Many of the test results (as described in the diagnosis section) are used to determine the extent or stage of laryngeal cancer. The stage of cancer describes how much cancer is in the body. It helps your doctor understand the seriousness of the cancer, how best to treat it, and what the chance of survival is.
For laryngeal cancer, doctors mostly depend on the TNM system created by the American Joint Committee on Cancer (AJCC). The TNM system is based on three key pieces of information:
- How big the main tumor (T) is
- If the cancer has spread to nearby lymph nodes (N)
- The spread (metastasis) to distant parts of the body (M)
Numbers or letters after T, N, and M provide more details about each of these factors. Lower numbers mean that the cancer is in an early stage. Higher numbers mean the cancer is more advanced.
The standardized stages of laryngeal cancer are:
- Stage 0 - abnormal cells in the top layer of cells lining of the larynx that may become cancer.
- Stage 1 - cancer has grown deeper, but is only in one part of the supraglottis, and the vocal cords move normally.
- Stage 2 - cancer has grown deeper and spread into more than one part of the supraglottis (or glottis), and the vocal cords move normally; it has not spread to nearby lymph nodes or to distant parts of the body.
- Stage 3 - tumor is only in the larynx but has caused a vocal cord to stop moving, or the tumor is growing into nearby areas such as the postcricoid, paraglottic space, pre-epiglottic (in front of the epiglottis) tissues, or the inner part of the thyroid cartilage (firm tissue that separates the thyroid gland from the front of the larynx); the cancer has spread to a single lymph node on the same side of the neck and is no larger than three centimeters.
- Stage 4A - cancer has spread to the cartilage around the thyroid or trachea, bone under the tongue, the thyroid, or nearby soft tissue (this is also known as moderately advanced local disease); it may or may not have spread to a single lymph node on the same side of the neck.
- Stage 4B – cancer has spread to the muscles in the upper spinal column, carotid artery, chest cavity lining, and/or lymph nodes (this is also known as very advanced local disease).
- Stage 4C - any size tumor has spread to other parts of the body.