Dr. Fiona Malcomson, PhD, PGDip, MRes, BSc (Hons) Malcomson
- A new study looked at whether combining weight-loss medication with healthy eating and physical activity could help breast cancer survivors reach a healthier weight.
- Women who had not lost at least five percent of their starting weight after two months of lifestyle changes lost more weight when medication was added.
- The study suggests that checking how much weight someone has lost early on can help healthcare teams identify who may need extra support. This could help them create weight-management plans that better fit each person’s needs.
Weight Management after Breast Cancer
Overweight and obesity are common among breast cancer survivors. People with obesity experience poorer outcomes compared to those without obesity. This includes increased risk of cancer recurrence and poorer quality of life.
Weight management after breast cancer can be challenging due to:
- Treatment side effects
- Hormonal changes
- Fatigue
- Changes in physical activity levels
Past research has shown that behavioral weight-loss programs that combine nutrition and physical activity can help breast cancer survivors lose weight and improve other health measures. However, some women may need extra support to lose weight.
New Research
The Adaptive Nutrition and Exercise Weight Loss Study (A-NEW Study) led by Dr. Vered Stearns, MD, and Dr. Jenni Sheng, MD, was partly funded by AICR.
The study aimed to see whether adding naltrexone/bupropion, an FDA-approved weight-loss medication taken as tablets, could improve weight loss following a behavioral intervention. The findings were published in the journal Clinical Cancer Research.
About the Study
The A-NEW Study enrolled breast cancer survivors who had obesity or were overweight and had a weight-related health condition (such as type 2 diabetes).
All participants began a six-month behavioral weight-loss program that included:
- Nutrition advice
- Physical activity advice
- Educational materials
- Remote coaching
Participants also monitored their diet, physical activity and weight.
After two months on this weight-loss program, the researchers used each participant’s response to guide the next step
- Fast responders: 15 women who had already lost at least five percent of their starting body weight continued with the behavioral weight-loss program.
- Slow responders: 38 women who did not meet the five percent weight-loss threshold were given the weight-loss medication in addition to the behavioral program.
This study design let researchers add treatment for women who had shown a limited early response to behavioral support alone.
What Did the Study Find?
At the end of the six-month weight-loss program:
- 13 of the 15 fast responders who continued behavioural support without medication were able to maintain weight loss of at least five percent. Their average weight loss was 10.8 percent.
- 16 of the 38 slow responders given weight-loss medication had lost at least five percent of their starting weight. The average weight loss among 32 women in this group who completed the study was 5.1 percent.
- Slow responders also had a significantly improved Hba1c (a routine blood test that measures your average blood sugar levels over the past two to three months) and triglycerides (the most common type of fat that circulate in the bloodstream).
- Participants who lost at least five percent of their initial body weight reported better physical function and less pain.
The weight-loss tablet was relatively well tolerated but some side effects were common. For example, nearly three-quarters reported symptoms such as constipation and nausea.
Researchers found that Black participants, younger women and pre-menopausal women were more likely to experience slower initial weight loss. This study was small. The research team highlights the need for larger, more diverse studies and weight-loss strategies that address barriers faced by different groups.
Personalizing Weight Management after Breast Cancer
Losing five percent of starting body weight is considered a clinically meaningful milestone. That’s because it can improve metabolic health, physical function and other health measures.
The A-NEW study suggests that assessing weight-loss progress early may help clinicians identify breast cancer survivors who could benefit from additional weight management options.
Importantly, the study also highlights that lifestyle changes alone may not be enough for everyone. Obesity is a complex chronic disease, and some people may benefit from different forms of support.
Advice for Breast Cancer Survivors
AICR’s latest report for Breast Cancer Survival encourages people who are not underweight to avoid gaining weight during and after treatment. Changes involving diet, physical activity or body weight should be discussed with a healthcare team and tailored to the individual’s needs and stage of treatment.
The personalized approach in this study complements AICR’s Cancer Prevention Recommendations for people living with and beyond cancer. AICR encourages survivors to follow the Recommendations if they can. If weight management is part of your care plan, work with your healthcare team on a program that fits your medical history, cancer treatment, symptoms and preferences.
