Patterns of Care for Patients with Early-Stage Glottic Cancer Undergoing Definitive Radiotherapy: A National Cancer Database Analysis

Publication date: Available online 6 April 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): William A. Stokes, Diana Abbott, Andy Phan, David Raben, Ryan M. Lanning, Sana D. Karam
PurposeTo characterize practice patterns, including temporal trends, in fractionation schedules among patients in the United States undergoing definitive radiotherapy for early-stage glottic cancer and to compare overall survival outcomes between fractionation schedules.Methods and MaterialsWe queried the National Cancer Database for patients with TisN0M0, T1N0M0, or T2N0M0 squamous cell carcinoma of the glottic larynx diagnosed between 2004 and 2012 and undergoing definitive radiotherapy. Dose per fraction was calculated to define cohorts undergoing conventional fractionation (CFxn) and hypofractionation (HFxn). Logistic regression was performed to identify predictors of receiving HFxn, and Cox regression was used to determine predictors of mortality. One-to-one propensity-score matching (PSM) was then employed to compare survival between fractionation schedules.Results10,539 patients were included, with 6,576 undergoing CFxn and 3,963 undergoing HFxn. T1 patients comprised a majority of each cohort. Use of HFxn increased significantly over the period studied (p<0.001), but even in the final year nearly one half of patients continued to receive CFxn. Receipt of HFxn was also independently associated with higher income and facility types other than community cancer program on logistic regression. On multivariate Cox regression, HFxn was associated with improved survival (hazard ratio [HR] for death 0.90, 95% confidence interval [95%CI] 0.83-0.97, p=0.008), a finding redemonstrated on univariate Cox regression among a well-matched PSM cohort (HR 0.88, 95%CI 0.80-0.96, p=0.003). Subgroup Cox multivariate analysis demonstrated a significant survival advantage with HFxn among T1 patients (HR 0.90, 95%CI 0.81-0.99; p=0.042), but a nonsignificant benefit among those with Tis (HR 0.86, 95%CI 0.57-1.30; p=0.472) or T2 disease (HR 0.88, 95%CI 0.76-1.02; p=0.099).ConclusionsUtilization of HFxn is increasing and is associated with improved survival over CFxn. Our findings support the broadened use of HFxn for patients with early-stage glottic cancer undergoing definitive radiotherapy.

Teaser

While a 2006 Japanese trial demonstrated that patients undergoing definitive radiotherapy for early-stage glottic larynx cancer derive a local control benefit from hypofractionation, it is unclear how its publication has influenced fractionation patterns in the US or whether hypofractionation translates to a survival advantage. In an analysis of care patterns and outcomes in the National Cancer Database, we identified both increased use of hypofractionation after 2006 through 2012 and improved overall survival with this approach.


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