PUBLISHED ON: 29 January 2020

New research, which is being presented at the UK Interdisciplinary Breast Cancer Symposium hosted by Breast Cancer Now, has found that changes in abdominal fat after surgery may affect the risk of recurrence.  

Symphony hall

New findings 

New research has suggested that many women may benefit from maintaining a stable weight, without it going up or down, after breast cancer surgery to limit the risk of breast cancer coming back. 

Scientists at Lund University, Sweden, gathered women’s body size measurements at surgery and then again one year later. They used this to investigate how any changes in their body shape and weight affected the chance of breast cancer returning. 

They saw different results, depending on whether the breast cancer was driven by the hormone oestrogen. However, the researchers stressed that further studies are needed to confirm these findings and investigate how changes in body shape and weight affect the risk of breast cancer coming back.  

Treatment impact on weight 

It’s not uncommon for people to gain weight during or after their breast cancer treatment. There could be several explanations for this. Changes in taste can happen during treatment. Steroids given alongside chemotherapy can lead to weight gain, as can the menopause brought on by treatment. People may also be less active than usual because they are recovering. 

Baroness Delyth Morgan, Chief Executive at Breast Cancer Now, which is hosting the UK Interdisciplinary Breast Cancer Symposium, explained the effect that treatment can have on a woman’s weight: 

‘Many women may begin to gain or lose weight as a result of their treatment, which can be unexpected and really distressing. So, it’s vital they are given the best possible support, information and advice to help manage this.’ 

In this new study, researchers led by Professor Helena Jernström and Helga Tryggvadottir at Lund University, Sweden, analysed 1,317 women’s body size measurements at breast cancer surgery and a year later. They calculated their waist-to-hip ratio, which is the circumference of a person’s waist divided by the circumference of their hips at their widest point. It indicates how much abdominal fat someone has. 

Impact on cancer coming back 

Researchers discovered that women with oestrogen receptor (ER) positive breast cancer whose waist-to-hip ratio changed up or down were twice as likely to see their breast cancer return, compared to women who maintained a stable body shape.  

But for women with ER negative breast cancer, changes in body shape were linked to a sevenfold reduction in risk of breast cancer returning. This highlights the role that the hormone oestrogen may have. 

Authors Professor Helena Jernström, from the Division of Oncology and Pathology at Lund University, and Oncology resident Helga Tryggvadottir, explained the importance of these findings: 

‘This study is the first suggesting that changes in waist-hip ratio during the first year after surgery impact the risk of breast cancer recurrence differently depending on whether the tumour is driven by oestrogen.  

‘Our study also emphasises the importance of considering women’s body constitution in making decisions about their treatment and care.’ 

The researchers also looked at changes in weight separately from evaluating changes in body shape. They found that women under 50 were more likely to gain weight during or after treatment, which was linked to higher chances of breast cancer coming back. The researchers also found, however, no benefit of weight loss after surgery in this group.  

Baroness Delyth Morgan added: ‘We’d urge women not to be unduly worried by these results. Thanks to decades of progress in research and care, most women will not see their breast cancer return. But we need to do more to help everyone keep their risk of recurrence as low as possible, and this study suggests that making sustainable changes to keep to a stable body shape after surgery could be the best approach for many.’ 

Keeping a stable weight 

The scientists emphasised the importance of further work before we make weight loss recommendations to women after their surgery. They believe that it is essential that we understand whether intentional and unintentional changes in body shape and weight have different effects. It is also essential that we further understand the biology behind these effects. 

‘These important findings highlight the need for women to be fully supported to keep their body shape and weight stable as best they can during and after breast cancer treatment,’ said Delyth. 

‘While these findings need to be confirmed in further studies, the suggestion that changes in body shape may affect women differently depending on their cancer type emphasises the need for health advice to be personalised to patients as much as possible, just as with treatments.’ 

The study, presented at the UKIBCS and also published in the journal Cancer Causes & Control, was funded by The Swedish Cancer Society, Lund University, the Mrs Berta Kamprad Foundation, the South Swedish Health Care Region, the Swedish Breast Cancer Group (BRO), and the Lund Hospital Fund. 


If you have any concerns about breast cancer or maintaining a stable weight, you can speak to our expert nurses on our free Helpline at 0808 800 6000 or by using our confidential Ask Our Nurses service. 

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