Pham Thao-Nguyen, Coupey Julie, Thariat Juliette, Valable Samuel
Université de Caen Normandie, CNRS, Normandie Université, ISTCT UMR6030, GIP CYCERON, F-14000, Caen, France; Laboratoire de Physique Corpusculaire UMR6534 IN2P3/ENSICAEN, France - Normandie Université, France; Department of Radiation Oncology, Centre François Baclesse, Caen, Normandy, France.
Université de Caen Normandie, CNRS, Normandie Université, ISTCT UMR6030, GIP CYCERON, F-14000, Caen, France.
Comput Biol Med. 2025 Mar;186:109702. doi: 10.1016/j.compbiomed.2025.109702. Epub 2025 Jan 25.
Radiation-induced lymphopenia (RIL) has been shown to adversely affect the prognosis of cancer patients undergoing radiotherapy (RT). This model-based meta-analysis investigated the prognostic significance of lymphocyte counts both early and late after RT and examined the dose‒response relationship between post-RT lymphocyte levels and patient survival.
A literature search of published articles on the effect of RIL on cancer prognosis was conducted using the PubMed and Cochrane databases. A survival model was developed, incorporating absolute lymphocyte count (ALC) thresholds during (1 month after RT initiation, nadir) and 6 months after RT (recovery) as covariates to estimate progression-free survival (PFS) and overall survival (OS). This survival model, with the lymphocyte count cutoff as a covariate, was then used to simulate the benefit of increased PFS and OS in populations without lymphopenia or severe lymphopenia compared to the total population.
A total of 35 studies met the inclusion criteria for survival analysis. Our survival model revealed an increase in survival in the subgroup without lymphopenia compared to the total population. The subgroup without lymphopenia 1 month after RT initiation showed a 10.28 % and 3.92 % increase in 24-month PFS and OS, respectively. The subgroup without lymphopenia at 6 months showed a 5.82 % and 2.78 % increase in 24-month PFS and OS, respectively.
This study highlights the critical role of lymphocyte nadir and recovery following RT in patient prognosis and strengthens the evidence for a causal relationship between RIL and patient outcomes. Expanding the dataset and including randomized controlled trials would provide a more comprehensive understanding of monitoring or knowledge of ALC profiles following RT.
辐射诱导的淋巴细胞减少症（RIL）已被证明会对接受放疗（RT）的癌症患者的预后产生不利影响。这项基于模型的荟萃分析研究了放疗早期和晚期淋巴细胞计数的预后意义，并探讨了放疗后淋巴细胞水平与患者生存率之间的剂量反应关系。
使用PubMed和Cochrane数据库对已发表的关于RIL对癌症预后影响的文章进行文献检索。建立了一个生存模型，将放疗开始后1个月（最低点）和放疗后6个月（恢复）的绝对淋巴细胞计数（ALC）阈值作为协变量，以估计无进展生存期（PFS）和总生存期（OS）。然后，将这个以淋巴细胞计数临界值作为协变量的生存模型用于模拟与总人群相比，无淋巴细胞减少症或严重淋巴细胞减少症人群中PFS和OS增加的益处。
共有35项研究符合生存分析的纳入标准。我们的生存模型显示，与总人群相比，无淋巴细胞减少症亚组的生存率有所提高。放疗开始后1个月无淋巴细胞减少症的亚组，其24个月PFS和OS分别增加了10.28%和3.92%。6个月时无淋巴细胞减少症的亚组，其24个月PFS和OS分别增加了5.82%和2.78%。
本研究强调了放疗后淋巴细胞最低点和恢复在患者预后中的关键作用，并加强了RIL与患者预后之间因果关系的证据。扩大数据集并纳入随机对照试验将有助于更全面地了解放疗后ALC谱的监测或相关知识。
