Is p53 an independent prognostic factor in patients with laryngeal carcinoma?

BACKGROUND: Carcinoma of the true vocal cord represents the earliest clinically recognizable invasive malignancy in the head and neck region and provides a unique model for studying possible prognostic genetic markers. The aim of this study was to determine whether p53 overexpression correlated with tumor recurrence in a homogenous population of patients with early stage glottic carcinoma treated with radiotherapy alone.

METHODS: One hundred and fourteen patients with T1N0M0 squamous cell carcinoma of the glottis were treated with curative radiotherapy between 1976 and 1990. With a median follow-up of 6 years, actuarial local control was 80% with 23 local recurrences. Laryngeal biopsy specimens obtained prior to radiation therapy were analyzed retrospectively in 22 patients. Forty-five patients with local control were used as a control group. p53 overexpression indicating a mutated p53 gene was analyzed by immunohistochemistry using the mouse monoclonal antibody D0-7.

RESULTS: Approximately 82% of carcinomas that recurred locally expressed p53 compared with only 29% of those with local control (P < 0.001). No significant relation was noted between p53 expression and histologic grade. Intensity of staining did not predict tumor recurrence.

CONCLUSIONS: The authors believe that this case-controlled study demonstrated the role of p53 as an independent prognostic factor in patients with early stage glottic carcinoma.