Impact of the COVID-19 pandemic on newly-diagnosed breast cancer

COVID-19大流行导致乳腺癌筛查和诊断的使用急剧减少 服务，乳房X光检查筛查在最低点下降了高达99%。筛查等 诊断延迟有可能导致乳腺癌人口分布的变化 特征，导致肿瘤更大，更高级别，更常见的淋巴结阳性-所有因素 与乳腺癌死亡率增加有关。在观察性研究中， 在黑人和绝经前妇女中，这表明乳腺癌分布的流行相关变化 癌症特征可能会恶化现有的乳腺癌差异。尽管有这些新出现的证据， 几乎没有真实世界的数据来量化延迟对乳腺癌流行病学的影响程度。 这种信息的缺乏阻碍了制定系统的、以证据为基础的干预措施的能力， 可能会减少过多的死亡。因此，本研究的目的是衡量大流行对 乳腺癌的流行病学，使用来自3,780名被诊断患有乳腺癌的妇女的数据， 大流行期间的北卡罗来纳州（北卡罗来纳州）医疗中心、圣雷克斯和纳什医院（2020年3月- 2021年11月），相比之下，在同一家医院诊断的8，947名乳腺癌患者在2021年11月之前， 大流行（2015年3月至2020年2月）。潜在的假设是，总体乳腺癌发病率 在大流行开始后下降，但在被诊断为肿瘤的乳腺癌中， 预后特征被过度代表。将通过以下方式对假设进行评估 具体目标：（1）通过比较大流行与大流行前乳腺癌发病率的变化， 总体发病率和根据预后特征（例如，诊断时的分期、肿瘤大小、肿瘤分级 淋巴结状态，乳腺癌亚型）;和（2）评估大流行与大流行前乳腺癌的差异。 根据社会经济地位指标的癌症发病率（例如，地区贫困指数，健康保险 状态）和与乳腺癌生存差异相关的患者因素（年龄、种族/民族）。这些趋势 将使用中断时间序列分析进行评估，这是一种严格的方法， 控制大流行前的趋势，同时测试干预措施的效果。患者癌症诊断和 个人信息将从医院癌症登记处获得，这些登记处提取高质量，标准化的 在类似数据通过其他来源公开可用之前约6个月的数据（例如，国家癌症登记处）， 从而能够及时识别乳腺癌发病率模式的变化。评估大流行病的 对乳腺癌流行病学的影响将有助于确定干预措施（例如，修改 诊断过程，针对受影响的人口统计学亚组，以减少失访等）缓解 减少与大流行病有关的护理延误的影响，并减少可归因于乳腺癌的超额死亡人数 to the pandemic流行.

The COVID-19 pandemic resulted in dramatic reductions in use of breast cancer screening and diagnostic services, with screening mammography plunging by up to 99% at the lowest point. Screening and other diagnostic delays have the potential to result in shifts in the population distribution of breast cancer characteristics, resulting in tumors that are larger, higher grade, and more often lymph node positive – all factors associated with increased breast cancer mortality. In observational studies, these effects were more pronounced among Black and premenopausal women, suggesting that pandemic-related changes in the distribution of breast cancer characteristics could worsen existing breast cancer disparities. Despite this emerging evidence, there is little real-world data that quantifies the magnitude of the delay’s effects on the epidemiology of breast cancer. This lack of information inhibits the ability to develop systematic, evidence-based interventions that might reduce excess deaths. Therefore, the objective of this study is to measure the pandemic’s impact on the epidemiology of breast cancer, using data from 3,780 women diagnosed with breast cancer at University of North Carolina (UNC) Medical Center, UNC Rex, and Nash UNC hospitals during the pandemic (March 2020- November 2021), compared to 8,947 breast cancer patients diagnosed at the same hospitals before the pandemic (March 2015-February 2020). The underlying hypothesis is that overall breast cancer incidence declined following the pandemic onset, but that among the breast cancers that were diagnosed tumors with poor prognostic characteristics were over-represented. The hypothesis will be evaluated by pursuing the following specific aims: (1) evaluating pandemic vs. pre-pandemic changes in breast cancer incidence by comparing incidence overall and according to prognostic characteristics (e.g., stage at diagnosis, tumor size, tumor grade, lymph node status, breast cancer subtype); and (2) evaluating pandemic vs. pre-pandemic differences in breast cancer incidence according to indicators of socioeconomic status (e.g., area deprivation index, health insurance status) and patient factors associated with breast cancer survival disparities (age, race/ethnicity). These trends will be evaluated using interrupted time series analysis, a methodologically rigorous approach that allows for the control of pre-pandemic trends while testing for an effect of the intervention. Patient cancer diagnosis and personal information will be obtained from hospital cancer registries, which abstract high-quality, standardized data ~6 months before similar data become publicly available through other sources (e.g., state cancer registry), allowing for the timely identification of changes in breast cancer incidence patterns. Evaluating the pandemic’s impact on the epidemiology of breast cancer will facilitate identification of interventions (e.g., modifications to the diagnostic process, targeting of affected demographic subgroups to decrease loss to follow-up, etc.) to alleviate the impact of pandemic-related delays in care and reduce the number of excess breast cancer deaths attributable to the pandemic.