Kay Yoon-Flannery, DO, MPH, FACS, FACOS

4.92 out of 5 (204 ratings, 65 reviews)
Ratings and Reviews


Cooper University Health Care Titles

  • Co-Director, Janet Knowles Breast Cancer Center
  • Breast Surgeon
  • Director of Quality and Process Improvement
  • Director of Physician Engagement

Cooper Medical School of Rowan University Titles

  • Assistant Professor of Surgery

Board Certifications

  • American Osteopathic Board of General Surgery

Specialty Certifications

Breast Ultrasound

Hidden Scar Breast Cancer Surgery

Other Languages


Professional Type

Cooper University Physician



About Me

What inspired you to become a cancer specialist?

As a young resident I had a patient who came in with a fungating breast cancer. Fungating cancers are when cancers break through the skin, creating a wound that can become infected and ulcerated. They generally develop when a patient ignores signs and symptoms (like a lump in the breast) and the cancer goes untreated for many months or years.

My patient’s wound was so severely infected that she was hospitalized. When I spoke with her she revealed to me that she was actually a retired nurse who had been estranged from her only daughter for many years and that she neglected to seek care because she did not want her first phone call to her daughter to be about a cancer diagnosis. That night I promised myself that I would be a breast surgeon and do everything I could so that patients do not get to an advanced stage like her.

What is your essential patient care philosophy?

Take care of patients as you would want your mother to be cared for. I always take my time to explain things to my patients and their family members because that’s how I would want my mother to be treated.

What do you hope your patients say about you to their family and friends?

That they feel confident having me not only as their surgeon, but as a partner in their cancer journey. That I explained things so they could understand and be an active participant in their own care.

What three words best describe you?

Passionate, decisive, and outspoken.

Office Locations

Camden, Sewell, Haddonfield
Cooper Surgical Care at Sewell

2 Plaza Drive
Suite 202
Sewell , NJ 08080
Phone: 855.632.2667
Maps & Directions

The Ripa Center Haddonfield

100 Grove Street
Haddonfield , NJ 08033
Phone: 856.325.6601
Maps & Directions

Education & Training

Medical SchoolUniversity of Medicine and Dentistry of New Jersey, Stratford, NJ
Graduate SchoolMPH - University of Medicine and Dentistry of New Jersey, Piscataway, NJ
InternshipUniversity of Medicine and Dentistry of New Jersey, Stratford, NJ
ResidencyGeneral Surgery - Rowan University School of Osteopathic Medicine, Stratford, NJ
FellowshipBreast Surgical Oncology - University of Pennsylvania Health System, Philadelphia, PA


  • Philadelphia Academy of Surgeons
  • Association of Women Surgeons
  • Society of Surgical Oncology
  • American Society of Breast Surgeons
  • American College of Surgeons
  • American College of Osteopathic Surgeons

Awards and Honors

  • SJ Magazine "Top Docs" - Breast Surgery - 2018, 2019, 2021, 2022, 2023
  • Best Breast Cancer Surgeon, Suburban Magazine - 2017
  • Fellow, American College of Surgeons - 2019
  • Fellow, American College of Osteopathic Surgeons - 2018
  • Chief Resident Award, Department of Surgery, Rowan-SOM - 2016
  • David Silverman Award, Department of Surgery, UMDNJ-SOM - 2011
  • Student Award for Excellence in Osteopathic Medicine, New Jersey Association of Osteopathic Physicians and Surgeons - 2011
  • Alumni Association Scholarship Award, UMDNJ-SOM - 2009, 2010
  • Graduate Merit Award, Executive Women of New Jersey - 2010
  • Outstanding Service Award, Department of Surgery, UMDNJ-SOM - 2009
  • Educational Scholarship, Student Osteopathic Surgical Association - 2009
  • Translating Osteopathic Understanding into Community Health (TOUCH), Council of Osteopathic Student Government Presidents - 2008
  • SJ Magazine "Top Female Docs" - 2023, 2024


Yoon-Flannery K, Fisher CS, Neff MA. A Surgeon’s Path: What to Expect after a General Surgery Residency. Springer. July 2018.

Yoon-Flannery K, DeStefano LM, De La Cruz LM, Fisher CS, Lin LY, Coffua LS, Mustafa RE, Sataloff DM, Tchou JC, Brooks AD. Quality of Life and Sexual Well-Being after Nipple Sparing Mastectomy: A Matched Comparison of Patients Using the Breast Q. Journal of Surgical Oncology. 2018 Jul;118(1):238-242.

Yoon-Flannery K, Blankenship SA, Fisher CS, Mustafa RE, Nocera N, Tchou J, Czerniecki BJ, De La Cruz L. A Systematic Review of the Surgical and Ablative Management of Breast Cancer Liver Metastasis. Advances in Breast Cancer and Therapy. Volume 2018. Issue 01.

Mustafa RE, DeStefano LM, Bahng J, Yoon-Flannery K, Fisher CS, Zhang PJ, Tchou J, Czerniecki BJ, De La Cruz LM. Evaluating the Upstaging Risk of Her2 Positive DCIS to Invasive Breast Cancer. Annals of Surgical Oncology. 2017 Aug; 24(10):2999-3003.

Grants and Research

  • Susan G. Komen South and Central Jersey, Korean, African American and Latinas of New Jersey Project (KAAL-NJ) - 2018 to present

Ratings and Reviews

Ratings and reviews come from patient responses to health care provider-related questions on the Clinician and Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS) Patient Experience Survey that Cooper sends to patients after outpatient office visits.  Learn more about our survey and how ratings are calculated >>

Overall Rating

4.92 out of 5 (204 ratings, 65 reviews)
Dec 12, 2023
My visits to Dr. Flannery's office are always pleasant.
Dec 12, 2023
Great experience Dr Flannery is the best
Dec 12, 2023
Everyone was very nice. Dr Flannery did wear a mask
Dec 12, 2023
Everything was good
Dec 12, 2023
I felt respected; everyone took time to listen to me and explained my situation and options. It was a very positive experience in a difficult time.
Dec 12, 2023
I am very grateful to Dr. Flannery. She is a very caring physician and surgeon!
Dec 12, 2023
Excellent facility and staff
Dec 12, 2023
Excellent care .. Thank you so much ! !
Dec 12, 2023
I'm very happy and confident with the care I receive from this doctor
Dec 12, 2023
Overall assessment Excellent