In the treatment of breast cancer, a cheap and safe drug containing progesterone could help, which could be used in every second breast cancer patient, writes Nature.
Progesterone is a female steroid hormone, one of the most important hormones produced in the ovary and also in the placenta during pregnancy. It enables the embryo to implant in the uterus and maintain the pregnancy. It works through receptors located, among others in the uterus and mammary glands.
Experts from the University of Cambridge and the University of Adelaide say that progesterone can also be used to inhibit the development of the so-called hormone-dependent breast cancer. They refer to laboratory tests in which the cancer cells were exposed to this hormone.
It has already been noted that breast cancer, whose cells have more progesterone receptors, is usually less lethal and has a better prognosis. However, it was not known what the mechanism of this was.
Prof. Carlos Caldas of the University of Cambridge, one of the researchers who investigated the problem, says that progesterone receptors are closely related to estrogen receptors, which have opposite effects because they stimulate cancer cells to grow. By acting on progesterone receptors, you can also make estrogen receptors less stimulating the development of cancer.
The development of the disease is also inhibited by tamoxifen, a non-steroidal anti-estrogen compound, which has been used for many years. Since it blocks the division of cancer cells with a large number of estrogen receptors, it is used in postoperative patients with lymph node metastases. It is also used to reduce the risk of cancer in women with the so-called in situ (pre-invasive) breast cancer after surgery and radiotherapy. It is also used prophylactically in women at particular risk of breast cancer.
The anti-estrogenic effects of tamoxifen are additionally enhanced by progesterone. In the laboratory, cancer cells were half the size of those treated with both substances compared to those treated with tamoxifen alone. It seems that this way the disease can be better treated and controlled, but clinical trials are needed to confirm this, said Prof. Caldas in a statement for BBC News.
According to Nature, estrogen receptors are present in 75 percent of people. women with breast cancer, and among them in as many as 75 percent. simultaneously there are progesterone receptors. It follows that progesterone may be useful in every second patient with this cancer.