ABSTRACT
Endometrial cancer is the most common gynecologic cancer in U.S. women and
accounts for 6% of all cancers in women (1). The lifetime risk of endometrial
cancer for the average U.S. woman is 2% to 3% (2), with a median age at
diagnosis of 63 years (3). As is the case with breast, colorectal, and most other
cancers, the majority of endometrial cancer is not hereditary. Risk factors for
endometrial cancer have been identified, many of which are thought to affect the
level of estrogen to which the endometrium is exposed. The strongest risk factor
for sporadic endometrial cancer is obesity, with a relative risk of 7.2 for women
200 lbs or greater versus 125 lbs or less (4). Other risk factors include nulliparity
(4), early age at menarche (4), diabetes mellitus (5), and the use of tamoxifen
(6,7). Unopposed estrogen therapy was found to significantly increase the risk of
endometrial cancer (8,9) and is therefore no longer recommended for women
who have an intact uterus. Combination estrogen/progesterone oral contra-
ceptives have been shown to decrease the risk of endometrial cancer (10). See
Table 1 for a summary of endometrial cancer risk factors and relative risks.
