Memorial Sloan Kettering surgical oncologist Martin Weiser

Martin R. Weiser, MD

Areas of Expertise

Conditions I Treat

  • Colon cancer
  • Rectal cancer
  • Anal cancer

My Specialties

  • Minimally invasive surgery
  • Robotic surgery
  • Laparoscopic surgery
Request an Appointment
Our Care Advisors can answer many of your questions. They will connect you with the best healthcare provider for your needs.
English
Share

Get to Know Me

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.

Read more

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.

What I Do at MSK

A colorectal (KOH-loh-REK-tul) surgeon is a doctor with special training in surgery on the colon and rectum.

  • Vice Chair for Faculty Affairs, Department of Surgery
  • Stuart H.Q. Quan Chair in Colorectal Surgery
Areas of Expertise

Conditions I Treat

  • Colon cancer
  • Rectal cancer
  • Anal cancer
  • Appendiceal (appendix) cancer and conditions

My Specialties

  • Minimally invasive surgery
  • Robotic surgery
  • Laparoscopic surgery
  • Nerve-sparing surgery
  • Preserving bowel, bladder, and sexual function
  • Clinical trials
Education & Honors

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

Awards and Honors

  • Castle Connolly: America’s Top Doctor (2025)
  • Castle Connolly: America’s Top Doctor (2024)
  • Top Doctors New York Metro Area, Castle Connolly (2023)
  • Castle Connolly: America's Top Doctors (2023)
  • Castle Connolly: New York Magazine Top Doctors (2012-2020)

Insurance Information

Understanding your insurance options is an important part of managing your cancer care. We have relationships with many common healthcare providers and plans.

Aetna

In Network Coverage Type
HMO, EPO PPO, POS, Transplant

Aetna Medicare Advantage (MTA and NYC retirees only)

In Network Coverage Type
PPO

Anthem BCBS and other BCBS licensee plans

In Network Coverage Type
PPO, POS, EPO, HMO

Anthem BCBS Health Plus

In Network Coverage Type
HMO

Blue Cross Blue Shield Federal Employee Program

In Network Coverage Type
HMO, PPO

Blue Cross Blue Shield states outside of NY/NJ

In Network Coverage Type
HMO, EPO PPO, POS

Carrum Health

In Network Coverage Type
Supplemental

Cigna

In Network Coverage Type
PPO, POS, HMO

Connecticare

In Network Coverage Type
POS, EPO, HMO

First Health

In Network Coverage Type
PPO

Straight NJ Medicaid

In Network Coverage Type
State Government

Straight NY Medicaid

In Network Coverage Type
State Government

Emblem

In Network Coverage Type
PPO, POS, EPO, HMO

Offers a qualified health plan from the Health Insurance Marketplace. Call Emblem to learn more.

Emblem Essential

In Network Coverage Type
HMO

Emblem Medicare Advantage (Medicare Choice PPO Network and VIP Prime Network Only)

In Network Coverage Type
PPO, HMO

Empire Essential

In Network Coverage Type
HMO

Empire Plan / NYSHIP (Blue Cross/UnitedHealthcare split plan)

In Network Coverage Type
PPO

Fidelis

In Network Coverage Type
HMO, EPO

Offers a qualified health plan from the Health Insurance Marketplace. Call Fidelis to learn more.

Fidelis Managed Medicaid & HARP

In Network Coverage Type
HMO

Fidelis Medicare Advantage

In Network Coverage Type
HMO

Healthfirst

In Network Coverage Type
EPO, HMO, PPO, POS

Offers a qualified health plan from the Health Insurance Marketplace. Call Healthfirst to learn more.

Healthfirst Managed Medicaid

In Network Coverage Type
HMO

Healthfirst Medicare Advantage

In Network Coverage Type
HMO, PPO

Healthsmart

In Network Coverage Type
PPO EPO

Horizon Blue Cross Blue Shield New Jersey (HMO)

In Network Coverage Type
HMO

Horizon Blue Cross Blue Shield New Jersey (PPO)

In Network Coverage Type
PPO

Horizon Blue Cross Blue Shield New Jersey Omnia Tier I (EPO)

In Network Coverage Type
EPO

Horizon Blue Cross Blue Shield New Jersey Omnia Tier II (EPO)

In Network Coverage Type
EPO

Horizon Medicare Advantage

In Network Coverage Type
PPO, HMO

Husky CT Medicaid

In Network Coverage Type
State Government

Magnacare

In Network Coverage Type
PPO, POS, EPO

Medicare Part A&B (traditional Medicare)

In Network Coverage Type
Federal Government

Metroplus

In Network Coverage Type
HMO

City Employee Health Plans (Gold and Gold Care)

Multiplan/Beech Street/PHCS

In Network Coverage Type
Supplemental

MVP

In Network Coverage Type
PPO/OAP

Non-Participating Plans with Out of Network Benefits

In Network Coverage Type
PPO, POS, EPO, HMO

NYC Medicare Advantage Plus for City Employees

In Network Coverage Type
TBD

Oscar

In Network Coverage Type
HMO/EPO

Oxford

In Network Coverage Type
PPO, EPO

World Trade Center Health Program (WTC)

In Network Coverage Type
State Government

Qualcare

In Network Coverage Type
PPO, POS, HMO

Tricare

In Network Coverage Type
PPO, HMO

UMR

In Network Coverage Type
PPO, POS

United Healthcare

In Network Coverage Type
PPO, POS, HMO

Don't see your carrier or plan? We can help you understand your coverage.

If you don't have health insurance or are worried that your care may not be fully covered, our financial assistance programs may be able to help.

If you have questions about insurance, call us at 646-497-9176.

Make an Appointment

Current Patients
Request an appointment by logging in to MSK MyChart or calling your Care Team. If you are not enrolled in MSK MyChart, ask your Care Team to send you an invitation. You can also go to MSK MyChart and select “Sign up now.”

Contact and Location

Dr. Weiser sees patients at one location.

Office Phone
Location
New York, NY
160 East 53rd Street New York NY 10022
Map MarkerA msk map marker icon
Leaflet © OpenStreetMap contributors; © CARTO.

Looking to see a doctor at a different location? See all MSK locations.

Colleagues

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.

See all Biobanking doctors

See all Surgery doctors

See all Colorectal Service doctors

Clinical Trials

Smiling doctors in the lab
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.

Search clinical trials

Research and Publications

View Dr. Weiser's Lab

Selected Book Chapters

Weiser MR and Saltz LB. Chapter 44 Adenocarcinoma of the Colon and Rectum. In Scientific American Surgery. 2015

Patel S and Weiser MR. Robotic Rectal Surgery. In Rectal Cancer: Modern Approaches to Treatment (Chang et al, editors) 2016

Pappou M and Weiser MR. Proctectomy. In The ASCRS Textbook of Colon and Rectal Surgery. 2016.

Weiser MR. Robotic Right Hemicolectomy. SAGES Manual. 2017

Pappou M and Weiser MR. Total Mesorectal Excision. In Textbook of Surgical Oncology 2016

Weiser MR. Open, Laparoscopic, and Robotic Right Hemicolectomy for Cancer. Mastery of Surgery. 2017

Fedler S and Weiser MR. Pelvic Exenteration. In Colon and Rectal Surgery: Abdominal Operations 2nd Ed. 2017.

Langan R and Weiser MR. Stage IV Colorectal Cancer. In Clinical Decision Making in Colorectal Surgery, 2nd edition, edited by Dr. Scott Steele, Justin Maykel, and Steven D. Wexner. Springer Science and Business Media. 2017

Weiser MR and Garcia-Aguilar J Basic Principles of the Operative Treatment of Colorectal Cancer In: Yeo CJ, ed. Shackelford’s Surgery of the Alimentary Tract, 8th edition. Elsevier; 2018.

Weiser MR. Perspective on colorectal neoplasms. In Zinner M and Ashley S (ed.), Maingot’s Abdominal Operations, 13th ed., in press. McGraw-Hill, New York.

Kleiman DA, Weiser MR. 2018. Locally advanced rectal cancer. In Hochwald SN and Cance WG (ed.), Complex General Surgical Oncology. Decker, Toronto. https://www.deckerip.com/products/cgso/

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.

See all on PubMed

Patient Reviews

Your trust is our main concern

We strive to keep reviews trustworthy, honest and fair. Learn more about our patient experience reviews.

4.9 358 reviews

  • 4.8 Provider's Explanations Easy to Understand
  • 4.8 Trusts Provider with Care
  • 4.8 Provider Listened Carefully
  • 4.9 Likelihood of Recommending Provider
Mar 25, 2025

Dr. Matin Weiser was both an excellent clinician with superb skills, but also a very kind physician with a lovely bedside manner. I could not have had a better experience, both with Dr. Weiser, his staff and the front desk. It is no wonder that MSK is a world-renowned cancer center! I could not be more grateful for the care and attention shown... [patient name removed]


Mar 18, 2025

We had first visit today , we come to see Dr. Martin. I am confident with Dr. Martin and his team. he explained treatment choice was reasonable, answer all my questions. I am hand in my mom to his team. All staff were friendly. Thank you all ! God bless !


Mar 18, 2025

It was all very good!


Mar 14, 2025

Happy to have him as my doctor.


Mar 11, 2025

In a word...BELIEVER. That said I should probably explain. Very simply Dr. Weiser was very forthcoming with how he was going to conduct his portion of the surgery. He repeatedly asked both my wife and I if we had any questions or concerns. He fully explained what we needed to do leading up to the surgery. And when we did ask questions he answered them completely without hesitation. That said when he left the room my wife and I felt that we were in exactly the right place with exactly the right surgeon. We became BELIEVERS.


View more +
Ratings and Comments Powered by NRC Health

Disclosures

Doctors and faculty members often work with pharmaceutical, device, biotechnology, and life sciences companies, and other organizations outside of MSK, to find safe and effective cancer treatments, to improve patient care, and to educate the health care community.

MSK requires doctors and faculty members to report (“disclose”) the relationships and financial interests they have with external entities. As a commitment to transparency with our community, we make that information available to the public.

Martin R. Weiser discloses the following relationships and financial interests:

  • UptoDate
    Intellectual Property Rights; Professional Services and Activities

If you’re a patient at MSK and would like more information about your doctor’s external relationships, please talk with your doctor.

The information published here is a complement to other publicly reported data and is for a specific annual disclosure period. There may be differences between information on this and other public sites as a result of different reporting periods and/or the various ways relationships and financial interests are categorized by organizations that publish such data.


This page and data include information for a specific MSK annual disclosure period (January 1, 2023 through disclosure submission in spring 2024). This data reflects interests that may or may not still exist. This data is updated annually.

Learn more about MSK’s COI policies here. For questions regarding MSK’s COI-related policies and procedures, email MSK’s Compliance Office at ecoi@mskcc.org.


View all disclosures