KEN YAMASHITA

Last Updated :2026/07/06

Affiliations, Positions
Endoscopy Center, Assistant Professor
E-mail
kenyama5hiroshima-u.ac.jp

Basic Information

Academic Degrees

  • Hiroshima University

Educational Activity

Course in Charge

  1. 2026, Undergraduate Education, Year, Clinical diagnosis and treatment I
  2. 2026, Undergraduate Education, First Semester, Internal Medicine I

Research Activities

Academic Papers

  1. Safety and Efficacy of Oral Tacrolimus Induction Therapy in Elderly Patients with Ulcerative Colitis: A Subanalysis of a Large Multicenter Retrospective Cohort Study., Gerontology, 2026
  2. Increased Extracolonic Cancer Incidence and Mortality in Patients with Serrated Polyposis Syndrome with a History of Colorectal Cancer: A Comparative Cohort Study., Digestion, 2026
  3. Endoscopic removal of a press-through pack from the small bowel using double-balloon enteroscopy., VideoGIE : an official video journal of the American Society for Gastrointestinal Endoscopy, 11(6), 2026
  4. Single-dose DSS-induced inflammation enhances colorectal tumorigenesis in APC and KRAS mutant mice, SCIENTIFIC REPORTS, 15(1), 20251124
    Link to Paper Search Results by DOI
  5. Investigating tumor-infiltrating lymphocytes as predictors of lymph node metastasis in deep submucosal invasive esophageal squamous cell carcinoma: a retrospective cross-sectional study, JOURNAL OF GASTROENTEROLOGY, 60(11), 1362-1371, 202511
    Link to Paper Search Results by DOI
  6. Endoscopic features differentiating non-Helicobacter pylori Helicobacter-induced gastric mucosa-associated lymphoid tissue lymphoma with a nodular gastritis-like appearance and H. pylori-induced conventional nodular gastritis, DIGESTIVE ENDOSCOPY, 37(9), 998-1009, 202509
    Link to Paper Search Results by DOI
  7. Lymph node metastasis and treatment outcomes of endoscopic submucosal dissection for superficial spreading esophageal squamous cell carcinoma ≥ 50 mm in size, ESOPHAGUS, 22(4), 614-621, 202510
    Link to Paper Search Results by DOI
  8. A Three-Way Comparison of Nodular Lesions in H. pylori- Induced Gastritis, Non- Helicobacter pylori Helicobacter (NHPH)-Induced Gastritis, and NHPH-Induced MALT Lymphoma Reveals Their Distinct Endoscopic Predictors: Distribution for Bacterial Etiology and Morphology for Malignancy, HELICOBACTER, 30(5), 20251014
    Link to Paper Search Results by DOI
  9. Clinical utility of repeated IgH gene rearrangement testing for the diagnosis and surveillance of gastric MALT lymphoma, SCIENTIFIC REPORTS, 15(1), 20250827
    Link to Paper Search Results by DOI
  10. ★, Efficacy of Hybrid Endoscopic Submucosal Dissection to Ensure Adequate Submucosal Layer for T1b Colorectal Carcinomas of 20-30 mm in Diameter, JOURNAL OF THE ANUS RECTUM AND COLON, 9(3), 295-301, 2025
    Link to Paper Search Results by DOI
  11. Rectal Neuroendocrine Tumor With Non-Atypical Mucous Cell Glands: A Case Report, JGH OPEN, 9(7), 202507
    Link to Paper Search Results by DOI
  12. Clinical Significance of Small-Bowel Mucosal Changes in Liver Cirrhosis Patients With Suspected Small-Bowel Bleeding: A Capsule Endoscopy Study, JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, 40(7), 1736-1744, 202507
    Link to Paper Search Results by DOI
  13. Effectiveness of endoscopic submucosal dissection in the management of internal hemorrhoids: a retrospective cohort study, THERAPEUTIC ADVANCES IN GASTROENTEROLOGY, 18, 2025
    Link to Paper Search Results by DOI
  14. Clinical Outcomes of Endoscopic Submucosal Dissection for Early Gastric Cancer Patients With Concurrent Advanced Malignancies With Expected Poor Prognosis, JGH OPEN, 9(7), 202507
    Link to Paper Search Results by DOI
  15. Management of T1 Colorectal Cancer, DIGESTION, 106(2), 122-130, 202503
    Link to Paper Search Results by DOI
  16. Efficiency of Real-time Computer-aided Polyp Detection during Surveillance Colonoscopy: A Pilot Study, JOURNAL OF THE ANUS RECTUM AND COLON, 9(1), 127-133, 2025
    Link to Paper Search Results by DOI
  17. A case of esophageal squamous cell carcinoma with epidermization showing a unique morphology, CLINICAL JOURNAL OF GASTROENTEROLOGY, 18(1), 23-28, 202502
    Link to Paper Search Results by DOI
  18. ★, Clinical usefulness of hybrid endoscopic submucosal dissection for T1b colorectal carcinomas ≤20 mm to ensure adequate vertical margins, DEN OPEN, 5(1), 202504
    Link to Paper Search Results by DOI
  19. Comparative analyses of short- and long-term outcomes between endoscopic submucosal dissection and endoscopic laryngo-pharyngeal surgery for superficial pharyngeal carcinomas, DEN OPEN, 5(1), 202504
    Link to Paper Search Results by DOI
  20. Clinical usefulness and acceptability of small-bowel capsule endoscopy with panoramic imaging compared with axial imaging in Japanese patients, DEN OPEN, 5(1), 202504
    Link to Paper Search Results by DOI
  21. [Methotrexate-related lymphoproliferative disease of the ileum with fistular formation between the small bowel and rectum:a case report]., Nihon Shokakibyo Gakkai zasshi = The Japanese journal of gastro-enterology, 122(6), 2025
  22. Endoscopic drainage for the treatment of intramural colonic abscess., Endoscopy, 57(S 01), 2025
  23. Gel immersion EMR of small-bowel inflammatory fibroid polyp using double-balloon endoscopy, Video Gastroenterol Endosc, 2024
  24. Endoscopic hand-suturing after per-anal endoscopic myectomy for deep T1 carcinoma in the lower rectum, Video Gastroenterol Endosc, 2024
  25. A case of colon cancer implanted on endoscopic resection ulcer certified by cancer genomic testing, CLINICAL JOURNAL OF GASTROENTEROLOGY, 17(6), 1047-1052, 202412
    Link to Paper Search Results by DOI
  26. A Proton Pump Inhibitor Independently Elevates Gastrin Levels as a Marker for Metachronous Gastric Cancer After Endoscopic Submucosal Dissection, JOURNAL OF CLINICAL MEDICINE, 13(21), 202411
    Link to Paper Search Results by DOI
  27. ★, Comparative prediction of lymph node metastasis in pT1 colorectal cancer among Western and Japanese guidelines, FRONTIERS IN ONCOLOGY, 14, 20241031
    Link to Paper Search Results by DOI
  28. WEE1 Inhibitor Adavosertib Exerts Antitumor Effects on Colorectal Cancer, Especially in Cases with p53 Mutations, CANCERS, 16(18), 202409
    Link to Paper Search Results by DOI
  29. Clinicopathologic Features of Early Gastric Cancer after Heli-cobacter pylori Eradication in Japanese Patients: Comparative Study between Early (<10 Years) and Late (>10 Years) Onset, CANCERS, 16(18), 202409
    Link to Paper Search Results by DOI
  30. Severe Refractory Diarrhea Associated with COVID-19: A Case Report, CASE REPORTS IN GASTROENTEROLOGY, 18(1), 318-326, 2024
    Link to Paper Search Results by DOI
  31. Genetic Analysis of Biopsy Tissues from Colorectal Tumors in Patients with Ulcerative Colitis, CANCERS, 16(19), 202410
    Link to Paper Search Results by DOI
  32. Predictive factors of portal hypertensive enteropathy exacerbations based on long-term outcomes, BMC GASTROENTEROLOGY, 24(1), 20240826
    Link to Paper Search Results by DOI
  33. ★, Vertical margin distance in T1 colorectal carcinoma resected by endoscopic submucosal dissection affects prognosis after additional surgery, INTERNATIONAL JOURNAL OF COLORECTAL DISEASE, 39(1), 20240816
    Link to Paper Search Results by DOI
  34. Pazopanib-induced enteritis in a patient with renal cell carcinoma, CLINICAL JOURNAL OF GASTROENTEROLOGY, 17(3), 434-440, 202406
    Link to Paper Search Results by DOI
  35. Verrucous gastritis-like lesion in intramucosal Helicobacter pylori-uninfected signet ring cell carcinoma with poorly differentiated adenocarcinoma, CLINICAL JOURNAL OF GASTROENTEROLOGY, 17(3), 412-418, 202406
    Link to Paper Search Results by DOI
  36. Analysis of anti-tumor effect and mechanism of GLS1 inhibitor CB-839 in colorectal cancer using a stroma-abundant tumor model, EXPERIMENTAL AND MOLECULAR PATHOLOGY, 137, 202406
    Link to Paper Search Results by DOI
  37. ★, Characteristics and Prognosis of Sporadic Neoplasias Detected in Patients with Ulcerative Colitis, DIGESTION, 105(3), 213-223, 202406
    Link to Paper Search Results by DOI
  38. ★, Usefulness and Educational Benefit of a Virtual Scale Endoscope in Measuring Colorectal Polyp Size, DIGESTION, 105(2), 73-80, 202404
    Link to Paper Search Results by DOI
  39. Hybrid endoscopic submucosal dissection as a salvage option for difficult colorectal conventional endoscopic submucosal dissection, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, 38(1), 222-228, 202401
    Link to Paper Search Results by DOI
  40. ★, Clinicopathological features and prognosis of primary small bowel adenocarcinoma: a large multicenter analysis of the JSCCR database in Japan, JOURNAL OF GASTROENTEROLOGY, 59(5), 376-388, 202405
    Link to Paper Search Results by DOI
  41. Long-term prognosis after endoscopic submucosal dissection for esophageal cancer in older adult patients, BMC GASTROENTEROLOGY, 24(1), 20240514
    Link to Paper Search Results by DOI
  42. Clinicopathological and genomic features of superficial esophageal squamous cell carcinomas in nondrinker, nonsmoker females, CANCER MEDICINE, 13(4), 202402
    Link to Paper Search Results by DOI
  43. Predictive factors for esophageal stenosis in patients receiving prophylactic steroid therapy after endoscopic submucosal dissection for esophageal squamous cell carcinoma, BMC GASTROENTEROLOGY, 24(1), 20240120
    Link to Paper Search Results by DOI
  44. Long-term outcomes of patients with obscure gastrointestinal bleeding after negative capsule endoscopy, JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, 39(1), 165-171, 202401
    Link to Paper Search Results by DOI
  45. Colonic invasive adenocarcinoma with squamoid morules: A case report, DEN OPEN, 4(1), 202404
    Link to Paper Search Results by DOI
  46. Can underwater endoscopic mucosal resection be an alternative to conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumors?, DEN OPEN, 4(1), 202404
    Link to Paper Search Results by DOI
  47. ★, Clinical outcomes of endoscopic submucosal dissection for large pedunculated colorectal carcinoma: A retrospective multicenter study, DEN OPEN, 4(1), 202404
    Link to Paper Search Results by DOI
  48. Diagnostic and therapeutic strategies for colorectal tumor with positive muscle-retracting sign, DEN OPEN, 4(1), 202404
    Link to Paper Search Results by DOI
  49. Indications for Dental Floss Clip Traction During Gastric Endoscopic Submucosal Dissection by Less-Experienced Endoscopists, JOURNAL OF GASTRIC CANCER, 23(4), 512-522, 202310
    Link to Paper Search Results by DOI
  50. Anti-tumor necrosis factor-alpha monoclonal antibody suppresses colorectal cancer growth in an orthotopic transplant mouse model, PLOS ONE, 18(3), 20230330
    Link to Paper Search Results by DOI
  51. Endoscopic findings suggestive of a high risk of non-radical cure after definitive chemoradiotherapy for cT1bN0M0 esophageal squamous cell carcinoma, ESOPHAGUS, 20(3), 541-547, 202307
    Link to Paper Search Results by DOI
  52. Efficacy of the specialized scissor-type knife for gastric endoscopic submucosal dissection: a propensity score matched retrospective study, ENDOSCOPY INTERNATIONAL OPEN, 11(04), E315-E321, 202304
    Link to Paper Search Results by DOI
  53. Outcomes of endoscopic submucosal dissection in patients who develop metachronous superficial esophageal squamous cell carcinoma close to a post-endoscopic submucosal dissection scar, ESOPHAGUS, 20(1), 124-133, 202301
    Link to Paper Search Results by DOI
  54. ★, Clinical outcomes of endoscopic resection for rectal neuroendocrine tumors: Advantages of endoscopic submucosal resection with a ligation device compared to conventional EMR and ESD, DEN OPEN, 2(1), 202204
    Link to Paper Search Results by DOI
  55. Efficacy of single-balloon overtube for endoscopic submucosal dissection in the proximal colon: A propensity score-matched analysis, DEN OPEN, 2(1), 202204
    Link to Paper Search Results by DOI
  56. ★, Case of gel immersion endoscopy: Efficacy of identification and achieving hemostasis for diverticular hemorrhage in the sigmoid colon, Dig Endosc, 34(4), e62-e63, 2022
  57. Endoscopic sinusotomy using the small-ceramic-tip-insulated electrosurgical knife for chronic pouch sinus after ileal pouch anal anastomosis in ulcerative colitis: a case report, Endoscopy, 54(12), E728-E729, 2022
  58. Characteristics and Treatment Outcomes of Small-bowel Angioectasia in Systemic Sclerosis Patients: A Retrospective Observational Study, Intern Med, 61(5), 615-622, 2022
  59. Diagnostic Accuracy of H. pylori Status by Conventional Endoscopy: Time-Trend Change After Eradication and Impact of Endoscopic Image Quality, Front Med (Lausanne), 8, 830730, 2022
  60. Development of multi-class computer-aided diagnostic systems using the NICE/JNET classifications for colorectal lesions, J Gastroenterol Hepatol, 37(1), 104-110, 2022
  61. Novel endoscopic ultrasonography classification for assured vertical resection margin (>= 500 mu m) in colorectal endoscopic submucosal dissection, JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, 37(12), 2289-2296, 202212
    Link to Paper Search Results by DOI
  62. Vertical tumor margin of endoscopic resection for T1 colorectal carcinoma affects the prognosis of patients undergoing additional surgery, SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES, 36(8), 5970-5978, 202208
    Link to Paper Search Results by DOI
  63. Two cases of ulcerative colitis that developed while using abatacept, CLINICAL JOURNAL OF GASTROENTEROLOGY, 15(5), 924-928, 202210
    Link to Paper Search Results by DOI
  64. ★, Long-term prognosis after treatment for T1 carcinoma of laterally spreading tumors: a multicenter retrospective study, 34(3), 481-490, 2019
  65. ★, Preceding endoscopic submucosal dissection for T1 colorectal carcinoma does not affect the prognosis of patients who underwent additional surgery: a large multicenter propensity score-matched analysis, 54, 897-906, 2019
  66. ★, Use of anticoagulants increases risk of bleeding after colorectal endoscopic submucosal dissection, 6(7), 857-864, 2018

Invited Lecture, Oral Presentation, Poster Presentation

  1. Clinical Usefulness and Acceptability of Small-bowel Capsule Endoscopy with Panoramic Imaging Compared with Axial Imaging, 2024/11/21, Without Invitation, English
  2. Clinical Usefulness and Acceptability of Small-bowel Capsule Endoscopy with Panoramic Imaging Compared with Axial Imaging, Hirata I, Tsuboi A, Shigenobu S, Matsubara Y, Takasago T, Nishimura T, Tanaka H, Yamashita K, Hiyama Y, Takigawa H, Urabe Y, Kuwai T, Oka S, 2024/10/31, Without Invitation, Japanese
  3. Efficiency of real-time computer-aided polyp detection in surveillance colonoscopy: a pilot study, 2024/10/12, Without Invitation, English
  4. Utility of cancer genome analysis using biopsy tissues from colorectal neoplasias developing from ulcerative colitis mucosa, 2024/10/12, Without Invitation, English
  5. Clinical utility and safety profile of endoscopic ischemic polypectomy for small-bowel polyps with Peutz-Jeghers syndrome compared with those of conventional polypectomy, 2024/07/04, Without Invitation, English
  6. Effect of operator's experience on delayed bleeding after colorectal EMR, 2024/07/04, Without Invitation, English
  7. Safety of balloon-assisted enteroscopy for patients taking antithrombotic medications, Hirata I, Tsuboi A, Shigenobu S, Matsubara Y, Takasago T, Nishimura T, Tanaka H, Yamashita K, Hiyama Y, Takigawa H, Urabe Y, Kuwai T, Oka S, 2024/05/30, Without Invitation, Japanese
  8. Predictive factors of portal hypertensive enteropathy exacerbations based on long-term outcomes using capsule endoscopic findings, 2024/05/18, Without Invitation, English
  9. Comparative analysis of conventional ESD vs. hybrid ESD for T1b colorectal carcinomas of 20-29 mm in diameter, 2024/05/18, Without Invitation, English
  10. LONG-TERM PROGNOSIS AFTER ENDOSCOPIC SUBMUCOSAL DISSECTION FOR ESOPHAGEAL CANCER IN ELDERLY PATIENTS, 2024/05/18, Without Invitation, English
  11. Comparison of outcomes between endoscopic submucosal dissection and Endoscopic laryngo-pharyngeal surgery for superficial laryngo-pharyngeal cancer, 2024/05/18, Without Invitation, English
  12. FOXP3+ T-CELLS AS PREDICTORS OF LYMPH NODE METASTASIS IN T1B COLORECTAL CANCER, 2023/10/12, Without Invitation, English
  13. CLINICOPATHOLOGICAL FEATURES AND SERUM RISK MARKERS OF METACHRONOUS GASTRIC CANCER AFTER ERADICATION, 2023/10/12, Without Invitation, English
  14. OUTCOMES OF ESD IN EARLY GASTRIC CANCER PATIENTS WITH ADVANCED MALIGNANT TUMORS OF OTHER ORGANS, 2023/10/12, Without Invitation, English
  15. LONG-TERM OUTCOMES OF PATIENTS WITH OBSCURE GASTROINTESTINAL BLEEDING AFTER NEGATIVE CAPSULE ENDOSCOPY​​​​, 2023/10/12, Without Invitation, English
  16. "Clinicopathological features of metachronous gastric cancer after eradication", International Gastric Cancer Congress (IGCC) 2023, 2023/06/14, Without Invitation, English
  17. Comparison of diagnostic ability for lymph node metastasis in T1 colorectal carcinoma by each national guideline, Yamashita K, Yamashita K, Oka S, Takehara Y, Morimoto S, Tanino F, Kamigaichi Y, Shimohara Y, Okamoto Y, Tanaka H, Shimamoto F, Tanaka S., 2023/02/04, Without Invitation, English
  18. Characteristics and prognosis of sporadic-like neoplasias in patients with ulcerative colitis, Yamamoto N, Yamashita K, Oka S, Takehara Y, Morimoto S, Tanino F, Kamigaichi Y, Shimohara Y, Okamoto Y, Tanaka H, Shimamoto F, Tanaka S., 2022/11/17, Without Invitation, English
  19. Vertical margin distance in pT1 colorectal carcinoma resected by endoscopic submucosal dissection affects the prognosis after additional surgery in multiple centers, Tanino F, Yamashita K, Oka S, Nagata S, Kuwai T, Asayama N, Tamaru Y, Shimamoto F, Tanaka S., 2022/11/17, Without Invitation, English
  20. Usefulness and educational effect of a virtual scale endoscope in measuring colorectal polyp size, 20230420, Without Invitation, English
  21. Is salvage hybrid ESD effective when ESD is difficult to complete?, 20230420, Without Invitation, English