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Epidermal growth factor receptor (EGFR) content was determined by a radioligand receptor assay in 140 primary laryngeal squamous cell carcinomas (median value of 8.4 fmol mg-1 protein, range 0-169.9 fmol mg-1 protein). Cox univariate regression analysis using EGFR as a continuous variable showed that EGFR levels are directly associated with the risk of death (chi 2 = 14.56, P-value = 0.0001) and relapse (chi 2 = 7.77, P-value = 0.0053). A significant relationship between EGFR status and survival was observed at the different arbitrary cut-off values chosen (8, 16 and 20 fmol mg-1 protein). The cut-off value of 20 fmol mg-1 protein was the best prognostic discriminator. In fact, the 5 year survival was 81% for patients with EGFR- tumours compared with 25% for patients with EGFR+ tumours (P < 0.0001). The 5 year relapse-free survival was 77% for patients with EGFR- tumours compared with 24% for patients with EGFR+ tumours (P < 0.010). When clinicopathological parameters and EGFR status were examined in the multivariate analysis, T classification and EGFR status retained an independent prognostic value. In this study we demonstrated that high EGFR levels single out patients with poor prognosis in laryngeal cancer.

The cyclin D1 (CCND1) gene is amplified, rearranged, and overexpressed frequently in human cancer, including squamous cell carcinoma. The gene dosage of CCND1 was examined in 51 primary laryngeal squamous cell carcinomas, and amplification of the gene was found in 9 (17.6%) cases. CCND1 amplification did not correlate with age, tumor localization and extension, cervical lymph node involvement, histopathological grading, and epidermal growth factor receptor levels. In a univariate analysis, CCND1 amplification, tumor extension, lymph node involvement, poor histological differentiation, and high epidermal growth factor receptor levels were correlated significantly with shorter overall survival. In a median follow-up period of 29 months, the overall survival rate was 71.4% for patients affected with tumors displaying a normal CCND1 dosage and only 25.0% for patients affected with tumors carrying amplified CCND1 (P = 0.0288). In a multivariate analysis, only CCND1 and tumor extension retained statistically significant prognostic values (P = 0.037 and 0.041, respectively). This is the first report in which CCND1 amplification is identified as a significant independent prognostic factor in laryngeal carcinoma. Evaluation of CCND1 amplification could be applicable to the clinical management of laryngeal cancer, allowing identification of patients with poor prognoses.

Sixty-three patients with primary laryngeal squamous-cell carcinoma were followed up for a median of 33 months after surgery. Cathepsin D (Cath D) concentration was assayed using a solid phase 2-site immunoradiometric assay in which the first monoclonal antibody (MAb) was coated on the ELISA solid phase and the second one, MIG8 radiolabeled with 1125-EGF, was used as the tracer. The median value of Cath D (13.8 pM/mg protein) was chosen as cut-off. Cath D > or = median value was closely related to neck lymph node involvement at presentation and to a short metastasis-free survival (MFS) and actual overall survival (OS). The 5-year MFS was 71% for patients with Cath D < median value tumors as compared with 0% for patients with Cath D > or = median value tumors. Lymph node status at presentation was not related to a short MFS and OS. Cox's univariate regression analysis using Cath D as a continuous variable showed that Cath D levels are correlated with neck lymph node metastasis. On multivariate analysis, Cath D status proved to be an independent factor for predicting a short MFS. Cath D assay may prove to be particularly useful in identifying laryngeal cancer patients who, with or without neck lymph node involvement at presentation, are at high risk of metastatic disease and poor outcome.

Western blotting analysis of the p21 ras oncoprotein was performed in seven normal laryngeal mucosa specimens and 43 primary laryngeal cancers. Varying p21 levels, expressed as optical density (OD), were found in normal mucosa (median 1.94 OD, range 0.90-2.17 OD) and in primary laryngeal tumours (median 1.74 OD, range 0.30-6.37 OD). When p21 expression in laryngeal cancer was compared with the normal counterpart, higher levels were found in neoplastic than in normal laryngeal tissue (median 2.54 OD, range 1.76-6.37 OD, vs median 1.94 OD, range 0.90-2.17 OD) (P = 0.023). Immunohistochemical analysis demonstrated that most of the tumour cells (more than 70%) were immunostained while the stromal component was unreactive. No correlation between p21 expression and tumour location, stage and histopathological grade was observed. The correlation between ras p21 protein expression and epidermal growth factor receptor (EGFR) levels was also investigated. EGFR-positive cases did not show any difference in p21 expression with respect to EGFR-negative cases (median 1.52 OD, range 0.30-6.37 OD, vs median 1.84 OD, range 0.93-3.71 OD). Our findings suggest that overexpression of p21 protein is associated with a malignant phenotype in laryngeal cancer. Further studies should be undertaken to evaluate whether the assessment of p21 protein expression may have clinical significance in laryngeal cancer.

Using an immunoradiometric assay, Cathepsin D (Cath D) levels were measured in the cytosol of 23 normal and 39 neoplastic human laryngeal tissues. Scattered Cath D levels (from 2.2 to 17.8 pM/mg protein; median = 7.6) were found in normal mucosa specimens. Cath D concentrations range from 2.0 to 29.3 pM/mg protein (median = 8.5) in laryngeal tumors. When a comparison between Cath D levels in normal and neoplastic tissue specimens from the same patient was done, Cath D levels were significantly higher in laryngeal cancers than in their normal counterparts (P = 0.03). No correlation with clinico-pathological parameters and steroid hormone and epidermal growth factor receptor status was found. Further studies should investigate whether the production of Cath D by laryngeal tumors could have a clinical relevance for this neoplasia.