Postradiotherapy Neck Dissection Improves Local Control in Head and Neck Squamous Cell Carcinoma Patients With Advanced Nodal Disease
Available data indicate that lymph node involvement predicts failure at primary and distant sites after chemoradiation for head and neck cancer. In a study reported in JAMA Otolaryngology Head & Neck Surgery, Ranck et al assessed the impact of postradiotherapy neck dissection on local and distant cancer control in patients with advanced squamous cell cancer of the head and neck without distant metastases who had complete response to chemoradiation. They found that postradiotherapy neck dissection was associated with improved control of nonregional disease in patients with advanced nodal disease.
Study Details
The study consisted of a retrospective review of 287 patients from the University of Illinois at Chicago Medical Center who were treated for stage III/IV disease with definitive radiation therapy with (n = 74) or without (n = 213) postradiotherapy neck dissection from January 1990 through December 2012.
The postradiotherapy neck dissection and non–postradiotherapy neck dissection groups were balanced for sex, Karnofsky performance status, comorbidities, and alcohol or tobacco use. The postradiotherapy neck dissection group had lower median age (53 vs 57 years, P = .04), more advanced disease (stage IVA/B in 92% vs 78%, P = .01), more oropharyngeal (46% vs 29) and fewer laryngeal primary tumors (16% vs 21%; P = .007 for trend), more advanced nodal disease (N2b-N3 in 86.5% vs 53%, P < .001), and lower primary tumor stage (T1-T2 in 32% vs 21%, P = .05). Chemoradiation (induction or concurrent) was used more frequently in the postradiotherapy neck dissection group (98.7% vs 93.0%, P=.04), and radiotherapy delay > 5 days was more common in the non–postradiotherapy neck dissection group (18% vs 33%, P = .006).
Benefits of Postradiotherapy Neck Dissection
Median follow-up was 25.4 months for all patients. The median time to post-treatment imaging was 5.0 weeks in the postradiotherapy neck dissection group and 6.9 weeks in the non–postradiotherapy neck dissection group (P < .001). Postradiotherapy neck dissection was associated with improved 2-year progression-free survival (74.6% vs 39.1%, P < .001) among patients with stage N2b or higher nodal disease (n = 176) but not among those with less-advanced disease (60.0% vs 68.2%, P = .98). Among patients with advanced disease, postradiotherapy neck dissection was also associated with improved 2-year local control (85.5% vs 53.5%, P < .001), locoregional control (78.9% vs 45.7%, P < .001), freedom from distant metastasis (79.5% vs 67.5%, P = .03), and overall survival (84.5% vs 61.7%, P = .004), but not regional control (96.9% vs 90.1%, P = .21).
Postradiotherapy neck dissection was associated with improved 2-year local control (87.4% vs 66.2%, P = .02) and progression-free survival (80.7% vs 53.4%, P = .01) among patients with advanced nodal disease who had a complete clinical response on post-treatment imaging (n = 103). A benefit of postradiotherapy neck dissection in local control or progression-free survival was observed across multiple disease sites, including the hypopharynx, larynx, oral cavity, and oropharynx.
On univariate analysis, postradiotherapy neck dissection, alcohol use, nodal stage, and chemoradiation were significantly associated with 2-year local control or progression-free survival in those with advanced nodal disease. On multivariate analysis including these factors and others known to affect outcome, postradiotherapy neck dissection was associated with significant improvement in 2-year local control (hazard ratio [HR] = 0.22, P < .001) and progression-free survival (HR = 0.42, P = .002) and nonsignificant improvement in freedom from distant metastases (HR = 0.53, P = .10) and overall survival (HR = 0.58, P = .12).
Late Toxicity
There were no significant differences between the postradiotherapy neck dissection and non–postradiotherapy neck dissection groups with regard to late toxic effects, including need for permanent feeding tube (47% vs 37%, P = .13), tracheostomy tube (27% vs 19%, P = .19), or osteoradionecrosis (11% vs 9%, P = .20).
The investigators concluded, “Postradiotherapy neck dissection improved control of nonregional sites of disease in patients with advanced nodal disease who achieved a complete response after chemoradiation. Thus, [postradiotherapy neck dissection] may affect the control of nonnodal sites through possible mechanisms, such as clearance of incompetent lymphatics and prevention of reseeding of the primary and distant sites.”
Michael T. Spiotto, MD, PhD, of The University of Chicago, is the corresponding author for the JAMA Otolaryngology Head & Neck Surgery article.
The study was supported by a Fanoni Anemia Research Foundation grant and the Burroughs Wellcome Career Award for Medical Scientists. The study authors reported no potential conflicts of interest.
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