Since 1995, he has been Professor of Epidemiology and Vital Statistics at the London School of Hygiene & Tropical Medicine. He was Deputy Chief Medical Statistician at the Office for National Statistics from 1995 to 2004 and Head of the Cancer and Public Health Unit at the School from 1998 to 2003.

He has previously worked for the World Health Organisation at the International Agency for Research on Cancer in Lyon (1987-1991), and was Medical Director of the Thames Cancer Registry in London (1991-1995). 

His main interests include trends and inequalities in cancer incidence, mortality and survival, and the application of these metrics to public health policy and cancer control.

He holds a post as Honorary Consultant in Oncology at UCL Hospitals NHS Foundation Trust. He is Head of the Cancer Survival Group, and sits on the School’s Information Governance Board.