The impact of obesity on survival outcomes following drug treatment for advanced malignancy

Obesity is known to increase the risk of developing many types of cancer. However, once someone has developed cancer being overweight may mean for some cancer types the prognosis is better but for other types worse. The reasons for this are not fully understood.

Aims and objectives

It is possible that this relationship between obesity and different outcomes after cancer diagnosis may be related to factors such as general ill health of some cancer patients with a low weight, obese patients coming into contact with doctors more often and hence there being a greater likelihood of picking up cancer earlier and some drug treatments working more effectively in obese patients. We plan to investigate this further.

How it will be done

In this study we will use national NHS databases that capture the data for all patients in England that have received cancer drug treatment in the past decade to try and understand how improved survival in obese patients may relate to their cancer treatment and other aspects of their medical history. The study will also look at how many patients in England receiving cancer drug treatment are overweight and any differences in the length of time patients live with cancer for those that are overweight.

Potential impact

This will be the largest study using patient records to assess why some patients with obesity may live longer with cancer whilst other obese patients fare worse. Information from this analysis may help us to identify ways in which we can improve the treatment of both obese and lean patients with cancer.

General Practice data - Demographic data (e.g. age at cancer diagnosis), ethnicity, smoking status, alcohol intake, BMI, selected obesity-related comorbidities as recorded in primary care, deprivation index

Hospital Episode Statistics - Admitted Patients - to identify selected obesity-related comorbidities in included individuals (e.g. ischaemic heart disease, stroke, diabetes, dyslipidaemia)

Hospital Episode Statistics - Outpatients - to identify selected obesity-related comorbidities in included individuals (e.g. ischaemic heart disease, stroke, diabetes, dyslipidaemia)

Dr Ashley Clift - University of Oxford 

Prof Julia Hippisley-Cox - University of Oxford

Dr Simon Lord - University of Oxford

Dr David Dodwell - University of Oxford 

Dr Zhe Wang - University of Oxford