title: Fertility drugs and the risk of breast cancer: a meta-analysis and review.
abstract: The risk of breast cancer has been associated with reproductive history. The purpose of this study was to determine the relationship between fertility drugs used in assisted reproductive procedures and the risk of breast cancer. We performed a literature search using the MEDLINE, the COCHRANE Library, and Scopus to identify studies linking breast cancer to fertility drugs. We excluded case series, case reports, and review articles from our analysis. The study populations included women who were treated for infertility with clomiphene, gonadotropins, gonadotropin-releasing hormones, or other unspecified fertility agents. We extracted information on study design, sample size, type of fertility drugs and number of treatment cycles, breast cancer incidence, and follow-up time from these studies. Eight case-control studies and fifteen cohort studies were included in the quantitative analyses. The Newcastle-Ottawa Quality Assessment Scales were used. Two investigators independently extracted study methods, sources of bias, and outcomes. We found that the risk of breast cancer was not significantly associated with fertility drug treatment. The follow-up periods were short in some of the studies analyzed in our study; however, we proceeded to test the trend in risk estimates across different durations of follow-up and found a trend for association using the nonparametric test; this was interpreted with caution in view of the lack of adjustment with other confounding factors. The current published data do not suggest higher risk of breast cancer in women who receive fertility treatment, but the lack of long-term follow up and the inherent weaknesses in some of the published studies have to be cautiously taken into account.
authors.affiliation: Department of Obstetrics and Gynecology, Lebanese American University, Beirut, Lebanon.
authors.forename: Tony G
authors.initials: TG
authors.lastname: Zreik
authors.forename: Ali
authors.initials: A
authors.lastname: Mazloom
authors.forename: Yanli
authors.initials: Y
authors.lastname: Chen
authors.forename: Marina
authors.initials: M
authors.lastname: Vannucci
authors.forename: Chelsea C
authors.initials: CC
authors.lastname: Pinnix
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fulton
authors.forename: Mersiha
authors.initials: M
authors.lastname: Hadziahmetovic
authors.forename: Nadia
authors.initials: N
authors.lastname: Asmar
authors.forename: Adnan R
authors.initials: AR
authors.lastname: Munkarah
authors.forename: Chakib M
authors.initials: CM
authors.lastname: Ayoub
authors.forename: Ferial
authors.initials: F
authors.lastname: Shihadeh
authors.forename: Ghina
authors.initials: G
authors.lastname: Berjawi
authors.forename: Antoine
authors.initials: A
authors.lastname: Hannoun
authors.forename: Pierre
authors.initials: P
authors.lastname: Zalloua
authors.forename: Christine
authors.initials: C
authors.lastname: Wogan
authors.forename: Bouthaina
authors.initials: B
authors.lastname: Dabaja
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000139:chemically induced*; D019317:Evidence-Based Medicine; D005260:Female; D005300:Fertility Agents, Female / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
chemical_list: D005300:Fertility Agents, Female