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Department of Colorectal Surgery

Masaaki Ito, Yuichiro Tsukada, Yuji Nishizawa, Koji Ikeda, Koichi Teramura, Nobuyoshi Takeshita, Hiro Hasegawa, Daichi Kitaguchi, Shusaku Iwai


Our main purpose is to bring together the outcomes of curability and postoperative function with low rate of severe complication for colorectal cancer patients. Achieving this goal requires not only the establishment of effective operative techniques but also an oncological consensus including consensus on the quality of life (QOL) and the various functions of patients with pelvic malignancies. New surgical procedures have been established, such as two-team operation of the therapeutic procedures with a trans-abdominal and trans-anal approach, named trans-anal total mesorectal excision (TaTME). This TaTME can be applied to nerve-sparing surgery, sphincter-saving surgery, bladder-sparing surgery, and minimally invasive surgery. We are also working to establish a methodology for providing effective preoperative treatments for advanced colorectal cancer (such as chemotherapy and chemo-radiation therapy) according to the patients' risk factor(s) of recurrence after curative surgery.

The Team and What We Do

The Department of Colorectal Surgery comprises nine colorectal surgeons and 10 residents. The outpatient clinic is open five days a week. More than 400 new patients with colorectal carcinomas visited this department during the last year. Treatment plans are discussed at a weekly conference of a multidisciplinary team including colorectal and hepatic surgeons, oncologists and radiologists. Many treatment strategies, such as local excision and other minimally invasive surgery using laparoscopy, and intensive radical surgery like total pelvic exenteration, with or without adjuvant chemo- or radiotherapy, have been introduced for the treatment of patients in any of the stages of colorectal cancer. Laparoscopy-assisted operations with wider lymphadenectomy or combined resection of adjacent organs are also increasingly being performed for patients with advanced colorectal carcinomas. Function-preserving surgery to keep postoperative patients’ QOL such as intersphincteric resection have been performed on more than 500 patients with very low rectal tumors. Moreover, a strong point of our team is having a lot of experience of the two-team TaTME rectal surgery starting from the perineal side and the perineal side at the same time, which contributes to shortening the operation time. In recent years, the postoperative anastomotic leakage rate for lower rectal cancer has decreased to 2-3%. The postoperative local recurrence rate for rectal cancer has also been less than 5%.

Table 1. Number of surgical cases from Apr. 2021 to Mar. 2022

Research activities

We have published the outcomes of anus-preserving surgery for low rectal cancer, especially those for TaTME in Japan and worldwide. The results of medical device development such as surgical navigation systems with artificial intelligence have been also published. The results of a phase Ib/II multicenter trial (VOLTAGE study) evaluating the safety, efficacy, and proof of concept (POC) of single-agent nivolumab as sequential therapy after preoperative chemoradiation in patients with locally advanced resectable rectal cancer showed that in patients with high-level microsatellite instability (MSI-H) LARC, CRT followed by immune checkpoint inhibitors also achieved a 60% (3/5) pCR rate suggesting increased efficacy of ICIs in this subgroup, albeit with a small sample size. We are proceeding with several clinical trials such as the NAIR study, JCOG1612, and JCOG1801 to improve rectal cancer patients’ prognoses and quality of life.

Clinical trials

A phase III randomized controlled trial comparing surgery plus adjuvant chemotherapy with preoperative chemoradiotherapy followed by surgery plus adjuvant chemotherapy for locally recurrent rectal cancer: RC-SURVIVE study (JCOG1801)

Single-arm confirmatory trial of the adjuvant chemoradiation for the patients with the high-risk rectal submucosal invasive cancer after the local resection: RESCUE study (JCOG1612)

Oxaliplatin and fluoropyrimidine chemotherapy first vs. upfront surgery for “very low” lying locally advanced rectal cancer without preoperative chemoradiation: The NAIR phase 3 trial

Evaluation of semi-standard treatment for lower and early-staged rectal cancer (high-risk pT1, low-risk pT2) in the late elderly patients: a multicenter prospective observational study.

COLOR III Trial: Transanal vs Laparoscopic TME (COLORIII)


Guiding university students in their studies

Guiding colorectal surgeons for obtaining medical specialist certification

Holding TaTME and lapaproscopic sigmoidectomy seminars for Japanese surgeons as training for surgical procedures

Future prospects

Establishment of less-invasive surgery for cure and function preserving in cancer patients with colorectal malignancies.

List of papers published


1. Kitaguchi D, Takeshita N, Hasegawa H, Ito M. Artificial intelligence-based computer vision in surgery: Recent advances and future perspectives. Annals of gastroenterological surgery, 6:29-36, 2022

2. Shiraishi T, Nishizawa Y, Nakajima M, Kado R, Ogawa H, Satoh N, Kitagawa K, Sakamoto M, Owada Y, Enomoto T, Yazawa S, Hamahata Y, Isogami Y, Enomoto H, Egawa A, Hasegawa H, Teramura K, Ikeda K, Tsukada Y, Sasaki T, Ito M. Protocol for the Japanese prospective multicenter observational study to evaluate the timing and frequency of stoma-related complications in patients with malignant rectal tumors. Journal of Japanese Society of Wound, Ostomy and Continence Management, 25:710-716, 2022

3. Mori T, Ikeda K, Takeshita N, Teramura K, Ito M. Validation of a novel virtual reality simulation system with the focus on training for surgical dissection during laparoscopic sigmoid colectomy. BMC surgery, 22:12, 2022

4. Enomoto H, Ito M, Sasaki T, Nishizawa Y, Tsukada Y, Ikeda K, Hasegawa H. Anastomosis-Related Complications After Stapled Anastomosis With Reinforced Sutures in Transanal Total Mesorectal Excision for Low Rectal Cancer: A Retrospective Single-Center Study. Diseases of the colon and rectum, 65:246-253, 2022

5. Bando H, Tsukada Y, Ito M, Yoshino T. Novel Immunological Approaches in the Treatment of Locally Advanced Rectal Cancer. Clinical colorectal cancer, 21:3-9, 2022

6. Kitaguchi D, Takeshita N, Matsuzaki H, Hasegawa H, Igaki T, Oda T, Ito M. Deep learning-based automatic surgical step recognition in intraoperative videos for transanal total mesorectal excision. Surgical endoscopy, 36:1143-1151, 2022

7. Katsumata K, Enomoto M, Ishizaki T, Fujita S, Kanemitsu Y, Ito M, Shiomi A, Komori K, Ohue M, Ota M, Akazai Y, Shiozawa M, Yamaguchi T, Bando H, Sekimoto M, Kobatake T, Machida R, Akasu T, Moriya Y. Risk factors for surgical site infection and association of surgical site infection with survival of lower rectal cancer patients without clinical lateral pelvic lymph node metastasis (clinical Stage II/III): Analysis of data from JCOG0212. Clinical & experimental metastasis, 38:459-466, 2021

8. Katayama H, Inomata M, Mizusawa J, Nakamura K, Watanabe M, Akagi T, Yamamoto S, Ito M, Kinugasa Y, Okajima M, Takemasa I, Okuda J, Shida D, Kanemitsu Y, Kitano S. Institutional variation in survival and morbidity in laparoscopic surgery for colon cancer: From the data of a randomized controlled trial comparing open and laparoscopic surgery (JCOG0404). Annals of gastroenterological surgery, 5:823-831, 2021

9. Nishizawa Y, Nishigori H, Tsukada Y, Sasaki T, Tsukamoto S, Kanemitsu Y, Nakano D, Yamaguchi T, Otsuka K, Nakamura T, Shiomi A, Iwasaki N, Tamura H, Wakabayashi M, Nomura S, Ito M. A multicentre confirmatory single-arm trial of the safety and efficacy of a transanal drain for prevention of anastomotic leakage after surgery for rectal cancer. Colorectal disease: the official journal of the Association of Coloproctology of Great Britain and Ireland, 23:3196-3204, 2021

10. Higashino T, Sakuraba M, Fukunaga Y, Oshima A, Masuda H, Ito M. Surgical outcome for colorectal or urinary tract-related fistula: Usefulness of vascularized tissue transfer-a retrospective study*. Journal of plastic, reconstructive & aesthetic surgery: JPRAS, 74:1041-1049, 2021

11. Fukui S, Kawai T, Nishizawa Y, Nishikawa A, Nakamura T, Iwamoto N, Horise Y, Masamune K. Locally operated assistant manipulators with selectable connection system for robotically assisted laparoscopic solo surgery. International journal of computer assisted radiology and surgery, 16:683-693, 2021

12. Fung TLD, Tsukada Y, Ito M. Essential anatomy for total mesorectal excision and lateral lymph node dissection, in both trans-abdominal and trans-anal perspective. The surgeon: journal of the Royal Colleges of Surgeons of Edinburgh and Ireland, 19:e462-e474, 2021

13. Shiraishi T, Sasaki T, Tsukada Y, Ikeda K, Nishizawa Y, Ito M. Radiologic Factors and Areas of Local Recurrence in Locally Advanced Lower Rectal Cancer After Lateral Pelvic Lymph Node Dissection. Diseases of the colon and rectum, 64:1479-1487, 2021

14. Kitaguchi D, Takeshita N, Matsuzaki H, Igaki T, Hasegawa H, Ito M. Development and Validation of a 3-Dimensional Convolutional Neural Network for Automatic Surgical Skill Assessment Based on Spatiotemporal Video Analysis. JAMA network open, 4:e2120786, 2021

15. Inoue A, Murata K, Komori T, Takeda T, Fujii M, Yamaguchi T, Yamaguchi T, Masuishi T, Shiota T, Morita S, Suzuki Y, Ito M, Kanemitsu Y, Shiozawa M, Yasui M, Kagawa Y, Sugihara K. Open versus laparoscopic surgery for primary appendiceal tumors: a large multicenter retrospective propensity score-matched cohort study in Japan. Surgical endoscopy, 35:5515-5523, 2021

16. Kanemitsu Y, Shitara K, Mizusawa J, Hamaguchi T, Shida D, Komori K, Ikeda S, Ojima H, Ike H, Shiomi A, Watanabe J, Takii Y, Yamaguchi T, Katsumata K, Ito M, Okuda J, Hyakudomi R, Shimada Y, Katayama H, Fukuda H. Primary Tumor Resection Plus Chemotherapy Versus Chemotherapy Alone for Colorectal Cancer Patients With Asymptomatic, Synchronous Unresectable Metastases (JCOG1007; iPACS): A Randomized Clinical Trial. Journal of clinical oncology: official journal of the American Society of Clinical Oncology, 39:1098-1107, 2021

17. Noguchi M, Shitara K, Kawazoe A, Yamamoto D, Takii Y, Saito Y, Sato T, Horimatsu T, Ishikawa H, Ito Y, Ito M, Ikematsu H. Short-term safety of adjuvant chemoradiotherapy after local resection for patients with high-risk submucosal invasive rectal cancer: a single-arm, multicenter phase II trial. Japanese journal of clinical oncology, 51:707-712, 2021

18. Inamori K, Togashi Y, Fukuoka S, Akagi K, Ogasawara K, Irie T, Motooka D, Kobayashi Y, Sugiyama D, Kojima M, Shiiya N, Nakamura S, Maruyama S, Suzuki Y, Ito M, Nishikawa H. Importance of lymph node immune responses in MSI-H/dMMR colorectal cancer. JCI insight, 6:2021

19. Kitaguchi D, Takeshita N, Matsuzaki H, Hasegawa H, Honda R, Teramura K, Oda T, Ito M. Computer-assisted real-time automatic prostate segmentation during TaTME: a single-center feasibility study. Surgical endoscopy, 35:2493-2499, 2021

20. Narihiro S, Miura N, Nishizawa Y, Hasegawa H, Ikeda K, Teramura K, Tsukada Y, Sasaki T, Ito M. Delorme surgery for colonic mucosal prolapse after intersphincteric resection. Surgery today, 51:916-922, 2021

21. Kondo A, Nishizawa Y, Tsukada Y, Sasaki T, Inoue M, Masuda H, Suzuki Y, Ito M. Potential benefit of laparoscopic surgery for rectal cancer on postoperative male sexual function. Colorectal disease: the official journal of the Association of Coloproctology of Great Britain and Ireland, 23:1745-1754, 2021

22. Enomoto H, Nishizawa Y, Inamori K, Hasegawa H, Ikeda K, Tsukada Y, Sasaki T, Ito M. Sacral neuromodulation for the prevention of a permanent stoma in patients with severe defecation disorder following intersphincteric resection. Surgery today, 51:1379-1386, 2021


1. Tsukada Y, Ito M. Japanese D3 dissection in cancer of the colon: technique and results. In: The Lymphatic System in Colorectal Cancer Basic Concepts, Pathology, Imaging and Treatment Perspectives, United Kngdom, Wim Ceelen Academic Press, pp 193-214, 2022