OBJECTIVE: Negative bcl-2 and HLA-DR protein expression have been
associated with responsiveness to adjuvant radiotherapy in surgically
treated parotid cancer patients. The aim of this study was to
investigate the prognostic significance of bax, cytochrome c, and
caspase-8 protein expression in a group of surgically treated patients
to determine whether they also suggest markers of responsiveness to
adjuvant radiotherapy.
STUDY DESIGN: Historical cohort study.
SETTING: Otolaryngology department in a university hospital.
SUBJECTS AND METHODS: The immunohistochemical expression of bax,
cytochrome c, and caspase-8 were studied in paraffin-embedded tissue
specimens originating from 27 surgically treated parotid cancer patients
and nine patients with Warthin parotid tumors (control group) and
correlated with the patients’ clinicopathological characteristics and
clinical outcome.
RESULTS: Caspase-8 negative staining was more frequently observed in
higher TNM stages and in tumors measuring more than 4 cm (P = 0.009 and
P = 0.018, respectively). Caspase-8 (-)/cytochrome c (-) patients
carried low-grade lesions without nodal involvement (P = 0.01 and P =
0.05, respectively). Caspase-8 (-) patients who received postoperative
radiotherapy presented a significantly increased disease-free survival
compared to those who did not (P = 0.04). Patients bearing bax (-)
tumors who received postoperative radiotherapy presented an improved
four-year disease-free survival compared to bax (-) patients who did not
receive any type of adjuvant radiotherapy (P = 0.017).
CONCLUSION: Bax, cytochrome c, and caspase-8 protein expression failed
to independently predict survival in parotid cancer patients. However,
patients with bax (-) or caspase-8 (-) tumors should be considered as
candidates for adjuvant radiotherapy in order to achieve better local
disease control. (C) 2010 American Academy of Otolaryngology Head and
Neck Surgery Foundation. All rights reserved
