Background: This study was designed to compare post-irradiation sarcomas (PIS) and de novo sarcomas (DN) of the head and neck in terms of tumor characteristics, prognostic factors, and survival outcomes.
Methods: All (N = 83) head and neck sarcoma patients treated at National Cancer Centre, Singapore (Feb 2002–May 2011) were included: DN (N = 60; 72 %); PIS (N = 23; 28 %). Clinicopathologic features and outcomes of all patients and histologically matched pairs were compared. Prognostic factors were identified using univariate and multivariate analyses.
Results: Median age, gender, smoking status, and tumor size were not significantly different. Significant differences were seen in histology (most prevalent: PIS–sarcoma-NOS; DN–angiosarcoma) and tumor subsite (most prevalent: PIS–nasal cavity and sinuses; DN–skin). Median latency of PIS development was 16.7 years. PIS patients had shorter overall survival (OS) and disease-specific survival (DSS) compared with DN patients, most clearly seen on histologically matched pair analysis: 2-year OS (PIS: 54 %; DN: 83 %; P = 0.028). Multivariate analyses showed that age >50 years (hazard ratio (HR) = 3.68; P = 0.007), ever-smokers (HR = 2.79; P = 0.017), and larger tumor-size (cm) (HR = 1.12; P = 0.045) were associated with worse OS, and age at >50 years (HR = 2.77; P = 0.04) and ever-smokers (HR = 2.94; P = 0.021) were associated with worse DSS. When treated with curative intent, no significant survival difference was noted between DN and PIS patients.
Conclusions: In our cohort, PIS constituted 28 % of head and neck sarcomas. Poorer prognosis traditionally associated with PIS compared with DN was not seen amongst patients treated with curative intent.