Decreased Risk of Endometrial Cancer among Oral-Contraceptive Users

Oral contraceptives and cancers of the breast and of the female genital tract. Interim results from a case-control study

“…It is therefore of interest, within the overall design of the study, that the negative associations with ovarian (Newhouse et al, 1977;Rosenberg et al, 1982;Centers for Disease Control Cancer and Steroid Hormone Study, 1985b) or endometrial (Kaufman et al, 1980; Centers for Disease Control Cancer and Steroid Hormone Study, 1983c) cancers previously reported in several studies conducted in different populations were consistently confirmed in the present data.…”

“…In general, they give suggestive evidence that oral contraceptives may confer protection against cancers of the endometrium (Kaufman et al, 1980;Centers for Disease Control Cancer and Steroid Hormone Study, 1983c) and of the ovary (Centers for Disease Control Cancer and Steroid Hormone Study, 1983b;Newhouse et al, 1977;Rosenberg et al, 1982;Weiss et al, 1981). The risk of cervical cancer for oral contraceptive users, on the other hand, was elevated in several studies (Harris et al, 1980;Kay, 1983;Vessey et al, 1983b; WHO Collaborative Study of Neoplasia and Steroid Contraceptives, 1985): the overall estimate of the increased risk, however, was relatively limited, and it is difficult in such a situation to distinguish between a causal association and a confounding effect potentially due to differences in sexual habits (Franceschi et al, 1986).…”

The epidemiology of endometrial cancer in young women

“…Although the current study has only 1 less endometrial cancer case who had ever used COCs than all other studies combined (Kaufman et al, 1980;Weiss & Sayvetz, 1980;Hulka et al, 1982;Kelsey et al, 1982), we still have too little data to be able to accurately estimate the protective effect of COC use or to confidently delineate the group of women for whom it is protective. We saw in Table VI that COC use does not appear to be protective in obese women, and the decreased risk in nonobese women is not statistically significant when considered together with numbers of FTPs.…”

“…Users of combination oral contraceptives have been reported to be at decreased risk of endometrial cancer in 4 recent case-control studies (Kaufman et al, 1980;Weiss & Sayvetz, 1980;Hulka et al, 1982;Kelsey et al, 1982). It is not obvious how combination oral contraceptive use may "interact" with other endometrial cancer risk factors: in the above studies the numbers of ever-users of combination oral contraceptives were small, and the possible modifying effects of other risk factors were not (and probably could not be) discussed in any detail.…”

Unopposed Exogenous Estrogen Administration And its Effect on The Histomorphology of Endometrium in Swiss Albino Mice

“…The "unopposed estrogen hypothesis" is evident in the contraceptive pills such as sequential oral contraceptives (SOCs) which prove to increase the risk of endometrial cancer by two folds leading to their removal from the market [7,8]. Extensive research has been conducted on the use of oral contraceptives over time and proved the efficacy of combined oral contraceptives (COCs) in which there is a fixed amount of estrogens and progesterones which proved to reduce the risk of endometrial cancer by 50% than women who have not used oral contraceptives [9,10]. In premenopausal women with polycystic ovarian syndrome (PCOS), chronic anovulatory cycles lead to deprivation of progesterones to counteract the activity of estrogens [11].…”