Dr. Karen Kostroff has over 35 years of experience as a breast cancer surgeon. Renowned for her clinical expertise, Dr. Kostroff is also committed to caring for her patients with compassion. She prioritizes giving patients the education and resources they need to make informed decisions about their care. Dr. Kostroff is recognized nationwide as a leader in diagnosing and treating women with breast cancer and who have hereditary breast cancer risks.

Dr. Kostroff’s purpose is her patients; she finds helping women through breast cancer extremely rewarding. Patients appreciate her attentiveness, her kindness, and her surgical skills. Dr. Kostroff works closely with other providers in the Northwell Health system to support patients and their families throughout the breast cancer journey.

She is an active member of the Northwell Health community and serves as the Chief of Breast Surgery for the entire Northwell Health system. Dr. Kostroff is the physician leader of Northwell Health’s breast navigation team and is part of a weekly tumor board that develops personalized treatment plans for patients. In addition, she is an Assistant Professor of Surgery at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell.

"Dr. Karen Kostroff is an outstanding physician. She explains treatment options thoroughly and demonstrates such kindness! Her skill & attentiveness are unequaled."

Education

  • Fellowship in Surgical Oncology, Brigham and Women’s Hospital, Harvard University
  • Residency in General Surgery, New York-Presbyterian/Weill Cornell Medical Center, with a concentration in Cancer Surgery and Breast Disorders at Memorial Sloan Kettering Cancer Center
  • BA and MD, Medical Honors Program, Boston University

Honors & Awards

  • Patient Choice Award, Northwell Health
  • Honoree, Katz Institute for Women’s Health
  • Honoree, UJA Federation of New York
  • Honoree, Power Women in Business Awards
  • Honoree, Long Island Business News Top 50 Women
  • New York Magazine’s Best Doctors
  • Excellence Award, Carol M. Baldwin Breast Cancer Research Fund
Office Supervisor

Vanessa Reyes

Vanessa has been a dedicated team member working with Dr. Kostroff for over 15 years. She navigates all surgical bookings as well as performs managerial tasks for the office. Vanessa’s loyalty to ensure patients have a good experience starts early in the process by always anticipating the needs of the patient and treats patients as if they were family. When not at work, Vanessa enjoys crocheting, going to the movies, reading and spending time with her family.
Administrative Support Coordinator

Jackie Carmen Perezlouis

Jackie has been with Northwell Health and a support staff member for Dr. Kostroff for over a decade. She plays a crucial role in providing general administrative support to ensure a smooth process when it comes to office billing and scheduling. She takes pride in her work and enjoys getting to know patients while helping them through difficult times. In Jackie’s spare time, she enjoys decorating and shopping.
Senior Administrative Support Assistant

Mary K. Dorney

Mary provides administrative support assistance for patients when it comes to helping them schedule their appointments and coordinating their surgery schedules. Mary enjoys meeting new patients and helps them to stay organized in the planning process. She is a sports enthusiast, has a love for music and values spending time with family and friends.
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