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Cell cycle modulators are important in carcinogenesis and may be of prognostic and therapeutic relevance. This study has examined the influence of the proliferation index (Ki-67) and immunocytochemical expression of epidermal growth factor receptor (EGFR), cyclin D1, and retinoblastoma protein on recurrence rates at the primary site in 50 patients with T2N0 laryngeal carcinomas treated with radical irradiation. Pre-treatment biopsies were retrieved and sections scored for the four immunocytochemical markers. Statistical analysis for association, interaction and survival was performed. Five cases showed loss of expression of Rb protein. The median Ki-67 index was 50%, the median cyclin D1 index 21% and the median EGFR index 47% of cells. EGFR and cyclin D1 expression were positively correlated and, whilst local recurrence tended to occur with a Ki-67 labelling index of <50%, this was not statistically significant. When interactions were examined using Multiple Logistic Regression it was found that there was a direct relationship between EGFR and cyclin D1 expression. If the EGFR index was >20% and the cyclin D1 index >10%, then the odds ratio in favour of a primary site recurrence was very high (5.32 +/-0.41). This study demonstrates that the relationship between EGFR index and cyclin D1 index has a very strong association with primary site recurrence for T2 N0 laryngeal carcinomas treated by irradiation.

The accepted method of modelling and predicting failure/survival, Cox's proportional hazards model, is theoretically inferior to neural network derived models for analysing highly complex systems with large datasets. A blinded comparison of the neural network versus the Cox's model in predicting survival utilising data from 873 treated patients with laryngeal cancer. These were divided randomly and equally into a training set and a study set and Cox's and neural network models applied in turn. Data were then divided into seven sets of binary covariates and the analysis repeated. Overall survival was not significantly different on Kaplan-Meier plot, or with either test model. Although the network produced qualitatively similar results to Cox's model it was significantly more sensitive to differences in survival curves for age and N stage. We propose that neural networks are capable of prediction in systems involving complex interactions between variables and non-linearity.

The present study involves an immunohistochemical analysis of p53 protein expression in head and neck tumours located at two separate subsites, the larynx and hypopharynx. It attempts to relate differences in expression to differences in the behaviour of these tumours. Detection of the p53 protein was performed using immunohistochemistry on 32 specimens of hypopharyngeal squamous cell carcinoma and 35 specimens of laryngeal squamous cell carcinoma. p53 overexpression was found in 66% of the hypopharyngeal tumours and in 51% of the laryngeal specimens analysed. Some differences between the two tumour types were noted in the pattern staining. p53 staining in those with hypopharyngeal tumours was associated with a statistically significant increased survival. For laryngeal carcinoma the converse was true but did not reach statistical significance. Differences in the behaviour of different head and neck tumour types may be reflected in differences in expression of the p53 protein. While p53 protein expression does not appear to be a useful prognostic indicator in laryngeal carcinoma it might be a useful prognostic indicator in tumours of the hypopharynx. Moreover, it may help predict those tumours which are radioresistant, thus suggesting other modes of treatment for these tumours. Of particular importance is the molecular basis for the observed differences in survival associated with p53 expression in the two tumour sites. This is under further investigation.

We report two cases of chemodectoma of the larynx. A 70-year-old man underwent a laryngectomy in April 1984 for a tumor diagnosed as a squamous cell carcinoma but which postoperatively proved to be a chemodectoma. Ipsilateral cervical metastases appeared 2 years later and were removed by local excision. Shortly thereafter he presented with recurrent nodes in both sides of the neck as well as cutaneous metastases on the trunk. He was given chemotherapy using a DTIC regime (5-3,3-dimethyl-1-triazino imidazole-4-carboxamide). A 53-year-old lady underwent a total laryngectomy in May 1984 for an extensive chemodectoma of the larynx. The tumor had already invaded the trachea and thyroid gland. Distant metastases were not found. So far she is free of recurrence. We discuss the histology, site, clinical course and therapy of this extremely rare tumor.

A case of laryngeal osteosarcoma in a 75-year-old man is described. The osteosarcoma probably arose by dedifferentiation of a chondrosarcoma of the cricoid cartilage. Laryngeal osteosarcoma is rare: the literature is reviewed and management discussed.