Article - Randomized Trial of Exercise and Nutrition on Chemotherapy Completion and Pathologic Complete Response in Women With Breast Cancer: The Lifestyle, Exercise, and Nutrition Early After Diagnosis Study.

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Take home message

Eating more vegetables, fruit and overall dietary fibre may be supportive of treatment for breast cancer, especially for women receiving chemotherapy for TNBC and HR+/HER2- breast cancer
Weight loss may not be necessary for these benefits
Staying physically active appears to have a beneficial role during cancer treatment.

Evidence category

A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)

Summary review

Introduction

This study evaluated the impact of nutritional counselling and exercise on response to chemotherapy in women newly diagnosed with breast cancer

Methods

Women diagnosed with stage I-III breast cancer were randomised to usual care (n=86) or home-based programme of exercise and nutritional advice (n=87)
Baseline age, BMI, menopausal status, breast cancer type and prescribed chemotherapy regime were recorded: mean age 53 + 11 years, BMI at recruitment of 29.7 + 6.7kg/m2
Covid-19 restrictions operated during part of the study duration
Interventions were delivered in-person or remotely by specialist oncology dietitians also trained in exercise
Exercise intervention - 150 minutes of moderate-to-vigorous exercise or 75 minutes of vigorous exercise, plus two sessions of progressive resistance exercises, weekly
Aim of the dietary advice: improved diet quality, benchmarked to Healthy Eating Index 2015
Participants were requested to follow plant-rich diet with >5 portions vegetables and fruit daily, total fibre intake of > 25g/day, <30g/day added sugars, <500g red meat/week, and ess than one alcoholic drink daily
Adherence was assessed using self-reported questionnaires
Outcomes included treatment side effects
Relative dose intensity (RDI) calculated as percentage of chemotherapy delivered compared to dose prescribed, (100% RDI referred to the entire schedule of planned treatment being delivered)
Complete pathological response to treatment (pCR) was assessed for women having surgery following neoadjuvant chemotherapy
Statistical analyses assessed relationships between changes in diet and exercise, RDI and pCR, using chi-squared tests and two-sided T-tests
Statistical significance defined as P < .05.

Results

Exercise increased significantly in the intervention group (P<0.001)
Intake of vegetables, fruit, and total fibre increased in intervention group (P=0.01) compared with the control group
Incidence of side effects, change in BMI and RDI did not differ between intervention and control groups (P>0.05)
72 women received neoadjuvant (before surgery) chemotherapy, assessed for pCR. In intervention group, 53% women had pCR compared with 28% in control group (p=0.037)
This statistically significant effect was limited to women with triple-negative breast cancer (TNBC) and hormone-receptor positive, HER2 negative (HR+/HER2-) breast cancer.

Conclusion

Randomisation to a nutrition intervention aimed at improving dietary quality, and exercise, was associated with a statistically significant increase in the rate of complete treatment response in women with TNBC or HR+/HER2- breast cancer. This appeared independent of change in weight.

Clinical practice applications

Physical activity and improved dietary quality, with emphasis on plant foods, limited intake of added sugar and red meat, and limited alcohol, appeared supportive of response to chemotherapy
The effect appears unrelated to change in weight
This study supports the delivery of advice on diet quality and exercise in women undergoing chemotherapy for breast cancer.

Considerations for future research

More detailed examination of food components such as intakes of essential fatty acids and of prebiotic foods would be worth considering, using validated instruments for assessing dietary intakes
Biomarker measurements could be used to assess the impact on glycaemic control, inflammation, changes in micronutrients
Body composition data would be useful to monitor.

Abstract

PURPOSE

Successful completion of chemotherapy is critical to improve breast cancer outcomes. Relative dose intensity (RDI), defined as the ratio of chemotherapy delivered to prescribed, is a measure of chemotherapy completion and is associated with cancer mortality. The effect of exercise and eating a healthy diet on RDI is unknown. We conducted a randomized trial of an exercise and nutrition intervention on RDI and pathologic complete response (pCR) in women diagnosed with breast cancer initiating chemotherapy.

METHODS

One hundred seventy-three women with stage I-III breast cancer were randomly assigned to usual care (UC; n = 86) or a home-based exercise and nutrition intervention with counseling sessions delivered by oncology-certified registered dietitians (n = 87). Chemotherapy dose adjustments and delays and pCR were abstracted from electronic medical records. T-tests and chi-square tests were used to examine the effect of the intervention versus UC on RDI and pCR.

RESULTS

Participants randomly assigned to intervention had greater improvements in exercise and diet quality compared with UC ( < .05). RDI was 92.9% ± 12.1% and 93.6% ± 11.1% for intervention and UC, respectively ( = .69); the proportion of patients in the intervention versus UC who achieved ≥85% RDI was 81% and 85%, respectively ( = .44). The proportion of patients who had at least one dose reduction and/or delay was 38% intervention and 36% UC ( = .80). Among 72 women who received neoadjuvant chemotherapy, women randomly assigned to intervention were more likely to have a pCR than those randomly assigned to UC (53% 28%; = .037).

CONCLUSION

Although a diet and exercise intervention did not affect RDI, the intervention was associated with a higher pCR in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative and triple-negative breast cancer undergoing neoadjuvant chemotherapy.