It is important that the healthcare professionals start the treatment by staging and deriving a detailed progression, of the disease for coming to an educated treatment decision.  Determining the stages of oral cancer plays an important role in evaluating the treatment options.

Oncologist and dental experts have to conduct a variety of diagnostic tests for the evaluation of oral cancer that helps in the development of individualized treatment plans based on these reports. If a patient is recently diagnosed with oral cancer, the doctor will review their pathology for confirming if the patient has received the correct diagnosis and staging information about their condition, and then create a treatment plan for them.

What is the TNM System?

TNM (Tumor, Node, & Metastases) is a system which assigns a number or letter for each cancer for describing their severity. This system was created by UICC (Union for International Cancer Control) for measuring different stages of oral cancer.

Tumor (T), is used for describing the original size of the tumor

Node (N), identifies if the cancer is present in the lymph nodes

Metastasis (M), helps in determining if cancer has spread in other organs   

Note: TNM system is not used for staging all types of cancer.

How are the stages of oral cancer differentiated?

A number from 0 to 4 or a letter X is assigned to every factor that associates with cancer. In this system, a higher number represents increasing severity. For instance, a patient’s report with a T1 score indicates that he/she is at a smaller risk of tumor compared to a T2 score. Not only the size of the tumor will be bigger at the T2 score, but the severity will also become more complex. The letter X in the TNM system represents that the information cannot be assessed.

Once the T, N, & M score is assigned to the patient, for determining the different stages of oral cancer.

Stages of Oral Cancer via TNM System

T Helps In Categorizing Oral Cavity Cancer

These measurements are referred for determining primary oral cancer tumors.

TX: At this stage primary tumor is unrecognizable, and cannot be assessed; hence the information is not known at this stage.

TO: No evidence of a tumor has been detected.

Tis: Carcinoma in situ is diagnosed, meaning that the disease is found in the top layer of oral cavity cell linings, but it is still localized. Cancer cells have not entered or invaded deeper layers of the oral tissues.

T1: Tumor is either 2 cm in size or smaller.

T2: Tumor has spread or become larger than 2 cm, but is still smaller than 4 cm.

T3: Tumor has spread in more than 4 cm area across the oral cavity.

T4 is described by division into two subgroups:

T4a: The tumor is rapidly growing in nearby structures. During this stage, oral cancer is also called a moderately advanced local disease. The areas which get afflicted by the cancer cells depend on the type of oral cancer:

Oral cavity cancers – the tumor grows in the nearby structures like the face or jaw bone, tongue muscle, maxillary sinus or the skin on the face.

Lip cancers – the tumor grows into the nearby bones, the floor of the mouth, skin on the nose or chin and the jawbone nerve or the inferior alveolar nerve.

T4b: At this stage, the tumor has already grown in the nearby structures and deeper tissues.  T4b cancer is also called very advanced local disease, and might include the following conditions:

The tumor is rapidly growing in other bones, like the skull (pterygoid plates) and skull base. This can occur during all types of oral cancer conditions.

The tumor has surrounded the internal carotid artery, which can happen because of any oral cancer condition.

For oral & lip cavity cancers: The tumor grows in the masticator space.

N categories for oral cavity cancers

NX: Nearby lymph nodes can’t be assessed; the information is unknown.

N0: The oral cancer is localized and has not spread in any nearby lymph nodes.

N1: cancer has interacted with one lymph node present on the same side of the neck or head as the primary tumor. The size of the lymph node is smaller than 3 cm.

N2 is categorized into three subgroups:

N2a: oral cancer has infected one lymph node located on the side of the primary tumor, and measures between 3–6 cm.

N2b: cancer has spread in two or more lymph nodes on the side of the primary tumor and all of them are bigger than 6 cm.

N2c: oral cancer has spread across more than one lymph nodes on both sides of the head and neck including the side with and without the primary tumor.  All of the lymph nodes measure over 6 cm.

M categorization for Oral cavity cancers

M0: No distant cancer spread is detected.

M1: oral cancer has spread across distant sites outside the neck and head region (for example, liver, lungs or bones).

Recurrent Oral Cancer

Recurrent cancer refers to a condition in which cancer afflicts a patient again after he/she has been treated from it completely. A person recovering from all of stages of oral cancer can suffer from recurrent cancer. If cancer returns to the same location where it first started, it is called local recurrence. And if it returns in the neighboring tissues or nodes, to where it started, it is called a regional recurrence. But if it comes to a different tissue or lymph node, it is called distant recurrence or distant metastasis.

Read this story of a father who successfully defeated oral cancer: 

https://medmonks.com/success-story/man-battling-against-cancer-the-daughters-perspective