METHODS: All Belgian residents diagnosed with in situ or invasive BC in 2015-2020 in the nationwide, population-based cancer registry database were included. Incidence trends for 2015-2019 were extrapolated to predict incidence and stage distribution for 2020 and compared with the observed values. National healthcare reimbursement data were used to examine treatment strategies. Exact tumor diameter and nodal involvement, extracted from pathology reports, were analyzed for 2019 and 2020.
RESULTS: 74,975 tumors were selected for analysis of incidence and clinical stage. Invasive BC incidence declined by -5.0% in 2020, with a drop during the first COVID-19 wave (Mar-Jun; -23%) followed by a rebound (Jul-Dec; +7%). Predicted and observed incidence (in situ + invasive) was not different in patients < 50 years. In the 50-69 and 70 + age groups, significant declines of -4.1% and - 8.4% respectively were found. Excess declines were seen in clinical stage 0 and I in Mar-Jun, without excess increases in clinical stage II-IV tumors in Jul-Dec. There was no increase in average tumor diameter or nodal involvement in 2020. Patients diagnosed in Mar-Jun received significantly more neoadjuvant therapy, particularly neoadjuvant hormonal therapy for patients with clinical stage I-II BC.
CONCLUSIONS: BC incidence decline in 2020 in Belgium was largely restricted to very early-stage BC and patients aged 50 and over. Delayed diagnosis did not result in an overall progression to higher stage at diagnosis in 2020. Observed treatment adaptations in Belgium were successful in prioritizing patients for surgery while preventing tumor progression in those with surgical delay. Continuation of monitoring BC incidence and stage in the future is crucial.
方法:2015-2020年在全国范围内诊断为原位或侵袭性BC的所有比利时居民,纳入了基于人群的癌症登记数据库.对2015-2019年的发病率趋势进行推断,以预测2020年的发病率和分期分布,并与观测值进行比较。国家医疗保健报销数据用于检查治疗策略。确切的肿瘤直径和淋巴结受累,从病理报告中提取,对2019年和2020年进行了分析。
结果:选择74,975个肿瘤进行发病率和临床分期分析。侵袭性BC发病率在2020年下降了-5.0%,在第一次COVID-19浪潮期间下降了(3月至6月;-23%),随后反弹(7月至12月;+7%)。预测和观察到的发病率(原位+侵入性)在<50岁的患者中没有差异。在50-69岁和70岁以上的年龄组中,分别显着下降了-4.1%和-8.4%。在3月至6月的临床0期和I期出现了过度下降,在7月至12月,临床II-IV期肿瘤没有过度增加2020年,平均肿瘤直径或淋巴结受累没有增加。在Mar-Jun诊断的患者接受了更多的新辅助治疗,特别是临床I-II期BC患者的新辅助激素治疗。
结论:2020年比利时的BC发病率下降主要限于非常早期的BC和50岁及以上的患者。延迟诊断并未导致2020年诊断时整体进展到更高阶段。在比利时观察到的治疗适应措施成功地优先考虑了手术患者,同时防止了手术延迟患者的肿瘤进展。未来继续监测BC的发病率和阶段至关重要。