Radiation-induced Sarcoma in the Head and Neck Region: a Clinicopathologic and Immunohistochemical Study of 13 Cases

Objectives: To study the clinical and histological features of radiation-induced sarcoma in the head and neck (RISHN).
Methods: Medical records of 13 patients with RISHN treated at our institution between 1990 and 2011 were studied, and paraffin-embedded samples were analyzed by haematoxylin and eosin staining and immunohistochemistry to determine mitosis counts and assess expression of Ki-67, bcl-2, and survivin.
Results: Positive bcl-2 was observed in 12 (100%) and survivin in 10 (76.9%) patients. The Ki-67 labeling index ranged from 1% to 90%, and it showed significant positive correlation with mitosis count in RISHN tissues, based on Spearman analysis. Percentage of distal metastasis with T2b was significantly higher than T1b stage (P=0.035).
Conclusions: Stage T2b may be a useful indicator for predicting distant metastasis of RISHN. The MIB-1 score may be used as a histological grading system for RISHN. In addition, bcl-2 and survivin protein may play an important role in pathogenesis and progression of RISHN.