Survival Patterns in Elderly Head and Neck Squamous Cell Carcinoma Patients Treated With Definitive Radiation Therapy

Abstract

We sought to assess the effect of age on overall survival (OS), cancer-specific survival (CSS), and non-cancer-related death (NCRD) in elderly (aged ≥70years) head and neck squamous cell carcinoma (HNSCC) patients treated with definitive radiation therapy. The results were compared with those of younger patients, and the most important prognostic factors for survival endpoints were determined. Treatments may be better justified based on identification of the main differences in survival between young and elderly patients. Data were analyzed from all consecutive HNSCC patients treated with definitive radiation therapy (66-70Gy) in our department between April 2007 and December 2014. A total of 674 patients, including 168 elderly patients (24.9%), were included in the study. Multivariate association models were constructed to assess the effect of age on survival endpoints. Multivariate analysis was performed to identify potential prognostic factors for survival in elderly patients. A total of 674 consecutive patients, including 168 elderly patients, were analyzed. The 5-year OS and NCRD rates were significantly worse for elderly patients than for young patients: 45.5% versus 58.2% (P=.007) and 39.0% versus 20.7% (P<.001), respectively. In the multivariate association analysis on the relationship between age and OS, lymph node involvement and worse World Health Organization (WHO) performance status were identified as significant confounders. Multivariate association analysis between age and NCRD identified Union for International Cancer Control stage as a significant confounder. After correction for confounders, the effect of age on OS and NCRD increased. Worse WHO performance status, lymph node involvement, and specific tumor site were independent prognostic factors for OS and CSS in the elderly patient group. Of the elderly patients, 80 (47%) died during follow-up; 45% of these deaths were ascribed to the index tumor.For elderly patients, radiation therapy combined with systemic forms of treatment was significantly associated with adverse NCRD rate (hazard ratio, 8.02; 95% confidence interval, 2.36-27.2; P=.001) after we performed a multivariate association analysis. Elderly HNSCC patients have worse survival outcomes than young HNSCC patients. Age is an independent prognostic factor for OS, mainly due to an increase in non-cancer-related mortality and comorbid diseases. The differences in CSS between young and elderly patients are negligible.