Differences in PD-L1 expression on tumor and immune cells between lung metastases and corresponding primary tumors. (December 2018)

• Record Type: Journal Article
• Authors: Takamori, Shinkichi; Takada, Kazuki; Tagawa, Tetsuzo; Toyokawa, Gouji; Hirai, Fumihiko; Yamashita, Nami; Okamoto, Tatsuro; Oki, Eiji; Yoshizumi, Tomoharu; Oda, Yoshinao; Maehara, Yoshihiko
• Is Part Of: Surgical oncology. Volume 27:Number 4(2018)
• Page Start: 637
• Page End: 641
• Publication Date: 2018-12
• Subjects: Programmed cell death-ligand 1 -- Metastatic lung tumor -- Immunotherapy; Cancer -- Surgery -- Periodicals; Neoplasms -- surgery -- Periodicals; Cancer -- Chirurgie -- Périodiques; Electronic journals; 616.994059
• DOI: 10.1016/j.suronc.2018.08.001
• Languages: English
• ISSNs: 0960-7404

Abstract

Abstract: Background: It has been reported that the tumor microenvironment, including tumor-associated immune cells (ICs) and programmed cell death-ligand 1 (PD-L1) expression, differs between primary and metastatic tumors. This study aimed to elucidate the differences in PD-L1 expression on tumor cells (TCs) and ICs between lung metastases and corresponding primary tumors. Methods: We analyzed paired lesions from 44 patients diagnosed with lung metastases between 2005 and 2017 at Kyushu University. The percentages of PD-L1-positive TCs and ICs in lung metastases and the primary tumor were classified into five categories (0: <1%; 1: 1%–4%; 2: 5%–9%; 3: 10%–49%; and 4: ≥50%). Lesions in which ≥1% of the TCs and ICs were PD-L1-positive were considered positive. Results: The primary cancers included rectal (n = 19), colon (n = 10), liver (n = 10), bile duct (n = 2), stomach (n = 1), gall bladder (n = 1) and breast (n = 1). Discrepancies in PD-L1 expression on TCs and ICs between lung metastases and primary lesions were observed in 5 (11.4%, κ = 0.23) and 9 (20.5%, κ = 0.11) of the 44 cases, respectively. PD-L1 expression on ICs was higher in lung metastases than paired primary tumors ( p = 0.026), although the percentage of PD-L1-positive TCs was not significantly different between lung metastases and primary tumors ( p = 0.767). Conclusions: There were significant differences in PD-L1 expression on TCs and ICs between lung metastases and primary tumors. Clinicians should be aware of these differences in the tumor microenvironment when treating patients with immunotherapy. Highlights: Discrepancy in PD-L1 expression between primary and metastatic non-small cell lung cancer has already been reported. Relationship in PD-L1 expression between metastatic lung tumors and corresponding primary cancers was investigated. There were significant differences in PD-L1 expression on tumor/immune cells between lung metastases and primary tumors. Clinicians should be aware of the differences in PD-L1 expression when treating patients with immunotherapy.