Radiotherapy in the treatment of verrucous carcinoma of the head and neck.
Because of reports of anaplastic transformation following irradiation, this study examines the incidence of anaplastic transformation and local control of these lesions. This review of seven patients who had verrucous carcinoma of the head and neck that was treated with irradiation shows local control in 71% of cases. There were no cases of anaplastic transformation. This report adds to the literature two cases of "de-differentiation" to less differentiated squamous carcinomas; one such case occurred after surgery alone. The literature is reviewed. Overall, anaplastic transformation is reported in 7% of patients who had irradiation. De-differentiation occurs after surgery as well. The rate of local control with irradiation is less than 50%; with surgery it is 85%. It is concluded that surgery should be used if the procedure has acceptable morbidity. Otherwise, irradiation can be used. Failures can be salvaged surgically. "Anaplastic transformation" should not affect treatment approach.