What is the relationship between breast cancer and endocrine hormones The breast is an organ closely related to endocrine hormones and is subject to the action of many endocrine hormones, such as estrogen, progesterone, prolactin, growth hormone, corticosteroid and thyroid hormone, to maintain the growth, development and lactation function of the breast. Hormones have a very important role in the development of breast cancer. Estrogen and estradiol (E2) are directly related to the development of breast cancer, estriol and progesterone are thought to have a protective effect, while prolactin has a facilitating role in the development of breast cancer, but the link between the various factors is not fully understood. Studies have shown that estrogen binding to and activating estrogen receptor (ER) can lead to proliferation of normal breast epithelial cells, and proliferating cells are more sensitive to carcinogens than quiescent cells, suggesting that estrogen is a tumor promoter that stimulates breast cancer cells to grow and proliferate in vivo, so drugs that can reduce E2 levels or block the effect of E2 on breast cancer cells have therapeutic effects on breast cancer. The effect of endocrine therapy mainly depends on the sensitivity of tumor to estrogen and the degree of reducing estrogen level after treatment. The first advantage of endocrine therapy for breast cancer is that there is a clear mechanism of action of endocrine therapy, which mainly blocks the stimulating effect of hormones on tumor growth and has no significant effect on normal cells, and it has been proved through years of practice that its efficacy is no less than that of chemotherapy. The remission of tumor is significantly prolonged and can last for several years. Endocrine therapy has significantly less toxic side effects compared with chemotherapy drugs. As we all know, chemotherapy has great side effects on patients, including hair loss, strong nausea and vomiting, white blood cell and platelet reduction, etc. Therefore, patients need to endure great pain when receiving chemotherapy, and sometimes need to be hospitalized, and even have difficulty in insisting on continuing treatment, which in turn fails to achieve the purpose of treatment and may miss the best time for treatment. Endocrine therapy is less toxic, less frequent and does not require hospitalization, and the quality of life of patients during treatment is higher. Patients can easily accept this treatment and can adhere to long-term treatment with medication, so that the efficacy of endocrine therapy can be maximized. Therefore, the remission period of patients with effective endocrine therapy is significantly longer than that of patients with effective chemotherapy, and it may even be as long as six months, one year or even several years. There are still misconceptions about endocrine therapy for breast cancer. Some statistics show that endocrine therapy has been widely used in breast cancer treatment in Europe and America, but there is still a certain gap between endocrine therapy and foreign countries in China. First of all, in terms of efficacy, endocrine therapy is not less effective than chemotherapy. However, some people are skeptical about “taking one pill a day as anti-cancer treatment”. In fact, it has been proved through long-term practice that endocrine therapy for breast cancer is a very important treatment tool, and as long as it is chosen appropriately, its efficiency and remission are comparable to chemotherapy. Some people mistakenly think that severe reactions to chemotherapy are “strong”, which is very wrong. Generally speaking, the effect of endocrine therapy can be seen 2-3 months after the start of the treatment, and the time of effect is not slower than that of chemotherapy. And the remission time for tumors is also longer. From the aspect of drug safety, the toxic side effects of endocrine therapy are significantly less than chemotherapy, and the serious toxic side effects like chemotherapy (such as hair loss, severe nausea and vomiting, decrease of white blood cells, etc.) will not occur, and most patients can accept and adhere to the treatment for a long time. The quality of life of patients will not be affected. With the increasing demand for quality of life nowadays, endocrine therapy will become an important means of breast cancer treatment. Development of endocrine therapy for breast cancer In the 1970s, triamcinolone acetonide was a breakthrough drug, which belonged to “anti-estrogen class” and had less toxic side effects than the previous drugs. Now, a new class of endocrine therapeutic drugs, “aromatase inhibitors”, has been gradually developed and applied in clinical treatment with clear efficacy, which is considered as a new trend of endocrine therapy for breast cancer and brings new treatment options for doctors and patients. Flon” (Letrozole) is one of the representative drugs for postmenopausal breast cancer, receptor positive or unknown. After rigorous research and comparison, Flon has surpassed triamcinolone in terms of efficacy, such as tumor remission and stopping tumor progression, and will become a new standard endocrine therapy for breast cancer. 4.What are the side effects of endocrine therapy for breast cancer? The main side effects of endocrine therapy are: loss of appetite, nausea, vomiting, diarrhea, headache, dizziness, depression, facial flushing, skin rash, leukocyte and platelet reduction in very few patients, but generally not serious. It is prohibited to use. The side effects of endocrine therapy drugs are relatively low, generally not serious, and can be tolerated by most patients. 5. What should breast cancer patients pay attention to when receiving endocrine therapy? Although endocrine therapy has clear efficacy, low toxic side effects and high quality of life during treatment, it should not be used arbitrarily and should follow the guidance of doctors and use reasonable doses correctly. Once treatment is started, it should be adhered to the end and not abandoned halfway, otherwise the best time for treatment may be lost and the efficacy of treatment will be affected. It is very important to review regularly to evaluate the effect of treatment, and any discomfort during treatment should be reported promptly to one’s primary care physician.