Kathleen Fenn, MD

Kathleen Fenn, MD, is a medical oncologist who specializes in caring for people with breast cancer. In particular, she focuses on early-stage breast cancers that are hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-positive, where tumor cells depend on hormones or produce certain proteins that encourage growth.

As an assistant professor of medicine (medical oncology) at Yale School of Medicine, Dr. Fenn’s research explores how the body’s immune system interacts with tumors. She has shared insights into what’s known as the tumor immune microenvironment at national conferences.

Dr. Fenn completed her medical training at Yale School of Medicine. She then pursued her internship, residency, and fellowship in internal medicine, hematology, and oncology at Columbia University Irving Medical Center.