Stages Of Cancer

By peace | July 9, 2006

The staging of a carcinoma has to do with the size of the tumor, and the degree to which it has penetrated. When the tumor is small and has not penetrated the mucosal layer, it is said to be stage I cancer. Stage II tumors are into the muscle wall, and stage III involves nearby lymph nodes. The rare stage IV cancer has spread (metastasized) to remote organs.

Staging of cancer describes the extent of cancerous growth including size of the primary tumour, level of spread to the lymph nodes and status of the metastasis.

Staging of cancer is often done to know the prognosis and to decide the treatment. There are different systems of staging, for example the Dukes & Astler Coller staging system, which is used in the colorectal cancer and the Clark’s level staging system, which is used in the malignant melanoma.

The most common and globally accepted staging system is the “TNM” classification that describes: size (or number) of the primary tumour, denoted by the letter “T”;involvement of the lymph nodes, denoted by the letter “N”; and status of the metastasis, denoted by the letter “M”. The letter “T” is followed by the letter “X” if the primary tumour is not assessed clinically; the letter “0″ if there is no evidence of the primary tumour; the letter “IS” if the tumour is in situ; or the number “1″, “2″, “3″ or “4″ that denotes size of the tumour. The greater the number, the larger is the size of tumour. Similarly, the letter “N” is followed by the letter “X” if involvement of the lymph nodes is not assessed clinically; the letter “0″ if there is no evidence of the lymph node involvement; or the number “1″, “2″, “3″ or “4″ that denotes extent of the lymph node involvement. The letter “M” is followed by the letter “X” if metastasis is not assessed clinically; the letter “0″ if there is no evidence of metastasis; or the number “1″, “2″ or “3″ that denotes the number of metastasised sites. These numbers are usually translated as Stage I, Stage II, Stage III, etc., for convenience of the patient.

Staging Mouth and Tongue Cancers

Mouth and tongue cancers are staged according to the TNM system, which measures tumor size (T), lymph node involvement (N), and metastasis (M). The higher the stage of oral cancer, the worse the prognosis. Localized oral cancer has a five-year survival rate of 82 percent. If mouth or tongue cancer spreads within the oral region, survival rates drop to 46 percent. Once oral cancer metastasizes to distant organs, survival drops to 21 percent.

Stages of Oral Cancer

Stage I: (T1N0M0). The oral tumor is smaller than two centimeters.
Stage II: (T2N0M0). The mouth tumor or tongue tumor is larger than two centimeters, but smaller than four.
Stage III: (T3N0M0, T1N1M0, T2N1M0, or T3N1M0). Oral tumors are at least two centimeters in size. Those labeled T3 are greater than 4 centimeters in size. Some lymph node involvement may be present (NO or N1).
Stage IVA: (T4N0M0, T4N1M0, or any T with N2M0). Any size mouth or tongue tumor. T4 denotes invasion of nearby organs. Multiple lymph node involvement, or a single large lymph node (three to six centimeters).
Stage IVB: (Any T with N3M0). Any size oral tumor, with lymph nodes reaching over six centimeters in size.
Stage IVC: (Any T, any N, M1). Oral cancer has spread to distant organs.