Koukourakis Ioannis M, Georgakopoulos Ioannis, Desse Dimitra, Tiniakos Dina, Kouloulias Vassilios, Zygogianni Anna
Radiation Oncology Unit, 1st Department of Radiology, Medical School, Aretaieion Hospital, National and Kapodistrian University of Athens, Athens, Greece.
Department of Pathology, Aretaieion University Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
Radiat Oncol J. 2024 Dec;42(4):263-272. doi: 10.3857/roj.2024.00052. Epub 2024 Dec 23.
Neoadjuvant radiotherapy (RT) or chemoradiotherapy (CRT) is the standard treatment for locally advanced rectal adenocarcinoma. The recent emerging data on preoperative immunotherapy as an effective therapeutic modality for mismatch repair deficient rectal carcinomas suggests that the immune system plays a significant role in tumor eradication. Although RT has been shown to stimulate anti-tumor immunity, it also leads to substantial lymphopenia, hindering the effect of immune response.
We retrospectively analyzed 33 rectal adenocarcinoma patients who underwent CRT in our department, aiming to identify the effects of CRT on the peripheral blood lymphocyte counts (LC) and the potential impact of CRT-induced lymphopenia on tumor response and prognosis of patients.
A statistically significant decrease in the LC of patients was observed after CRT (median values of 2,184/μL and 517/μL before and after treatment, respectively; p < 0.001). While no correlation between ypT-stage, ypN status, and LC was found, poor tumor regression grade was significantly associated with lower LC (p = 0.036). Moreover, lymphopenia was associated with poorer distant metastasis-free survival (p = 0.003). Distant metastases were documented in 0% of patients with post-CRT LC above 518/μL vs. 44.5% of patients with lower LC values.
Although further investigation is demanded, given the limited number of patients analyzed in the study, lymphopenia emerges as a significant adverse event that rectal adenocarcinoma patients face during treatment with neoadjuvant CRT, with subsequent implications on tumor response and prognosis. Protection of the immune system during CRT emerges as an important target for clinical research.
新辅助放疗（RT）或放化疗（CRT）是局部晚期直肠腺癌的标准治疗方法。最近关于术前免疫治疗作为错配修复缺陷型直肠癌有效治疗方式的新出现的数据表明，免疫系统在肿瘤根除中起重要作用。虽然放疗已被证明可刺激抗肿瘤免疫，但它也会导致严重的淋巴细胞减少，从而阻碍免疫反应的效果。
我们回顾性分析了在我科接受CRT治疗的33例直肠腺癌患者，旨在确定CRT对外周血淋巴细胞计数（LC）的影响，以及CRT诱导的淋巴细胞减少对患者肿瘤反应和预后的潜在影响。
CRT治疗后患者的LC出现统计学上的显著下降（治疗前和治疗后的中位数分别为2,184/μL和517/μL；p < 0.001）。虽然未发现ypT分期、ypN状态与LC之间存在相关性，但较差的肿瘤退缩分级与较低的LC显著相关（p = 0.036）。此外，淋巴细胞减少与较差的无远处转移生存期相关（p = 0.003）。CRT后LC高于518/μL的患者中0%发生远处转移，而LC值较低的患者中这一比例为44.5%。
尽管鉴于本研究分析的患者数量有限，需要进一步研究，但淋巴细胞减少是直肠腺癌患者在接受新辅助CRT治疗期间面临的一个重要不良事件，随后会对肿瘤反应和预后产生影响。在CRT期间保护免疫系统成为临床研究的一个重要目标。
