Surgical Oncologist

Vice Chair for Education and Faculty Development, Department of Surgery; Stuart H.Q. Quan Chair in Colorectal Surgery

Martin R. Weiser, MD

About Me

I am a surgical oncologist who specializes in colorectal surgery in patients with primary, metastatic, or recurrent cancers of the colon, rectum, anus, or appendix. My expertise in minimally invasive (laparoscopic and robotic) surgery enables me to remove these tumors while minimizing trauma to the patient. Whenever possible I use nerve-sparing surgical techniques that preserve sphincter, bladder, and sexual function.

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My clinical research focuses on improving the staging of tumors and methods to predict patients’ outcomes following cancer surgery. I monitor and update Memorial Sloan Kettering’s colorectal cancer database, which tracks these outcomes to ensure that we are providing the highest quality of care. My laboratory research focuses on understanding and targeting the mechanisms underlying tumor spread and metastasis.

In my practice I emphasize personalized patient care. Physician assistants, nurses, and staff members at our clinic pay careful attention to each patient’s particular needs. We also emphasize a team approach and work closely with specialists in radiation oncology, medical oncology, and other services. Members of this team discuss individual cases at our weekly multidisciplinary conferences to make sure that we can provide the most comprehensive care possible.

I recently served as program chair of the annual meeting of the American Society of Colon and Rectal Surgeons. I am a member of the American Joint Committee on Cancer (AJCC) staging committee, which develops the nationally used staging system for colorectal cancer used by cancer centers throughout the US, as well as the National Comprehensive Cancer Network (NCCN) colorectal database committee, and I am on the steering committee for national cooperative research groups (CALGB and ACOSOG). I also serve as editor of the colorectal surgery section of UpToDate Inc., an online resource for patients and physicians (

I have coauthored many papers and book chapters on a variety of topics including laparoscopic surgery, colon and rectal cancers, rare anorectal tumors, cancer staging, predictors of outcome following surgery, and the mechanisms of tumor metastasis. I lecture nationally and internationally on the management of colorectal cancer, anal cancer, appendiceal cancer, and minimally invasive surgery.

  • Clinical Expertise: Colon and Rectal Cancer Surgery; Minimally Invasive Surgery
  • Awards and Honors: New York Magazine Top Doctors (2012-2016)
  • Languages Spoken: English
  • Education: MD, University of Chicago
  • Residencies: General Surgery - Brigham and Women's Hospital
  • Fellowships: Surgical Oncology - Memorial Sloan Kettering Cancer Center; Colon and Rectal Surgery - Mount Sinai Medical Center
  • Board Certifications: Surgery; Colon and Rectal Surgery

My Research

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See Martin R. Weiser’s laboratory
research at Memorial Sloan Kettering.

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Selected Book Chapters
“Adenocarcinoma of the colon and rectum.” Weiser MR, Saltz LB, Posner MC. In: Shackelford’s Surgery of the Alimentary Tract. 7th ed. Yeo CJ, ed. Philadelphia: WB Saunders; 2012.

“Left hemicolectomy for cancer.” Weiser MR. In: Mastery of Surgery. 6th ed. Fischer JE, ed. Chicago: Lippincott Williams & Wilkins; 2012.

“Endorectal ultrasound for preoperative staging.” Loh B, Weiser MR, Wong WD. In: Intersphincteric Resection of Low Rectal Tumors. Schiessel R, Metzger P, eds. New York: Springer; 2012.

“Rectal cancer.” Kim H, Weiser MR. In: Clinical Scenarios in Surgery: Decision Making and Operative Techniques. Dimick JB, Upchurch GR Jr, Sonnenday CJ. Philadelphia: Lippincott Williams & Wilkins; 2013.

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Visit PubMed for a full listing of Martin R. Weiser’s journal articles

Pubmed is an online index of biomedical articles maintained by the U.S. National Library of Medicine and the National Institutes of Health.

Clinical Trials

Research is integral to our mission at Memorial Sloan Kettering, and clinical trials help us discover better forms of patient care and treatment. For you, this could mean access to a new therapy or therapy combination. Click to see a list of the trials I’m currently leading.


Most major health insurers offer plans that include MSK as one of their in-network providers. If MSK is in-network, it means all our doctors are too. Medicaid and New York State Medicare also provide benefits for care at MSK.

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