Breast Health · Breast Cancer Risk
Gompel A et al., 2023 · Climacteric
A recent Perspective article asserted that progesterone secretion during ovulatory cycles is the cause of breast cancer. However, we challenge most of the evidence developed in this publication. First, there is a lack of evidence that progesterone is mutagenic for breast cells. Cause of a cancer should mean initiation by mutation, as opposed to promotion. Second, subclinical ovulatory disturbances occur rather frequently in normal-length menstrual cycles. Third, the authors attribute a potential carcinogenic effect to progesterone secreted during menstrual cycles but not to progesterone during pregnancy. They did not discuss breast cancer evidence from progesterone/progestin therapeutics. They argue that in genetic primary amenorrhea, a hypothetic lower risk of breast cancer could be due to the lack of progesterone, despite the progesterone/progestin in hormone replacements these women receive. Fourth, they advocate a regulatory effect of progesterone on several genes potentially involved in cancer genesis. In particular, they attribute a lower risk of breast cancer in women with Mayer-Rokitansky-Küster-Hauser syndrome to a defect in the progesterone-stimulated Wnt4 gene. However, this defect is only present in a small subset. Thus, the postulated progesterone breast cancer risk is unconvincing, which we discuss point by point in this commentary.
Ovarian Hormones · Progesterone
Sitruk-Ware R et al., 1987 · Contraception
Progesterone (P), the natural hormone, binds to its specific receptors to induce specific progestational effects. In addition to this binding, P is able to interfere with the binding sites of other steroids. Therefore the natural hormone exhibits an anti-estrogenic activity, and anti-androgenic activity and also exerts anti-mineralocorticoid effects. For a long time progesterone could not be used in clinical applications because of a rapid liver inactivation after oral administration. An oral micronized preparation of progesterone is now available which produces adequate plasma and tissue levels of progesterone. The preparation reproduces the anti-estrogenic effect of the natural hormone on the endometrium at the dose of 200 mg daily. It also reproduces the anti-mineralocorticoid effect and has no androgenic action. No side effects have been reported as far as lipids profile, coagulation factors and blood pressure are concerned. Therefore oral micronized progesterone appears suitable for hormonal replacement therapy in various areas, essentially postmenopause therapy, premenstrual syndrome, correction of irregular cycles and pregnancy maintenance.
