Background: Treatment delays have been associated with overall survival in head and neck cancer (HNC) but have not been explored in laryngeal squamous cell cancer (LSCC) in a national sample. There are no national benchmarks for treatment delays in LSCC and it is unclear if delays are associated with overall survival.
Objectives: To characterize treatment delays in LSCC patients treated with either primary surgical treatment or primary non-surgical treatment. Specifically, we identified median durations of treatment delays, associated delays with patient-, tumor-, and treatment-related variables, and associated delays with overall survival (OS).
Methods: We identified a retrospective cohort of LSCC patients treated with primary surgery or radiation, 2004-2013, included in the National Cancer Database. We identified median durations for diagnosis-to-treatment initiation (DTI), surgery-to-adjuvant start (SRT), radiation treatment duration (RTD), total treatment package (TTP), and diagnosis-to-treatment end (DTE) in surgical patients and DTI, RTD, and DTE in non-surgical patients. For each interval, we compared delayed (fourth quartile) patients to non-delayed (first and second quartile) patients. We associated delays with patient, tumor, and treatment characteristics with multivariable binary logistic regression. We associated delays with overall survival with cox proportional hazards regression, controlling for clinically-relevant covariates. RTD was controlled for in analyses of TTP and DTE.
Results: 33,819 patients were included in this study. 10,503 (31%) received surgical treatment and 18,175 (69%) non-surgical treatment. Median durations of DTI, SRT, RTD, TTP, and DTE were 28, 42, 48, 91, and 107 days for surgical patients; median DTI, RTD, and DTE were 33, 50, and 85 days in non-surgical patients (figure 1). Non-white race and Medicare, Medicaid, and no insurance were associated with delays in most intervals examined. Treatment at an academic institution was associated with decreased delays in RTD but increased delays were observed in most other intervals examined. In surgical patients, delayed SRT, RTD, and TTP were associated with decreased OS (HR=1.15 (1.03-1.29), p=0.015, HR=1.21(1.09-1.36), p=0.001, and HR=1.16 (1.02-1.31), p=0.025, respectively); delayed DTI and DTE were not (HR=0.96 (0.87-1.06), p=0.440 and HR=1.13 (0.99-1.29), p=0.062, respectively) (figure 2). In non-surgical patients, delayed DTI, RTD, and DTE were associated with decreased OS (HR=1.08 (1.02-1.14), p=0.007, HR=1.37 (1.30-1.44), p<0.001, and HR=1.09 (1.03-1.16), p=0.003, respectively).
Conclusions: The median durations we identified here can serve as national benchmarks for individual institutions. Treatment delays are associated with multiple patient-, tumor-, and treatment-related factors. Delayed SRT and TTP (≥56 and 107 days, respectively) are associated with worse OS in surgical patients, delayed DTI and DTE (≥47 and 101 days, respectively) are associated with worse OS in non-surgical patients, and delayed RTD (≥52 and 55 days in surgical and non-surgical patients, respectively) is associated with OS in both groups. These treatment durations could be considered quality indicators in LSCC.