Treatment of squamous cell carcinoma of the tongue base: irradiation, surgery, or palliation?

OBJECTIVES

Squamous cell carcinoma of the tongue base has a poor prognosis, and treatment is accompanied by a number of major problems. In view of this, it is important to recognize which patients will benefit from treatment with curative intent and which treatment method to use.

METHODS

One hundred sixty-five patients with squamous cell carcinoma of the tongue base were identified on our database. Eighty-two patients were treated by radical irradiation, and 41 by surgery. A further 42 patients were considered unsuitable for curative treatment.

RESULTS

The 5-year cause-specific survival rate was 41% for those treated by irradiation, 58% for those treated by surgery, and 9% for untreated patients. There was no difference in the efficacy of treatment methods (p = .5362), but a highly significant difference was seen in survival rate between treated and untreated patients (p = .0028). The decision regarding administration of curative treatment was based on the extent of locoregional involvement at the primary site (p = .0139; odds ratio, 0.43) and in the neck (p = .0078; odds ratio, 0.23). No factors affected the decision to treat by irradiation or surgery. When the observed survival rate was calculated, there was no significant difference in 5-year survival rate between treated and untreated patients (p = .2762). Those with early (T1-2) disease at the primary site had an improved survival rate from 0.5 to 4 years compared with those who were untreated (T3-4; p = .0081; odds ratio, 2.2). In addition, those with early (T1-2) disease had a better survival rate than those with advanced cancers (p = .0139; odds ratio, 2.09). There was, however, no difference in survival rate at 5 years. Those with early disease compared with those with advanced disease were twice as likely to be alive at 2 years; however, all survival advantages had disappeared by 5 years.

CONCLUSIONS

In terms of observed survival, treating tongue base squamous cell carcinoma that is locally advanced (T3-4) at presentation offers no survival advantage over palliation alone. Treating early disease (T1-2) doubles the survival rate for up to 4 years, but by 5 years this survival advantage is lost. The present study finds radiotherapy and surgery to be equivalent at controlling this disease.