This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Prognosis of breast cancer is best determined by: March 2011 \nSelect and explain. \nA. Axillary node involvement, B. Skin infiltration, C. Size of the tumour, D. Estrogen receptor status', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: Axillary node involvement The best indicators of likely prognosis in breast cancer remain tumour size and lymph node status; however, it is realized that some large size tumours will remain confined to the breast for decades whereas some very small tumours are inoperable at diagnosis. Hence, the prognosis of a cancer depends not on its chronological age but on its invasive and metastatic potential', 'role': 'assistant'}]