Defects in the system controlling the cell cycle can lead to an increased proliferation of cancer cells. The aim of this study was to analyse the immunohistochemical expression of chosen cell cycle proteins (P16, cyclin D1 and retinoblastoma protein) and their connection with the clinical course of the disease in laryngeal squamous cell cancer (LSCC). Cancer tissue sections obtained from 58 patients after total laryngectomy served to determine the level of the proteins’ expression using immunohistochemical staining and commercial antibodies. A decreased level of P16 expression in 47 per cent, of retinoblastoma protein in 12 per cent and strong cyclin D1 expression in 48 per cent of cases was revealed. Our results show significant correlation between decreased P16 expression and increased tumour dedifferentiation. Overexpression of cyclin D1 was statistically more common in locally advanced tumours (T3–T4). Low expression of retinoblastoma protein was significantly correlated with both positive P16 immunostaining and with strong cyclin D1 expression. Our study confirms that dysfunction of cell cycle regulation is a common event and may play a significant role in the development of squamous cell carcinoma of the larynx.

The expression of proliferating cell nuclear antigen in paraffin sections from 154 cases of laryngeal squamous cell carcinoma were examined. There was significant difference in PCNA expression between the control group and cancer patients (p<0.001). The mean score of PCNA was higher in patients with poor prognosis than in patients with satisfactory outcome after treatment (p<0.05). There was no significant correlation between the PCNA count and the patient's age and sex, T and N stage and site of the tumour.

Univariate analysis revealed that the PCNA score correlated with the patients' survival rates. In multivariate analysis the prognostic value of PCNA was on the statistical borderline (p = 0.049). In our study clinical features like N and T status had a more important influence on survival rate. Nevertheless it appears that the immunohistological examination of PCNA in paraffin section could be a complementary prognostic tool for laryngeal carcinoma. PCNA expression may also be a valuable tool for differentiating malignant from benign laryngeal epithelium.

A case of bilateral laryngeal nerve paralysis caused by a small goitre is reported. After thyroidectomy the return of vocal fold movements was observed. A review of the literature is presented. The possibility of acute airway distress caused by a slightly enlarged goitre is emphasized.