Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
Department of Cancer Epidemiology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
Radiother Oncol. 2024 Oct;199:110390. doi: 10.1016/j.radonc.2024.110390. Epub 2024 Jun 17.
To evaluate the prognostic value of peripheral lymphocyte count (PLC) in the breast cancer patients after breast-conserving surgery (BCS) with radiotherapy (RT).
This post hoc analysis was performed using data of 628 patients from a phase III, randomized controlled trial comparing hypofractionated RT (HFRT) with conventional fractionated RT (CFRT) after BCS. PLCs were obtained before, during, and after RT until the 1-year follow-up. The optimal cut-off PLCs were determined using the maxstat package in R. Survival rates were estimated using the Kaplan-Meier method and compared with the log-rank test.
A total of 275 (46.1 %) patients developed lymphopenia during RT, among them, 17 (2.8 %) had grade 3 lymphopenia and no one developed grade 4 lymphopenia. With a median follow-up of 110.8 months, patients with pre-RT PLCs of < 1.77 × 10/L had a significantly lower 10-year breast cancer-specific survival (BCSS) rate (P = 0.013) and overall survival (OS) rate (P = 0.026). Patients with a nadir PLC of < 1.35 × 10/L had a significantly poorer 10-year OS rate (P = 0.048). Multivariate analysis showed that a pre-RT PLC of < 1.77 × 10/L was an independent factor influencing BCSS and OS, while the effect of the nadir PLC did not remain significant. Neither PLC nor lymphopenia recovery at post-RT 1, 3, and 6 months and 1 year was associated with survival.
Radiation-induced lymphopenia in patients with breast cancer after BCS tends to be mild. The lower pre-RT PLC predicted poorer survival.
评估保乳手术后（BCS）联合放疗（RT）的乳腺癌患者外周血淋巴细胞计数（PLC）的预后价值。
本研究为 III 期随机对照试验的事后分析，比较了 BCS 后接受低分割放疗（HFRT）与常规分割放疗（CFRT）的 628 例患者的数据。在 RT 前、RT 期间和 RT 后直至 1 年随访期间获得 PLC。使用 R 中的 maxstat 包确定最佳截断 PLC。使用 Kaplan-Meier 方法估计生存率，并使用对数秩检验进行比较。
共有 275 例（46.1%）患者在 RT 期间发生淋巴细胞减少症，其中 17 例（2.8%）发生 3 级淋巴细胞减少症，无人发生 4 级淋巴细胞减少症。中位随访时间为 110.8 个月，RT 前 PLC 值<1.77×10/L 的患者 10 年乳腺癌特异性生存率（BCSS）（P=0.013）和总生存率（OS）（P=0.026）显著降低。PLC 最低点<1.35×10/L 的患者 10 年 OS 率显著较低（P=0.048）。多因素分析显示，RT 前 PLC 值<1.77×10/L 是影响 BCSS 和 OS 的独立因素，而最低点 PLC 的影响则不再显著。RT 后 1、3、6 个月和 1 年时的 PLC 或淋巴细胞减少症恢复均与生存无关。
BCS 后乳腺癌患者的放疗诱导性淋巴细胞减少症倾向于轻度。较低的 RT 前 PLC 预示着生存较差。
