OBJECTIVE In Europe and America breast cancer commonly occurs in women of middle and old age, with a median age of about 57 years. Modified radical mastectomy now called standard radical mastectomy, has taken the place of traditional radical mastectomy. Patients with breast cancer at an early stage commonly receive BCT (breast conservative therapy). The TNM stage (especially the lymph node status) affects the prognosis, and adjuvant therapy can improve survival. In China, only a few reports have been pubIished studying large numbers of breast cancer patients. This study was designed to analyze the clinical features, surgical pattern and treatment outcome of resectable breast cancer, as well as to explore the prognostic factors and the effect of adjuvant therapy, with a goal to improve the level of diagnosis and treatment.METHODS Records of the 6,263 patients with resectable breast cancer who had been admitted into our hospital from June 1964 to June 2003 were analyzed retrospectively.RESULTS Of the 6,263 cases, 98.8% were female. Breast cancer occurred most frequently in patients of ages 40～49 years (41.0%), especially in patients 45～49 years old (25.2%). A breast lump, which occurred in 96.2% of the patients, was the main clinical manifestation. The overall 5- and 10-year survival rates were 75.16% and 40.44%. Of the patients in TNM stages 0-1,Ⅱ, and Ⅲ, the 5-year survival rates were 96.8%, 73.7% and 46.4% respectively and the 10-year survival rates were 78.7%, 64.6% and 33.5% respectively. The 5-, and 10-year survival rates were higher in the lymph node negative group than in the lymph node positive group (80.3% vs. 55.6%, and 59.2% vs. 31.9%, P＜0.01). Since the 1980s there was no significant difference in survival rates of patients who received a radical mastectomy compared to a modified radical mastectomy(P＞0.05). Of the 73 patients who underwent breast conservative therapy, no local recurrence or metastasis occurred during a maximal follow-up of 17 years. Of the patients in stage T2T4, the 5-, and 10-year survival rates were significantly higher in the group treated with adjuvant chemotherapy compared to the non-chemotherapy group (78.2% vs. 60.1%, and 48.9% vs. 30.7%, P＜0.01).CONCLUSION According to our data, breast cancer most frequently occurred in patients of ages 45～49 years. The TNM stage (especially the lymph node status) relates to breast cancer prognosis. The prognosis was worse in patients with positive lymph nodes compared to the patients with negative lymph nodes. The efficacy of a modified radical mastectomy is equal to that of a radical mastectomy, and breast conservative therapy can be applied to patients in an early stage. Adjuvant chemotherapy and endocrine therapy can improve the survival of resectable breast cancer patients.