Loss of retinoblastoma protein expression in laryngeal squamous cell carcinoma

Laryngeal carcinomas are among the most curable malignancies, but some of t hem show poor clinical outcomes with local recurrence or regional neck meta stasis. Multiple genetic alterations of oncogenes and tumor suppressor gene s are thought to occur in the development some turners. The frequency, howe ver, and the prognostic significance of these genes or gene products still remain unknown in laryngeal carcinoma, Epidemiologic data suggest that ciga rette smoking is closely related to the development of these neoplasms; and human papillomavirus (HPV) infections have also been postulated to play a role in development of laryngeal tumor. The objective of this study was to investigate the presence of retinoblastoma protein (pRb), p53 protein, and HPV infection in laryngeal squamous cell carcinoma, as well as the correlat ion of these factors with clinicopathologic and carcinogenic factors. Tumor s from 79 patients with primary laryngeal squamous cell carcinoma were stud ied, The expression of pRb was immunohistochemically assessed in 79 such tu mors, and the expression of p53 was assessed in 76 tumors. HPV Type 16 expr ession was estimated by nonisotopic in situ hybridization in 78 cases. Foll ow-up periods ranged from 15 to 90 months. pRb was detected in 82% of the t umors and p53 in 43%, Lack of staining for pRb was significantly associated with a high-histologic grade (P <.05), high T classification (P <.05), rec urrence (P <.05), and a relatively short disease-free interval (P <.01), p5 3 overexpression was observed frequently in heavy smokers with an average B rinkman index of more than 800, but it was not associated with any of the c linicopathologic factors studied. These findings suggest that tumors exhibi ting loss of pRb expression have a more aggressive biologic behavior than d o those that express pRb and that loss of pRb expression might predict clin ical outcome in patients with primary laryngeal squamous cell carcinoma.