What is the Tumor, Node, Metastasis (TNM) staging for sinonasal cancer?

From the Guidelines

The TNM staging system for sinonasal cancer is a critical tool for determining prognosis and guiding treatment decisions, and it classifies tumors based on their size and extent (T), lymph node involvement (N), and presence of metastasis (M) 1. The TNM staging system is used to classify various types of cancer, including sinonasal cancer, which arises from the sinonasal cavity.

• The T stage categorizes the size and extent of the primary tumor, with T1 being the least severe and T4 being the most severe.
• The N stage categorizes the involvement of regional lymph nodes, with N0 indicating no involvement and N3 indicating significant involvement.
• The M stage categorizes the presence of distant metastasis, with M0 indicating no metastasis and M1 indicating metastasis is present.

For sinonasal cancer, the T stage is defined as follows:

• T1 tumors are confined to one subsite with or without bone invasion.
• T2 tumors invade two subsites or an adjacent region within the nasoethmoidal complex, with or without bone invasion.
• T3 tumors extend to the medial wall or floor of the orbit, maxillary sinus, palate, or cribriform plate.
• T4a tumors invade anterior orbital contents, skin of nose or cheek, minimal extension to anterior cranial fossa, pterygoid plates, or sphenoid/frontal sinuses.
• T4b tumors invade orbital apex, dura, brain, middle cranial fossa, cranial nerves, nasopharynx, or clivus. The N stage is defined as follows:
• N0 indicates no regional lymph node metastasis.
• N1, N2, and N3 represent increasing involvement of regional lymph nodes based on size, number, and laterality. The M stage is defined as follows:
• M0 indicates no distant metastasis.
• M1 indicates distant metastasis is present. This staging system is essential for determining the prognosis and guiding treatment decisions for patients with sinonasal cancer, as it provides a standardized way to classify the extent of the disease 1.

From the Research

TNM Staging System for Sinonasal Cancer

The TNM staging system is used to classify the extent of spread of sinonasal cancer. The system includes:

• T (Tumor): describes the size of the original tumor
• N (Node): indicates whether the cancer has spread to nearby lymph nodes
• M (Metastasis): indicates whether the cancer has spread to other parts of the body

Staging of Sinonasal Cancer

According to the study 2, the sixth edition of the American Joint Committee on Cancer (AJCC) staging system for sinonasal squamous cell carcinoma includes stages I, II, III, IVA, and IVB. The study found that the new AJCC staging system seems to be more accurate in predicting the survival rates for patients with advanced but surgically resectable sinonasal squamous cell carcinoma (stage IVA).

Comparison of AJCC Staging Systems

The study 3 compared the 1997 and 1977 AJCC staging systems for maxillary sinus carcinoma and found that the 1997 system was superior in predicting both survival and local control. The study also identified significant prognostic factors for survival, including age, gender, and lymph node classification.

Updates to the AJCC Staging Manual

The eighth edition of the AJCC Cancer Staging Manual, effective as of January 1,2018, incorporates prognostic biomarkers to more accurately predict clinical outcomes and treatment response 4. The study 5 highlights the changes made in the 8th edition, particularly for otorhinolaryngologic tumors, including the classification of oropharyngeal carcinomas caused by HPV and the classification of lymph node metastases.

Future of TNM Staging

The study 6 discusses the future of cancer staging, including the use of enhanced registry data standards to support personalization of cancer care through cancer outcome prediction models and nomograms. The seventh edition of the AJCC cancer staging manual, effective for cancers diagnosed on or after January 1,2010, includes marked increases in the use of international datasets and the enhanced use of nonanatomic prognostic factors in defining the stage grouping.

Some key points about the TNM staging for sinonasal cancer include:

• The sixth edition of the AJCC staging system includes stages I, II, III, IVA, and IVB 2
• The 1997 AJCC staging system was superior to the 1977 system in predicting survival and local control for maxillary sinus carcinoma 3
• The eighth edition of the AJCC Cancer Staging Manual incorporates prognostic biomarkers to more accurately predict clinical outcomes and treatment response 4
• The 8th edition includes changes to the classification of otorhinolaryngologic tumors, including oropharyngeal carcinomas caused by HPV and lymph node metastases 5
• The future of cancer staging lies in the use of enhanced registry data standards to support personalization of cancer care 6