Memorial Sloan Kettering surgical oncologist Martin Weiser

Martin R. Weiser, MD

Surgical Oncologist


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

Clinical Expertise

Colon and Rectal Cancer Surgery; Anal Cancer; Appendiceal Cancer; Minimally Invasive Surgery

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Dr. Weiser accepts the following list of insurance providers. Select your insurance provider to see more details.

Contact and Location

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Memorial Sloan Kettering has locations throughout New York City, Long Island, New Jersey, and Westchester. These locations offers many services, including screening, chemotherapy, and medical testing.

About Me


MD, University of Chicago


General Surgery - Brigham and Women's Hospital


Surgical Oncology - Memorial Sloan Kettering Cancer Center; Colon and Rectal Surgery - Mount Sinai Medical Center

Board Certifications

Surgery; Colon and Rectal Surgery

As a surgical oncologist, I specialize in treating cancers of the gastrointestinal tract such as colon cancer, rectal cancer, anal cancer, small bowel cancers, and appendiceal cancer. I am skilled at treating primary, metastatic, and recurrent tumors. My expertise in minimally invasive (laparoscopic and robotic) surgery enables me to remove tumors without causing significant trauma to the patient. Whenever possible, I use nerve-sparing surgical techniques that preserve sphincter, bladder, and sexual function.

My clinical research focuses on increasing the accuracy of tumor staging and improving the methods of predicting outcomes following cancer surgery. I monitor and update Memorial Sloan Kettering’s colorectal cancer database, which we use to track patient outcomes and ensure that we are providing the highest quality of care. My laboratory research focuses on understanding the mechanisms underlying tumor spread and metastasis and on targeting those mechanisms in designing effective treatments. This work includes developing new tools to identify and measure tumor DNA in the bloodstream. I am also the surgical lead for the international prospective randomized trial PROSPECT, which is aimed at individualizing rectal cancer treatment in order to improve outcomes and reduce treatment-related toxicity.

In my practice, I emphasize personalized patient care. Physician assistants, nurses, and staff 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 multidisciplinary team discuss individual cases at our weekly conferences with the goal of providing the most comprehensive care possible.

I have served as MSK’s Medical Staff President, Chair of the Colorectal Task Group for the Society of Surgical Oncology, Colorectal Track Leader for the Education Committee of the American Society of Clinical Oncology, and Program Chair of the Annual Meeting of the American Society of Colon and Rectal Surgeons. Currently, I serve on the staging committee and the precision medicine committee of the American Joint Committee on Cancer, which works on updating the colorectal cancer staging system used by cancer centers throughout the United States.  

I am a member of the editorial boards of the Journal of Clinical Oncology, Annals of Surgical Oncology, International Journal of Surgery, and Scientific American Surgery, and I serve as the Colorectal Surgery section editor for UpToDate, an online resource for patients and physicians. I often review submitted manuscripts for the New England Journal of Medicine, Science, the Journal of the American Medical Association, and Lancet Oncology. My publications include over 250 research articles, book chapters, reviews, and editorials on a variety of topics, such as laparoscopic and robotic surgery, the biology of colon and rectal cancers, the treatment of rare anorectal tumors, cancer staging, predictors of outcomes following surgery, and the mechanisms of tumor metastasis. I also lecture nationally and internationally on the management of colorectal, anal, and appendiceal cancers and on the latest advances in minimally invasive surgery.

In my practice, I emphasize personalized patient care. Physician assistants, nurses, and staff at our clinic pay careful attention to each patient’s particular needs.

Dr. Weiser

Awards and Honors

  • Castle Connolly: New York Magazine Top Doctors (2012-2018)


Doctors at Memorial Sloan Kettering work as teams, with specialists from all different areas. This allows us to consider all your needs together, and to give you the best possible care.

Clinical Trials

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Find a Clinical Trial for You

Memorial Sloan Kettering's doctors and scientists are constantly developing new treatments for cancer. MSK is typically running hundreds of clinical trials at a given time.

You may be able to participate in a clinical trial even if you are new to MSK. Search our online directory to find trial information and see more about who can participate.

Research and Publications

View Dr. Weiser's Lab

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.

Publications on PubMed

Visit PubMed for a full listing of Dr. Weiser’s journal articles. Pubmed is an online index of research papers and other articles from the US National Library of Medicine and the National Institutes of Health.