Staging by Lymph Node Categories Shown to Better Predict Survival in Patients With Oropharyngeal Cancer
The current staging system for oropharyngeal cancer (OPC) does not adequately differentiate human papillomavirus (HPV)-positive from HPV-negative OPC, a recent study published online ahead of print in the Journal of Clinical Oncology. This study suggests regional OPC lymph node (N) categories and nasopharyngeal (NPC) N categories might be more useful in staging HPV-positive OPC.1
Patients with HPV-positive OPC typically present with more advanced disease, yet their survival is higher than patients with HPV-negative OPC. The current tumor node metastasis (TNM) staging system, developed by the American Joint Commission on Cancer and the Union for International Cancer Control, was developed for HPV-negative OPC.
"Staging is a critical component of designing treatment plans and for predicting and helping patients understand their prognosis," stated corresponding author, Erich M. Sturgis, MD, professor, Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, in Houston.
"Patients with HPV-positive OPC tend to present with more advanced disease, but also typically have better survival rates than those with HPV-unrelated OPC. These cancers are markedly different and require different staging criteria."
In this study, researchers developed stage groupings based on data from 661 patients with HPV-positive OPC diagnosed between 2003 and 2012 at a single center. Recursive partitioning analysis resulted in new stage groupings based on OPC N categories or NPC N categories. Traditional TNM staging resulted in no differences in overall survival (OS) among different stages (P=.141).
Recursive partitioning analysis for NPC N categories resulted in balanced staging and better separation between groups for OS at 5 years than the analysis for OPC N categories. The risk of death increased with NPC N category stage (P<.001). For example, patients with stage III disease at diagnosis had 5 times the risk of death than patients with stage IA disease at diagnosis when using the NPC N category staging system.
"The revised staging system has greater predictive power than the current system, which has been shown to be insufficient for HPV-positive OPC. Although confirmation of our findings in patients at other institutions is needed, we believe that NPC N categories should be strongly considered as an alternative to the traditional OPC N categories as the TNM staging system evolves," concluded Sturgis.
1. Dahlstrom KR, Garden AS, William WN Jr, Lim MY, Sturgis EM. Proposed staging system for patients with HPV-related oropharyngeal cancer based on nasopharyngeal cancer N categories [published online ahead of print February 16, 2016]. J Clin Oncol. doi:10.1200/JCO.2015.64.6448.