[Clinical analysis of 40 cases of malignant tumor of the floor of the mouth]

This is a retrospective review for 40 patients with malignant tumour of the floor of mouth.In the group,squamous carinoma is 62.5%.adenoid cystic carcinoma is 22.5%.Both of them are the major type,stage III.IV were 72.5%,Generally ipsilateral;radical mandibular and neck dissection was performed sellectively.65% of patient were given preoprative chemotherapy.Total 5 years survival rate was 50%,for stage I-III were 78.6%.Although preoperative chemotherapy was given that the group of lower pathological differetiation was still in lower survival rate,higher recurrence and mortality than those given surgery alone. Survival rate for squamous carcinoma was higher than that for adenoid cystic carcinoma.