Meet Maria Widmar: Colorectal Surgeon at MSK

Dr. Maria Widmar uses minimally invasive surgery to treat colorectal cancers and inflammatory bowel diseases (IBD) at MSK in Manhattan, MSK Nassau and MSK Commack.
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 Memorial Sloan Kettering colorectal surgeon Maria Widmar

Maria Widmar, MD, MPH

Colorectal Surgeon

Areas of Expertise

Conditions I Treat

  • Colon cancer
  • Rectal cancer
  • Anal cancer

My Specialties

  • Minimally invasive surgery
  • Laparoscopic surgery
  • Robotic surgery
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Dr. Widmar's Office Information
Languages: English, Portuguese, and Spanish
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Get to Know Me

I am a board-certified colorectal surgeon with advanced training in caring for people with colon cancer and rectal cancer.

I specialize in non-surgical management for rectal cancer, also known as active surveillance or a “watch and wait” approach. This involves closely monitoring a patient’s condition and delaying treatment until symptoms appear or change.

I also specialize innerve-sparing surgical techniques to preserve bladder, sphincter, and sexual function. In addition, I have focused my training on robotic surgery, and whenever possible, I use advanced minimally invasive techniques, which are associated with faster recovery and fewer complications. I see patients at Memorial Sloan Kettering Commack and Memorial Sloan Kettering Nassau. I also see select patients at the Rockefeller Outpatient Pavilion in New York City.

I chose to dedicate my career to treating colorectal cancer because I recognized the significant impact this diagnosis can have on patients and their families—and because I wanted patients to receive the best treatment available so they could get back to living their lives.

The comprehensive care we provide at Memorial Sloan Kettering Cancer Center (MSK) is personalized and easy to navigate from start to finish. At the initial consultation, my goal is for the patient to leave with a full understanding of their diagnosis, a clear picture of the next steps in their treatment, and confidence in their care team. I am proud to work at an institution that prioritizes scientific evidence and a patient-centered approach.

I’ve made New York City my home for nearly two decades, studying and training at many of its great institutions, including New York University, The Mount Sinai Hospital, NewYork-Presbyterian/Columbia/Weill Cornell Medical Center, and now MSK. My research focuses on achieving the best outcomes for people with colorectal cancer, including active surveillance for rectal cancer, avoiding radiation therapy, and reducing complications after surgery.

I also have a strong interest in applying economics research to help make high-quality cancer care available more widely.

What I Do at MSK

I'm a colorectal (KOH-loh-REK-tul) surgeon, which is a doctor with special training in surgery on the colon and rectum.

  • Assistant Attending Surgeon
Areas of Expertise

Conditions I Treat

  • Colon cancer
  • Rectal cancer
  • Anal cancer
  • Appendiceal (appendix) cancer and conditions
  • Inflammatory bowel disease (IBD)
  • Crohn's disease
  • Ulcerative colitis

My Specialties

  • Minimally invasive surgery
  • Laparoscopic surgery
  • Robotic surgery
Education & Honors

Education

  • MD, Icahn School of Medicine at Mount Sinai
  • MPH, Icahn School of Medicine at Mount Sinai

Residencies

  • General Surgery - Icahn School of Medicine at Mount Sinai
  • General Preventive Medicine and Public Health - Icahn School of Medicine at Mount Sinai

Fellowships

  • Research Fellowship in Colorectal Surgery - Memorial Sloan Kettering Cancer Center
  • Clinical Fellowship in Colorectal Surgery - Weill Cornell Medical Center
  • Clinical Fellowship in Advanced Colorectal Surgical Oncology - Memorial Sloan Kettering Cancer Center

Board Certifications

  • Surgery

Awards and Honors

  • David A. Dreiling Chief Resident Award for Excellence in Surgical Achievement (2017)
  • Cancer Prevention and Control Research Prize Winner, American College of Preventive Medicine Annual Conference (2015)
  • Dr. Arthur H. Aufses, Sr. Prize in Surgery, Icahn School of Medicine at Mount Sinai (2010)

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.

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.

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Contact and Location

Office Phone
Location
Commack, NY
Uniondale, NY
New York, NY
Memorial Sloan Kettering Commack Nonna’s Garden Foundation Center
650 Commack Road Commack NY 11725
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Memorial Sloan Kettering Nassau
1101 Hempstead Turnpike Uniondale NY 11553
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Rockefeller Outpatient Pavilion
160 East 53rd Street New York NY 10022
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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.

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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.

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Research and Publications

Publications on PubMed

Visit PubMed for a full listing of Dr. Widmar’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.

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Disclosures

Members of the MSK Community 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. These activities outside of MSK further our mission, provide productive collaborations, and promote the practical application of scientific discoveries.

MSK requires doctors, faculty members, and leaders 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. Not all disclosed interests and relationships present conflicts of interest. MSK reviews all disclosed interests and relationships to assess whether a conflict of interest exists and whether formal COI management is needed.

Maria Widmar discloses the following relationships and financial interests:

No disclosures meeting criteria for time period


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, 2024 through disclosure submission in spring 2025). 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.


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