184 THE LARYNX, BRONCHI AND OESOPHAGUS regurgitating air in the form of a kbelch\ Speech is produced by coordinated movements of lips, tongue, teeth and palate. If the patient feels strongly about losing his larynx, radiotherapy can be offered as the primary treatment with total laryngectomy being reserved for the recurrences. This form of treatment gives poorer results and a higher complication rate especially with regard to fistula formation. CARCINOMA-IN-SITU This usually presents as a leucoplakia of the cord (p. 162). Unless there are signs of invasion, it is unwise to use radiotherapy for this tumour as it can be kept under control perfectly safely with vocal cord stripping repeated as often as required at microlaryngoscopy. SUBGLOTTIC CANCER PATHOLOGY. Again, this is predominantly a squamous-cell cancer and is more common in males who smoke. The subglottis is by far the rarest region to be affected by laryngeal cancer and this is fortunate because the results are so much poorer than in cancer of the glottis and supraglottis. The subglottis is a small area extending from the lower border of the cricoid to the under surface of the vocal cords. Cancer of the thyroid gland and the trachea can spread to involve the subglottis and cancers of the subglottis spread to the thyroid gland, in 20 per cent of cases, and to the trachea. Twenty per cent also involve the strap muscles of the neck and the same percentage gives rise to cervical node metastases. There are 6-8 paratracheal nodes in the mediastinum and these, too, may be involved by spread of subglottic cancer. SYMPTOMS. If the vocal cord is involved early the presenting symptom is hoarseness but if the tumour is lower in the subglottis the patient will present with respiratory obstruction and a normal voice. These latter usually present as surgical emergencies. INVESTIGATION. Examination must be made for cervical node metastases and to ascertain the extent of spread of the tumour. Since subglottic tumours may involve the thyroid gland this should be scanned. There is a higher proportion of second primary tumours in these cases and so particular attention should be paid to the chest X-ray to see if the patient has a second chest primary tumour. TREATMENT. Neither radiotherapy nor surgery in the form of total laryngec- tomy gives good results in this tumour. As things stand at the moment it is advisable to give the patient primary radiotherapy and to reserve a total laryngectomy for any recurrence. At the same time the paratracheal nodes should be removed. In the future use will perhaps be made of planned combined radiotherapy and total laryngectomy, the patient receiving about 3500 r over a 2-week period, and then 2 weeks later having a total laryngec- tomy. In the case of a large subglottic tumour presenting with respiratory obstruction a case could be made for doing an emergency laryngectomy. If a tracheostomy is done as the emergency procedure, it will have to be placed so near tumour that there is a 60 per cent chance of the tumour implanting in the tracheal stoma unless the area is removed within 72 hours.