FoxP3+ regulatory T cells in oral tongue squamous cell carcinoma in young and older patients

Abstract Regulatory T (Treg) cells can suppress antitumor immune response, but little is known about possible age-related differences in the number of these cells in the microenvironment of oral tongue squamous cell carcinoma (OTSCC). The aim of this study was to determine the number of FoxP3+ Treg cells in the microenvironment of OTSCC in young (≤ 45 years) and older (≥ 60 years) patients, and to correlate the findings with clinicopathological parameters (sex, tumor size/extent, regional lymph node metastasis, clinical staging, and histopathological grade of malignancy). Forty-eight OTSCCs (24 diagnosed in young patients and 24 diagnosed in older patients) were selected. Lymphocytes exhibiting nuclear immunopositivity for FoxP3 were quantified at the tumor invasive front and the results were analyzed statistically using the non-parametric Mann-Whitney test. FoxP3+ lymphocytes were observed in all cases assessed. The number of FoxP3+ lymphocytes in OTSCC tended to be higher in older patients (p = 0.055). Analysis of OTSCC in males and in early clinical stages revealed a higher number of Treg cells in older patients than in young ones (p < 0.05). In older patients, the number of Treg cells tended to be higher in smaller tumors (p = 0.079). Tumors with intense inflammatory infiltrate exhibited a larger number of Treg cells, both in young (p = 0.099) and older patients (p = 0.005). The results suggest a greater participation of Treg cells in immunoinflammatory responses in the microenvironment of OTSCC in older patients, particularly in males and in early stages.

调节性T细胞（Regulatory T cells, Treg）可抑制抗肿瘤免疫应答，但目前对于口腔舌鳞状细胞癌（oral tongue squamous cell carcinoma, OTSCC）微环境中此类细胞的数量是否存在年龄相关差异，仍知之甚少。本研究旨在探究年轻（≤45岁）与老年（≥60岁）口腔舌鳞状细胞癌患者肿瘤微环境中FoxP3+ Treg细胞的数量，并将该结果与临床病理参数（性别、肿瘤大小/侵犯范围、区域淋巴结转移、临床分期以及恶性组织学分级）进行相关性分析。本研究共纳入48例口腔舌鳞状细胞癌标本，其中年轻患者组24例，老年患者组24例。对肿瘤侵袭前沿区域中FoxP3核免疫阳性的淋巴细胞进行计数，并采用非参数曼-惠特尼检验（non-parametric Mann-Whitney test）开展统计学分析。所有受试标本均检测到FoxP3+淋巴细胞。老年患者口腔舌鳞状细胞癌组织中FoxP3+淋巴细胞的数量呈升高趋势（p = 0.055）。对男性患者及临床早期患者的亚组分析显示，老年患者的Treg细胞数量显著高于年轻患者（p < 0.05）。在老年患者中，肿瘤体积较小者的Treg细胞数量呈升高趋势（p = 0.079）。无论年轻还是老年患者，伴明显炎性浸润的肿瘤组织中Treg细胞数量均更多：年轻患者组（p = 0.099），老年患者组（p = 0.005）。本研究结果提示，Treg细胞在老年口腔舌鳞状细胞癌患者的肿瘤微环境免疫炎性应答中参与度更高，尤其在男性患者及临床早期病例中更为显著。