Final answer:
Cancer staging is the classification of cancer based on factors such as the size of the tumor and the extent to which it has spread. In breast cancer, stage A is defined as any size tumor with cancer spread to the chest wall and/or skin of the breast and up to 10 axillary or clavicular lymph nodes.
Step-by-step explanation:
Cancer staging is the classification of cancer based on factors such as the size of the tumor and the extent to which it has spread. The stages of cancer are used to determine the prognosis and appropriate treatment for a patient. In the case of breast cancer, any size tumor with cancer spread to the chest wall and/or skin of the breast and up to 10 axillary or clavicular lymph nodes is classified as stage A.