Adjuvant trial of levamisole in patients with squamous cancer of the head and neck: a preliminary report.

A preliminary report is made of a randomized double-blind study comparing levamisole with placebo as surgical adjuvant treatment of patients with squamous cancer of the head and neck. The study groups were comparable according to the prognostic factors of type (primary or recurrent), site (oral cavity, pharynx, larynx), and stage of disease and were also similar in pretreatment immune function and in radiation exposure. Of 65 evaluable patients, 31 were treated with levamisole and 34 received placebo. Although there was no difference in the distribution of the time to recurrence of the overall treatment group, there was a difference of borderline significance in favor of levamisole in the primary disease patients (P less than 0.006). Further analysis of subgroups in the primary disease category showed decreased recurrence rates in patients receiving levamisole who had cancer of the oral cavity P less than 0.01 or who had stage II disease, P less than 0.02. Considering site and stage simultaneously, the only significant difference was in stage II patients with oral cancer. The above results, though encouraging, must be viewed with caution due to small sample sizes and relatively short follow-up of most patients.