Expression of programmed death-1 ligand-1 in esophageal squamous cell carcinoma and its effect on radiosensitivity and prognosis / 肿瘤研究与临床

ABSTRACT

Objective To investigate the relationship of programmed death ligand-1 (PD-L1) with clinicopathological characteristics,radiosensitivity and prognosis of the patients with esophageal squamous cell carcinoma(ESCC). Methods Ninety ESCC patients who received radical radiotherapy diagnosed by ESCC in Affiliated Hospital of North Sichuan Medical College were enrolled. Twenty cases of normal esophageal mucosa were used as the controls. The expression of PD-L1 was detected by using immunohistochemical SP method. Results The expression of PD-L1 protein was not correlated with age, gender, the maximum diameter of tumor, the length of lesion, the local aggressive of tumor, clinical stage and primary tumor volume (all P> 0.05). However, it was statistically correlated with the lymphatic metastasis (χ2= 4.404, P= 0.036). Meanwhile, PD-L1 positive expression was sensitive to radiation(χ2=4.888, P< 0.05). Single factor analysis showed that the maximum diameter of tumor and radiosensitivity were correlated with progression-free survival (PFS) (χ2=6.239,P =0.013;χ2=6.852,P =0.008; χ2= 6.312, P= 0.012) and overall survival (OS) (χ2=8.170, P = 0.004; χ 2= 4.261, P = 0.039; χ2= 5.003, P= 0.025) of ESCC patients. Multifactor analysis showed that the radiosensitivity and the maximum diameter of tumor affected PFS (OR= 0.512, 95 % CI 0.275-0.954, P= 0.035) and OS (OR= 0.507, 95 % CI 0.266-0.968, P= 0.039) in ESCC patients, respectively.Conclusions The level of PD-L1 expression is increased significantly in ESCC tissues compared with the normal esophageal mucosa tissues. PD-L1 may be a novel biomarker for predicting metastatic potential and radiosensitivity in ESCC patients, rather than the prognosis predictors of ESCC patients treated by radiotherapy.