title: EBUS-TBNA as a Promising Method for the Evaluation of Tumor PD-L1 Expression in Lung Cancer.
abstract: Because most lung cancers are diagnosed at advanced stages, we are forced to conduct molecular testing using small biopsy samples. Endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) is emerging as a minimally invasive biopsy technique. Here, we examined the usefulness of EBUS-TBNA to evaluate programmed death-ligand 1 (PD-L1) expression in lung cancer.
  
  
  
  Using 97 consecutive cases of lung cancer diagnosed by EBUS-TBNA, from which 20 transbronchial biopsy (TBB) samples were available, we evaluated the number and morphological intactness of tumor cells in EBUS-TBNA and TBB samples. Additionally, given the intratumoral heterogeneity in primary lesions and the small sample size of biopsies, we also compared the tumor PD-L1 expression between the biopsy samples and the corresponding surgical materials.
  
  
  
  EBUS-TBNA collected a significantly larger number of tumor cells than TBB (P < .001); the median number (interquartile range) of cells was 1149 (379-3334) in EBUS-TBNA and 435 (218-1085) in TBB. The crush rate in EBUS-TBNA was significantly lower than in TBB (P < .001). These showed the excellence of EBUS-TBNA. Additionally, PD-L1 positivity of EBUS-TBNA showed a good concordance with the corresponding primary tumor (r = 0.75; P = .086; n = 6) as well as with lymph node metastasis (r = 0.93; P = .02; n = 5). Moreover, PD-L1 positivity between EBUS-TBNA and TBB (n = 16), TBB and the corresponding primary tumor (n = 41), and lymph node metastasis and the corresponding primary tumor (n = 47) showed a moderate correlation (all r > 0.48; all P < .001), strengthening the potential concordance between EBUS-TBNA and primary tumor in PD-L1 positivity.
  
  
  
  Our study suggests EBUS-TBNA as a promising method to evaluate PD-L1 expression in lung cancer.
authors.affiliation: Division of Pathology, The Cancer Institute, Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan; Department of Integrated Pulmonology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Sakakibara
authors.affiliation: Division of Pathology, The Cancer Institute, Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Inamura
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tambo
authors.affiliation: Division of Pathology, The Cancer Institute, Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Ninomiya
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Kitazono
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Yanagitani
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Horiike
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Ohyanagi
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Matsuura
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakao
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Mingyon
authors.initials: M
authors.lastname: Mun
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Sakae
authors.initials: S
authors.lastname: Okumura
authors.affiliation: Department of Integrated Pulmonology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Inase
authors.affiliation: Thoracic Oncology Center, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishio
authors.affiliation: Division of Pathology, The Cancer Institute, Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan; Department of Pathology and Clinical Laboratories, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Motoi
authors.affiliation: Division of Pathology, The Cancer Institute, Department of Pathology, The Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan. Electronic address: ishikawa@jfcr.or.jp.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishikawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060890:B7-H1 Antigen / Q000378:metabolism*; D001999:Bronchoscopy; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008198:Lymph Nodes / Q000378:metabolism* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged
chemical_list: D060890:B7-H1 Antigen; C423236:CD274 protein, human
keywords: EBUS-TBNA; Immunotherapy; Lung cancer; PD-L1; TBB