PIK3CA Mutational Status Is Associated with High Glycolytic Activity in ER+/HER2- Early Invasive Breast Cancer: a...

Area of Science:

• Oncology
• Molecular Biology
• Radiology

Background:

• PIK3CA mutations in breast cancer can lead to PI3K/AKT/mTOR pathway hyperactivation.
• This pathway activation may increase cancer cell glycolysis, impacting tumor metabolism.

Purpose of the Study:

• To investigate the association between PIK3CA mutational status and tumor glycolysis.
• Focus on invasive estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) early breast cancer.

Main Methods:

• Retrospective analysis of 67 ER+/HER2- early breast cancer patients.
• Used [¹⁸F]FDG PET/CT for assessing tumor glucose metabolism (SUV_max).
• Pyrosequencing identified PIK3CA mutations; clinico-pathologic data and MRI were also analyzed.

Main Results:

• PIK3CA mutations were found in 45% of tumors, associated with smaller tumor diameter and lower nuclear grade.
• Glycolytic activity correlated with nuclear grade, proliferation, lymph node metastasis, and metabolic tumor volume.
• In ductal carcinomas, [¹⁸F]FDG uptake was independently associated with PIK3CA status and nuclear grade, but not tumor size or nodal status.
• No significant association was found in lobular carcinomas or with survival outcomes.

Conclusions:

• In ER+/HER2- invasive ductal breast cancer, [¹⁸F]FDG uptake is independently linked to PIK3CA mutations.
• [¹⁸F]FDG PET/CT shows potential as a biomarker for monitoring response to therapies targeting the PI3K/AKT/mTOR pathway.