Obese cancer survivors are more likely to lose weight than those with a healthy weight and obese people without cancer, according to a study published in BMC Cancer*.
“The weight loss seen in this study could be due to one of two reasons. The obese patients could be intentionally deciding to lose weight, or the weight loss could be a sign of more advanced disease” – Professor Jane Wardle
Cancer Research UK scientists studied weight change in healthy people and cancer patients over the age of 50, before and after diagnosis.
The four-year study revealed that cancer survivors lost more weight than those who had not developed the disease. Further analysis showed that all the weight loss was among those who were overweight or obese before diagnosis, with no weight loss among patients who were a healthy weight from the start.
This is the first study of its kind to look at weight change that considers pre-cancer diagnosis weight.
In the UK, obese cancer survivors lost an average of 1.48kg (3.26 lbs) versus cancer-free obese individuals who lost an average of 0.25kg (0.55 lbs). In the US, obese cancer survivors lost an average of 2.35kg (5.18 lbs) in comparison to cancer-free obese participants who gained an average of 0.53kg (1.17 lbs).
Professor Jane Wardle, director of the Cancer Research UK Health Behaviour Centre at UCL, said: “Understanding weight loss among cancer survivors is vital to understand how to give the right health information to patients. Obese people are less likely to take part in cancer screening programmes – so they’re often diagnosed at a later stage.
“The weight loss seen in this study could be due to one of two reasons. The obese patients could be intentionally deciding to lose weight, or the weight loss could be a sign of more advanced disease.”
Data were taken from the English Longitudinal Study of Ageing (ELSA) in the UK and the Health and Retirement Study (HRS) in the US**.
Dr Julie Sharp, Cancer Research UK’s head of health information, said: “This study provides an interesting insight into weight loss among obese cancer survivors. Obesity is the second largest preventable risk factor linked to cancer and is associated with poorer outcomes in cancer patients.
“It will be important to follow up these patients to confirm whether their weight loss was the result of deliberate lifestyle changes or caused by their disease. This will help doctors understand how to advise and support overweight patients to improve their chances of survival.”
For media enquiries contact Stephanie McClellan in the Cancer Research UK press office on 020 3469 5314 or, out of hours, on 07050 264 059.
* The impact of a cancer diagnosis on weight change: findings from prospective, population-based cohorts in the UK and the US. Jackson et al. BMC Cancer. doi:10.1186/1471-2407-14-926
** In the UK survey there were 264 cancer cases with 1538 remaining cancer free. In the US survey there were 2553 cancer cases with 4946 remaining cancer free.