To determine how advanced the Colorectal Cancer is there are two different systems. First, we will discuss the staging system for Colon Cancer, which has 4 levels. Stage I clinically indicates that there is cancer and has moved through the superficial mucosa of the colon and/or rectum but has not spread beyond the colon wall or rectum. The Stage II clinically means that the cancer has moved through the wall of the colon and/or rectum but there is no lymphatic spread yet. Stage III clinically means the cancer has now invaded lymphatics and is in the lymph nodes, but has not spread distantly yet. Finally, Stage IV of Colon Cancer diagnosis means that the cancer has now spread to distant sites; which is known as metastatic disease. Metastatic spread means the cancer has now spread to other organs. Typical organs which are affected by metastatic colon cancer include the Liver and Lungs. Recommended Read:  Treatment Options for Colorectal Cancer For Rectal Cancer, there are actually five stages. There is a Stage 0 which indicates that there are cancerous cells only affecting the superficial rectal lining, and may even be a within the polyp itself. Stage I indicates that the tumor or cancerous cells are now penetrating the rectal mucosa and may even penetrate the rectal wall.