Long-term relationship of ovulation-stimulating drugs to breast cancer risk.
Cancer Epidemiol Biomarkers Prev
; 23(4): 584-93, 2014 Apr.
Article
en En
| MEDLINE
| ID: mdl-24700523
ABSTRACT
BACKGROUND:
Although fertility drugs stimulate ovulation and raise estradiol levels, their effect on breast cancer risk remains unresolved.METHODS:
An extended follow-up was conducted among a cohort of 12,193 women evaluated for infertility between 1965 and 1988 at five U.S. sites. Follow-up through 2010 was achieved for 9,892 women (81.1% of the eligible population) via passive as well as active (questionnaires) means. Cox regression determined HRs and 95% confidence intervals (CI) for fertility treatments adjusted for breast cancer risk factors and causes of infertility.RESULTS:
During 30.0 median years of follow-up (285,332 person-years), 749 breast cancers were observed. Ever use of clomiphene citrate among 38.1% of patients was not associated with risk (HR = 1.05; 95% CI, 0.90-1.22 vs. never use). However, somewhat higher risks were seen for patients who received multiple cycles, with the risk for invasive cancers confirmed by medical records being significantly elevated (HR = 1.69; 95% CI, 1.17-2.46). This risk remained relatively unchanged after adjustment for causes of infertility and multiple breast cancer predictors. Gonadotropins, used by 9.6% of patients, mainly in conjunction with clomiphene, showed inconsistent associations with risk, although a significant relationship of use with invasive cancers was seen among women who remained nulligravid (HR = 1.98; 95% CI, 1.04-3.60).CONCLUSIONS:
Although the increased breast cancer risk among nulligravid women associated with gonadotropins most likely reflects an effect of underlying causes of infertility, reasons for the elevated risk associated with multiple clomiphene cycles are less clear. IMPACT Given our focus on a relatively young population, additional evaluation of long-term fertility drug effects on breast cancer is warranted.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ovulación
/
Neoplasias de la Mama
/
Fármacos para la Fertilidad Femenina
Tipo de estudio:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Adult
/
Female
/
Humans
País/Región como asunto:
America do norte
Idioma:
En
Revista:
Cancer Epidemiol Biomarkers Prev
Asunto de la revista:
BIOQUIMICA
/
EPIDEMIOLOGIA
/
NEOPLASIAS
Año:
2014
Tipo del documento:
Article