Kidney Cancer Staging and Grading
There are two terms that patients should understand regarding the diagnosis and treatment of their cancer: staging and grading. These terms are used by the doctor when it comes to planning treatment, prescribing medications, deciding on surgical treatments or even estimating the likely long-term outcome or course of the disease.
Staging is a way to describe the extent or severity of an individual’s cancer. As the tumor develops, it can invade nearby organs and tissues, or cells can break off and enter the bloodstream or lymphatic system. The cancer then spreads (also called metastasizing) to form new tumors in other organs.
Doctors determine a cancer’s “clinical stage” by using a combination of physical examinations, imaging (such as CT or MRI scans), laboratory tests, biopsies, pathology reports and even physical symptoms a patient describes. If the tumor is removed, microscopic examination by the pathologist often reveals a more complete “pathologic stage”.
Although competing staging systems still exist for some types of cancer, the universally-accepted staging system is that of the “TNM Classification”. The “T” describes the size of the tumor and whether it has invaded nearby tissue, the “N” describes regional lymph nodes that are involved, and the “M” describes distant metastasis (spread of cancer from one body part to another).
Cancer grading (also called tumor grading) is a system used to classify the aggressiveness of cancer cells in terms of how abnormal they look under a microscope and how quickly the tumor is likely to grow and spread. This information can be obtained from a small sample (biopsy) of the tumor. However, as in staging, the information can be more accurate by microscopic examination of the entire tumor following complete removal. For most cancers, grades are described on a scale from 1 to 3 (or 4) from least to most aggressive. However, grading systems can be different for each type of cancer.
Kidney Cancer Staging:
T1: Tumor 7 cm or less in diameter and limited to the kidney
T1a: Tumor 4 cm or less in greatest dimension and limited to kidney
T1b: Tumor more than 4 cm but not more than 7 cm, and limited to kidney
T2: Tumor more than 7 cm in greatest dimension limited to the kidney
T3: Tumor extends into major veins or invades the adrenal gland or perinephric tissues, but not beyond Gerota’s fascia
T3a: Tumor directly invades the adrenal gland or perinephric tissues but not beyond Gerota’s fascia
T3b: Tumor grossly extends into the renal vein or its segmental (muscle-containing) branches, or vena cava below the diaphragm
T3c: Tumor grossly extends into the vena cava above the diaphragm or invades the wall of the vena cava
T4: Tumor invades beyond Gerota’s fascia