What Is Involved in Renal Tumor Staging?

Renal tumor staging is a process by which doctors discover and describe the extent and severity of cancerous tumors in the kidneys. The initial clinical stage involves the examination of imaging and laboratory tests to determine a preliminary diagnosis. Pathological renal tumor staging is a more sensitive process that combines clinical findings with results from additional imaging or surgery. To help explain the diagnosis to patients and medical team members, renal tumor staging results are often scored based on three determining factors, then divided into four major categories by severity.

Renal tumors are usually discovered during routine tests, or if a patient is experiencing symptoms that warrant investigation. The tests performed during this preliminary period might include laboratory work, such as blood and urine tests. Some imaging tests, including bone scans, computer tomography (CT) scans, or magnetic resonance imaging (MRI) tests, may also be ordered. Using these results, a doctor can sometimes give an initial diagnosis of kidney cancer, known as a clinical diagnosis.

Once the preliminary diagnosis has been made, more tests may be done to help determine the extent of the cancer. Doctors may perform a biopsy, in which a small sample of tissue is removed from the kidneys and examined microscopically. Imaging scans and laboratory work may also be done on other parts of the body, to determine if the renal tumor has metastasized, or spread, to other organs. These additional tests allow the doctors to make a definitive decision about renal tumor staging.

Many doctors use a renal tumor staging scale known as Tumor, Node, Metastasis (TNM). First, the tumor is graded based on size and incursion into nearby body systems, receiving a score from 0-4. The node score is based on whether lymph nodes near the kidney have been infected, and is graded either 0 for not infected, or 1 for infected. Similarly, the metastasis score is either 0 for cancer that has not spread, or 1 for cancer that has metastasized to a distant region. Using the ratings on the TNM scale, doctors then determine the renal tumor staging on a Roman-numeral scale of I-IV, with I being the least severe, and IV the most severe.

Cancer staging is only the beginning of treatment for most patients. Depending on renal tumor staging, patients and doctors can work together to determine the best course of treatment for each individual case. Stages I and II are often treated and fully cured through a surgery that removes the infected kidney. Renal tumors at stage III or IV, or those that are recurring conditions, may be treated with a combination of surgery, drug therapy, and radiation. While the process of renal tumor staging can be a deeply upsetting and worrying time, it can also the first step to treatment and recovery.