Significance of PD-L1 expression in carbon-ion radiotherapy for uterine cervical adeno/adenosquamous carcinoma

Moito Iijima, Noriyuki Okonogi, Nakako Izumi Nakajima, Yukie Morokoshi, Hiroaki Kanda, Taiju Yamada, Yusuke Kobayashi, Kouji Banno, Masaru Wakatsuki, Shigeru Yamada, Tadashi Kamada, Daisuke Aoki, Sumitaka Hasegawa

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


Objective: Programmed cell death-ligand 1 (PD-L1) is expressed in tumor cells and has been shown to predict clinical outcomes of several types of malignancies. The aim of this study was to investigate the effects of carbon-ion (C-ion) beam irradiation on PD-L1 expression in human uterine cervical adeno/adenosquamous carcinoma (UCAA) cells and clinical samples and to identify the prognostic factors for outcomes after C-ion radiotherapy (CIRT). Methods: The effects of C-ion irradiation on PD-L1 expression in human UCAA and cervical squamous cell carcinoma cells were examined by flow cytometry. We examined PD-L1 expression in UCAA biopsy specimens from 33 patients before CIRT started (pre-CIRT) and after 12 Gy (relative biological effectiveness [RBE]) irradiation (post-12Gy-C) in 4 fractions of CIRT to investigate the correlation between PD-L1 status and clinical outcomes. Results: The PD-L1 expression was upregulated by C-ion beam in a dose-dependent manner in HeLa and SiHa cells through phosphorylated Chk1. The overall frequencies of pre-CIRT and post-12Gy-C PD-L1 positivity were 45% (15/33) and 67% (22/33), respectively. The post-12Gy-C PD-L1 expression was significantly elevated compared to the pre-CIRT PD-L1 expression. There was no significant relationship between the pre-CIRT PD-L1 status and clinical outcomes, such as local control (LC), progression-free survival (PFS), and overall survival (OS). However, the post-12Gy-C PD-L1 expression had better correlation with PFS, but not with LC and OS. Conclusion: CIRT can induce PD-L1 expression in UCAA and we propose that PD-L1 expression after starting CIRT may become as a predictive prognostic marker in CIRT for UCAA.

Original languageEnglish
Article numbere19
JournalJournal of gynecologic oncology
Issue number2
Publication statusPublished - 2020


  • B7-H1 Antigen
  • Disease-free Survival
  • Heavy Ion Radiotherapy
  • Treatment Outcome
  • Uterine Cervical Neoplasms

ASJC Scopus subject areas

  • Oncology
  • Obstetrics and Gynaecology


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