After qualifying from Bristol University in 1995, she underwent specialist training at The Christie. Dr Armstrong was awarded a PhD from The University of Manchester in 2002 investigating the use of idiotypic vaccines against B Cell Lymphoma.
In 2007 she was appointed as a Consultant Medical Oncologist at The Christie NHS Foundation Trust and subsequently as an Honorary Senior Lecturer at the University of Manchester. She has a particular interest in breast cancer in young women, including fertility preservation and pregnancy as well as survivorship issues. Dr Armstrong is involved in both clinical and laboratory research. Within the laboratory she has a focus on immunotherapy research including adoptive T cell therapy approaches. She is Principal Investigator for a broad portfolio of phase I-III studies within the breast disease group (lead for investigational agents for triple-negative trials) and is the Chief Investigator for the IMpALA clinical trial, funded by Breast Cancer Now, to determine if aspirin augments immune checkpoint blockade in patients with triple negative breast cancer. She is the Co-Chair for the NCRN Breast Clinical Studies Symptom Management Subgroup and was the Clinical Lead for the 2018 NICE Early and Locally Advanced Breast Cancer Guideline update.