This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast, Subject name: Anatomy
Molecular classification of breast cancer is based on which of the following 
Select and explain. 
A. Gene expression profiling, B. Expression of hormone receptors like ER, PR and HER-2 neu, C. Histology, D. Response to chemotherapy
A: Gene expression profiling
Answer: A: Gene expression profiling 
Explanation: Refer Robbins page no 1061 Invasive carcinoma can be divided based on molecular and morpholog characteristic into several clinically impoant subgroups. Breast carcinoma have a wide variety of morphological apperance.One third can be classified morphologically into special histologic types some of which are strongly assosciated with clinically relevant biologic characteristic