**5.4 Stage 3**

It's broken down into four sections: 3A, 3B, and 3C. Stage 3A refers to a tumour that has caused swelling or ulceration on the breast skin and has spread to up to 9 axillary lymph nodes or sentinel lymph nodes, whereas stage 3B refers to a tumour of any size that has caused swelling or ulceration on the breast skin and has spread to up to 9 axillary lymph nodes or sentinel lymph nodes. Because it has progressed to 9 axillary lymph nodes or sentinel lymph nodes, stage 3B breast cancer is deemed inflammatory. Tumour spread to 10 or more axillary lymph nodes, as well as lymph nodes above and below the clavicle, is classified as stage 3C [19].
