Endometrial cancer risk of Hormonal Contraception

Combination oral contraceptive use was associated with a decreased risk in endometrial carcinoma, which decrease with duration of use (RR=0.28 at 5 years of use); however, the estimated protective effect was reduced and became statistically non-significant when allowance was made for weight and parity ^(36,37).

The benefic effect of HC use was only clearly evident in women who had less than 3 live-births and who had BMI less than 22 kg/m ² ⁽³⁸⁾. Overall, progestin effect is not dose-dependent; in fact, high progestin potency HCs did not confer significantly more protection than low progestin potency HCs (OR=0.52).

However, among women with a body mass index of 22 kg/m ² or higher, those who used high progestin potency oral contraceptives had a lower risk of endometrial cancer than those who used low progestin potency oral contraceptives (OR=0.31)while those with a BMI below 22.0 kg/m² did not ^(38,39).

A reduced risk of endometrial carcinoma with HCs use was present only among users of five or more years' duration ⁽⁴⁰⁾. Oral contraceptives present a chemopreventive opportunity for endometrial cancer and ovarian cancer as risk is dramatically lower among women who have used these preparations than among those who have not So, the highest protective effect was produced by preparations with the lowest estrogen and the highest progesterone content.

Endometrial cancer risk is not elevated when combined therapy is given in a cyclic manner with progestin administered only part of the time and it is reduced when both oestrogen and progestin are administered on a daily basis ⁽⁴¹⁾.

In most cases, the endometrioid adenocarcinoma of the endometrium is preceded by hyperplasia with different risk of progression into carcinoma.

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Two percent of the cases with complex hyperplasia (8/390) progressed into carcinoma and 10.5% into atypical hyperplasia. Fifty-two percent of the atypical hyperplasias (58/112) progressed into carcinomas. In the case of progestogen treatment (n = 208 cases ) 61.5% showed remission confirmed by re-curetting, compared with 20.3% of the cases without hormonal treatment (n = 182; P < 0.0001). Endometrial hyperplasia without atypia,it is known respond to hormonal treatment.

In postmenopausal situation, atypical hyperplasia should be treated with total hysterectomy ⁽⁴²⁾.Endometrial and ovarian cancer are the fourth and fifth most common malignancies in women, with approximately 40,000 new endometrial and 25,000 new ovarian cancers expected to be diagnosed in the Unites States, per year. Combined oral contraceptives reduce the risk of endometrial about 50%.

The risk of carcinomas decreases with an increasing duration of oral contraceptive use and this reduced risk lasts for 10-15 years after cessation. A significantly lower risk of developing an endometrial carcinoma can be observed for contraceptives with a high progestin and a low estrogen concentration. Due to the protective effect, the use of oral contraceptives is a useful means chemoprevention in women at high risk of endometrial cancer .