Updated on 2024/12/22

写真a

 
SASAKI Kenta
 
Organization
University Medical and Dental Hospital Medical Oncology Assistant Professor
Title
Assistant Professor
External link

Degree

  • 博士(医学) ( 2023.3   新潟大学 )

  • 学士(医学) ( 2015.3   新潟大学 )

  • 修士(生命科学) ( 2004.3   京都大学 )

  • 学士(理学) ( 2002.3   京都大学 )

Research History

  • Niigata University   Medical Oncology, University Medical and Dental Hospital   Assistant Professor

    2023.4

Professional Memberships

 

Papers

  • Sunitinib therapy for imatinib-resistant and/or intolerant gastrointestinal stromal tumors: comparison of safety and efficacy between standard and reduced dosage regimens Reviewed

    Kenta Sasaki, Tatsuo Kanda, Yoshifumi Matsumoto, Takashi Ishikawa, Seiichi Hirota, Yasuo Saijo

    Japanese Journal of Clinical Oncology   53 ( 4 )   297 - 303   2023.1

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Oxford University Press (OUP)  

    Abstract

    Background

    Sunitinib therapy for patients with imatinib-resistant and/or intolerant gastrointestinal stromal tumors (GISTs) often causes severe adverse events (AEs) that lead to treatment discontinuation.

    Methods

    We retrospectively reviewed the clinical records of imatinib-resistant and/or intolerant GIST patients who underwent sunitinib therapy in our institutions between 2007 and 2020. Forty-one patients were enrolled and divided into two groups on the basis of the starting dosage: the standard dosage group (50 mg/day, 21 patients) and the reduced dosage group (37.5 mg/day, 20 patients). Tolerability, safety and clinical efficacy of the two groups were compared.

    Results

    Three patients (14%) in the standard dosage group and another three (15%) in the reduced dosage group (P = 1.000) discontinued sunitinib therapy because of AEs. The incidences of grade 3 or more severe treatment-related AEs were 90 and 75%, respectively (P = 0.238). Two possible treatment-related deaths were noted in the standard dosage group. Clinical efficacy was comparable between the two groups: median time to treatment failure and overall survival were 4.5 months [interquartile range (IQR), 3.6–9.0] and 13.7 months (IQR, 7.5–22.9) in the standard dosage group and 4.6 months (IQR, 2.7–17.0) and 13.4 months (IQR, 9.3–36.8) in the reduced dosage group, respectively.

    Conclusions

    The reduced dosage of 37.5 mg sunitinib tended to decrease toxicity and the incidences of severe AEs and treatment-related deaths. This reduced dosage regimen showed equivalent clinical efficacy including patient survival. The reduced dosage of 37.5 mg sunitinib can be adopted as an alternative therapy for patients with imatinib-resistant and/or intolerant GISTs.

    DOI: 10.1093/jjco/hyac202

    researchmap

  • Termination of Palliative Chemotherapy Near the End of Life: A Retrospective Study of Gastrointestinal Cancer Patients. Reviewed International journal

    Yoshifumi Matsumoto, Akito Higuchi, Marika Shiba, Kenta Sasaki, Takuro Saiki, Yujiro Honma, Kazuyoshi Kimura, Qiliang Zhou, Yasuo Saijo

    Palliative medicine reports   4 ( 1 )   169 - 174   2023

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    BACKGROUND: Palliative chemotherapy is commonly used for advanced cancer patients. The timing of chemotherapy termination is crucial for efforts to maintain quality of life. PATIENTS AND METHODS: This retrospective study included gastrointestinal cancer patients who were treated with chemotherapy and died between 2013 and 2022 at Niigata University Medical and Dental Hospital. Data were reviewed regarding age, gender, cancer type, reason for chemotherapy termination, cause of death, survival after chemotherapy termination, and place of death. RESULTS: In total, 388 patients were included; the median survival after chemotherapy was 73 days. Patients aged <67 years had shorter survival durations (59 days), compared with patients aged >67 years (82 days). Ten (2.6%) patients began a new chemotherapy regimen, whereas 17 (4.4%) patients received chemotherapy, within 4 weeks before death. The most common reason for chemotherapy termination was disease progression, and most deaths occurred in hospitals. CONCLUSION: The rates of chemotherapy and initiation of new chemotherapeutic regimens near the end of life were lower than previously reported. Most deaths occurred in hospitals, highlighting the need for development of hospices.

    DOI: 10.1089/pmr.2023.0027

    PubMed

    researchmap

  • Efficacy of BRAF inhibitor and anti-EGFR antibody in colorectal neuroendocrine carcinoma. Reviewed

    Mae Nakano, Yoshifumi Shimada, Yoshifumi Matsumoto, Takuro Saiki, Qiliang Zhou, Kenta Sasaki, Masato Moriyama, Kosuke Yoshihara, Manabu Natsumeda, Yoko Kuriyama, Yasumasa Takii, Gen Watanabe, Hajime Umezu, Shujiro Okuda, Takeshi Ikeuchi, Toshifumi Wakai, Yasuo Saijo

    Clinical journal of gastroenterology   15 ( 2 )   413 - 418   2022.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Neuroendocrine neoplasms of the colon and rectum are colorectal epithelial neoplasms with neuroendocrine differentiation. A platinum regimen used for small cell lung cancer is the currently recommended chemotherapy for gastroenteropancreatic neuroendocrine carcinomas (GEP-NECs), regardless of the organ. The BRAF V600E mutation has been recently reported as a druggable driver mutation in colorectal NECs. In BRAF V600E mutant colorectal cancer, a combination of BRAF inhibitor and anti-epidermal growth factor receptor (EGFR) antibody, with or without a MEK inhibitor, is recommended. Here, we report the case of 77-year-old man who had lymph node recurrence after surgery for primary ascending colonic NEC. Two cytotoxic regimens, cisplatin plus irinotecan and modified FOLFOX6, were administered as first- and second-line chemotherapies with no remarkable response observed. At this point, genetic analysis confirmed the tumor harbored a BRAF V600E mutation. Thus, a regimen of BRAF inhibitor plus anti-EGFR antibody was administered. After commencing this regimen, carcinoembryonic antigen levels decreased within normal range, and there was dramatic shrinkage of the lymph node metastases observed by chest and abdominal computed tomography scans. To our knowledge, this is the first reported case of a colorectal NEC responding to a BRAF inhibitor and anti-EGFR antibody.

    DOI: 10.1007/s12328-022-01599-4

    PubMed

    researchmap

  • Treatment of Gastric and Gastroesophageal Cancer Patients with Hemodialysis by CapeOX. Reviewed

    Kenta Sasaki, Qiliang Zhou, Yoshifumi Matsumoto, Takuro Saiki, Masato Moriyama, Yasuo Saijo

    Internal medicine (Tokyo, Japan)   58 ( 19 )   2791 - 2795   2019.10

     More details

    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    Two patients underwent hemodialysis. Case 1 with stage IV gastric cancer was treated with reduced doses of capecitabine (1,000 mg/m2/day, days 1 to 14) and oxaliplatin (65 mg/m2, day 1). Although grade 1 thrombocytopenia occurred in the first cycle, grade 3 thrombocytopenia developed in the second cycle because of increasing dosage. After the dosage was reduced, chemotherapy was continued safely. Case 2 with stage IA gastroesophageal cancer was treated with radiotherapy followed by chemotherapy. Treatment with the same dose of CapeOX therapy as in case 1 resulted in no severe toxicity. We conclude that a half-dose of the CapeOX regimen is safe for gastric cancer patients undergoing hemodialysis.

    DOI: 10.2169/internalmedicine.2718-19

    PubMed

    researchmap

  • Treatments and outcomes of older patients with esophageal cancer: Comparison with younger patients. Reviewed International journal

    Yoshifumi Matsumoto, Kazuyoshi Kimura, Qiliang Zhou, Kenta Sasaki, Takuro Saiki, Masato Moriyama, Yasuo Saijo

    Molecular and clinical oncology   11 ( 4 )   383 - 389   2019.10

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    The number of older patients with esophageal cancer (EC) is increasing due to the population aging and increasing life expectancy. However, no optimal treatment strategy for older patients with EC has been established to date. The aim of the present study was to review and compare the treatment modalities and outcomes of 990 younger and older patients diagnosed with EC in our institution. The patients were divided into younger (≤74 years) and older (≥75 years) groups. The majority of the patients in both groups had early-stage EC and were treated by endoscopic submucosal dissection (ESD). The older patients with locally advanced (stage II and III) EC were more likely to undergo chemoradiotherapy rather than esophagectomy. Among the older patients, 22% selected best supportive care. The disease-specific survival rate of the older patients was significantly lower compared with that of the younger patients, which was likely due to the less intense treatment modalities applied. The prognosis following esophagectomy was significantly better compared with that of chemoradiotherapy in the younger, but not in the older patients. In conclusion, the poorer prognosis of older patients (aged ≥75 years) with stage I EC may improve with multidisciplinary treatment after ESD. Although CRT is currently considered the optimal treatment for older patients with stage II/III EC, more efficient treatment modalities are urgently required.

    DOI: 10.3892/mco.2019.1909

    PubMed

    researchmap

  • Molecular mechanisms of hyperplasia induction by human papillomavirus E7. Reviewed International journal

    T Ueno, K Sasaki, S Yoshida, N Kajitani, A Satsuka, H Nakamura, H Sakai

    Oncogene   25 ( 30 )   4155 - 64   2006.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Infections of human papillomavirus (HPV) induce a variety of benign tumors, such as warts and condylomas. During the process of aberrant cell proliferation, genetic mutations are accumulated in the cells, from which malignant tumor cells arise. The viral oncoproteins E6 and E7 are known to help disrupt the cell cycle checkpoint machinery and accelerate chromosomal instability, events which are critical in malignant conversion. However, the mechanisms involved in the hyperplasia caused by HPV infection have remained unknown. We analysed the effects of regulatory genes of HPV18, a typical high-risk-type HPV, on the formation of the epithelial organ by using an organotypic culture system, and found that E7 had potent activity to induce hyperplasia, to which the disruption of the pRb pathway was well correlated. However, analysis with the E7 variants indicated that other pocket proteins are also involved in the activity.

    PubMed

    researchmap

  • Requirement of E7 oncoprotein for viability of HeLa cells. Reviewed International journal

    Akiko Nishimura, Tomomi Nakahara, Takaharu Ueno, Kenta Sasaki, Satoshi Yoshida, Satoru Kyo, Peter M Howley, Hiroyuki Sakai

    Microbes and infection   8 ( 4 )   984 - 93   2006.4

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Most human papillomavirus (HPV)-positive cervical cancers contain integrated copies of the viral genome in their chromosomes and express the viral oncoproteins E6 and E7. A virus-encoded transcription factor, E2, is known to repress E6/E7 expression in HPV-positive cancer cells, leading to growth inhibition, which indicates that E6/E7 is required for the survival of the cells. We found that the E2-mediated growth inhibition of HeLa cells, an HPV18-positive cancer cell line, was coupled with a reduction in telomerase activity, an effect which was rescued by the complementation of E7 expression, but not E6 expression, indicating that the cell viability and the telomerase activity in HeLa cells are maintained by an E7-associated function. Analysis of E7 mutants suggested that the binding to the pRB family of pocket proteins was involved in the ability of E7 to rescue the growth potential and telomerase activity inhibited by E2 expression. We also showed that the telomerase activity upregulated by E7 expression was determined by the hTERT promoter activity, and that c-Myc upregulation caused by pRB inactivation could account for the promoter activity. The activation of p53 and consequent accumulation of p21Cip1, which were triggered by the downregulation of E6, appeared not to be essential for the E2-mediated growth arrest.

    PubMed

    researchmap

  • Downregulation of CD4 is required for maintenance of viral infectivity of HIV-1. Reviewed International journal

    Masakazu Tanaka, Takaharu Ueno, Tomomi Nakahara, Kenta Sasaki, Akinori Ishimoto, Hiroyuki Sakai

    Virology   311 ( 2 )   316 - 25   2003.7

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    Downregulation of virus receptors on the cell surface is considered to be important in preventing superinfection. HIV-1 encodes multiple gene products, Env, Vpu, and Nef, involved in downregulation of CD4, a major HIV-1 receptor. We found that simultaneous mutations in both vpu and nef severely impaired virus replication. We examined the involvement of CD4 downregulation mediated by Vpu and Nef in the modification of virus infectivity. The mutation in vpu increased CD4 incorporation into virions without affecting the Env content in it, inhibiting the attachment step of virions to the CD4-positive cell surface. Although a single mutation in nef suppresses virus infectivity via a CD4-independent mechanism, it could augment CD4 incorporation in virions in combination with a vpu mutation. These results indicated that CD4 downregulation was necessary for maintenance of Env function in the virion.

    PubMed

    researchmap

  • The P5 activator of a group IC ribozyme can replace the P7.1/7.2 activator of a group IA ribozyme. Reviewed International journal

    Yoshiya Ikawa, Kenta Sasaki, Hiroyuki Tominaga, Tan Inoue

    Journal of biochemistry   133 ( 5 )   665 - 70   2003.5

     More details

    Language:English   Publishing type:Research paper (scientific journal)  

    The P5 or P7 extensions in the group I intron ribozyme serve as "modular activator units" by stabilizing the conserved core of the ribozyme. The P5 extension of a group IC1 intron was introduced to a barely active group IA2 intron lacking its original P7 extension. The inserted P5 extension significantly activated the chimeric construct. Because the CYT-18 protein factor is also known to activate mutant group IA2 and IC1 introns lacking their P7 and P5 extensions, respectively, the RNA and protein activator units function in an analogous manner.

    PubMed

    researchmap

▶ display all