Based on the TNM classification, cancers are then grouped into stages I to IV, often with further subdivisions (like IIa, IIb). Here's a general overview:
Stage 0: Also known as carcinoma in situ. Cancer is where it started and hasn't spread. Stage I: Early-stage cancer, usually a small tumor that hasn't deeply invaded nearby tissues or spread to lymph nodes. Stage II and Stage III: Larger tumors that have invaded nearby tissues and possibly lymph nodes, but not other parts of the body. Stage IV: Advanced cancer that has spread to other organs or parts of the body.
