Adult weight gain could increase cancer risk

November 06, 2016

Substantial weight gain over many years increases the risk of obesity-related cancers in men by 50 per cent and in women by almost 20 per cent, according to new research* presented at the National Cancer Research Institute's (NCRI) Cancer Conference in Liverpool, today (Monday).

Researchers at The University of Manchester and The Health eResearch Centre, looked at weight gain over many years and assessed the risk of developing obesity-related cancers.

This is a new way of looking at the long-term impact of being obese throughout a person's life and the link to developing cancer.

In the study of approximately 300,000 people in America, including around 177,500 men and 111,500 women, researchers categorised the population into five different lifetime weight trajectories**. They looked at changes in BMI between the ages of 18 and 65.

Some people gained a little weight between the ages of 18 and 65 years, while others became morbidly obese. The population was then followed up for an average of 15 years to see who went on to develop obesity-related cancers.

It found that men who went from a BMI of around 22 to 27*** had a 50 per cent increased risk of developing obesity-related cancer compared to a man who stayed within a healthy weight range. And in men who went from being overweight to morbidly obese, the risk went up by 53 per cent compared to the same group.

Women who went from a BMI of 23 to around 32, had a 17 per cent increased risk in comparison to women whose weight started off in the healthy bracket and remained stable.

Of the 300,000 people in the study, there were around 9,400 women and 5,500 men who were diagnosed with obesity-related cancers after the age of 65.

Being overweight or obese is the second biggest preventable cause of cancer in the UK after smoking and contributes to around 18,100**** cases of cancer every year. It is linked to a range of cancer types including bowel, breast, and pancreatic.

Several of the obesity-related cancer types can only affect women - for example, womb cancer and ovarian cancer. Dr Hannah Lennon, lead author and researcher at The University of Manchester, said: "This research shows how important it is to look at weight gain over a person's lifetime - to give a clearer picture of cancer risk through life compared to assessing someone's BMI at a single point.

"This study could also be really useful in public health. It could help identify people who would benefit the most from taking action to control their weight before any health problems arise - including a cancer diagnosis." Sir Harpal Kumar, Cancer Research UK's chief executive said: "This is a really interesting way to look at lifetime risk of obesity-related cancers and helps us understand the effects of weight gain over time.

"It's important that people are informed about ways to reduce their risk of cancer. And while there are no guarantees against the disease, keeping a healthy weight can help you stack the odds in your favour and has lots of other benefits too. Making small changes in eating, drinking and taking exercise that you can stick with in the long term is a good way to get to a healthy weight - and stay there."

Dr Karen Kennedy, Director of the NCRI, said: "This study provides a deeper understanding of the health implications caused by the obesity epidemic. It helps paint the picture of how risk could accumulate over time for different people, and could provide health professionals with a means to asses an individual's risk."
-end-
This work is funded by Cancer Research UK as part of the National Awareness and Early Diagnosis Initiative (NAEDI). Supported by the Farr Institute and linked with the new NIHR Manchester BRC Cancer Prevention and Early Detection theme.

For media enquiries contact Stephanie McClellan in the NCRI press office on 0203 469 5314 or, out of hours, on 07050 264 059.

Notes to editor:

* NCRI abstract: Lifetime BMI trajectories and obesity-related cancer risk in a US retrospective cohort study http://abstracts.ncri.org.uk/abstract/lifetime-bmi-trajectory-classes-and-obesity-related-cancer-risk-in-a-us-retrospective-cohort-study/

*** A BMI of between 18.5 and 25 kg/m^2 is considered a healthy weight; between 25-30 is overweight; over 30 is obese. For men, this is equivalent to an extra 2.5 stone increase for the average height man of 177cm between the ages of 18 and 65, because even the 'normal/reference' trajectories allows for a little weight gain as we age. This is the lean marked category compared to lean moderate category. For women example, this is the lean marked category compared to lean stable category.

**** Calculated by the Statistical Information Team at Cancer Research UK, the estimated population attributable fractions overweight and obesity for cancer cases (ICD10 C00-C97, excl. C44) in the UK in 2011 using Parkin, D. M. & Boyd, L. Overweight and obesity-attributable cancer burden in the UK in 2010. Br J Cancer 2011;105 (S2):S6-S13.

Cancer Research UK

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.