Background Approximately 40,000 individuals die from metastatic breast cancer each year. We examined what fractions of annual breast cancer-specific death (BCSD) are due to stage I, II, III, IV disease and if these proportions changed over time. Methods We used data from SEER covering 1975 to 2017. After filtering for female sex at birth, one primary tumor type, surgery, AJCC (6th edition) stage > 0, no bilateral cancer, and survival data available, the final analysis included 972,763 patients. Temporal trends were assessed using a linear model and ANOVA test. Results The contribution of stage I and II cancers to BCSD increased significantly from 16.2% to 23.1%, and from 30.7% to 39.5%, respectively between 2000 and 2017. The contribution of stages III and IV cancers decreased from 36.4% to 30.3%, and from 16.7% to 7.1%. In 2000, 0.92%, 4.0% and 10.7% of BCSD were due to T1a, T1b, and T1c node-negative cancers which increased significantly to 1.9%, 5.8%, and 14.7% by 2017. These temporal trends were similar for hormone receptor-positive and -negative cancers. The contribution of BCSD to all-cause mortality declined from 23.9% to 16.6% for stage I, and from 47.7% to 36.9% for stage II cancers by 2017. Conclusions Patients with stage I/II breast cancers have excellent prognosis, yet these cancers account for over 60% of current BCSD because of their large absolute numbers. To further reduce breast cancer death strategies are needed to identify and treat patients with stage I/II disease who remain at risk for recurrence.

中文翻译：

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2000 年至 2017 年诊断时按临床分期划分的乳腺癌特异性死亡趋势


背景每年大约有 40,000 人死于转移性乳腺癌。我们研究了每年乳腺癌特异性死亡 (BCSD) 中由 I、II、III、IV 期疾病引起的比例以及这些比例是否随时间变化。方法 我们使用了涵盖 1975 年至 2017 年 SEER 的数据。在筛选出生时女性、一种原发肿瘤类型、手术、AJCC（第 6 版）分期 > 0、无双侧癌症以及可用的生存数据后，最终分析包括 972,763患者。使用线性模型和方差分析测试评估时间趋势。结果 2000年至2017年间，I期和II期癌症对BCSD的贡献分别从16.2%显着增加至23.1%，从30.7%显着增加至39.5%。III期和IV期癌症的贡献从36.4%下降至30.3%，并从 16.7% 降至 7.1%。 2000 年，0.92%、4.0% 和 10.7% 的 BCSD 是由 T1a、T1b 和 T1c 淋巴结阴性癌症引起，到 2017 年，这一数字显着增加至 1.9%、5.8% 和 14.7%。这些时间趋势与激素受体相似-阳性和阴性癌症。到 2017 年，BCSD 对 I 期癌症的全因死亡率的影响从 23.9% 下降到 16.6%，对 II 期癌症的影响从 47.7% 下降到 36.9%。 结论 I/II 期乳腺癌患者预后良好，但这些癌症由于其绝对数量较大，因此占当前 BCSD 的 60% 以上。为了进一步减少乳腺癌死亡，需要采取策略来识别和治疗仍有复发风险的 I/II 期疾病患者。