Abstract：
Divergent trends of breast cancer incidence by subtype have been reported in the United States and elsewhere; however, it remains unknown whether this trend has continued until the era of the COVID-19 pandemic. Using high-quality population-based cancer registry data, representing 83% of the US population, this study examined breast cancer incidence rates by estrogen receptor (ER) status in women aged 20-84 years from 2004 to 2020. The incidence rate of ER-positive cancer increased by 1.75% per year from 2004 to 2009 (95% confidence interval [CI] = 1.26%-3.15%) and has slowed to a 0.87% annual increase (95% CI = 0.41%-1.03%) from 2009 to 2019, followed by a 10.2% reduction from 2019 to 2020. Trends were generally similar across race and ethnicity, although young women (20-49 years), Asian or Pacific Islander, and Hispanic women experienced steady increases until 2019. The incidence rate of ER-negative cancer decreased by 3.13% annually (95% CI = -4.2% to -2.55%) from 2004 to 2012, and the decrease stabilized from 2012 to 2019 (annual percent change: 0.55%; 95% CI = -1.30% to 0.92%), followed by a 6.0% reduction from 2019 to 2020, with trends generally consistent by age and across racial and ethnic groups. The stabilization of the steep decline in ER-negative cancer suggests a departure from the encouraging trajectories projected in earlier studies. Coupled with the deceleration in the rise of ER-positive cancer, the latest trend signals a potential stabilization in the previous rise of the proportional burden of ER-positive cancer. Understanding the impact of the pandemic on each subtype of breast cancer individually may provide a more comprehensive insight into its long-term sequelae on survival and mortality.
摘要：
在美国和其他地方已经报道了不同亚型乳腺癌发病率的不同趋势；然而，目前尚不清楚这种趋势是否一直持续到COVID-19大流行的时代。使用高质量的基于人群的癌症登记数据，占美国人口的83%，这项研究通过雌激素受体(ER)状态调查了2004年至2020年20~84岁女性的乳腺癌发病率.从2004年到2009年，ER阳性癌症的发病率每年增加1.75％（95％置信区间[CI]=1.26％-3.15％），并且从2009年到2019年已放缓至每年增加0.87％（95％CI=0.41％-1.03％），然后从2019年到2020年减少10.2％。种族和族裔之间的趋势通常相似，虽然年轻女性（20-49岁），亚洲或太平洋岛民，西班牙裔女性经历了稳定的增长，直到2019年。从2004年到2012年，ER阴性癌的发病率每年下降3.13％（95％CI=-4.2％至-2.55％），从2012年到2019年，下降幅度趋于稳定（年度百分比变化：0.55％；95％CI=-1.30％至0.92％），从2019年到2020年，下降了6.0%，各年龄以及不同种族和族裔群体的趋势基本一致。ER阴性癌症急剧下降的稳定表明与早期研究中预测的令人鼓舞的轨迹不同。再加上ER阳性癌症上升的减速，最新趋势表明ER阳性癌症的比例负担在之前的上升中可能趋于稳定.单独了解大流行对每种乳腺癌亚型的影响可能会更全面地了解其对生存和死亡率的长期后遗症。
