Sekimizu, Mariko



School of Medicine, Department of Otorhinolaryngology, Head and Neck Surgery (Shinanomachi)


Assistant Professor/Senior Assistant Professor

Career 【 Display / hide

  • 2010.04


Academic Background 【 Display / hide

  • 2004.03


    University, Graduated

Licenses and Qualifications 【 Display / hide

  • 日本耳鼻咽喉科学会専門医, 2011.04

  • がん治療認定医, 2017.04


Research Areas 【 Display / hide

  • Life Science / Otorhinolaryngology


Papers 【 Display / hide

  • Pretherapeutic Predictive Factors for Histological High-Grade Parotid Gland Carcinoma

    Mikoshiba T., Ozawa H., Watanabe Y., Kawaida M., Sekimizu M., Saito S., Yoshihama K., Nakamura S., Nagai R., Imanishi Y., Kameyama K., Ogawa K.

    Laryngoscope (Laryngoscope)  132 ( 1 ) 96 - 102 2022.01

    ISSN  0023852X

     View Summary

    Objective: The histological grade of parotid gland carcinoma (PGC) is an important prognostic factor; however, the diagnosis prior to treatment has been challenging to make. This study aimed to investigate whether the pretreatment clinical findings, including hematological inflammatory, nutritional, and immune markers, could predict the histological grade of PGC. Study Design: Retrospective study. Methods: We retrospectively enrolled 111 patients with PGC and evaluated the correlation between histological grade and pretreatment clinical findings such as age, sex, tumor staging, facial nerve paralysis, pain or tenderness, adhesion to the surrounding tissues or tumor immobility, and hematological markers. Results: Sixty patients (54%) were diagnosed with histological high-grade PGC. Univariate analysis revealed that age, T classification, N classification, TNM stage, facial nerve paralysis, adhesion/immobility, C-reactive protein (CRP), and CRP-to-albumin ratio (CAR) were significant predictors of PGC histological grade. On multivariate analysis, high T classification (T3, 4), high N classification (≥1), and elevated CRP (≥0.22 mg/dL) were independent predictors of high-grade PGC. Conclusions: Pretreatment T classification, N classification, and CRP are significant predictors of the histological grading of PGC. Our results are useful for treatment planning and obtaining appropriate informed consent from the patients before treatment. Level of Evidence: 4 Laryngoscope, 132:96–102, 2022.

  • Transoral Removal of Tumors of the Dorsal Aspect of the Soft Palate: A Technical Note

    Nakamura S., Ozawa H., Sekimizu M., Ikari Y., Nakahara N., Saito S., Yoshihama K., Nishiyama Y., Ogawa K.

    Laryngoscope (Laryngoscope)  131 ( 9 ) 2011 - 2014 2021.09

    ISSN  0023852X

  • Endoscopic Endonasal Management of Pterygopalatine Fossa Tumors

    Ozawa H., Sekimizu M., Saito S., Nakamura S., Mikoshiba T., Toda M., Ogawa K.

    Journal of Craniofacial Surgery (Journal of Craniofacial Surgery)  32 ( 5 ) E454 - E457 2021.07

    ISSN  10492275

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    Surgical removal of pterygopalatine fossa (PPF) tumors with endoscopic endonasal approach is still challenging. The present study aimed to evaluate our endoscopic endonasal management of PPF tumors based on the tumor pathology and purpose of the surgery. This comprised both a single nostril approach for biopsy and a binostril approach for complete resection of benign and noninfiltrating tumors. Based on this strategy, 12 patients underwent endoscopic endonasal surgery for PPF tumors between 2013 and 2018. The patients' data were analyzed retrospectively to demonstrate the significance of our treatment scheme. The surgery was terminated only after taking a biopsy specimen in 6 patients. Other 6 patients underwent gross total resection or bulk tumor reduction. Final pathological diagnosis was malignant in 6 cases and benign in the remaining 6. Post-operative treatment was needed in 7 patients. Four operations for the 6 patients who underwent either debulking or radical surgery were performed by the binostril approach; while 5 surgeries for the 6 biopsy patients were performed by the single nostril approach. Postoperative complications were tolerable. Endoscopic resection should be adopted preferentially for benign tumors that can be removed in a piecemeal fashion. However, as most malignant tumors were impossible to resect with a negative margin, priority should be given to tumor biopsy using an endoscopic approach, which is less invasive than an open approach, and an appropriate treatment customized to the pathological diagnosis should be administered.

  • Cyclooxygenase‑2 expression is associated with chemoresistance through cancer stemness property in hypopharyngeal carcinoma

    Saito S., Ozawa H., Imanishi Y., Sekimizu M., Watanabe Y., Fumihiro I.T.O., Ikari Y., Nakahara N., Kameyama K., Ogawa K.

    Oncology Letters (Oncology Letters)  22 ( 1 )  2021.07

    ISSN  17921074

     View Summary

    Cyclooxygenase‑2 (COX‑2) is one of the two isoforms of COX, an enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. COX‑2 is associated with the progression in various types of cancer, and its expres‑ sion has been associated with a poor prognosis in head and neck squamous cell carcinoma (HNSCC). Furthermore, COX‑2 expression has been associated with resistance to anticancer drugs. However, the precise mechanism of COX‑2 for chemoresistance in HNSCC has not been fully elucidated. The present study aimed to investigate the effect of COX‑2 on cancer stem cell (CSC) property and to reveal its effect on chemoresistance using in vitro and clinicopathological assays in HNSCC cells and tissues. The current study analyzed the immunohistochemical expression levels of COX‑2 and clinicopathological factors using matched samples of pretreatment biopsy and surgical specimens from patients with hypopharyngeal carcinoma who underwent tumor resec‑ tion with preoperative chemotherapy, including docetaxel. Additionally, the chemoresistance to docetaxel with or without a COX‑2 inhibitor (celecoxib) was examined in HNSCC cell lines by MTS assays. To evaluate the association of COX‑2 expression with stemness property, the expression levels of CSC‑associated genes after exposure to celecoxib were assessed by reverse transcription‑quantitative PCR. A sphere formation assay was also performed using ultra‑low attachment dishes and microscopic imaging. The immunohistochemical analysis of biopsy specimens revealed a negative association between COX‑2 expression in biopsy specimens and the pathological effect of induction chemotherapy in surgical specimens. The cell survival rate under exposure to docetaxel was decreased by the addition of celecoxib. COX‑2 inhibition led to downregulation of CSC‑associated gene expression and sphere formation. The present findings suggested that COX‑2 expression may be associated with chemoresistance through the cancer stemness property, and inhibition of COX‑2 may enhance chemo‑sensitivity in HNSCC. Therefore, COX‑2 may be an attractive target for the treatment of HNSCC.

  • Prognostic Value of the Lymphocyte-to-Monocyte Ratio in Patients with Parotid Gland Carcinoma

    Mikoshiba T., Ozawa H., Watanabe Y., Sekimizu M., Saito S., Yoshihama K., Nakamura S., Imanishi Y., Kameyama K., Ogawa K.

    Laryngoscope (Laryngoscope)  131 ( 3 ) E864 - E869 2021.03

    ISSN  0023852X

     View Summary

    Objective: Previous studies have evaluated various markers as prognostic predictors in patients with many types of cancers. However, the influence of such factors on the outcomes of patients with parotid gland carcinoma (PGC) is unknown. This study investigated the roles of alternative markers in the prognoses of patients with PGC. Methods: Overall, 101 patients who underwent curative treatment for PGC were retrospectively evaluated, and their 5-year overall and disease-free survival rates were calculated. The prognostic values of clinical and pathologic factors were determined. Results: The 5-year overall and disease-free survival rates were 73.1% and 62.8%, respectively. Multivariate analysis revealed that a low lymphocyte-to-monocyte ratio (LMR), high T classification, high N classification, and perineural invasion were independent predictors of poor prognosis. Conclusions: Thus, we identified LMR as an independent prognostic factor for patients with PGC. Patients with low LMRs who are amenable to treatment may require adjuvant treatment to improve their prognoses. Level of Evidence: 4 Laryngoscope, 131:E864–E869, 2021.

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