Colorectal carcinogenesis: Insights into the cell death and signal transduction pathways: A review

Figure 1 Different stages during the progression of colorectal carcinogenesis. Stage 0: The cancerous cells grow within the inner lining of the mucosa; Stage I: The cancerous cells grow throughout the mucosa and submucosa. The cancerous growth invades into the muscular layer of the colon; Stage II: The cancerous growth penetrates through the wall of the colon without spreading to neighbouring tissues or lymph nodes; Stage III: The cancer penetrates through layers of muscle into the serosa, the layer of visceral peritoneum. The cancer begins to spread to the lymph nodes; Stage IV: A tumour nodule forms in the tissue surrounding the colon, cancer cells appears within the lymph nodes, and the cancer begins to metastasize.