Expression of epidermal growth factor receptor and cyclin D1 in pretreatment biopsies as a predictive factor of radiotherapy efficacy in early glottic cancer

Abstract

To evaluate the prognostic value of the expressions of epidermal growth factor receptor (EGFR) and cyclin D1 in early glottic cancer treated with radiotherapy only. One hundred fifty-one patients with T1-2, N0 glottic cancer who had been treated with radiotherapy at Seoul National University Hospital since 1992 through 2004. Immunohistochemical staining for EGFR and cyclin D1 were performed on the formalin-fixed paraffin-embedded tissues of 25 patients who developed local recurrence and on the tissues of 25 matched patients free from disease. Patterns and degrees of expression were compared between these 2 groups. High EGFR (p = .047) and high cyclin D1 (p = .040) expressions were both found to be significantly associated with a poor prognosis. No association was found between EGFR and cyclin D1 status (p = .158), but EGFR and cyclin D1 status in combination were found to be significantly associated with local control. The patients with both high EGFR and high cyclin D1 expression had the poorest outcome compared with the others (14 months vs 29 months of median time to progression). Patterns of EGFR and cyclin D1 expression changed after recurrence, but these changes were not found to alter the ultimate prognosis. The molecular biomarkers, EGFR and cyclin D1 have a prognostic significance in early glottic cancer. These markers in combination seem to play an important role in tumor relapse and may be useful for selecting patients with a poor outcome after radiotherapy.