RESUMO
IMPORTANCE: Though described as an important prognostic indicator, facility case volume thresholds for patients with head and neck squamous cell carcinoma (HNSCC) have not been previously developed to date. OBJECTIVE: To identify prognostic case volume thresholds of facilities that manage HNSCC. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of 351â¯052 HNSCC cases reported from January 1, 2004, through December 31, 2014, by Commission of Cancer-accredited cancer centers from the US National Cancer Database. Data were analyzed from August 1, 2018, to April 5, 2019. EXPOSURES: Treatment of HNSCC at facilities with varying case volumes. MAIN OUTCOMES AND MEASURES: Using all-cause mortality outcomes among adult patients with HNSCC, 10 groups with increasing facility case volume were created and thresholds were identified where group survival differed compared with each of the 2 preceding groups (univariate log-rank analysis). Groups were collapsed at these thresholds and the prognostic value was confirmed using multivariable Cox regression. Prognostic meaning of these thresholds was assessed in subgroups by category (localized [I/II] and advanced [III/IV]), without metastasis (M0), with metastasis (M1), and anatomic subsites (nonoropharyngeal HNSCC and oropharyngeal HNSCC with known human papillomavirus status). RESULTS: Of 250â¯229 eligible patients treated at 1229 facilities in the United States, there were 185â¯316 (74.1%) men and 64â¯913 (25.9%) women and the mean (SD) age was 62.8 (12.1) years. Three case volume thresholds were identified (low: ≤54 cases per year; moderate: >54 to ≤165 cases per year; and high: >165 cases per year). Compared with the moderate-volume group, multivariate analysis found that treatment at low-volume facilities (LVFs) was associated with a higher risk of mortality (hazard ratio [HR], 1.09; 99% CI, 1.07-1.11), whereas treatment at high-volume facilities (HVFs) was associated with a lower risk of mortality (HR, 0.92; 99% CI, 0.89-0.94). Subgroup analysis with Bonferroni correction revealed that only the moderate- vs low- threshold had meaningful differences in outcomes in localized stage (I/II) cancers, (LVFs vs moderate-volume facilities [MVFs]: HR, 1.09 [99% CI, 1.05-1.13]; HVF vs MVF: HR, 0.95 [99% CI, 0.90-1.00]), whereas both thresholds were meaningful in advanced stage (III/IV) cancers (LVF vs MVF: HR, 1.09 [99% CI, 1.06-1.12]; HVF vs MVF: HR, 0.91 [99% CI, 0.88-0.94]). Survival differed by prognostic thresholds for both M0 (LVF vs MVF: HR, 1.09 [99% CI, 1.07-1.12]; HVF vs MVF: HR, 0.91 [99% CI, 0.89-0.94]) and nonoropharyngeal HNSCC (LVF vs MVF: HR, 1.10 [99% CI, 1.07-1.13]; HVF vs MVF: HR, 0.93 [99% CI, 0.90-0.97]) site cases, but not for M1 (LVF vs MVF: HR, 1.00 [99% CI, 0.92-1.09]; HVF vs MVF: HR, 0.94 [99% CI, 0.83-1.07]) or oropharyngeal HNSCC cases (when controlling for human papillomavirus status) (LVF vs MVF: HR, 1.10 [99% CI, 0.99-1.23]; HVF vs MVF: HR, 1.07 [99% CI, 0.94-1.22]). CONCLUSIONS AND RELEVANCE: Higher volume facility threshold results appear to be associated with increases in survival rates for patients treated for HNSCC at MVFs or HVFs compared with LVFs, which suggests that these thresholds may be used as quality markers.
RESUMO
Objective Studies have suggested that the lymph node yield and lymph node density from selective or elective neck dissections are predictive of patient outcomes and may be used for patient counseling, treatment planning, or quality measurement. Our objective was to systematically review the literature and conduct a meta-analysis of studies that investigated the prognostic significance of lymph node yield and/or lymph node density after neck dissection for patients with head and neck cancer. Data Sources The Ovid/Medline, Ovid/Embase, and NLM PubMed databases were systematically searched on January 23, 2017, for articles published between January 1, 1946, and January 23, 2017. Review Methods We reviewed English-language original research that included survival analysis of patients undergoing neck dissection for a head and neck malignancy stratified by lymph node yield and/or lymph node density. Study data were extracted by 2 independent researchers (S.C. and M.O.). We utilized the DerSimonian and Laird random effects model to account for heterogeneity of studies. Results Our search yielded 350 nonduplicate articles, with 23 studies included in the final synthesis. Pooled results demonstrated that increased lymph node yield was associated with a significant improvement in survival (hazard ratio, 0.833; 95% CI, 0.790-0.879). Additionally, we found that increased lymph node density was associated with poorer survival (hazard ratio, 1.916; 95% CI, 1.637-2.241). Conclusions Increased nodal yield portends improved outcomes and may be a valuable quality indicator for neck dissections, while increased lymph node density is associated with diminished survival and may be used for postsurgical counseling and planning for adjuvant therapy.
