New Staging System Proposed for HPV-Related Oropharyngeal Cancer

The New Staging
In the new system, the 7th edition N categories were reclassified as follows:
• ICON-S N0 = no lymph nodes involved;
• ICON-S N1 = ipsilateral lymph nodes;
• ICON-S N2 = bilateral or contralateral lymph nodes; and
• ICON-S N3 = lymph nodes > 6 cm (with no subdivision of T4 disease).
The new proposed ICON-S classification consists of the following stages:
• stage I (T1–T2N0–N1);
• stage II (T1–T2N2 or T3N0–N2); and
• stage III (T4 or N3) (with metastatic disease classified as stage IV).

In an exploratory training cohort (n = 702), lymph node involvement in the lower neck was significantly associated with survival in ICON-S stage III disease but not in stage I or II disease and was not a significant independent predictor. There was no significant difference in survival for less than five versus five or more involved nodes across ICON-S stages.
The authors of the study say that ICON-S stage classification predicts prognosis in different jurisdictions. Historical data can be converted readily into the ICON-S classification. They also anticipate that the ICON-S TNM will address the other aims of staging beyond prognostication, including determining clinical trials eligibility and stratification, monitoring adherence to clinical guidelines, assessing treatment outcome, facilitating translational research, and supporting cancer control activities.