Effect of radiotherapy interruptions on survival in medicare enrollees with local and regional head-and-neck cancer.
OBJECTIVE
To investigate whether interruptions in radiotherapy are associated with decreased survival in a population-based sample of head-and-neck cancer patients.


METHODS
Using the Surveillance, Epidemiology, and End Results-Medicare linked database we identified Medicare beneficiaries aged 66 years and older diagnosed with local-regional head-and-neck cancer during the period 1997-2003. We examined claims records of 3864 patients completing radiotherapy for the presence of one or more 5-30-day interruption(s) in therapy. We then performed Cox regression analyses to estimate the association between therapy interruptions and survival.


RESULTS
Patients with laryngeal tumors who experienced an interruption in radiotherapy had a 68% (95% confidence interval, 41-200%) increased risk of death, compared with patients with no interruptions. Patients with nasal cavity, nasopharynx, oral, salivary gland, and sinus tumors had similar associations between interruptions and increased risk of death, but these did not reach statistical significance because of small sample sizes.


CONCLUSIONS
Treatment interruptions seem to influence survival time among patients with laryngeal tumors completing a full course of radiotherapy. At all head-and-neck sites, the association between interruptions and survival is sensitive to confounding by stage and other treatments. Further research is needed to develop methods to identify patients most susceptible to interruption-induced mortality.
Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
Megan Dann
MD
Fesinmeyer
Vivek
V
Mehta
David
D
Blough
Lauri
L
Tock
Scott D
SD
Ramsey
D000368:Aged; D016001:Confidence Intervals; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy; D007822:Laryngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy; D009669:Nose Neoplasms / Q000401:mortality / Q000532:radiotherapy; D010255:Paranasal Sinus Neoplasms / Q000401:mortality / Q000532:radiotherapy; D012044:Regression Analysis; D012189:Retrospective Studies; D018426:SEER Program / Q000706:statistics & numerical data; D012468:Salivary Gland Neoplasms / Q000401:mortality / Q000532:radiotherapy; D018401:Sample Size; D014481:United States; D028761:Withholding Treatment