美国和其他地方报道了按亚型划分的乳腺癌发病率的不同趋势；然而，这种趋势是否一直持续到 COVID-19 大流行时代仍不得而知。这项研究使用代表美国人口 83% 的高质量人口癌症登记数据，根据 2004 年至 2020 年 20-84 岁女性雌激素受体 (ER) 状态检查乳腺癌发病率。从 2004 年到 2009 年，阳性癌症每年增加 1.75%（95% 置信区间 [CI] = 1.26%-3.15%），并且从 2009 年开始放缓至每年 0.87% 的增幅（95% CI = 0.41%-1.03%）到 2019 年，发病率从 2019 年到 2020 年下降了 10.2%。尽管年轻女性（20-49 岁）、亚洲或太平洋岛民和西班牙裔女性的发病率在 2019 年之前稳步上升，但不同种族和民族的趋势总体相似。 2004年至2012年，ER阴性癌症的发病率每年下降3.13%（95% CI = -4.2%至-2.55%），2012年至2019年下降趋势稳定（年百分比变化：0.55%；95% CI = -1.30） % 降至 0.92%），随后从 2019 年到 2020 年下降了 6.0%，各年龄层以及不同种族和族裔群体的趋势总体一致。 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相背离。再加上 ER 阳性癌症增长的放缓，最新趋势表明 ER 阳性癌症比例负担之前的上升趋势可能趋于稳定。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。© 2024 UICC。

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.© 2024 UICC.