Cancer is normally diagnosed by stage and with most cancer types there are four stages.
Stage 1 usually means that a cancer is small and contained within the organ it started in
Stage 2 usually means that the tumour is larger than in stage 1 but the cancer hasn't started to spread into the surrounding tissues. Sometimes stage 2 means that cancer cells have spread into lymph nodes close to the tumour. This depends on the particular type of cancer
Stage 3 usually means the cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes nearby.
Stage 4 means the cancer has spread from where it started to another body organ. For example to the liver or lung. This is also called secondary or metastatic cancer
Cancer diagnosed at Stage 1 or 2 is considered an early diagnosis.