A study using National Cancer Database data has shown that the number of metastatic nodes is a primary independent factor associated with an increased mortality risk in patients with hypopharyngeal and laryngeal cancers. The study was reported in JAMA Oncology by Allen S. Ho, MD, of the Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California, and colleagues.
The study involved 8,351 patients (78% male) with squamous cell carcinoma of the larynx or hypopharynx undergoing upfront surgical resection with curative intent at U.S. hospitals between 2004 and 2013. Neck dissection of a minimum of 10 nodes was required. Among these patients, 4,710 had metastatic nodes, and 3,641 had no metastatic nodes.
Mortality risk increased continuously without a plateau with an increasing number of metastatic nodes, with a hazard ratio (HR) per node of 1.19 (P < .001), and an increased risk being most pronounced for up to 5 positive nodes. Extranodal extension was likewise associated with an increased mortality risk (HR = 1.34, P < .001). An increasing number of nodes examined was associated with a reduced mortality risk, with a hazard ratio per 10 nodes examined of 0.97 (P < .001) and no identified inflection point in benefit.
In a multivariate analysis adjusting for the number of positive nodes, no significant association with mortality risk was found for nodal size, contralateral node involvement (TNM stage N2c), or lower node involvement (levels 4–5).
The investigators concluded: “The number of metastatic nodes is a predominant independent factor associated with mortality in hypopharyngeal and laryngeal cancers. Moreover, standard nodal staging factors like [lymph node] size and contralaterality have no independent prognostic value when accounting for positive [lymph node] number. Deeper integration of quantitative metastatic nodal disease may simplify staging and better triage the need for adjuvant therapy.” ■