HPV-mediated (p16-positive) oropharyngeal cancer (staging)
Human papillomavirus (HPV)-mediated oropharyngeal (p16+) cancer staging refers to TNM staging of squamous cell carcinomas of the oropharynx that test positive for p16, an immunohistochemical proxy for HPV infection. Nodal metastases of p16+ squamous cell carcinoma without an identified primary tumor are also staged under this system. This classification is new in the 8 edition of the American Joint Committee on Cancer Staging Manual, published in 2017 .
Primary tumor (T)
- T0: no primary identified
- T1: tumor ≤2 cm in greatest dimension
- T2: tumor >2 cm and ≤4 cm
- T3
- tumor >4 cm, or
- tumor extension to lingual surface of epiglottis
- T4: moderately advanced local disease in which tumor invades any of the following or beyond:
- larynx (except lingual surface of epiglottis)
- extrinsic muscles of the tongue (except palatoglossus within the oropharynx)
- medial pterygoid muscle
- hard palate
- mandible
Regional lymph node (N)
Clinical (cN) criteria
Clinical criteria apply to all patients before surgical treatment, by using information from physical examination, imaging, and/or needle biopsies.
- NX: regional lymph nodes cannot be assessed
- cN0: no regional lymph node metastasis
- cN1: one or more ipsilateral lymph nodes, all ≤6 cm
- cN2: contralateral or bilateral lymph nodes, all ≤6 cm
- cN3: lymph node(s) >6 cm
Pathological (pN) criteria
Pathological criteria apply only to patients treated with surgery who thus have many specimens available for histopathologic examination.
- NX: regional lymph nodes cannot be assessed
- pN0: no regional lymph node metastasis
- pN1: metastasis in ≤4 lymph nodes
- pN2: metastasis in >4 lymph nodes
Distant metastases (M)
The terms pM0 and MX are not valid TNM categories. The following categories may be used:
- cM0: no evidence of metastases
- cM1: distant metastasis
- pM1: distant metastasis, microscopically confirmed
Stage groups
Clinical (cTNM)
- stage I
- [T0, T1, T2], [N0, N1], M0
- stage II
- [T0, T1, T2], N2, M0
- T3, [N0, N1, N2], M0
- stage III
- [T0, T1, T2, T3, T4], N3, M0
- T4, [N0, N1, N2, N3]
- stage IV
- [Any T], [Any N], M1
Pathological (pTNM)
- stage I
- [T0, T1, T2], [N0, N1], M0
- stage II
- [T0, T1, T2], N2, M0
- [T3 or T4], [N0, N1], M0
- stage III
- [T3, T4], N2, M0
- stage IV
- [Any T], [Any N], M1
Both clinical and pathological distant metastasis assessments (cM0, cM1, or pM1) can be used for pTNM stage grouping.