The most    compelling  theory  of  epithelial  ovarian carcinogenesis  suggests    that
serous, endometrioid,   and clear   cell    carcinomas  are derived from    the fallopian
tube    and endometrium—not directly    from    the ovary.
Risk    factors include BRCA1 gene, positive    family  history,    high    number  of
lifetime    ovulations, infertility,    and use of  perineal    talc    powder. Protective
factors include conditions  that    decrease    the total   number  of  lifetime    ovulations.
Removal or  occlusion   of  the fallopian   tubes:  bilateral   salpingectomy   or  tubal
ligation
Decreased   lifetime    ovulations: combination steroid contraception,  chronic
anovulation,    breastfeeding,  and short   reproductive    life