Familial Nasopharyngeal Carcinoma 6

314 B. O’Sullivan and E. YuTable 24.1. UICC Nasopharynx TNM Classification (7th edition, in preparation)T-primary tumorT1T2T3T4Tumor confined to nasopharynx, or tumor extends to soft tissue of oropharynx and/or nasal fossa withoutparapharyngeal extensionTumor with parapharyngeal extensionTumor invades bony structures and/or paranasal sinusesTumor with intracranial extension and/or involvement of cranial nerves, infratemporal fossa, hypopharynx,orbit, or masticator spaceN-regional lymph nodesN0N1N2N3N3aN3bNo regional lymph node metastasisUnilateral metastasis in lymph node(s), 6 cm or less in greatest dimension, above the supraclavicular fossaand/or unilateral or bilateral, retropharyngeal lymph nodes 6 cm or less in greatest dimensionBilateral metastasis in lymph node(s), 6 cm or less in greatest dimension, above the supraclavicular fossaMetastasis in lymph node(s) greater than 6 cm in dimension or in the supraclavicular fossaGreater than 6 cm in dimensionIn the supraclavicular fossaStage I T1 N0 M0Stage IIStage IIIT1T2T1T2T3N1N0, N1N2N2N0, N1, N2Stage IVA T4 N0, N1, N2 M0Stage IVB Any T N3 M0Stage IVC Any T Any N M1UICC TNM Prognostic Factors Committee, Geneva, 2009 (UICC 7th edition, in preparation). Format and wording may differfrom the AJCC version, in preparationM0M0M0M0M0both studies shows that patients with retropharyngealnodes alone have a risk of distant metastasis thatit similar to N1 disease (Tang et al. 2008; Tham et al.2009). In addition, the proposal that they should becorrespondingly classified as N1 disease, and thatthis should be independent of laterality (Tham et al.2009) forms the basis for revision of this element inthe 7th edition of TNM (Table 24.1).Within the more advanced N-categories, potentialareas for improvement may also exist. Thuswhile N3 disease is associated with the least favorableprognosis, this appears to be confined to thecircumstance where regional nodes extend to thesupraclavicular fossa (N3b disease). N3a disease, asubcategory representing less than 5% of cases,appears not to have adverse impact beyond N2 (Leeet al. 2004; Low et al. 2004; Liu et al. 2008), but thishas not been modified for the 7th edition, in partdue to the statistical issues associated with the smallnumber of cases.24.5Anatomic Issues Relevantto Contemporary Imaging24.5.1Lateral Tumor ExtensionAs discussed above, in the forthcoming TNM classification,T2 disease will refer to instances of parapharyngealextension, defined as “posterolateral infiltrationof tumor”, as it was in the 5th and 6th editions.However with contemporary imaging, this definitionis unduly vague. This is especially true since many ofthe main components of the pre and poststyloid