Significance of Fas protein in squamous cell carcinoma of the larynx

Abstract

The purpose was to elucidate the clinical significance of Fas protein in laryngeal squamous cell carcinoma (LSSC). Medical records of 30 patients who were operated for LSCC between 1991 and 1997 were reviewed, and histopathological and immunohistochemical studies of the archival tumor tissues were performed. Conventional histopathology included tumor grading, mitotic counting (MC) and status of the cervical lymph nodes. The monoclonal antibodies to Fas (DAKO M 3554) and nm23 (DAKO A0096 Lot 035) proteins were used for immunohistochemical staining. Streptavidin-Biotin, horseradish method was used. Positive staining for both Fas and nm23 was obtained in 27 (90%) tumor samples. There was no correlation between neck metastasis and Fas positivity (r = 0.126, p = 0.505 and chi2 = 0.062, p = 0.996, respectively). Fas positivity did not correlate to grade (r = 0.282, p = 0.130), tumor size or T (r = 0.0457, p = 0.810, chi2 = 0.0.018, p = 0.999) or laryngeal site of involvement (chi2 = 0.0937, p = 0.992). However, a correlation was found between Fas and MC (r = 0.482. p = 0.007). There was also a correlation between Fas and nm23 positivity (r = 0.614, p < 0.0001). Fas protein expression has no prognostic value in LSCC, because the Fas values do not correlate with grade, stage or nodal status of neck. However, 90% of LSCCs expressed Fas protein. Understanding the functional status of the Fas receptor proteins may lead to development of new therapeutic options for LSSC in the future.