ASCO CONFERENCE COVERAGE

Lifestyle Program Improves Cardiometabolic Outcomes in Survivors of Breast Cancer

Edited by:
Anthony Calabro, MA

Key Highlights

  • The multicenter phase 3 trial enrolled women aged 30 to 74 years within 12 months of a primary stage I-III breast cancer diagnosis.
  • Breast cancer recurrence at 33 months did not differ between the intervention and control arms.
  • In women with hormone-positive breast cancer, greater adherence to the intervention program was associated with lower recurrence risk.
  • The intervention arm had greater weight loss and larger reductions in metabolic syndrome prevalence than the control arm.

A lifestyle program that combined a low-glycemic index Mediterranean diet, additional daily brisk walking, and oral vitamin D supplementation did not reduce breast cancer recurrence overall compared with standard lifestyle advice, but it improved cardiometabolic outcomes, according to a study presented at the 2026 American Society of Clinical Oncology Annual Meeting in Chicago, IL.  

Researchers conducted a phase 3 trial across 7 oncology centers in Italy. Women aged 30 to 74 years were enrolled within 12 months of a primary stage I-III breast cancer diagnosis and randomized to 33 months of either standard advice on a Mediterranean diet and avoidance of sedentary behavior or high-intensity advice on a low-glycemic index Mediterranean diet plus 30 minutes of additional daily brisk walking. Oral vitamin D3 was administered throughout the study. The primary outcome was breast cancer recurrence at 33 months in an intention-to-treat analysis; cardiometabolic risk factors were secondary outcomes.

Study Findings

The trial included 249 participants in the positive control arm and 243 in the intervention arm. Approximately 58% of patients were aged 50 years or older, 94% were postmenopausal, 86% had stage I-IIB disease, and 75% had hormone-positive breast cancer. A total of 37 recurrences were observed, with no difference between arms (hazard ratio [HR], 0.94; 95% CI, 0.49-1.79).

Independently of randomization arm, women with hormone-positive breast cancer who were more adherent to the intervention program had a 76% lower risk of recurrence (HR, 0.24; 95% CI, 0.06-0.95). Weight loss was greater in the intervention arm than in the control arm, at 3 kg, or 4.2% of initial body weight, vs 1.7 kg, or 2.4% of initial body weight (P = .0034). Body mass index decreased from 27.5 to 26.3 kg/m² in the intervention arm and from 27.2 to 26.6 kg/m² in the control arm (P = .0032). Metabolic syndrome prevalence decreased by 65% in the intervention arm and 34% in the control arm (P = .008), and the probability of metabolic syndrome remission was 2.5-fold higher in the intervention arm.

Clinical Implications

According to the study authors, the lifestyle program was safe and low cost and resulted in weight loss and reduced metabolic syndrome prevalence. They also stated that the program was significantly associated with lower recurrence in women with hormone-positive breast cancer.

Expert Commentary

“A safe and low-cost lifestyle program with low-glycemic index Mediterranean diet, daily brisk walking, and oral vitamin D supplementation resulted in weight loss, reduced metabolic syndrome prevalence, and was significantly associated with lower recurrences in women with hormone-positive breast cancer,” the researchers concluded.

Reference
Augustin L, Di Lauro V, Libra M, et al. The effects of Mediterranean diet, physical activity, and vitamin D on breast cancer recurrence and cardiometabolic health: a multicenter randomized trial. Presented at: 2026 American Society of Clinical Oncology Annual Meeting; abstract 511.