PD-1 Expression Status on CD8+ Tumour Infiltrating Lymphocytes Associates With Survival in Cervical Cancer
Fan P., Li X., Feng Y., Cai H., Dong D., Peng Y., Yao X., Guo Y., Ma M., Dong T., Wang R.
Despite the expansion of PD-1 checkpoint blockade to multiple types of cancer, whether the programmed cell death 1 (PD-1) expression status on CD8+ tumour infiltrating lymphocytes (TILs) could be a prognostic factor in cervical cancer is still unclear. In this study, we performed ex vivo phenotypic analysis of PD-1 expression on CD8+ TILs by flow cytometry from 47 treatment-naïve cervical cancer patients. With a median follow-up of 26.1 months (95% confidence interval [CI], 24-28.2 months), we then linked the quantitative cellular expression results to progression-free survival and overall survival. Based on the intensity of PD-1 expression, we further categorised the cervical cancer patients into PD-1high expressers (29.8%, 14/47) and PD-1low expressers (70.2%, 33/47). Multivariate analysis revealed that PD-1high expressers are correlated with early recurrence (HR, 5.91; 95% CI, 1.03-33.82; P= 0.046). Univariate analysis also demonstrated that PD-1high expressers are associated with poor overall survival in cervical cancer (HR, 5.365; 95% CI, 1.55-18.6; P=0.008). Moreover, our study also demonstrated that CD8+/CD4+ TIL ratio and HPV infection status are risk factors for early relapse and mortality in cervical cancer patients. In conclusion, this study confirms that PD-1 expression status is an independent prognostic factor for progression free survival in cervical cancer. These findings could be important in predicting the relapse of cervical cancer as a cellular diagnosis method and could be important knowledge for the selection of prospective PD-1 blockade candidates.