Clinical research evidence and types of evidence Evidence for breast-conserving treatment of early breast cancer 1. Breast-conserving treatment (breast-conserving surgery followed by radiotherapy) and radical surgery (or modified radical surgery) are equally effective, with no difference in survival and distant metastasis rates, and breast-conserving treatment should be pursued in appropriate patients (Class I evidence). 2.For most early stage breast cancer, axillary lymph node dissection at level I and II is the standard treatment (Class II evidence). 3. Radiation therapy after complete local tumor resection significantly reduces the rate of local recurrence and decreases the likelihood of further mastectomy. Postoperative radiotherapy should not be omitted even in selective patients (Class I evidence). 4. Radiation therapy after breast-conserving surgery for intraductal breast cancer significantly reduces local recurrence (Class I evidence). Evidence of postoperative adjuvant therapy 1. Postoperative radiotherapy in high-risk patients after radical breast cancer significantly reduces the rate of local regional recurrence and improves long-term survival (Class I evidence). 2. Ovariectomy reduces recurrence and mortality in female breast cancer patients less than 50 years of age (Class I evidence). 3. In patients less than 70 years of age, combination chemotherapy reduces recurrence rates and mortality (Class I evidence). 4.The efficacy of 4-6 months of combination chemotherapy is better than less than 4 months of chemotherapy, and the efficacy of 4-6 months of chemotherapy and 8 months of chemotherapy is the same, but the latter has increased toxic side effects (Class I evidence). 5, Combination chemotherapy regimens containing adriamycin were superior to CMF regimens, improving overall survival and disease-free survival, but with increased risk of alopecia, cardiotoxicity, and febrile neutropenia (Class I evidence). 6. High-dose chemotherapy was limited to clinical studies rather than conventional therapeutic approaches (Class II evidence). 7. Triamcinolone significantly improves overall survival and disease-free survival in estrogen receptor-positive patients regardless of age, primary tumor size, axillary lymph node status, and menopausal status (Class I evidence). Triamcinolone reduces the incidence of contralateral breast cancer (Class I evidence). 1. The potential toxicities of triamcinolone include endometrial cancer, pulmonary embolism, deep vein thrombosis, and vaginal dryness, which are negligible compared to its therapeutic gains (Class II evidence). 2. Chemotherapy combined with triamcinolone improves disease-free survival compared with triamcinolone alone or chemotherapy alone (Class I evidence). 3. There is no evidence that close follow-up improves survival or enhances quality of survival (Class II evidence).