Prognostic Value of Circulating Lymphocyte Subsets in Cervical Cancer Following Postoperative Radiotherapy

<b>Background and objective:</b> The prognostic value of circulating lymphocyte subsets in cervical cancer patients receiving postoperative radiotherapy remains unclear. This study aimed to explore the prognostic significance of these lymphocyte subsets in this patient population. <b>Methods:</b> Peripheral blood samples were collected from 101 cervical cancer patients prior to receiving postoperative radiotherapy. Flow cytometry was utilized to determine the proportions and absolute counts of lymphocyte subsets, including total T cells, CD4+ T cells, CD8+ T cells, natural killer (NK) cells, and B cells. The Kaplan-Meier method and Cox regression analysis were employed to estimate the overall survival (OS) and identify the key prognostic factors. Receiver operating characteristic (ROC) curves were generated to assess the predictive accuracy. <b>Results:</b> The survival analysis indicated that patients with a decreased proportion of NK cells (<i>P</i> = 0.02) or reduced NK cell counts (<i>P</i> = 0.01) exhibited significantly poorer overall survival (OS) compared to those with higher levels of NK cells. In univariate Cox analysis, both the proportion of NK cells (<i>P</i> = 0.025; HR, 0.33; 95% CI, 0.12-0.87) and NK cell counts (<i>P</i> = 0.015; HR = 0.28) significantly influenced OS. In multivariate analysis, the proportion of CD4+ T cells (<i>P</i> = 0.02; HR, 0.08; 95% CI, 0.01-0.72) and NK cell counts (<i>P</i> = 0.08; HR, 0.11; 95% CI, 0.01-1.37) emerged as independent prognostic factors. The areas under the ROC curves (AUCs) for NK cell counts in predicting 1-, 2-, and 3-year survival were 0.66, 0.76, and 0.68, respectively. Patients diagnosed with stage IIIC1 exhibited a significant reduction in both the absolute counts and the proportion of NK cells compared to those diagnosed with earlier stages, specifically IB3 and IIA. <b>Conclusions:</b> Our study found that pre-treatment levels of circulating NK cell counts and proportions serve as promising prognostic biomarkers for cervical cancer patients undergoing postoperative radiotherapy.