Grading and Staging of Cancer
What is grading of cancer?
After the determination is made as to the type of cancer, the cancer is graded - a measurement of how aggressive the tumor is. Most cancer cells are graded by how much they look like normal cells. Grading is done in the lab using cancerous cells taken during biopsy.
Cancers are usually graded from low to high. Low grade cancers look like normal tissue under the microscope. High grade tumors look very abnormal and are generally more aggressive with a poor outcome.
What is staging of cancer?
Once cancer is diagnosed, more tests will be done to find out if the cancer cells have spread to other parts of the body. This testing is called staging. To plan treatment, a physician needs to know the stage of the disease. Stage refers to the extent, or the size, of the cancer. Each cancer, by organ, has its own staging system.
Stages of cancer:
Stage 0 or carcinoma in situ
Carcinoma in situ is very early cancer. The abnormal cells are found only in the first layer of cells of the primary site and do not invade the deeper tissues.
Cancer involves the primary site, but has not spread to nearby tissues.
Cancer has spread to nearby areas but is still inside the primary site.
Cancer has spread throughout the nearby area.
Cancer has spread to other parts of the body.
stage IVA: cancer has spread to organs close to the pelvic area
stage IVB: cancer has spread to distant organs, such as the lungs
Recurrent disease means that the cancer has come back (recurred) after it has been treated.
Once a stage is assigned and treatment given, the stage is never changed. For example:
If a stage I cancer of the cervix is treated, and two years later a metastasis is found in the lung, it is not now stage IV, but remains a "stage I, with recurrence to the lung." However, some cancers may be re-staged.
The important thing about staging is that it determines the appropriate treatment, provides a prognosis, and allows for comparison of treatment results between different treatments.