Dr Marsden qualified in medicine at Nottingham University in 1976. He then trained in internal medicine in Nottingham and Southampton, and completed specialist training in dermatology in Newcastle and Nottingham.
He has been a consultant dermatologist in Birmingham since 1987, and since 1992 his clinical practice has been limited to the field of skin cancer.
Dr Marsden has a strong interest in research and has been Principal Investigator or Chief Investigator on several major UK and international melanoma clinical trials. He is lead author of the current (2010) UK Melanoma Guidelines
He has published extensively on skin cancer in the medical literature and is a regular contributor to both UK and international skin cancer meetings.