Table I. Clinical characteristics of the patients.

N: code number of individual patient, *G: glottic; SG: supraglottic; TG: transglottic. **NO: refers in all cases to previously smokers. ***NO: drinking alcoholic beverages randomly; D: drinking alcoholic beverages daily; H: drinking heavy quantity of alcoholic beverages daily. †Follow-up information up to 43 months post treatment. R1: Patients included in the study after recurrence of an older primary cancer. R2: Patients included in the study for a primary cancer, treated and then had a recurrence. M: Patients included in the study for a primary cancer, treated and then metastasized. P2: Second primary