What does "early-stage" breast cancer mean?

Breast cancer is categorized as Stage I, II (A or B), III (A, B, or C), or IV. The stage is based on the size of the tumor and whether the cancer has spread. Stages I, IIA, IIB, and IIIA are considered "early-stage" breast cancer and refer to cancers that may have spread to nearby lymph nodes but not to distant parts of the body.