Staging of cancer
Staging of cancer is a classification process applied to a specific malignant tumor at the time of diagnosis. It may be repeated at critical points. The staging system describes the exent of the disease at the time and therefore provides a basis for treatment and prognosis.
Example of staging - Breast cancer
T Size of tumor
N Involvement of lymph nodes
M Pressence of metastasis
Breast cancer
Stage I : T1 - tumor 2 cm or less in diameter; N0 - no lymph nodes involved; M0 - no metastasis
Stage II : T0 to T2-tumor less than 5 cm in diameter; N1-nodes involved; M0-no metastasis
Stage III : T3-tumor larger than 5 cm in diameter; N1 or N2-nodees involved; tumor may be fixed; M0-no metastasis
Stage IV : Y4-tumor any size but fixed to chest wall or skin; N3-clavicular nodes involved (spread); M1-metastasis present
A simplified version of staging is presented in Table 5-3. Subgroups for each stage have also been established for many types of cancer. Generally, stage I tumors are small and well localized, easy to treat, and have a good prognosis, whereas stage IV tumors are wall advanced, difficult to treat at multiple sites, and have a poorer prognosis.