The Impact of Chemoradiation Treatment Time on Survival in Patients With Head and Neck Cancer

Abstract

Lengthening radiation treatment time (RTT) yields inferior control rates for head and neck squamous cell carcinoma. The consequences of extended RTT in the setting of chemoradiation are unclear. The primary objective was to assess the impact of RTT in head and neck cancers on overall survival (OS) using a modern dataset. Patients diagnosed with tongue, hypopharynx, larynx, oropharynx, or tonsil cancer were identified using the National Cancer Data Base. RTT was defined as date of first RT to date of last RT. In the definitive setting (70 gray [Gy] in 35 fractions), prolonged RTT was defined as >56 days, accelerated RTT was defined as <49 days, and standard RTT was defined as 49 to 56 days. In the adjuvant setting (60 Gy in 30 fractions), prolonged RTT was defined as >49 days, accelerated RTT was defined as <42 days, and standard RTT was defined as 42 to 49 days. X2 tests were used to identify predictors of RTT. The Kaplan-Meier method was used to compare OS among groups. Cox proportional hazards model was used for OS analysis in patients with known comorbidity status. A total of 21,006 patients met the inclusion criteria, a majority of which (69%) received concurrent chemotherapy. Of 16,841 patients receiving primary radiation, 23% had an accelerated RTT, 20% had a prolonged RTT, and 57% had a standard RTT. Of 4165 patients receiving adjuvant radiation, 29% had an accelerated RTT, 14% had a prolonged RTT, and 57% had a standard RTT. Concurrent chemotherapy predicted for patients with prolonged RTT in the primary (P<.001, 6.7% increase) and adjuvant radiation groups (P<.001, 3.7% increase). Other predictors of prolonged RTT in the primary and adjuvant setting included female gender, African American race, higher Charlson comorbidity index, uninsured status, community cancer facility, higher stage, lower income, and lower education. Tumor location (oropharynx or hypopharynx primary) predicted for prolonged RTT in patients receiving primary radiation but not adjuvant radiation. On multivariable analysis, accelerated RTT was associated with an improved OS (hazard ratio [HR] 0.878, 95% confidence interval [CI] 0.781-0.986, P=.029), while a prolonged RTT was associated with inferior OS (HR 1.266, 95% CI 1.138-1.410, P<.001).Abstract 126; Table 1RTT predicted for survival for definitive and adjuvant radiation.4-Year actuarial survivalnAccelerated RTTStandard RTTProlonged RTTPDefinitive treatment16,84162.2%60.5%51.9%<.001Adjuvant treatment416574.5%65.4%55.0%<.001 Open table in a new tab Prolonged RTT is associated with worse OS in patients receiving primary or adjuvant radiation, even in the setting of chemoradiation. Expeditious completion of radiation should continue to be a quality metric for the management of head and neck malignancies.