This study examines the effect of COVID-19 pandemic and associated lockdowns on access to crucial diagnostic procedures for breast cancer patients, including screenings and treatments. To quantify the impact of the lockdowns on patient outcomes and cost, the study employs a mathematical model of breast cancer progression. The model includes ten different states that represent various stages of health and disease, along with the four different stages of cancer that can be diagnosed or undiagnosed. The study employs a natural history stochastic model to simulate the progression of breast cancer in patients. The model includes transition probabilities between states, estimated using both literature and empirical data. The study utilized a Markov Chain Monte Carlo simulation to model the natural history of each simulated patient over a seven-year period from 2019 to 2025. The simulation was repeated 100 times to estimate the variance in outcome variables. The study found that the COVID-19 pandemic and associated lockdowns caused a significant increase in breast cancer costs, with an average rise of 172.5 million PLN (95% CI [82.4, 262.6]) and an additional 1005 breast cancer deaths (95% CI [426, 1584]) in Poland during the simulated period. While these results are preliminary, they highlight the potential harmful impact of lockdowns on breast cancer treatment outcomes and costs.

翻译：本研究探讨了COVID-19大流行及相关封锁措施对乳腺癌患者关键诊断程序（包括筛查与治疗）可及性的影响。为量化封锁对患者预后及医疗成本的影响，本研究采用乳腺癌进展数学模型。该模型包含十个不同状态，分别代表健康与疾病各阶段，以及四种可诊断或未诊断的癌症分期。研究采用自然病程随机模型模拟乳腺癌患者的疾病进展过程。模型中的状态间转移概率基于文献数据与实证数据联合估计。研究运用马尔可夫链蒙特卡洛模拟，在2019至2025年共七年的周期内模拟每位患者的自然病程。为估算结果变量的变异程度，该模拟过程重复执行100次。研究发现，COVID-19大流行及相关封锁措施导致乳腺癌诊疗成本显著上升，在模拟期间波兰平均增加1.725亿波兰兹罗提（95%置信区间[0.824亿，2.626亿]），并额外造成1005例乳腺癌死亡（95%置信区间[426例，1584例]）。尽管这些结果为初步结论，但凸显了封锁措施对乳腺癌治疗结局及医疗成本可能产生的有害影响。