Principles of drug treatment for endometrial cancer

The treatment principles for endometrial cancer should be determined based on a comprehensive consideration of factors such as clinical stage, degree of differentiation of cancer cells, and the patient's general condition. Because most endometrial cancers are adenocarcinomas, which are not sensitive to radiotherapy, surgery is the main treatment, and other comprehensive treatments include radiotherapy, chemotherapy, and other drugs. The following is a detailed introduction to the principles of drug treatment.

Progestin therapy is mostly used for cases of recurrence or metastasis after surgery or radiotherapy. It is also used for patients with well-differentiated, early-stage, young adenocarcinoma who need to preserve fertility. Progestin drugs are recommended as a component of comprehensive treatment. Progestin can also reduce the postoperative vaginal recurrence rate, so it can also be widely used as an adjuvant treatment after surgery or radiotherapy.

The mechanism of action of progesterone in treating endometrial cancer is currently believed to be that it acts directly on tumor cells, causing them to transform from malignant to normal endometrium, inhibiting the synthesis of cancer cell DNA and RNA, reducing division, and thus inhibiting the reproduction of cancer cells. Finally, the tumor is replaced by hyperplastic or atrophic endometrium.

Commonly used drugs include: medroxyprogesterone acetate, megestrolacetate, 17-hydroxyprogesterone caproate, and norgestrel.

Medroxyprogesterone acetate: Also known as medroxyprogesterone acetate. Short-acting can be taken orally; long-acting (depo-provera) is used for injection, 200-400 mg, intramuscular injection, twice a week, for 3-6 months, or after 12 weeks, change to a maintenance dose of 200 mg/d. Oral use is less common, usually for the first 5-6 weeks, at least 3 mg per week, and then 400 mg/d for long-term use.

Megestrol acetate: Trade name Funing Tablets, 40-160 mg/d, after oral administration for 12 weeks, change to maintenance dose of 500 mg, twice a week.

Progesterone acetate: 500 mg/d, intramuscular injection, once a day. After 12 weeks, change to 500 mg, twice a week, for a total of 6 months.

The objective efficacy of progestin-based drugs in treating endometrial cancer is between 30 and 35 percent, with sustained remission and even cure rates of about 90 percent.

Progestogens are non-cytotoxic drugs with high safety and little toxicity. Common side effects include mild water and sodium retention and digestive tract reactions, and other side effects include hypertension, acne, breast pain, etc. 0.6% may have allergic reactions, but no death has been caused. Patients with impaired heart, liver, and kidney function should use them with caution.

Anti-estrogen drug treatment Tamoxifen is a non-steroidal anti-estrogen drug that has a slight androgenic effect. It competes with estradiol for estrogen receptors (ER), occupies the receptors and acts as an anti-estrogen. After taking this drug, the PR in the tumor increases, which is conducive to progesterone treatment. It is usually used for advanced cases, postoperative recurrence or metastasis. It can be used alone (progesterone treatment is ineffective) or with pregnancy hormones, or combined with chemotherapy drugs.

The dosage is 20 mg/d, taken orally. If the effect is not obvious after a few weeks, the dosage can be doubled. It has been reported that the loading dose for the first application is 80 mg/d. Side effects include nausea, vomiting, rash, hot flashes, bone marrow suppression, thrombocytopenia, vaginal bleeding, hypercalcemia, etc.