Number of Positive Nodes Best Prognostic Indicator for Patients With Head and Neck Cancer
The number of positive nodes is a better indicator of prognosis in patients with head and neck cancer than lymph node ratio and the American Joint Committee on Cancer (AJCC) staging system, according to a recent study.
Staging is an important process in cancer treatment, as it allows physicians to track the progression of a disease and communicate clearly with patients about how their care is performing. The most commonly used system for head and neck cancer is the TNM staging system of the AJCC, which stages on the basis of tumor size (T), the regional lymph nodes involved (N), and whether the disease has metastasized into other regions of the body (M). In the AJCC system, just one positive lymph node can be associated with as much as a 50% reduction in overall survival. However, the evolving nature of oncology and the rise of human papillomavirus-associated cancers has led to a need for improved lymph node-based prognostics.
To help identify the best method of determining the prognosis of patients with head and neck cancer, researchers led by Vasu Divi, MD, Stanford University (Stanford, CA) compared the prognostic value of the number of lymph nodes, lymph node ratio, and the current AJCC system in a study published in the journal Cancer.
A total of 12,437 patients diagnosed with head and neck cancer between 2004 and 2012 were analyzed. Patients were primarily male and white; with more than half (57%) having at least one pathologically confirmed positive lymph node. The 5-year survival rate for the study population was 56%. The sample was grouped by which method was used to stage their disease.
Researchers found that patients with one positive node had the lowest risk of recurrence whereas patients with more than five nodes had the highest. Statistical analysis of the three methods also revealed that the number of positive nodes was a better measure by which to group patients by prognosis than the current AJCC system and was also superior to lymph node ratio. Also, while prior findings have suggested that two or more positive lymph nodes leads to worse survival, it seemed to be most pronounced when more than five nodes were involved.
The authors noted several study limitations, including those associated with using Surveillance, Epidemiology, and End Results Program data, which they said restricted the quality of information, the availability of selected variables, and the number of patient characteristics included in the data.
Despite these limitations, researchers concluded that the number of positive lymph nodes demonstrated superior prognostic value compared with lymph node ratio and AJCC TNM staging. Future research should seek to validate these results and provide more information for the development of a new nodal staging system.—Sean McGuire
Roberts TJ, Colevas AD, Hara W, Holsinger FC, Oakley-Girvan I, Divi V. Number of positive nodes is superior to the lymph node ratio and American Joint Committee on Cancer N staging for the prognosis of surgically treated head and neck squamous cell carcinomas. [Published online March 11, 2016]. Cancer. 2016. doi: 10.1002/cncr.29932.