Squamous carcinoma of the base of the tongue: a clinicopathologic study of 81 cases.
Ninety-one patients were treated for squamous cell carcinoma of the base of the tongue between 1960 and 1974. Eighty-one of those patients were treated in a consistent manner, either by radiotherapy alone or preoperative radiotherapy plus total en bloc excision with a radical neck dissection. Eighteen patients were treated by radiotherapy alone (1800-7900 rads) to the primary site and bilaterally to the neck. Fifteen of these patients died within five years. Sixty-three patients were treated with preoperative irradiation (1800-7900 rads) followed by total primary excision with ipsilateral neck dissection. This latter group had a 50% five-year survival. Death due to uncontrolled tumor occurred within five years, whereas death after five years postinitial therapy was due to unrelated reasons. Unfavorable prognostic features were poor differentiation of the tumor, lack of histologic evidence of radiation-induced regression of the tumor, and more than three neck lymph node metastases in the initial neck dissection. Cox regression analysis showed that absence of histologic response to therapy was associated with a failure rate 4.05 times higher than that seen in patients whose tumors did respond. Primary tumor size did not affect prognosis as long as the tumor was technically resectable. Primary recurrences occurred in at least 20% of cases regardless of the presence or absence of surgical margin involvement.