Clinical significance of beta1 integrin expression as a prediction marker for radiotherapy in early glottic carcinoma

OBJECTIVE: To determine the significance of beta1 integrin expression as a prediction marker for the response to radiotherapy in patients with early glottic carcinoma. STUDY DESIGN: Retrospective study in a tertiary referral center. METHODS: Among the T1/T2 glottic carcinoma patients treated with radiotherapy from 1992 to 2002, 52 had more than 2 years of follow-up and available pretreatment biopsy specimens. The immunohistochemical staining was performed for the assay of beta1 integrin expression, and the staining pattern of each was classified as diffuse, localized, or negative. The associations between the patterns of beta1 integrin expression and clinicopathologic parameters, including response to radiotherapy, involvement of the anterior commissure, and grade of histologic differentiation, were evaluated. RESULTS: After radiotherapy, 42 patients remained tumor free, and 10 patients had recurrent or persistent disease. Six (12%) specimens were negative for beta1 integrin expression, 39 (75%) had a localized staining pattern, and 7 (13%) had a diffuse staining pattern. Recurrence rate was significantly higher in the diffuse group (53%) than in the localized (13%) or negative (17%) groups (P=.023). The pattern of beta1 integrin expression was also closely related to histologic differentiation (P=.008), although the association between response to radiotherapy and histologic differentiation was not significant CONCLUSION: The pattern of expression of beta1 integrin, which has been known as a stem cell marker of the epidermis, may be helpful in predicting the response to radiation in patients with early glottic carcinoma.