Overview
We hypothesize that promoting a fasting state will strengthen the anti-cancer effects of PI3K inhibitors in metastatic breast cancer (MBC) treatment. The primary objective of this study is to assess acceptability of prolonged fasting in this population.
Eligibility
Inclusion Criteria:
- Age ≥18 years
- Histologically confirmed metastatic breast cancer
- Menopausal or medically ovarian suppressed
- Currently receiving capivasertib therapy (2 tablets twice daily, 4 days per week)
- Stable on current capivasertib regimen for at least 2 weeks
- an ECOG performance status of 0-1
- BMI ≥25kg/m2
- Able to provide informed consent
- Willing to comply with study procedures including CGM wear, food tracking by mCC app and dietary modifications
- Access to smartphone or tablet for mobile application use
Exclusion Criteria:
- Type 1 diabetes mellitus
- Uncontrolled type 2 diabetes (HbA1c \>9.0%)
- History of severe hypoglycemia
- Eating disorders or contraindications to fasting
- Pregnancy or breastfeeding
- Significant gastrointestinal disorders affecting food absorption
- Unable to fast for medical reasons
- Concurrent participation in other dietary intervention studies
- A history of significantly abnormal lab results within 4 weeks of consent date, such as hematologic (Hgb \< 10.0, platelets \< 100), hepatic (LFTs \> 2X nl), renal (Cr \> 1.5)
