A triple-negative breast cancer surrogate subtype classification that correlates with gene expression subtypes

Area of Science:

• Oncology
• Genomics
• Pathology

Background:

• Triple-negative breast cancer (TNBC) presents heterogeneous subtypes.
• Existing Vanderbilt classification aids in understanding TNBC heterogeneity.
• A need exists for a practical surrogate classification for TNBC subtypes.

Purpose of the Study:

• To develop and validate a surrogate classification for TNBC subtypes.
• To establish a practical diagnostic test based on immunohistochemistry.
• To correlate the surrogate classification with the established Vanderbilt subtypes.

Main Methods:

• Patients undergoing curative surgery for TNBC were included.
• Gene expression analysis and immunohistochemistry (IHC) were performed.
• Classification and Regression Tree (CART) modeling was used to develop surrogate subtype definitions.

Main Results:

• A cohort of 145 TNBC patients was analyzed.
• Surrogate subtypes were defined using androgen receptor, tumor-infiltrating lymphocytes (TILs), and p16 staining.
• The surrogate classification achieved a 0.708 accuracy in predicting Vanderbilt subtypes.

Conclusions:

• A novel TNBC surrogate subtype classification was successfully developed.
• This classification demonstrates correlation with the Vanderbilt subtype classification.
• The developed test is practical, accessible, and applicable in clinical settings.