A brisk daily walk or cycle ride boosts women's chances of surviving breast cancer by 60%, new research finds.
And even regular moderate physical activity more than halves their risk of dying from the disease, according to scientists.
"Our findings have implications for patient counselling on the benefits of exercise with regard to cancer outcomes," says corresponding author Dr Reina Haque.
The research is based on 315 older women in the US, who were followed for up to nearly nine years. Participants filled in two questionnaires about their exercise habits, as well as any other routines, before their initial diagnosis, at least two years prior.
In a nutshell, those who worked out more, were more likely to remain cancer-free after treatment, the study published in JAMA Network Open details.
Studies have previously associated exercise, before and after treatment, with cancer survival and living longer. "The protective effect of physical activity on risk of developing breast cancer is known," Dr Haque, of Kaiser Permanente Southern California, acknowledges.
"However, its effect after breast cancer diagnosis remains controversial. It has been suggested both moderate and strenuous exercise have comparable benefits.
"But survival outcomes have been studied rarely among patients with cancer."
That's why, she adds, "The aim of this study was to evaluate the association of physical activity beyond essential daily functioning with risk of all-cause mortality among breast cancer survivors."
More than 55,000 women are diagnosed with breast cancer every year in the UK, with around 11,500 deaths annually, according to Cancer Research UK. However, there is also a survival rate of 76% for 10 or more years.
"The findings of this cohort study suggest even moderate physical activity was associated with a 60% lower risk of death among breast cancer survivors, similar to a previous cohort," explains Dr Haque. "The mortality risk was similar among participants who were active and those with moderate physical activity levels."
She adds, "Our findings further suggest survivorship care plans should consider incorporating physical activity because even moderate activity may be vital for extending survival as well as health-related quality of life."
It adds to evidence that exercise should be prescribed to patients after surgery or chemotherapy, which could include walking, gardening, housework and swimming, or more vigorous activity six weeks after.
Reacting to the new study, Patricia Bischof, scientific research officer at Breast Cancer UK, says, "These results support what many other studies and meta-studies have also shown: physical activity is associated with a reduced all-cause mortality as well as reduced breast cancer mortality.
"There are several possible mechanisms that could explain this. Physical activity helps lower the levels of certain circulating hormones and reduces inflammation, which can help lower the likelihood of cancer developing and progressing.
"Being active also keeps body weight under control, which plays a significant role in breast cancer survival. It is a very positive and encouraging study because it demonstrates how lifestyle changes can have a positive effect on survival following a breast cancer diagnosis."
Exercise and cancer first-hand
Sandra Greene, 54, from Grays, Essex, attributes exercising to saving her through her breast cancer journey.
In May 2021, she found a lump on her breast while out on a run, as her sports bra was unusually uncomfortable and chafing on her chest.
An MRI scan revealed she had two tumours in her breast and she was diagnosed with what is known as multifocal lobular breast cancer, going on to have 18 months of treatment.
The mum underwent a mastectomy (an operation to remove a breast) and reconstruction in October 2021, and was put on a seven-year course of hormone therapy. Despite a challenging journey, exercise was a huge help in getting her back to normality as quickly as possible.
"I am a big advocate in believing that if you are keeping yourself fit and healthy, it doesn’t matter whether you’re talking about cancer or any other illness, it helps you deal with that scenario and recovery afterwards," says Greene. "I‘ve read lots of stories about people who have had cancer who have taken a long time to recover after their treatment.
"But because I was fit and healthy and exercised regularly I was back on my feet so much quicker, back to work so much quicker, back onto my normal life so much quicker.
"I had my operation in mid-October and within three weeks I was walking three to four miles a day, and by January I was running 5k again."
Of course, everyone is different, and even extremely healthy people can have less luck with cancer.
For Greene, a financial ombudsman who lives with her husband Neil and youngest son Callum, she was headstrong about dealing with her diagnosis and recovery in a way that felt right to her.
"When I found out I had cancer there was that temptation to think life must stop while I deal with it but I decided to take a very different view," she recalls. "I thought I am going to carry on doing everything I normally do and I am just going to fit in all these hospital appointments around that.
"I remember my operation was on a Saturday during Covid, so I had to have a Covid test on the Tuesday, but the night before the test I was still out running. I also had to have a minor operation to have a lymph node biopsy and two weeks later I ran the Cancer Research summer run."
She acknowledges, "I understand that everybody deals with it in their own way but that’s the way I dealt with it."
But for her personally, she can't praise staying active enough. "I think that the exercise I was doing beforehand helped me cope with the diagnosis physically as well as mentally. It helped me with getting on with my life when I was living with cancer and it helped me get back on track much quicker with my life after my treatment."
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But Greene has still had to combat the side effects that can happen from the hormone treatment she's on.
"The worst thing for me is that it can make your bones brittle, it can make you very achy, so when I get up first thing in the morning it does take a little bit of work to get myself going," explains Greene. "Sometimes I feel like a little old lady, but I try not let that stop me from doing all the things I want to do.
"I think if I wasn’t running and also doing yoga, I think those side effects would be even worse. Keeping up the exercise limits the impact the side effects have on me."
She runs three times a week and does yoga once a week.
With a long history of cancer in her family – both her sisters have had breast cancer, her mother-in-law died of lung cancer and her dad currently has prostate – she has always got involved with fundraising events, but recently took part in a half marathon walk for Helen Rollason Cancer Charity and is planning to do Cancer Research’s Winter 10k in February.
"If you didn’t exercise at all before, now would be a good time to start, even if it is just light walking, because with cancer it can really help you get through the journey physically.
“It also hugely helps with mental wellbeing. If I didn’t exercise I would have really struggled and it would have been easy to fall into a little bit of depression.
“Exercise helps to keep a positive mind and helps deal with whatever you’re facing.”
For advice or support you can contact Breast Cancer Care on 0808 800 6000 or Breast Cancer Now on 0808 800 6000. Consult a medical professional before planning exercise routines with cancer.
Additional reporting SWNS.