A Brief Guide to Sinonasal Tumor Staging

Sinonasal cancer staging helps to assess the stages of cancer in the nasal cavity. The process also enables doctors to decide the treatment required for sinus cancer and gauging the chances of recovery. Sinonasal tumor staging involves the compilation of results of medical examinations such as biopsy, endoscopy and imaging procedures including MRI and CT scans. The stages are assigned according to the size of cancer and the involvement of lymph nodes. Read on to find out more about sinonasal cancer staging. 

The TNM Staging Process

The TNM staging process has been developed by The American Joint Committee on Cancer to evaluate the primary factors for treating cancers including the sinonasal and head cancers. The system describes:

1. Tumor (T) Stages

T stage assesses the size of the primary tumor while investigating if cancer has spread to the nasal cavity tissues, paranasal sinuses and skull bones. There are 4T stages of sinonasal cancer

• T1- T1 stage indicates that the tumor present in one part of the nasal cavity, but might have spread to the nasal bones.
• T2- The stage indicates tumor has started advancing to nasal and paranasal cavities.
• T3- During this stage, the tumor spreads to the eye socket bones and the palate.
• T4- Tumor spreads to the nearby nerves and organs such as eye, skull, brain, cheek and the skin.

2. Node (N) Stages

Lymph nodes are immunity cells that protect the body against infections and mostly the first target for the cancer cells in the human body. The N-stage estimates lymph node involvement near the primary tumor. The stage can be further classified as:

• N0- No lymph nodes with cancer cells
• N1- Cancer cells present in one lymph node on the same side of the neck but node size is 3cm or less

• N2a- Same as N1, node size lies between 3cm and 6cm

• N2b- Cancer cells present in more than one lymph node on the same side of neck and none of them are more than 6cm

• N2c-Cancer cells are present in lymph nodes on the other half of the neck with an approximate size 6cm

• N3- One or more lymph nodes contain cancer cells, and one of them is more than 6cm

3.    Metastasis (M)

The stage indicates that cancer has spread from the sinonasal cavity to other parts of the body. Sinus cancer primarily targets lungs as the first site for metastasis followed by the bones. Further classification of M is as follows:

• M0- Cancer cells are localized and haven’t spread to other parts of the body.
• M1- Cancer cells have attacked other parts of the body such as the brain, lungs, and the liver.

The Way Forward

Low-grade cancers grow slow and are less likely to spread as compared to high-grade cancer. During the process of cancer staging, doctors assign the values of T, N and M to the disease based on the microscopic appearance. The doctors thoroughly review the medical, family history and other factors to develop a treatment plan for patients.