@article {SATO1401, author = {YUKI SATO and DAICHI FUJIMOTO and KEIICHIRO UEHARA and HAYATO KAWACHI and KAZUMA NAGATA and ATSUSHI NAKAGAWA and KOJIRO OTSUKA and ICHIRO SAKANOUE and HIROSHI HAMAKAWA and YUTAKA TAKAHASHI and YUKIHIRO IMAI and KEISUKE TOMII}, title = {Reduced Tumour Proportion Scores for Programmed Cell Death Ligand 1 in Stored Paraffin Tissue Sections}, volume = {38}, number = {3}, pages = {1401--1405}, year = {2018}, publisher = {International Institute of Anticancer Research}, abstract = {Background/Aim: We evaluated the effects of storage of formalin-fixed, paraffin-embedded (FFPE) sections on the tumour proportion score (TPS) for programmed cell death ligand 1 (PD-L1), as indicator in non-small cell lung cancer (NSCLC) tissues of treatment efficacy. Materials and Methods: NSCLC postoperative specimens with PD-L1 TPS >=50\% were obtained and cut into five serial sections. One section was stained immediately, and four were stored at 4{\textdegree}C for 2, 4, 6, or 8 weeks. Slides were subjected to PD-L1 immunohistochemistry using the anti-PD-L1 clone 28-8. PD-L1 TPS were blindly evaluated by two independent pathologists. Results: Twelve specimens (60 slides) were evaluated. After slide storage for 2, 4, 6, and 8 weeks, a TPS of \<50\% was obtained in five (41\%), four (33\%), seven (58\%), and eight (67\%) patients, respectively. Conclusion: TPS values for PD-L1 were reduced by long-term slide storage of FFPE specimens. Sectioned slides should be stained for PD-L1 without delay.}, issn = {0250-7005}, URL = {https://ar.iiarjournals.org/content/38/3/1401}, eprint = {https://ar.iiarjournals.org/content/38/3/1401.full.pdf}, journal = {Anticancer Research} }