There are generally five stages of cancer , numbered from 0 to 4, though most commonly stages 1 to 4 are used to describe the progression of cancer:
- Stage 0 : Abnormal cells are present but have not spread beyond their original location. This is often called carcinoma in situ and is considered pre-cancer or non-invasive
- Stage 1 : The cancer is small and localized to one area or organ. It has not spread to nearby tissues or lymph nodes
- Stage 2 : The tumor is larger than in stage 1 and may have started to invade nearby tissues or lymph nodes, depending on the cancer type
- Stage 3 : The cancer is larger and has spread more extensively into surrounding tissues and lymph nodes
- Stage 4 : The cancer has metastasized, meaning it has spread to distant parts of the body or other organs. This is also called advanced or metastatic cancer
Some cancers have specific variations in staging. For example, breast cancer and some others include stage 0, while Wilms tumor (a childhood kidney cancer) can have a stage 5, which indicates involvement of both kidneys
. However, the stage 5 designation is rare and not used for most cancers. The staging system often uses Roman numerals (I, II, III, IV) and incorporates the TNM system, which assesses tumor size (T), lymph node involvement (N), and metastasis (M)
. In summary, most cancers are classified into four main stages (1 to 4) , with stage 0 representing non-invasive abnormal cells, making a total of five possible stages in many staging systems. Stage 4 is the most advanced, indicating spread to distant organs.
