Objective: To analyze the clinicopathological characteristics of T1 breast cancer, the risk of lymph node metastasis and related prognostic factors. Methods: The National Cancer Institute Surveillance, Epidemiology and Results (SEER) database was utilized to search and screen out 73 421 female patients with T1 breast cancer from 2010 to 2015 for retrospective analysis. Logistic regression was used to assess the risk factors of lymph node metastasis. Kaplan-Meier survival analysis was used to analysis overall survival (OS) and breast cancer-specific survival (BCSS); Log-rank test and Cox risk model were used for prognostic analysis. Results: A total of 73 421 female patients were enrolled, including 61 955 (84.4%) N0 stage, 9 995 N1 stage (13.6%), 1 087 N2 stage (1.5%) and 384 N3 stage (0.5%). Patients with invasive cancer, histological grade 3, T1c stage, progesterone receptor (PR) positive and human epidermal growth factor receptor-2 (HER-2) positive were most likely to develop lymph node metastasis (all P<0.05). The median follow-up time was 55 months. The 5-year survival rate was 93.8%, and the 5-year BCSS rate was 98.2%. Cox regression analysis showed that T stage (HR=1.517, 95%CI: 1.382-1.666, P<0.01), N stage (HR=5.173, 95%CI: 4.424-6.049, P<0.01), estrogen receptor (ER) status (HR=0.774, 95%CI: 0.607-0.987, P=0.039), PR status (HR=0.745, 95%CI: 0.689-0.806, P<0.01) and subtype (HR=1.439, 95%CI: 1.078-1.478, P=0.011) were independent prognostic risk factors for the OS. Histological grade (HR=2.100, 95%CI: 1.766-2.483, P<0.01), T stage (HR=1.310, 95%CI: 1.193-1.439, P<0.01), N stage (HR=21.230, 95%CI: 17.980-25.060, P<0.01), PR status (HR=0.855, 95%CI: 0.791-0.925, P<0.01) were independent prognostic risk factors for the BCSS in T1 breast cancer. Conclusions: The lymph node metastasis rate of T1 breast cancer is low and the overall prognosis is good. Pathological type, histological grade, tumor size and subtype maybe helpful in predicting the lymph node metastasis of T1 breast cancer.
目的： 分析T1期乳腺癌临床病理特征、淋巴结转移风险及相关预后因素。 方法： 利用美国国立癌症研究所监测、流行病学和结果（SEER）数据库搜索并筛选出2010至2015年T1期乳腺癌女性患者73 421例进行回顾性分析，采用logistic回归分析淋巴结转移影响因素，Kaplan-Meier生存分析观察总生存（OS）和乳腺癌特异性生存（BCSS）；单因素log-rank检验和Cox风险模型进行预后分析。 结果： 73 421例女性患者中N0期61 955例（84.4%），N1期9 995例（13.6%），N2期1 087例（1.5%），N3期384例（0.5%）。浸润性癌、组织学分级3级、T1c期、孕激素受体（PR）阳性、分子分型为人类表皮生长因子受体2（HER-2）阳性患者更易发生淋巴结转移（均P<0.05）。中位随访时间55个月，T1期乳腺癌患者5年生存率为93.8%，5年乳腺癌特异性生存率为98.2%。多因素Cox比例风险模型回归分析结果提示T分期（HR=1.517， 95%CI：1.382~1.666，P<0.01）、N分期（HR=5.173， 95%CI：4.424~6.049，P<0.01）、雌激素受体（ER）（HR=0.774， 95%CI：0.607~0.987，P=0.039）、PR（HR=0.745， 95%CI：0.689~0.806，P<0.01）、分子分型（HR=1.439， 95%CI：1.078~1.478，P=0.011）是影响OS的预后风险因素，组织学分级（HR=2.100， 95%CI：1.766~2.483，P<0.01）、T分期（HR=1.310， 95%CI：1.193~1.439，P<0.01）、N分期（HR=21.230， 95%CI：17.980~25.060，P<0.01）、PR（HR=0.855， 95%CI：0.791~0.925，P<0.01）是影响BCSS的独立预后风险因素。 结论： T1期乳腺癌总体淋巴结转移率低，预后较好。病理类型、组织学分级、肿瘤大小、分子分型等指标有助于预测T1期乳腺癌淋巴结转移情况。.