How lifestyle changes can support women with breast cancer

BRUSSELS - Can adaptations in eating behaviour and physical exercise make a difference for women undergoing chemotherapy for advanced breast cancer? A recent phase-2 study, funded by Anticancer Fund and published in the British Journal of Cancer, explored this question with promising results. In this edition, we share the study’s findings and talk to lead investigator Michelle Harvie about what they mean and what comes next.

Diet and exercise may help women with advanced breast cancer during chemotherapy

Researchers wanted to know if a combination of a special eating plan, regular exercise, and modest weight loss, could delay the progression of cancer, reduce chemotherapy toxicity and improve quality of life in women with advanced breast cancer.

The study, called B-AHEAD-3, involved 68 women with advanced breast cancer and an average body mass index (BMI) of 30 kg/m2 or higher. All participants were receiving chemotherapy. They were randomly split into two groups:

• One group followed a special diet called intermittent energy restriction (IER) and did resistance exercises.
• The other group did the same exercises but did not follow the special diet.

A specific diet and easy exercises at home

The IER diet is straightforward, although strict: for two days each week, the study-participants ate very few calories and carbohydrates. On the other five days, they followed a healthy Mediterranean-style diet, rich in fruits, vegetables, whole grains, and healthy fats.

The exercise program was designed to be done at home and included strength-building exercises using resistance bands or light weights.

Encouraging results

The study found that women who followed both the diet and exercise plan had better outcomes than those who only exercised. On average, their cancer did not get worse for 42 weeks, compared to 26 weeks in the exercise-only group.

Other remarkable endpoints of the study: there was no increase in chemotherapy toxicity, the diet was well tolerated and led to modest weight loss.

Because the study was relatively small, this difference was not statistically significant, meaning the findings could be due to chance. Still, the results are encouraging and point to a possible benefit worth testing in larger studies.

Importantly, in addition to physical benefits, the women in the diet and exercise group also felt better emotionally. They reported less anxiety and depression, and their overall quality of life improved. These improvements were large enough to be considered clinically meaningful.

Conclusion

This study shows that specific lifestyle changes during chemotherapy can make a difference for women with advanced breast cancer. A larger study involving more patients is needed to confirm these promising results with greater certainty.

Food, fitness and the future of breast cancer research
– A talk with Michelle Harvie

Read our interview with Michelle Harvie, the B-AHEAD-3 study’s principal investigator, and an award-winning research dietitian.

Michelle Harvie is a research dietitian at the Nightingale Centre, University Hospital South Manchester Trust. She qualified as a dietitian in 1991 and obtained a PhD, studying weight gain in cancer patients, in 2000. Her scientific findings have been published in many major scientific publications and she was awarded the British Dietetic Association Rose Simmond’s Award for Best Published Dietetic Research for her work on weight gain amongst breast cancer patients receiving adjuvant chemotherapy.

Breast cancer awareness has grown a lot of thanks to Pink October. From your perspective, what are the biggest advances in breast cancer treatment over the past decade?

Many new targeted treatments are now available in the clinic for many groups of patients. For patients with oestrogen-positive disease (70–80% of those diagnosed), CDK4/6 inhibitors help endocrine therapy work better in both advanced and early breast cancer. Around 15% of those diagnosed have triple-negative disease, which cannot be targeted with endocrine or Herceptin-based therapies. These patients can now receive immunotherapy and antibody–drug conjugates, which help delay cancer progression. About 5% of patients with BRCA mutations can now receive PARP inhibitors.

The OPTI-Train study reported at the European Society for Medical Oncology Congress that breast cancer patients who received supervised high-intensity exercise, including resistance training, during adjuvant chemotherapy had improved overall survival compared with those who had chemotherapy alone. There was no effect on recurrence, however. Exercise is a potentially important therapy and should be part of the treatment pathway for patients with cancer.

And the biggest challenges?

Global rates of breast cancer are increasing, especially in developing countries in Asia and Africa. Breast cancer often occurs at a younger age in these populations. Black populations have a higher tendency for oestrogen-negative disease.

There is a need for effective prevention strategies. Current breast cancer risk-reducing medications like tamoxifen and aromatase inhibitors lower rates of oestrogen-positive disease, but there are currently no approved medications for oestrogen-negative disease.

About the B-AHEAD-3-trial: many patients and their families wonder how realistic it is to follow a lifestyle programme during chemotherapy. Based on your experience, what made it easier to stick to the diet and exercises?

The diet is not as restrictive as people may think. It involved two days each week of a lower-carbohydrate, lower-calorie diet, where possible immediately before the chemotherapy infusion. Those days allowed ~1,000 kcal and ~50 g of carbohydrate—about two-thirds to one-half of what people might normally eat in a day. On the other days, participants were asked to follow a healthy Mediterranean diet where possible, which did include some treats.

All participants had one-to-one consultations with a designated dietitian throughout the trial, who helped adapt the diet to personal preferences and family meals. We also helped women work with their families to allay fears about over-restriction and to emphasise that people with metastatic breast cancer on chemotherapy should eat well and not be overly restrictive.

If you could highlight one or two areas where more research is urgently needed in breast cancer, what would they be?

We tried to help patients reduce weight and body fat and maintain muscle mass during chemotherapy, which is important for treatment response and for minimising side effects. The B-AHEAD-3 study suggested some potential benefits, and certainly no harm, with a combined diet-and-exercise weight-loss programme. Since the trial, GLP-1 agonists have emerged as weight-loss medications. These could be useful for cancer patients. However, there is an urgent need for data on their safety and effects in patients with cancer, and whether they could also be a strategy for prevention.

What would be your main message to women to help them reduce their risk of getting breast cancer?

Follow cancer risk-reduction guidelines.

• Try to maintain a healthy weight across adult life and avoid/limit weight gain.
• Be physically active—aim for at least 150 minutes of moderate-intensity exercise per week, and more if you can.
• Limit alcohol.
• Choose a diet with plenty of wholegrains, vegetables, fruit and beans; limit sugar-sweetened drinks, red and processed meat, ultra-processed foods and takeaways.
• Do not use supplements for cancer prevention.
• For mothers: breastfeed your baby if you can, and avoid smoking.

This advice applies both to the general population and to those at higher risk with a family history.