Nasopharyngeal cancer (staging)

Nasopharyngeal cancer staging refers to TNM staging of malignant tumors of the nasopharynx. The vast majority of applicable tumors are nasopharyngeal carcinomas, but other epithelial malignancies of the nasopharynx are included, such as minor salivary gland tumors. The following article reflects the 8th edition published by the American Joint Committee on Cancer, which is used for staging starting January 1, 2018 ^1,2.

Primary tumor (T)

• TX: primary tumor cannot be assessed
• T0: no evidence of primary tumor, but EBV-positive nodal involvement
• Tis: carcinoma in situ
• T1: 
  • tumor is confined to the nasopharynx, or
  • tumor extends to oropharynx and/or nasal cavity without parapharyngeal involvement
• T2: 
  • tumor extends to parapharyngeal space, and/or
  • tumor involves adjacent soft tissue: medial pterygoid, lateral pterygoid, or prevertebral muscles
• T3: tumor infiltrates bony structures at skull base, cervical vertebra, pterygoid structures (medial/lateral pterygoid plate/process, pterygomaxillary fissure, or pterygopalatine fossa), and/or paranasal sinuses
• T4: tumor invasion of any one or more of the following:
  • intracranial content
  • cranial nerves
  • hypopharynx
  • orbit
  • parotid gland
  • extensive soft tissue infiltration beyond the lateral surface of the lateral pterygoid muscle

Regional lymph node (N)

• NX: nodes cannot be assessed
• N0: no regional nodal metastasis
• N1: metastasis above the caudal border of cricoid cartilage involving
  • unilateral cervical lymph node(s), and/or
  • unilateral or bilateral retropharyngeal lymph node(s) ≤6 cm in greatest dimension
• N2: bilateral cervical lymph node metastasis ≤6 cm, above caudal border of cricoid cartilage
• N3
  • unilateral or bilateral cervical lymph node metastasis >6 cm, and/or
  • lymph node metastasis extending below the caudal border of cricoid cartilage

Distant metastases (M)

The terms pM0 and MX are not valid TNM categories. The following categories may be used, either in the clinical classification (c) for patients with cancer identified before treatment and/or in the pathological classification (p) for patients for whom surgery is the first definitive therapy:

• cM0: no evidence of metastases
• cM1: distant metastasis
• pM1: distant metastasis, microscopically confirmed

Stage groupings

• Stage 0
  • Tis, N0, M0
• Stage I
  • T1, N0, M0
• Stage II
  • [T0, T1], N1, M0
  • T2, [N0, N1], M0
• Stage III
  • [T0, T1, T2], N2, M0
  • T3, [N0, N1, N2], M0
• Stage IVA
  • T4, [N0, N1, N2], M0
  • [Any T], N3, M0
• Stage IVB
  • [Any T], [Any N], M1

Changes from prior versions

Compared to the 7th edition of the AJCC staging system, prevertebral muscle involvement was added as a T2 criterion in the 8th edition. Involvement of the infratemporal fossa/masticator space as a T4 criterion was changed to the lateral border of the lateral pterygoid muscle. Involvement of the supraclavicular fossa as a N3 criterion was changed to lower level (levels IV and Vb) as demarcated by the caudal border of the cricoid cartilage. Stage IVA and IVB were merged into stage IVA, while stage IVC was upgraded to stage IVB.

See also

• nasopharyngeal carcinoma
• adenoid cystic carcinoma