| Staging is used by the doctors to evaluate how | | | | reached the local lymph nodes. |
| much the cancer has invaded the organism and to | | | | Duke stage D shows that the cancer has spread |
| decide further what methods of therapy to apply. | | | | towards other tissues and organs. |
| The colon cancer staging began with the Duke's | | | | The TNM staging refers to tumor, nodes and |
| classification system which contained three stages: | | | | metastasis. |
| A, B, and C. After a while Astler-Coller brought | | | | T1: the cancer has affected the mucosa and the |
| modifications to this classification, adding one more | | | | submucosa too. |
| stage: the D stage. In 1978 Gunderson & | | | | T2: the cancer has extended to the muscularis |
| Sosin brought other modifications to the | | | | propria. |
| classification and a few years ago, the American | | | | T3: the cancer has passed through the muscularis |
| Joint Committee on Cancer has come with a new | | | | propria and has reached the subserosa. |
| classification called TNM containing four stages. | | | | T4: the cancer has affected all the colon's layers |
| Nowadays the doctors use more often the TNM | | | | and it is spreading o the nearby organs. |
| classification and the Duke's classification in staging | | | | N0: it means that no lymph nodes are affected |
| the colon cancer. | | | | yet. |
| Duke stage A refers to the fact that the cancer | | | | N1: the cancer has affected 1 to 3 local lymph |
| affects only the mucosa of the bowel and does | | | | nodes. |
| not get further to other structures of the colon. | | | | N2: the cancer is found in more than 4 local lymph |
| Duke stage B1 shows that the cancer has | | | | nodes. |
| reached the muscularis propria of the colon but | | | | M0: it means that no metastases are present. |
| did not get through it. | | | | M1: it means that distant metastasis can be seen. |
| In Duke stage B2 the tumor has got through the | | | | Another classification which is more accurate |
| muscularis propria of the colon. | | | | contains both the Duke's and the TNM |
| In Duke stage C1 the cancer has reached the | | | | classification. |
| muscularis propria and has also affected the local | | | | Stage I: T1 N0 M0; T2 N0 M0 means that the |
| lymph nodes. | | | | disease has extended in the inner layers of the |
| In Duke stage C2 the tumor has got through the | | | | colon but it has not spread to other structures |
| muscularis propria of the colon and has also | | | | yet. |