Dietary and Physical Activity Changes and Adherence to WCRF/AICR Cancer Prevention Recommendations following a Remotely Delivered Weight Loss Intervention for Female Breast Cancer Survivors: The Living Well after Breast Cancer Randomized Controlled Trial.

BACKGROUND

Diet, exercise, and weight management are key in improving outcomes for breast cancer survivors, with international recommendations for cancer survivors relating to these behaviors. However, few behavioral interventions have reported outcomes aligned specifically with these recommendations.

OBJECTIVE

To evaluate a remotely delivered weight loss intervention vs usual care for female breast cancer survivors, on changes in multiple diet and physical activity behaviors.

DESIGN

A randomized controlled trial with assessments at study baseline, 6-, 12-, and 18 months (ie, mid-intervention, post-intervention, and non-contact follow-up).

PARTICIPANTS/SETTING: Participants were recruited between October 2012 and December 2014 through hospitals in Brisbane, Australia, and the state-based cancer registry. Eligible participants (women aged 18 to 75 years with body mass index 25 to 45 kg/m who were diagnosed with stage I through III breast cancer during previous 2 years) were randomly allocated to intervention (n = 79) or usual care (n = 80).

INTERVENTION

Participants randomized to the intervention group received 22 counseling telephone calls targeting diet and physical activity aimed at achieving 5% to 10% weight loss, and optional text messages, over 12 months. Usual care participants received their standard medical care and brief feedback following each assessment, which was similar to that provided to intervention participants with the exception that usual care participants' results were not compared with national and study recommendations.

MAIN OUTCOME MEASURES

Dietary intake (24-hour recalls), physical activity (hip-worn GT3X+ accelerometer [Actigraph]), sitting time (thigh-worn activPAL3 [PAL Technologies Limited), and adherence to World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) recommendations for cancer survivors (0 to 7 score) were measured at each assessment, with data collected between November 2012 and October 2016.

STATISTICAL ANALYSES PERFORMED

Intervention effects were assessed by linear mixed models, accounting for repeated measures and baseline values. Significance was set at P < 0.05.

RESULTS

At baseline, participants were aged 55 ± 9 years, with a body mass index of 31.4 ± 5.0 kg/m, 10.7 ± 5.0 months postdiagnosis, and primarily non-minority. At baseline, only 8% (n = 12) of participants met ≥5 out of seven WCRF/AICR recommendations (WCRF/AICR adherence score = 3.8 ± 1.0). At 12 months, significant intervention effects were observed in walking/running (+21 minutes/week; 95% CI 4 to 38) and WCRF/AICR adherence scores (+0.3 points; 95% CI 0.0 to 0.6) only. At 18 months, significant intervention effects were observed for energy intake (-229 kcal/day energy; 95% CI -373 to -84), total fat (-10 g/day; 95% CI -18 to -2), and saturated fat (-5 g/day; 95% CI -9 to -1), and were sustained for WCRF/AICR adherence scores (+0.5 points; 95% CI 0.2 to 0.8).

CONCLUSIONS

This remotely delivered weight loss intervention led to sustained improvements in WCRF/AICR adherence scores, and some improvements in diet and physical activity. These findings provide support for the health benefit of programs targeting lifestyle behaviors in line with cancer survivor recommendations, and the potential for dissemination of such programs for women following treatment for early-stage breast cancer.