Functions and indications: 1. After 2-3 years of adjuvant tamoxifen treatment, exemestane tablets are used for the adjuvant treatment of early invasive breast cancer in postmenopausal women with positive estrogen receptors, until a total of 5 years of adjuvant endocrine therapy is completed. 2. Advanced breast cancer in natural or artificial postmenopausal women whose disease has progressed after tamoxifen treatment. 3. The efficacy of this product in patients with negative estrogen receptors is not yet clear. Exemestane capsules: Suitable for postmenopausal patients with advanced breast cancer whose disease has progressed after tamoxifen treatment Usage and dosage: The dosage and dosage of this product may vary for different dosage forms and specifications. Please read the specific drug instructions for use, or follow the doctor's advice. Adult and elderly patients: Exemestane tablets: The recommended dose for the treatment of early and advanced breast cancer patients is 25 mg, once a day, one tablet each time, and it is recommended to take it after meals. After 2-3 years of tamoxifen treatment, patients with early breast cancer should continue to use this product for treatment if there is no recurrence or contralateral breast cancer until 5 years of combined sequential adjuvant endocrine therapy (i.e., tamoxifen followed by exemestane) are completed. Patients with advanced breast cancer should continue to take this product until tumor progression. The combined use of strong inducers of cytochrome P-450 (CYP) 3A4 will reduce the exposure of exemestane. When patients are also receiving strong inducers of CYP3A4, such as rifampicin and phenytoin, the recommended dose of this product is 50 mg, once a day, after meals (see [Drug Interactions] and [Pharmacokinetics]). [Exemestane Capsules] 1 capsule (25 mg) once a day, orally after meals. Patients with mild hepatic and renal insufficiency do not need to adjust the dosage. Adverse reactions: 1. Among patients with early breast cancer who received adjuvant therapy with tamoxifen followed by exemestane, 7.4% of patients withdrew from treatment due to adverse events. The most commonly reported adverse reactions were mild to moderate hot flashes (22%), arthralgia (18%), fatigue (16%), headache (13.1%), insomnia (12.4%), and increased sweating (11.8%). 2. Discontinuation due to adverse events was similar in the exemestane and tamoxifen groups (6.3% vs 5.1%). The incidence of myocardial ischemic events (myocardial infarction, angina, myocardial ischemia) was 1.6% in the exemestane group and 0.6% in the tamoxifen group. The incidence of heart failure: 0.4% in the exemestane group and 0.3% in the tamoxifen group. 3. Among all patients with advanced breast cancer, the proportion of withdrawal from the study due to adverse events was 2.8%. The most commonly reported adverse reactions were hot flashes (14%), nausea (12%), fatigue (8%), increased sweating (4%), and increased appetite (3%). 4. Most adverse reactions are normal pharmacological reactions (such as hot flashes) caused by the blockade of estrogen production. Contraindications: Contraindicated for use in patients with known allergies to the active ingredients of the drug or any excipients, as well as premenopausal and pregnant or lactating women