In addition to helping prevent breast cancer in the first place, exercise during and following treatment can significantly reduce chances of cancer recurrence, writes oncologist and clinical researcher Dr Nick Zdenowski.
What percentage of people will have their breast cancer come back?
Nine out of ten breast cancers are diagnosed at an early stage, where the goal is cure. In the remaining one out of ten, the cancer has become metastatic, or stage 4, at the time of diagnosis.
The goal of screening mammography is to find more cancers when they are at the very earliest stages, before they have progressed to stage 4. Of those who are initially diagnosed with early stage breast cancer, unfortunately around 15% will experience metastatic recurrence. Another 15% or so will experience another primary breast cancer, that can then typically be treated like any other breast cancer with surgery and other treatments.
Over 3,000 Australians lost their lives to breast cancer in 2021, many as a result of breast cancer recurrence
Why does it happen?
Breast cancer recurrence, particularly incurable metastatic recurrences, remains a great challenge. We have identified many treatments that reduce the chance of the cancer coming back, but despite that, over 3,000 Australians lost their lives to breast cancer in 2021, many as a result of breast cancer recurrence.
Recurrence is more likely if the cancer was diagnosed at a later stage (larger tumour, especially with lymph node spread), or is of a higher risk subtype. Triple negative breast cancer, a more aggressive cancer that usually occurs at an earlier age, does not have a specific target to treat, and is often faster growing, so is more likely to come back.
Breast cancer comes back when it has travelled via the lymph channels or bloodstream, and tiny deposits, too small to be seen on scans or in blood tests, have reached other organs such as bone, liver or lung. Sometimes those cells can be killed off by the treatments that we have available, but there is a dire need for more and better treatments so that we can prevent breast cancer from recurring.
What can patients do to mitigate the chances of their breast cancer returning?
First, people can focus on preventing the occurrence of breast cancer in the first place, through regular exercise, avoiding alcohol, eating lots of vegetables and whole grains, and maintaining a normal weight.
We also know that screening mammograms find breast cancer at an earlier stage, when it is less likely to come back following treatment.
Treatments, including surgery, chemotherapy, radiotherapy, targeted therapy and hormone blocking therapy, also reduce the chance of recurrence.
Those who exercise after their diagnosis have a 30% lower chance of breast cancer recurrence or death
How much of an impact does exercise have on reducing the chances of their breast cancer coming back?
There are many studies showing that people who exercise regularly are less likely to experience breast cancer, and have a lower chance of breast cancer recurrence or death after a breast cancer diagnosis. Those who exercise after their diagnosis have a 30% lower chance of breast cancer recurrence or death, which is substantial when you consider that this benefit is almost as much of a benefit as taking hormone blocking tablets.
Exercise during treatment for breast cancer means that the treatment is more likely to be completed, and therefore more likely to be beneficial in preventing recurrence, with fewer side effects.
What sort of exercise is best?
The main thing is to exercise regularly! Whether that is resistance or cardiovascular exercise doesn’t really matter. It is important to have at least a moderate intensity, meaning that your heart rate increases, you feel a bit short of breath and feel like you are working fairly hard. If you are walking, that means about 100 steps per minute.
The main thing is to exercise regularly! Whether that is resistance or cardiovascular exercise doesn’t really matter.
The threshold for benefits is 30 minutes per day, five days per week, at a minimum. Different exercises have different benefits – functional, fitness, aerobic, strength, flexibility, and mental health components are all helpful following a breast cancer diagnosis. The benefits of exercise are independent of weight, other health conditions, or menopausal status. The more exercise, and the higher the intensity, the better.
What studies have been done into the connection between exercise and reducing the chance of breast cancer coming back?
There have been many studies looking at the wide and varied benefits of exercise after a breast cancer diagnosis. Most of those studies are observational, meaning that exercise levels are self-reported and subject to mis-reporting. However, multiple meta-analyses have been done to bring the data together, and they have shown that, on the whole, exercise reduces risk of recurrence. There are very few drawbacks to regular exercise, and many benefits from a breast cancer and general wellbeing perspective, so current guidelines support integration of exercise into the follow-up and survivorship phase after a breast cancer diagnosis.
Is there any research happening at the moment around exercise and breast cancer recurrence?
Yes! A search of clinicaltrials.gov, the central database for major research, identified 233 actively recruiting studies around the world at the moment.
Because the benefits in reduction of recurrence are accepted as fact, the focus is now on implementation. These studies are looking at how best to get exercise to be a routine part of the treatment of breast cancer for every patient, regardless of where they live, their ethnic origin, age, or exercise history.
There are home-based, gym-based, supervised, telephone, video and electronic programs being trialled around the world. There is a fairly widespread understanding now that exercise after breast cancer is beneficial, which is wonderful to see. Putting that into practice is the next challenge that needs to be resolved. Fitness professionals are well placed to work with allied health professionals to help patients integrate exercise into their lives, both for recovery and prevention of cancer recurrence.
Join the live Q&A on preventing recurrence – 11 May
In Breast Cancer Trials’ latest Q&A event, moderated by TV presenter Annabel Crabb, a panel of experts will discuss the important topic of preventing cancer recurrence. Discussion will include the latest in research and clinical trials, personal experiences of breast cancer, living with the fear of recurrence and how to manage that fear, as well as what help is available.
The expert panel includes Professor Sherene Loi, Professor Prue Francis, Associate Professor and clinical psychologist, Lesley Stafford and Ms Leslie Gilham, a Breast Cancer Trials participant and Chair of the Breast Cancer Trials Consumer Advisory Panel.
This free online Q&A is taking place on 11 May 2022 from 5-6.30pm AEST. Go to breastcancertrials.org.au/news/qa-events to register for the event and pose a question to the panel.
Dr Nick Zdenkowski, BMed FRACP PhD
Nick is a medical oncologist and a clinical researcher. He treats patients with a range of different types of cancer, and has a special interest in the care of patients with breast and gastro-intestinal cancer.
