<=4 nodes? Does it matter how many nodes were taken in all? Does it matter if they're unilateral or bilateral (in setting of B/L neck dissections)?
Clinical ENE? How do you define that? CT-based? Need an MRI to make that call? The FDG-avidity on PET/CT (exaggerating on this one)? There's going to be a number of patients that are cN1 vs cN3b based off a radiologist read about 'extranodal extension cannot be excluded'.
I'm OK with pathologic ENE being included in pathological staging given the decisions it makes for us regarding adding chemo to adjuvant RT.
Any chance you can go through all of the a's and b's of pathologic nodal staging? What's pN2b? what's pN1b? what's pN3a?
In general the head and neck changes are as follows:
There is the introduction of a new TNM system for p16+ oropharynx as mentioned. The T stage is identical to p16- with the exception being that T4 is not broken down into T4a or T4b. There is additionally a clinical and pathologic nodal stage which was mentioned above. There is also a separate stage grouping for clinical and pathological staging.
For the rest of head and neck, the nodal staging has changed a bit. In the absence of ENE it is unchanged. However, if there is CLINICAL ENE (defined as being OVERT ENE based on clinical exam or imaging) it is automatically cN3b (N3b is a new N stage).
Pathologically, in the absence of ENE it is unchanged. However, in the presence of ENE, a single node < 3cm is now pN2. ENE with ANYTHING MORE than a single node < 3cm is pN3b. That means that [ENE] + [Single ipsilateral node > 3cm OR multiple ipsilateral nodes OR bilateral nodes OR contralateral nodes] is N3b. Stage grouping is unchanged (N3a vs. N3b does not alter stage grouping)
For Lip/OC, DOI was added as a criteria for T staging.
T1 = <=2 cm with DOI <= 5mm
T2 = <=2cm with DOI 5-10mm OR 2-4cm with DOI < 10mm
T3 = Tumor > 4cm OR DOI > 10mm
The last change is in nasopharynx.
Adjacent muscle involvement (medial/lateral pterygoids and prevertebral muscles) is now T2 (was T4)
N3a and N3b were merged into a single N3 category and the definition of N3 is now any lymph nodes below the caudal border of the cricoid cartilage
p16+ H&N of unknown primary should follow the p16+ OPX system whereas p16- should follow the standard H&N Unknown Primary staging
There's a number of other changes pertinent to us.