Purpose: There still exist some arguments regarding the use of postmastectomy radiotherapy (PMRT) for patients with breast cancer carrying one to three positive axillary lymph nodes considering the heterogeneity of this cohort. Here, we developed a prognostic nomogram to estimate the probability of long-term outcome in patients receiving or not receiving PMRT in order to assist in making individually locoregional treatment decisions for this particular cohort.
Methods: Altogether, 20,336 women, aged 18 to 80 years, diagnosed with breast cancer, and carrying one to three positive nodes were identified in the Surveillance, Epidemiology, and End Results (SEER) database. We applied multivariant Cox hazard model to determine the impact of covariates on disease-specific survival (DSS) and overall survival (OS). Then, the nomogram was built accordingly. Internal and external validations were performed to examine the accuracy of nomograms.
Results: Age of diagnosis, tumor grade, size, estrogen and progesterone receptor status, and number of positive nodes were independent factors of DSS and OS in the multivariate analysis. Incorporating these factors into the constructed nomogram showed high accuracy when predicting 5- and 10-year survival, with internally and externally bootstrap-corrected concordance indexes in the range of 0.6 to 0.8.
Conclusion: Besides the number of involved nodes, extra variables existed as predictors of survival outcomes in this cohort; therefore, the recommendation of PMRT or no PMRT requires comprehensive consideration. This clinically validated nomogram provided a useful tool that could aid decision making by estimating DSS and OS benefits from PMRT, useful in predicting 5- and 10-year DSS and OS for patients with one to three positive nodes after mastectomy.
Implications for practice: This study evaluated population-based data to identify prognostic factors associated with patients with breast cancer with one to three lymph nodes and help clinicians to weigh the benefit of postmastectomy radiotherapy (PMRT). Surveillance, Epidemiology, and End Results (SEER) data were used to develop a prognostic nomogram to predict the likelihood of long-term survival with and without PMRT in order to optimize the individual locoregional control strategy for this particular cohort. This clinically validated nomogram provides a useful tool to predict 5- and 10-year disease-specific survival and overall survival for patients with one to three positive nodes and can aid tailored clinical decision making by estimating predicted benefit from PMRT.
摘要
目的。考虑到这一队列的异质性，对存在1~3 个阳性腋窝淋巴结的乳腺癌患者采取乳腺切除术后放射治疗(PMRT)仍存在一些争论。在此，我们绘制了一个预测列线图来估算接受或未接受 PMRT 的患者长期预后的概率，以帮助为这一特定队列做出个体化局部治疗决定。
方法。在监测、流行病学和最终结果(SEER)数据库中，共发现 20 336 名 18 至 80 岁的女性被诊断患有乳腺癌，并存在1~3 个阳性淋巴结。我们应用多变量 Cox 风险模型来确定协变量对疾病特异性生存率(DSS)和总生存率(OS)的影响。而后，相应构建了列线图。进行了内部和外部验证，以检查列线图的准确性。
结果。在多变量分析中，诊断年龄、肿瘤分级、大小、雌激素和孕激素受体状态以及阳性淋巴结数量是 DSS 和 OS 的独立因素。在预测 5 年和 10 年生存率时，将这些因素纳入所构建的列线图中显示出了很高的准确性，内部和外部引导纠正的一致性指数在 0.6 到 0.8 之间。
结论。除了有关淋巴结的数量外，该队列中还存在作为生存结果预测因子的额外变量；因此，是否推荐 PMRT 需要综合考虑。此经临床验证的列线图提供了一个有用的工具，可以通过评估 PMRT 对 DSS 和 OS 的益处来帮助制定决策，而且对预测存在1~3 个阳性淋巴结的患者在乳腺切除术后 5 年和 10 年的 DSS 和 OS 很有用。
实践意义:本研究评估了基于人群的数据，以确定与存在1~3 个淋巴结的乳腺癌患者相关的预后因素，并帮助临床医师权衡乳腺切除术后放射治疗(PMRT)的益处。使用监测、流行病学和最终结果(SEER)数据绘制预后列线图，来预测接受或未接受 PMRT 的长期生存的可能性，以优化这一特定队列的个体化局部控制策略。此经临床验证的列线图为预测存在1~3 个阳性淋巴结患者的 5 年和 10 年疾病特异性生存率和总生存率提供了一个有用的工具，并且可以通过估计 PMRT 的预估获益来帮助制定定制化临床决策。
Keywords: Axillary lymph nodes; Breast cancer; Postmastectomy radiotherapy; Survival.
© AlphaMed Press 2019.