This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetal Skull and Maternal Pelvis, Subject name: Gynaecology & Obstetrics
A patient is diagnosed with carcinoma of the breast. The most important prognostic factor in the treatment of this disease is 
Select and explain. 
A. Age at diagnosis, B. Size of tumor, C. Axillary metastases, D. Estrogen receptors on the tumor
C: Axillary metastases
Answer: C: Axillary metastases 
Explanation: Recognition of the high risk associated with axillary metastases for early death and poor 5-year survival has led to the use of postsurgical adjuvant chemotherapy in these patients. Patients who have estrogen- or progesterone-receptive tumors (i.e., receptor present or receptor-positive) are particular candidates for this adjuvant therapy, as 60% of estrogen-positive tumors will respond to hormonal therapy. Age and size of the tumor are certainly factors of importance, but they are secondary to the presence or absence of axillary metastases.