Radiation Oncology/Head & Neck/Nasopharynx/Staging

Nasopharynx Cancer Staging Staging AJCC 7th edition (2009): Tumor T1 - confined to nasopharynx, or tumor extends to oropharynx and/or nasal cavity without parapharyngeal extension T2 - tumor with parapharyngeal extension (posterolateral infiltration of tumor, i.e. beyond the pharyngobasilar fascia) T3 - involves bony structures and/or paranasal sinuses T4 - intracranial extension and/or involvement of cranial nerves, infratemporal fossa, hypopharynx, orbit, or masticator space Nodes N1 - unilateral nodes, 6 cm or less, above the supraclavicular fossa, and/or retropharyngeal lymph nodes 6 cm or less (unilateral or bilateral) N2 - bilateral nodes, 6 cm or less, above the supraclav fossa N3a - lymph node greater than 6 cm N3b - extension to the supraclav fossa (defined as the triangular region described by Ho, bounded by the superior margin of the sternal head of the clavicle, the superior margin of the lateral end of the clavicle, and the point where the neck meets the shoulder. This includes some of level IV as well as V.) Overall stage I - T1 N0 II - T1-T2 N1, T2 N0 (i.e. T2 or N1) III - T3 N0-2, or T1-3 N2 (i.e. T3 or N2) IVA - T4 N0-2 IVB - N3 IVC - M1 Changes from 6th edition T2a lesions moved to T1. T2b moved to T2. Stage IIB was moved to II and Stage IIA merged with Stage I New designation for retropharyngeal lymph nodes (all are N1 nodes) Notes Shift of more advanced N-stages into lower stage groupings — N1 is stage II instead of III, N2 is III instead of IV Retropharyngeal nodes staging has been controversial, since CT is often unable to differentiate them from parapharyngeal involvement of primary tumor. However, MRI appears more sensitive, and patients who are N0 but with positive RLN by MRI have prognosis similar to patients with N1 disase as should probably be classified as such Older staging systems AJCC 6th edition (2002) Tumor T1 - confined to nasopharynx T2 - extends to soft tissues T2a - extends to oropharynx and/or nasal cavity without parapharyngeal extension T2b - any tumor with parapharyngeal extension (i.e. beyond the pharyngobasilar fascia) T3 - involves bony structures and/or paranasal sinuses T4 - intracranial extension and/or involvement of cranial nerves, infratemporal fossa, hypopharynx, orbit, or masticator space Nodes N1 - unilateral nodes, 6 cm or less, above the supraclavicular fossa N2 - bilateral nodes, 6 cm or less, above the supraclav fossa N3a - lymph node greater than 6 cm N3b - extension to the supraclav fossa (defined as the triangular region described by Ho, bounded by the superior margin of the sternal head of the clavicle, the superior margin of the lateral end of the clavicle, and the point where the neck meets the shoulder. This includes some of level IV as well as V.) Overall stage I - T1 N0 IIA - T2a N0 IIB - T1-T2 N1, T2b N0 (i.e. T2b or N1) III - T3 N0-2, or T1-3 N2 (i.e. T3 or N2) IVA - T4 N0-2 IVB - N3 IVC - M1 Notes Division of Stage II into A and B compared to other H&N sites Shift of more advanced N-stages into lower stage groupings — N1 is stage II instead of III, N2 is III instead of IV Retropharyngeal nodes staging has been controversial, since CT is often unable to differentiate them from parapharyngeal involvement of primary tumor. However, MRI appears more sensitive, and patients who are N0 but with positive RLN by MRI have prognosis similar to patients with N1 disase as should probably be classified as such AJCC 5th edition (1997) same as 6th edition AJCC 4th edition (1988): T1 - tumor confined to one wall of the nasopharynx T2 - two walls or more T3 - extension to oropharynx and nasal cavity T4 - invades skull base or cranial nerve N1 - single ipsilateral node <= 3 cm N2a - single ipsilateral node 3-6 cm N2b - multiple ipsilateral nodes < 6 cm N2c - contralateral or bilateral nodes < 6 cm N3 - nodes > 6 cm Overall stage: I - T1 N0 II - T2 N0 III - T3 or N1 IV - T4 or N2-3 or M1 (similar to other H&N sites in newest staging system) Note: downstaging of disease in AJCC 4th edition — N1 was moved to Stage II and N2 was moved to Stage III. This is an important difference to note when comparing older trials to newer treatment modalities since the definition of "advanced stage" has changed. Chinese Staging (1992) T1 - nasopharynx only T2 - nasal cavity, oropharynx, soft palate, anterior cervical vertebrae soft tissue, proximal parapharyngeal space T3 - distal parapharyngeal space, CN involvement, base of skull, pterygoprocss zone, pterygopalatine fossa T4 - multiple CN involvement, paranasal sinus, cavernous sinus, orbit, infratemporal fossa, or C1-C2 vertebra N0 - no nodes N1 - upper cervical LN <4cm N2 - lower cervical LN, or 4-7 cm N3 - SCV, or >7cm, or fixed, or skin infiltration Staging: I - T1N0 II - T2 or N1 III - T3 or N2 IVA - T4 or N3 IVB - M1 Ho's Staging (1978) T1 - nasopharynx only T2 - extension to nasal fossa, oropharynx, or parapharyngeal region T3 - bony involvement, skull base, cranial nerve palsy, orbits, laryngopharynx, or infratemporal fossa N0 - no nodes N1 - above laryngeal cartilage N2 - below laryngeal cartilage but above SCV fossa N3 - SCV lymph nodes