KEIO RESEARCHERS INFORMATION SYSTEM

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• 博士（医学）, Keio University, 2010.01

Licenses and Qualifications 【 Display / hide 】

Licenses and Qualifications 【 Display / hide 】

• 耳鼻咽喉科専門医, 2003.09

• 日本癌治療医認定医機構　癌治療認定医, 2008.04

• 日本頭頸部外科学会　頭頸部がん専門医, 2010.10

Research Areas 【 Display / hide 】

Research Areas 【 Display / hide 】

• Life Science / Tumor diagnostics and therapeutics

• Life Science / Otorhinolaryngology

Research Keywords 【 Display / hide 】

Research Keywords 【 Display / hide 】

• Thyroid tumor

• Skull Base Tumor

• Head and Neck Cancer

• Carotid Body Tumor

Research Themes 【 Display / hide 】

Research Themes 【 Display / hide 】

• Genetic factor and tumor progression mechanism of carotid body tumor, 

  2014

  -

  Present

• Head and Neck Cancer metastasis, 

  2003

  -

  Present

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Prognostic impact of MRI-based cervical skeletal muscle mass on survival in parotid gland carcinoma

  Kasahara, K; Mikoshiba, T; Idei, K; Matsui, Y; Kono, T; Sekimizu, M; Ozawa, H

  JAPANESE JOURNAL OF CLINICAL ONCOLOGY  2026.03

  ISSN  0368-2811

  • Access to Document (DOI)

• Nationwide analysis of olfactory neuroblastoma in Japan: evolving treatment approaches and prognostic outcomes

  Sekimizu, M; Mikoshiba, T; Nagai, R; Ishikawa, N; Okada, T; Kitayama, M; Kawakita, D; Nibu, KI; Yoshimoto, S; Ozawa, H

  JAPANESE JOURNAL OF CLINICAL ONCOLOGY 56 ( 3 ) 282 - 289 2026.03

  ISSN  0368-2811

  • Access to Document (DOI)

• A primate model revealed specific age-related changes in spiral ganglion neurons in the cochlea

  Ueno M., Hosoya M., Shimanuki M.N., Nishiyama T., Oishi N., Ozawa H.

  Hearing Research 471 2026.02

  ISSN  03785955

  　View Summary

  Type I spiral ganglion neurons, which play a major role in hearing by conveying electrical sound signals to the brain, are divided into electrophysiological and molecular subtypes. The differences in vulnerability among the subtypes reported in rodents are of pathophysiological importance for age-related hearing loss. However, the changes in spiral ganglion neurons in primates and humans have not been established. In this study, we investigated the age-related changes in the spiral ganglion neurons of the common marmoset, a primate model animal. Here, we show that the overall number of spiral ganglion neurons decreased in middle-aged individuals and was most pronounced during the basal turn. However, no subtype-specific reduction, as reported in rodents, was identified. Our observations indicate that aging-related changes observed in the cochlea of rodents are not always applicable to primates. The usefulness and importance of common marmosets in the study of age-related hearing loss are also highlighted.

  • Access to Document (DOI)

• The prognostic impact of sarcopenia and systemic inflammation in head and neck cancer patients treated with immune checkpoint inhibitors

  Kasahara K., Kono T., Sato Y., Okubo K., Sasaki A., Hentona K., Mokudai Y., Oguchi K., Izawa M., Shinden S., Ozawa H.

  Auris Nasus Larynx 53 ( 1 ) 1 - 6 2026.02

  ISSN  03858146

  　View Summary

  Objective Sarcopenia and systemic inflammatory markers predict prognosis in various cancers, including head and neck cancer (HNC) treated with surgery or chemoradiotherapy. Their significance in patients receiving immune checkpoint inhibitors (ICIs), however, remains unclear. This study aims to determine whether skeletal muscle loss and systemic inflammation influence treatment response and survival in ICI-treated HNC, and whether composite indices provide prognostic value. Methods A retrospective cohort of 179 patients with histologically confirmed recurrent or metastatic (R/M) HNC who received ICI therapy between April 2017 and July 2024 was analyzed. Sarcopenia was assessed using the lumbar skeletal muscle index (LSMI), calculated from cervical CT images. Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were derived from pre-treatment blood samples. Overall survival (OS) and progression-free survival (PFS) were evaluated using Kaplan–Meier estimates, and prognostic factors were identified through Cox regression analysis. Results Among the 179 patients, 98 (54.7%) were classified as sarcopenic. These patients had significantly shorter median OS compared to non-sarcopenic patients (12.1 vs. 39.8 months; p < 0.001). Univariate analysis identified sarcopenia, BMI, NLR, and PLR as significant predictors of OS. However, multivariate Cox analysis revealed that only sarcopenia remained an independent prognostic factor for both OS (HR 1.94; 95% CI: 1.15–3.27; p = 0.013) and PFS (HR 1.92; 95% CI: 1.33–2.75; p < 0.001). Inflammatory markers and their composite indices failed to retain prognostic significance in adjusted models. Conclusion Sarcopenia independently predicts poor survival outcomes in patients with R/M HNC undergoing ICI therapy, whereas conventional inflammatory markers such as NLR, PLR, and LMR, alone or in combination with sarcopenia, lack independent prognostic value. Routine pre-treatment evaluation of skeletal muscle mass using CT imaging may offer a practical and effective tool for patient risk stratification.

  • Access to Document (DOI)

• Drug Repurposing Screen Identifies Pimozide as a ROS-Inducing Therapy With Anti-Tumor Efficacy in HNSCC PDX Models

  Okazaki, S; Nakamura, S; Soma, T; Yoshikawa, M; Asoda, S; Nakajima, Y; Tsuchihashi, K; Ohmura, M; Goitsuka, R; Imai, K; Saya, H; Nagano, O; Ozawa, H

  CANCER SCIENCE 117 ( 2 ) 511 - 521 2026.02

  ISSN  1347-9032

  • Access to Document (DOI)

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Papers, etc., Registered in KOARA 【 Display / hide 】

Papers, etc., Registered in KOARA 【 Display / hide 】

• Characterization of CD44v-positive oral cancer stem cells using PDX model and establishment of novel drug therapy

  Ozawa, Hiroyuki

  科学研究費補助金研究成果報告書 2022

• Functional analysis of hypoxia and hypoxia inducible factor in tumor-immune respose of head and neck cancers

  Ozawa, Hiroyuki

  科学研究費補助金研究成果報告書 2022

• AR-navigated transcanal endoscopic inner ear sugery

  Ozawa, Hiroyuki

  科学研究費補助金研究成果報告書 2019

• Development of head and neck cancer treatment targeting HIF1-alpha

  Ozawa, Hiroyuki

  科学研究費補助金研究成果報告書 2019

• Regenerative medicine for hypothyroidism with thyroid follicular cells derived from human iPS cells

  Ozawa, Hiroyuki

  科学研究費補助金研究成果報告書 2019

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Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• Assessment of patient satisfaction with dupilumab for chronic rhinosinusitis with nasal polyps

  Oka A., Kanai K., Matsune S., Hosoya K., Komachi T., Murakami R., Okubo K., Hirano K., Suzaki I., Shimura T., Tokudome T., Kanzaki S., Wakabayashi K.i., Ozawa H., Okamoto Y., Kondo K., Nishijima H., Nishijima A., Okano M.

  Allergy European Journal of Allergy and Clinical Immunology 80 ( 2 ) 614 - 616 2025.02

  ISSN  01054538

  • Access to Document (DOI)

Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• Analysis of immune mechanisms and development of immunotherapy in head and neck paragangliomas

  2024.04

  -

  2027.03

  基盤研究(C), Principal investigator

• 頭頸部癌における低酸素応答因子の免疫応答への影響の解析とその臨床応用

  2020.04

  -

  2023.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

• Development of head and neck cancer treatment targeting HIF1-alpha

  2017.04

  -

  2020.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

• Analysis of HIF1-alpa expression for head and neck cancer metastasis

  2014.04

  -

  2017.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  　View Summary

  The aim of the present study was to investigate the molecular targets of HIF1-α relevant to metastasis, and to find out an impact of HIF1-α to HNSCC metastasis by clinicopathological assays. In immunohistochemical study, the HIF-1α expression was higher in cancer cells than in normal cells of the adjacent normal mucosa. Univariate analysis revealed that high expression of HIF-1α was significantly correlated with T-classification (P=0.012), lymph node metastasis (P=0.002) and lymphatic invasion (P=0.03). HIF-1 inhibitor downregulated the expression of HIF-1α, twist, Oct3/4 and Nanog of head and neck cancer cells.
  These results suggest that HIF-1α plays a key role for the tumor progression of HNSCC through EMT and CSC property. From the present study, HIF-1α inhibition may have the possibility to suppress tumor metastasis, thus HIF-1α is attractive target for the treatment of HNSCC.

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• CLINICAL CLERKSHIP IN OTORHINOLARYNGOLOGY

  2026

• OTORHINOLARYNGOLOGY, HEAD AND NECK SURGERY: SEMINAR

  2026

• CLINICAL ONCOLOGY

  2026

• OTORHINOLARYNGOLOGY, HEAD AND NECK SURGERY

  2026

• ADVANCED OTORHINOLARYNGOLOGY, HEAD AND NECK SURGERY

  2026

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Courses Previously Taught 【 Display / hide 】

Courses Previously Taught 【 Display / hide 】

• Head and Neck cancer

  Keio University

  2017.04

  -

  2018.03

• Skull base tumors

  Keio University

  2017.04

  -

  2018.03

Memberships in Academic Societies 【 Display / hide 】

Memberships in Academic Societies 【 Display / hide 】

• The Oto-Rhino-Laryngological Society of Japan

  　

• Japan Society for Head and Neck Cancer

  　

• Japan Society for Head and Neck Surgery

  　

• Japanese Society for Skull Base Surgery

  　

• The Society of Practical Otolaryngology

  　

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