Reliability of Small Biopsy Samples Compared With Resected Specimens for the Determination of Programmed Death-Ligand 1 Expression in Non--Small-Cell Lung Cancer.
BACKGROUND
Several studies have assessed the expression of programmed death-ligand 1 (PD-L1) in resected surgical specimens of non-small-cell lung cancer (NSCLC). However, the expression of PD-L1 in smaller biopsy samples of advanced NSCLC has not been reported.


METHODS
A total of 79 patients with NSCLC at our institution with available biopsy samples and resected specimens were retrospectively enrolled in the present study. PD-L1 expression was assessed by immunohistochemistry and scored using the hybrid scoring method. The concordance rates for the expression of PD-L1 between the 2 samples were analyzed.


RESULTS
The pathologic stage of the patients (51 men, 28 women; median age, 68 years) was stage I in 37, stage II in 18, and stage III in 24. The diagnostic procedures included transbronchial biopsy in 59, transbronchial needle aspiration biopsy in 14, and computed tomography (CT)-guided needle biopsy in 6. The positivity rate of PD-L1 in these samples was 38.0% (27 transbronchial biopsies, 6 transbronchial needle aspiration biopsies, 3 CT-guided needle biopsies) versus 35.4% in the resected specimens. The median hybrid score was 0 (range, 0-170), and the mean score was 28.7 ± 43.4. Comparing the biopsy samples and resected specimens with a score of ≥ 1 as positive for PD-L1 staining, 6 tumors were discordant for PD-L1 expression and 73 were concordant, for a concordance rate of 92.4% and κ value of 0.8366.


CONCLUSIONS
PD-L1 status showed good concordance between the biopsy samples and resected specimens. These small samples, even those derived from transbronchial needle aspiration biopsies, appear adequate for the assessment of PD-L1 expression.
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan; Department of Thoracic Medical Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
Satoru
S
Kitazono
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan; Department of Experimental Therapeutics, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center Hospital, Tokyo, Japan. Electronic address: yutakafu@ncc.go.jp.
Yutaka
Y
Fujiwara
Department of Pathology, National Cancer Center Hospital, Tokyo, Japan.
Koji
K
Tsuta
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan.
Hirofumi
H
Utsumi
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan.
Shintaro
S
Kanda
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan.
Hidehito
H
Horinouchi
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan.
Hiroshi
H
Nokihara
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan; Department of Experimental Therapeutics, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center Hospital, Tokyo, Japan.
Noboru
N
Yamamoto
Department of Endoscopy, Respiratory Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan.
Shinji
S
Sasada
Department of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan.
Shun-ichi
S
Watanabe
Department of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan.
Hisao
H
Asamura
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan.
Tomohide
T
Tamura
Department of Thoracic Oncology, National Cancer Center Hospital, Tokyo, Japan.
Yuichiro
Y
Ohe
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060890:B7-H1 Antigen / Q000235:genetics*; D001706:Biopsy / Q000379:methods; D001707:Biopsy, Needle / Q000379:methods; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
D060890:B7-H1 Antigen
Concordance rate; Immunohistochemistry; Operative; Surgical procedures