Which factor is NOT typically used to assess the stage of breast cancer?

The factor that is not typically used to assess the stage of breast cancer is the patient's age. When staging breast cancer, the primary considerations involve specific tumor characteristics such as tumor size, lymph node involvement, and whether metastasis is present.

Tumor size is crucial as it helps to classify the local extent of the cancer. Lymph node involvement indicates whether the cancer has spread to nearby nodes, which is critical in determining the disease extent and potential for further metastasis. Metastasis presence is significant as it refers to the spread of cancer beyond the breast and nearby lymph nodes to other parts of the body, marking a more advanced stage of cancer.

In contrast, a patient's age does not directly influence the staging process as it does not provide information regarding the tumor's biological behavior or extent of spread. While a patient's age may impact treatment decisions or prognosis, it is not a parameter used in the staging classification itself, making it the least relevant factor in this context.

Understanding these staging factors is essential for determining the appropriate treatment path and evaluating prognosis in breast cancer management.