Clinical Characteristics of Recurrent Nasopharyngeal Carcinoma in High-Incidence Area

Table 1

Staging systems for nasopharyngeal carcinoma.

The sixth edition of the AJCC staging system	Fuzhou 1992 staging system of China
Tumor in nasopharynx (T)	Primary tumor (T)
T1: tumor confined to the nasopharynx	T1: Tumor confined to the nasopharynx
T2: tumor extends to soft tissues of oropharynx and/or nasal fossa; T2a: without parapharyngeal extension; T2b: with parapharyngeal extension	T2: Involvement of nasal fossa, oropharynx, soft palate prevertebral soft tissue, and parapharyngeal space extension before SO line*
T3: tumor invades bony structures and/or paranasal sinuses	T3: extension over SO line, involvement of anterior or posterior cranial nerves alone, skull base, pterygoid process zone, and pterygopalatine fossa
T4: tumor with intracranial extension and/or involvement of cranial nerves, infratemporal fossa, hypopharynx, orbit, or masticator space	T4: involvement of both anterior and posterior cranial nerves, paranasal sinus, cavernous sinus, orbit, infratemporal fossa, and direct invasion of first or second cervical vertebra
Regional lymph nodes (N)	Regional lymph nodes (N)
N0: no regional lymph node metastasis	N0: no enlarged lymph node
N1: unilateral metastasis in lymph node(s), ≤6 cm in greatest dimension, above the supraclavicular fossa	N1: the diameter of upper neck lymph node <4 cm, movable
N2: bilateral metastasis in lymph node(s), ≤6 cm in greatest dimension, above the supraclavicular fossa	N2: lower neck^§ lymph node or the diameter between 4 and 7 cm
N3: metastasis in lymph node(s); N3a: >6 cm in greatest dimension; N3b: extension to the supraclavicular fossa	N3: supraclavicular lymph node or the diameter >7 cm or fixed or skin infiltration
Distant metastasis (M); M0: no distant metastasis; M1: distant metastasis	Distant metastasis (M); M0: absence of distant metastasis; M1: presence distant metastasis
Stage grouping	Stage grouping
Stage I: T1 N0 M0	Stage I: T1 N0 M0
Stage IIA: T2a N0 M0	Stage II: T2 N0-1 M0
Stage IIB: T1-2 N1 M0; T2b N0 M0; T1-2	Stage III: T3 N0-2 M0; T1-3 N2 M0
N1 M0	Stage IVA: T4 any N, M0
Stage III: T1-3 N2 M0; T3 N0-1 M0	Stage IVB: any T, any N, M1
Stage IVA: T4 N0-2 M0; any T N3, M0
Stage IVB: any T N3 M0
Stage IVC: any T, any N M1

*The line connected from the styloid process to the midpoint on posterior edge of the great occipital foramen.
^§The border between upper and lower neck is the lower margin of the cricoid cartilage.