Diet and exercise for breast cancer patients
A randomised phase II trial of intermittent energy restriction and resistance exercise in women receiving chemotherapy for advanced breast cancer (B-AHEAD3).
- Breast cancer
Why this trial?
Research has shown that energy restriction and weight control protect normal cells from the effects of chemotherapy whilst increasing the sensitivity of cancer cells to treatment - the so-called ‘differential stress response’. Many breast cancer patients are above an ideal weight and many patients gain fat and lose muscle during chemotherapy.
Too much fat and reduced lean body mass (fat-free body mass) have increased chemotherapy toxicity and poorer outcome. Weight loss is therefore recommended in breast cancer patients who are overweight.
The benefits of losing weight by diet have not been fully investigated in women with advanced breast cancer. This study is designed to assess the value of dietary restriction with respect to the effectiveness of chemotherapy to halt progression of the disease and the reduction of side effects.
If successful, this approach may be widely used to help women with advanced breast cancer and possibly other cancers.
Why this drug?
The main aim of dietary intervention is to reduce energy intake. Studies in animals indicate that energy restriction, mainly achieved by reduced carbohydrate intake, is associated with reduced tumour growth and progression.
In the trial outlined here, the approach used is intermittent energy restriction (IER). Previous studies suggest this may be the best way to achieve weight loss. Previous randomised trials in women without breast cancer indicate that IER is associated with greater weight loss, preservation of fat-free mass and other benefits, compared with standard continuous energy restriction (CER). The researchers developed an IER diet that involves two consecutive days of severe energy restriction and five days of normal healthy eating.
In this randomised trial, 134 women receiving chemotherapy treatment for advanced breast cancer will be assigned to one of two treatment groups. The women will be recruited by 12 centres in the UK.
The first group (control group) consists of 67 patients. Patients in this group receive chemotherapy and follow a regular diet while taking part in resistance training three times a week.
The second group (the intervention group) also consists of 67 patients who will follow the 5/2 diet whilst receiving chemotherapy. During restricted diet days, these patients are allowed a maximum caloric intake of 800 to 1000 kcal and 50 g of carbohydrates per day. The other five days, they follow a Mediterranean diet. This includes eating lots of fruits and vegetables, nuts, fish, low-fat dairy products, white meat and limited quantities of red meat. Patients also participate in resistance training 3 times per week.
The trial will test whether an energy restricted diet adds to the anti-tumour effect and lessens chemotherapy toxicity compared to a resistance exercise-only intervention.
- Dr. Michelle Harvie, Genesis Breast Cancer Prevention Centre, Manchester University NHS Foundation Trust, Manchester, UK (Principal Investigator)
- Dr. Sacha Howell, University of Manchester and The Department of Medical Oncology, Manchester, UK
- Manchester University NHS Foundation Trust, Manchester, UK
More info on Cancer Reseach UK: B-AHEAD3
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