IWASAKI Masahiro



School of Medicine, Department of Obstetrics and Gynecology

Job title

Associate Professor

Research Experience 【 display / non-display

  • 2009

    Sapporo Medical University   School of Medicine  

Research Areas 【 display / non-display

  • Life sciences   Obstetrics and gynecology  


Papers 【 display / non-display

  • Radiotherapy for HPV-related cancers: prediction of therapeutic effects based on the mechanism of tumor immunity and the application of immunoradiotherapy.

    Masanori Someya, Yuki Fukushima, Tomokazu Hasegawa, Takaaki Tsuchiya, Mio Kitagawa, Toshio Gocho, Shoh Mafune, Yutaro Ikeuchi, Yoh Kozuka, Yoshihiko Hirohashi, Toshihiko Torigoe, Masahiro Iwasaki, Motoki Matsuura, Tsuyoshi Saito, Koh-Ichi Sakata

    Japanese journal of radiology   40 ( 5 ) 458 - 465  2022.01  [Domestic journal]

     View Summary

    Human papillomavirus (HPV)-related cancer is one of the diseases entities for which the applications of radiotherapy have been increasing. Recently, the process of carcinogenesis from HPV infection and the mechanism of tumor immunity that develops during disease progression have been elucidated. In this review, we will describe the mechanism of tumor immunity and how chemoradiotherapy may overcome and improve the efficacy of tumor immunity. We will also discuss the usefulness of proteins involved with tumor immunity as a predictive marker of radiotherapy response, and present an overview of ongoing clinical trials of combinations of immune checkpoint inhibitors and radiotherapy to demonstrate the promising combination therapy that has been currently emerging.

    DOI PubMed

  • Primary malignant melanoma of the uterine cervix—Two case reports—

    SUZUKI Miwa, TANAKA Ryoichi, TAKAHASHI Madoka, SATOHISA Seiro, TERAMOTO Mizue, IWASAKI Masahiro, ITO Eiki, SAITO Tsuyoshi

    J. Jpn. Soc. Clin. Cytol. ( The Japanese Society of Clinical Cytology )  54 ( 6 ) 389 - 393  2015

     View Summary

    Background : Primary malignant melanomas of the cervix is a rare tumor. Although there is no consensus as to a comprehensive treatment, complete radical surgery is generally the treatment cornerstone in the same manner as for melanomas in other organs. We summarized herein 2 cases of uterine cervical melanoma.
    Cases : Our patients presented with vaginal bleeding. Case 1, a 76 year-old-woman, was initially considered as having a poorly differentiated squamous cell carcinoma. Although she had undergone irradiation, the original lesion had grown larger. A biopsy was taken and sent for histopathological examination, which revealed melanoma of the cervix, confirmed by immunohistochemistry. She was diagnosed as having stageⅠB1 cervical melanoma. She underwent a radical hysterectomy and pelvic lymph node dissection. The patient was under surveillance for 108 months of follow up without evidence of local or distant disease. In case 2, a 58 year-old-woman, a 5 cm tumor was identified in the cervix. Pap smear revealed the presence of pigmented malignant melanoma cells and she was also diagnosed as having stageⅣB cervical melanoma. She underwent an operation and chemotherapy, but died because her disease continued to progress rapidly.
    Conclusions : Malignant melanoma should be considered in the differential diagnosis of cervical malignancies. Early diagnosis with cytology and pathology is essential in order to decide a therapeutic strategy.

    DOI CiNii

  • Prediction of the therapeutic effect of dienogest in ovarian endometrial cysts using the apparent diffusion coefficient

    Motoki Matsuura, Masato Tamate, Yuta Tabuchi, Sakura Takada, Ryoichi Tanaka, Masahiro Iwasaki, Tsuyoshi Saito

    GYNECOLOGICAL ENDOCRINOLOGY ( INFORMA HEALTHCARE )  30 ( 8 ) 597 - 599  2014.08  [Refereed]

     View Summary

    The purpose of this study was to investigate whether apparent diffusion coefficient (ADC) mean values can be used for predicting the treatment response in ovarian endometrial cyst patients with dienogest (DNG) administration. Eighteen patients received DNG (2 mg/day, orally) for 60 days, among whom 26 ovarian endometrial cysts were retrospectively identified. Mean ADC values of individual ovarian endometrial cysts were obtained by ADC maps inside the tumor. There was a significant correlation between ADC values and reduction ratio. When calculating the mean ADC values for three groups; more than 50%, 50-25% and less than 25%, ADC values significantly increased with increasing reduction ratio; 2.05 x 10(-3) mm(2)/s, 1.28 x 10(-3) mm(2)/s and 0.94 x 10(-3) mm(2)/s, respectively (p = 0.0180). Multiple regression analysis by reduction ratio (%), ADC mean values (x 10(-3) mm(2)/s), tumor longest diameter (cm) and CA125 (Wml) revealed that tumor reduction ratio by DNG administration could be predicted by the following equation; R=19.3 + 24.0x - 0.4y + 0.1z (R: Reduction ratio, x: ADC mean, y: Longest diameter, z: CA125). In conclusion, the ADC mean value is useful for the prediction of the treatment response in ovarian endometrial cyst patients with DNG administration.

    DOI PubMed

Misc 【 display / non-display

  • A case of primary ovarian Granulocytic Sarcoma

    IKEDA Keiko, FUJIMOTO Takashi, SUZUKI Miwa, UMEMURA Kouta, IWASAKI Masahiro, SUZUKI Takahiro, ITOU Eiki, SAITO Tuyoshi

      28 ( 1 ) 77 - 81  2010.01


  • Recurrent cervical cancer

    Japanese journal of clinical medicine   67   191 - 194  2009.08


  • A case of carcinosarcoma of the ovary arising in endometriosis

    RYOSAKA Miwa, SAITO Tsuyoshi, NAGAI Miho, IWASAKI Masahiro, SUZUKI Takahiro, ITO Eiki, KUDO Ryuichi

      23 ( 1 ) 98 - 102  2005.01


  • Apocrine adenocarcinoma of the vulva with intraepithelial spreading paget cells

    FUJIMOTO Takashi, ITOU Eiki, IWASAKI Masahiro, SAITO Tuyoshi, KUDO Ryuichi

      22 ( 3 ) 272 - 276  2004.06


  • Managements of malignant ovarian germ cell tumor

    SUGIMURA Masaki, HONMA Hiroyuki, IWASAKI Masahiro, KOBAYASHI Kanji, ISHIOKA Shin-ichi, SAGAE Satoru, KUDO Ryuichi

      17 ( 2 ) 175 - 180  1999.12


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