estimated adjusted rate ratios (RRs).


RESULTS
Clomiphene use did not significantly increase risk of melanoma (RR=1.66; 95% CI, 0.9-3.1), thyroid (RR=1.42; 95% CI, 0.5-3.7), cervical (RR=1.61; 95% CI, 0.5-4.7), or colon cancer (RR=0.83; 95% CI, 0.4-1.9). We found no relationship between clomiphene dose or cycles of use and cancer risk at any site. Clomiphene use may impart stronger effects on risks of melanoma (RR=2.00; 95% CI, 0.9-4.6) and thyroid cancer among women who remained nulliparous (RR=4.23; 95% CI, 1.0-17.1). Gonadotropins did not increase cancer risk for these sites.


CONCLUSIONS
Fertility drugs do not appear to have strong effects on these cancers. Nonetheless, follow-up should be pursued to assess long-term risks and to monitor effects among women who remain nulliparous.
Althuis
Michelle D
MD
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.
Scoccia
Bert
B
Lamb
Emmet J
EJ
Moghissi
Kamran S
KS
Westhoff
Carolyn L
CL
Mabie
Jerome E
JE
Brinton
Louise A
LA
D002996:Clomiphene / Q000009:adverse effects*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D005260:Female; D005300:Fertility Agents, Female / Q000009:adverse effects*; D006062:Gonadotropins / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008545:Melanoma / Q000139:chemically induced / Q000453:epidemiology*; D018570:Risk Assessment; D013964:Thyroid Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D002583:Uterine Cervical Neoplasms / Q000139:chemically induced / Q000453:epidemiology*
D005300:Fertility Agents, Female; D006062:Gonadotropins; D002996:Clomiphene