Immunohistochemistry of immune checkpoint markers PD-1 and PD-L1 in prostate cancer

45Citations
Citations of this article
38Readers
Mendeley users who have this article in their library.
Get full text

Abstract

Recent availability of immune checkpoint inhibitors has facilitated research involving programmed cell death protein 1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1). However, the incidence and clinical implication of PD-1 and PD-L1 expression in prostate cancer remain poorly understood. The current study aimed to determine the status of PD-1/PD-L1 expression in prostate cancer specimens and its prognostic significance.We immunohistochemically stained for PD-1 and PD-L1 in our tissue microarray (TMA) consisting of radical prostatectomy specimens. The expression of PD-1/PD-L1 was designated as positive when moderate to strong staining or weak staining was seen in at least 1% or 10%, respectively, of tumor cells and/or associated immune cells. We then evaluated the relationship between the expression of each protein and clinicopathological features available for our patient cohort.PD-1 and PD-L1 were positive in 3 (1.5%) and 1 (0.5%) of 201 non-neoplastic prostate tissues, and also in 17 (7.7%) and 29 (13.2%) of 220 prostate cancers, respectively. PD-1 and PD-L1 were also expressed in tumor-infiltrating lymphocytes/macrophages in 172 (78.2%) and 33 (15.0%) cases, respectively. PD-L1 expression in tumor cells was more often seen in high pT stage (pT2: 10.8% vs pT3/4: 20.4%; P=.072; pT2/3a: 11.4% vs pT3b/4: 31.6%; P=.013) or lymph node-positive (pN0: 10.1% vs pN1: 27.3%; P=.086) cases, whereas PD-1 expression in tumor cells was not significantly associated with pT/pN stage. In addition, there were no statistically significant associations between PD-1/PD-L1 expression in tumor cells or tumor-infiltrating lymphocytes/macrophages versus patient age, preoperative prostate-specific antigen level, or Gleason score. Kaplan-Meier analysis coupled with log-rank test further revealed no significant associations between PD-1/PD-L1 expression in tumor cells (P=.619/P=.315), tumor-infiltrating lymphocytes/macrophages (P=.954/P=.155), or either or both of them (P=.964/P=.767) versus disease recurrence after radical prostatectomy.PD-1/PD-L1 expression was detected in a subset of prostate cancers. In particular, PD-L1 expression was considerably up-regulated in nonorgan-confined tumors. However, PD-1/PD-L1 expression in our TMA was found to be not very helpful in predicting tumor recurrence in prostate cancer patients who underwent radical prostatectomy.

Cite

CITATION STYLE

APA

Sharma, M., Yang, Z., Miyamoto, H., & Lucarelli, G. (2019). Immunohistochemistry of immune checkpoint markers PD-1 and PD-L1 in prostate cancer. Medicine (United States), 98(38). https://doi.org/10.1097/MD.0000000000017257

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free