[Precancerous conditions and carcinomas of the lower lip. Coincidence with leukoplakia and carcinomas of the oral cavity and larynx].

In a prospective study of 102 patients with pre-neoplasia and/or manifest squamous-cell carcinoma of the lower lip the synchronous occurrence of intra-oral, pharyngeal or laryngeal leukoplakia and carcinoma was assessed. There was a coincidence rate of almost 15% leukoplakias, including individual carcinomas. This high coincidence is probably due to a combination of various "risk profiles" in patients with threatened or manifest lower-lip cancer. Chronic exposure to sunlight, especially in the presence of a genetic disposition, is the most important risk factor in lower-lip cancer and its preceding stages, while chronic alcoholism and smoking abuse have little etiological significance.