Impact of Concomitant Chemotherapy on Outcomes of Radiation Therapy for Head-and-Neck Cancer: A Population-Based Study

Purpose: Clinical trials have shown that the addition of chemotherapy to radiation therapy (RT) improves survival in advanced head-and-neck cancer. The objective of this study was to describe the effectiveness of concomitant chemoradiation therapy (C-CRT) in routine practice. Methods and Materials: This was a population-based cohort study. Electronic records of treatment from all provincial cancer centers were linked to a population--based cancer registry to describe the adoption of C-CRT for head-and-neck cancer patients in Ontario, Canada. The study population was then divided into pre- and postadoption cohorts, and their outcomes were compared. Results: Between 1992 and 2008, 18,867 patients had diagnoses of head-and-neck cancer in Ontario, of whom 7866 (41.7%) were treated with primary RT. The proportion of primary RT cases that received C-CRT increased from 2.2% in the preadoption cohort (1992-1998) to 39.3% in the postadoption cohort (2003-2008). Five-year survival among all primary RT cases increased from 43.6% in the preadoption cohort to 51.8% in the postadoption cohort (P<.001). Over the same period, treatment-related hospital admissions increased significantly, but there was no significant increase in treatment-related deaths. Conclusions: C-CRT was widely adopted in Ontario after 2003, and its adoption was temporally associated with an improvement in survival