[Postoperative radiotherapy in N0 laryngeal cancer]

A retrospective study to re-assess the indications for postoperative radiation therapy in squamous cell carcinoma of the larynx staged N0 after gross resection.

Between January 1975 and December 2000, 166 patients with squamous cell carcinoma of the larynx were treated by total laryngectomy with or without neck dissection. Surgery was completed by external radiotherapy delivering 45 to 65 Gy to the tumour bed and 45 to 50 Gy to cervical lymphatic chains. Minimal follow-up was 36 months and median follow-up was 98 months.

The rate of nodal recurrence was 6% (median time for relapse was 9 months). The survival rates at 1, 2, 3 and 5 years were 93.5, 84, 80 and 69% respectively, with a 8 year 3 month median survival. The univariate analysis showed 4 parameters, which significantly increased the risk of local recurrence: the medical necessity for immediate tracheotomy, the subglottic involvement, the involvement of the whole larynx and the presence of lymphatic embols in the neck dissection. There was no statistically significant difference between the patients with or without a neck dissection. Fifty-nine secondary cancers were observed, 15 of them occurring in the head and neck area. The late complications consisted of cervical subcutaneous fibrosis (7%), oesophageal stricture (4%), oeso-tracheal fistula (l%), hypothyroidism (3%), bone necrosis (1%).

Prophylactic cervical radiotherapy in laryngeal cancers resulted in 6% cervical node recurrence rate. This value may represent the maximal rate to accept if one would favour new therapeutic strategies based on restricted indications for radiotherapy.