New classification of stage IV squamous cell carcinoma of the oropharynx

The recent progress in reconstructive surgery for the treatment of head and neck carcinomas has made it possible to radically resect cancers. However. the choice of treatment for oropharyngeal carcinoma is rather difficult. Radical treatment sometimes results in severe complications, suggesting that some modes of treatment might reduce the quality of life. The 5-year survival rate of patients with stage IV oropharyngeal carcinoma is still very poor. It is necessary to re-classify stage IV squamous cell carcinoma of the oropharynx in relation to the prognosis. Foote et al. (Base of tongue carcinoma: patterns of failure and predictors of recurrence after surgery alone. Head Neck 1993:15:300-307) demonstrated the two subgroups of stage IV oropharyngeal squamous cell carcinoma, as favorable stage IV and unfavorable stage IV. In this study, we have re-examined the validity of these subsets and we have demonstrated the new subsets of stage IV squamous cell carcinoma of the oropharynx.

We have examined 221 cases of oropharyngeal squamous cell carcinoma at the Cancer Institute Hospital in Tokyo between 1971 and 1994. A total of 107 cases of stage IV were included. We analyzed these cases retrospectively.

Based on the subsets demonstrated by Foote et al., there were no significant differences between the two groups in our cases, suggesting that these subsets were not useful for the choice of the treatment. In order to make a new classification in view of better choice of treatment, either radical treatment or palliative therapy, these cases were divided into two new groups of stage IV. one group with relatively good results (T1-3 N2 M0 and T4 NO-1 M0; new favorable stage IV), and the other with very poor results (any-T any-N M1 and any-T N3 M0 and T4 N2 M0; new unfavorable stage IV). Patients with the new favorable stage IV have a 5-year survival rate of 30.4%, and those with the new unfavorable stage IV had a survival rate of 0%.

These new subsets of stage IV can be directly related to the prognosis, and are therefore useful in the choice of treatment.