Table 1.

Relative comparison of risk factors for ovarian cancer (OC) in women and the domestic hen (WT = wild-type; R/O = restricted ovulator).

Item	Womena	WT Hensb	R/O Hensb
Incidence of OC	1–2%	27%	3%
Lifetime ovulations	400–500c	422 Eggs	28 Eggs
Progesterone	Protective	Normald	Lowere
Estrogen	Increases risk	Normald	Highere
Gonadotropins	Increases risk	Normald	Highere

^aData from Riman et al. (1998).

^bData from Giles et al. (2010).

^cApproximate number.

^dPlasma levels of hormones.

^ePlasma levels of hormones relative to WT hens.

Adapted from Giles et al. (2010); reproduced with permission from Int. J. Gynecol. Cancer 20:738–744. Copyright IGCS and ESGO (2010).