KEN YAMASHITA

Last Updated :2025/06/24

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

Basic Information

Academic Degrees

  • Hiroshima University

Educational Activity

Course in Charge

  1. 2025, Undergraduate Education, Intensive, Introduction to clinical clerkship
  2. 2025, Undergraduate Education, First Semester, Internal Medicine I

Research Activities

Academic Papers

  1. Gel immersion EMR of small-bowel inflammatory fibroid polyp using double-balloon endoscopy, Video Gastroenterol Endosc, 2024
  2. Endoscopic hand-suturing after per-anal endoscopic myectomy for deep T1 carcinoma in the lower rectum, Video Gastroenterol Endosc, 2024
  3. Management of T1 Colorectal Cancer, DIGESTION, 106(2), 122-130, 202503
  4. 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
  5. A case of esophageal squamous cell carcinoma with epidermization showing a unique morphology, CLINICAL JOURNAL OF GASTROENTEROLOGY, 18(1), 23-28, 202502
  6. ★, Clinical usefulness of hybrid endoscopic submucosal dissection for T1b colorectal carcinomas ≤20 mm to ensure adequate vertical margins, DEN OPEN, 5(1), 202504
  7. A case of colon cancer implanted on endoscopic resection ulcer certified by cancer genomic testing, CLINICAL JOURNAL OF GASTROENTEROLOGY, 17(6), 1047-1052, 202412
  8. 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
  9. ★, Comparative prediction of lymph node metastasis in pT1 colorectal cancer among Western and Japanese guidelines, FRONTIERS IN ONCOLOGY, 14, 20241031
  10. WEE1 Inhibitor Adavosertib Exerts Antitumor Effects on Colorectal Cancer, Especially in Cases with p53 Mutations, CANCERS, 16(18), 202409
  11. 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
  12. Severe Refractory Diarrhea Associated with COVID-19: A Case Report, CASE REPORTS IN GASTROENTEROLOGY, 18(1), 318-326, 2024
  13. Genetic Analysis of Biopsy Tissues from Colorectal Tumors in Patients with Ulcerative Colitis, CANCERS, 16(19), 202410
  14. Predictive factors of portal hypertensive enteropathy exacerbations based on long-term outcomes, BMC GASTROENTEROLOGY, 24(1), 20240826
  15. 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
  16. ★, 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
  17. Pazopanib-induced enteritis in a patient with renal cell carcinoma, CLINICAL JOURNAL OF GASTROENTEROLOGY, 17(3), 434-440, 202406
  18. 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
  19. 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
  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
  21. ★, Characteristics and Prognosis of Sporadic Neoplasias Detected in Patients with Ulcerative Colitis, DIGESTION, 105(3), 213-223, 202406
  22. ★, Use of anticoagulants increases risk of bleeding after colorectal endoscopic submucosal dissection, 6(7), 857-864, 2018
  23. ★, Long-term prognosis after treatment for T1 carcinoma of laterally spreading tumors: a multicenter retrospective study, 34(3), 481-490, 2019
  24. ★, 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
  25. ★, Usefulness and Educational Benefit of a Virtual Scale Endoscope in Measuring Colorectal Polyp Size, DIGESTION, 105(2), 73-80, 202404
  26. 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
  27. ★, 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
  28. ★, 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
  29. Efficacy of single-balloon overtube for endoscopic submucosal dissection in the proximal colon: A propensity score-matched analysis, DEN OPEN, 2(1), 202204
  30. Long-term prognosis after endoscopic submucosal dissection for esophageal cancer in older adult patients, BMC GASTROENTEROLOGY, 24(1), 20240514
  31. Clinicopathological and genomic features of superficial esophageal squamous cell carcinomas in nondrinker, nonsmoker females, CANCER MEDICINE, 13(4), 202402
  32. 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
  33. Long-term outcomes of patients with obscure gastrointestinal bleeding after negative capsule endoscopy, JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, 39(1), 165-171, 202401
  34. Colonic invasive adenocarcinoma with squamoid morules: A case report, DEN OPEN, 4(1), 202404
  35. Indications for Dental Floss Clip Traction During Gastric Endoscopic Submucosal Dissection by Less-Experienced Endoscopists, JOURNAL OF GASTRIC CANCER, 23(4), 512-522, 202310
  36. 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
  37. ★, Clinical outcomes of endoscopic submucosal dissection for large pedunculated colorectal carcinoma: A retrospective multicenter study, DEN OPEN, 4(1), 202404
  38. Diagnostic and therapeutic strategies for colorectal tumor with positive muscle-retracting sign, DEN OPEN, 4(1), 202404
  39. Anti-tumor necrosis factor-alpha monoclonal antibody suppresses colorectal cancer growth in an orthotopic transplant mouse model, PLOS ONE, 18(3), 20230330
  40. 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
  41. ★, 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
  42. 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
  43. Characteristics and Treatment Outcomes of Small-bowel Angioectasia in Systemic Sclerosis Patients: A Retrospective Observational Study, Intern Med, 61(5), 615-622, 2022
  44. 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
  45. Development of multi-class computer-aided diagnostic systems using the NICE/JNET classifications for colorectal lesions, J Gastroenterol Hepatol, 37(1), 104-110, 2022
  46. 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
  47. 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
  48. 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
  49. 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
  50. Two cases of ulcerative colitis that developed while using abatacept, CLINICAL JOURNAL OF GASTROENTEROLOGY, 15(5), 924-928, 202210

Invited Lecture, Oral Presentation, Poster Presentation

  1. 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
  2. Efficiency of real-time computer-aided polyp detection in surveillance colonoscopy: a pilot study, 2024/10/12, Without Invitation, English
  3. Clinical Usefulness and Acceptability of Small-bowel Capsule Endoscopy with Panoramic Imaging Compared with Axial Imaging, 2024/11/21, Without Invitation, English
  4. 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
  5. 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
  6. Predictive factors of portal hypertensive enteropathy exacerbations based on long-term outcomes using capsule endoscopic findings, 2024/05/18, Without Invitation, English
  7. "Clinicopathological features of metachronous gastric cancer after eradication", International Gastric Cancer Congress (IGCC) 2023, 2023/06/14, Without Invitation, English
  8. Usefulness and educational effect of a virtual scale endoscope in measuring colorectal polyp size, 20230420, Without Invitation, English
  9. 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
  10. 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
  11. 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
  12. Is salvage hybrid ESD effective when ESD is difficult to complete?, 20230420, Without Invitation, English
  13. FOXP3+ T-CELLS AS PREDICTORS OF LYMPH NODE METASTASIS IN T1B COLORECTAL CANCER, 2023/10/12, Without Invitation, English
  14. CLINICOPATHOLOGICAL FEATURES AND SERUM RISK MARKERS OF METACHRONOUS GASTRIC CANCER AFTER ERADICATION, 2023/10/12, Without Invitation, English
  15. OUTCOMES OF ESD IN EARLY GASTRIC CANCER PATIENTS WITH ADVANCED MALIGNANT TUMORS OF OTHER ORGANS, 2023/10/12, Without Invitation, English
  16. LONG-TERM OUTCOMES OF PATIENTS WITH OBSCURE GASTROINTESTINAL BLEEDING AFTER NEGATIVE CAPSULE ENDOSCOPY​​​​, 2023/10/12, Without Invitation, English
  17. Comparative analysis of conventional ESD vs. hybrid ESD for T1b colorectal carcinomas of 20-29 mm in diameter, 2024/05/18, Without Invitation, English
  18. LONG-TERM PROGNOSIS AFTER ENDOSCOPIC SUBMUCOSAL DISSECTION FOR ESOPHAGEAL CANCER IN ELDERLY PATIENTS, 2024/05/18, Without Invitation, English
  19. Comparison of outcomes between endoscopic submucosal dissection and Endoscopic laryngo-pharyngeal surgery for superficial laryngo-pharyngeal cancer, 2024/05/18, Without Invitation, English
  20. Effect of operator's experience on delayed bleeding after colorectal EMR, 2024/07/04, Without Invitation, English
  21. Utility of cancer genome analysis using biopsy tissues from colorectal neoplasias developing from ulcerative colitis mucosa, 2024/10/12, Without Invitation, English