The incidence of thyroid cartilage invasion through the anterior commissure in clinically early-staged laryngeal cancer

In this study, the incidence of thyroid cartilage invasion in early-stage laryngeal tumors involving anterior commissure was assessed. Medical charts and pathology reports of 62 patients who underwent supracricoid partial laryngectomy as the primary treatment of early-staged laryngeal squamous cell carcinoma were retrospectively reviewed. Patients were divided into two groups according to the macroscopic examination of the surgical specimen: tumors limited to the glottis with the involvement of anterior commissure (TLG); tumors invading both supra- glottis and glottis with the involvement of anterior com- missure (TISG). Thirty-seven of the cases were classified as TLG group (59.7 %) and the remaining 25 of them were classified as TISG group (40.3 %). Thyroid cartilage invasion was observed totally in ten patients (16.1 %), as macroscopic invasion in two cases and microinvasion in eight patients. Only two were in the TLG group (cartilage invasion rate of 5.4 %), the remaining eight were in the TISG group (cartilage invasion rate of 32 %). Thyroid cartilage invasion rate of TISG group was significantly higher than that of TLG group (p = 0.011, p\0.05). Tumors limited to the glottis with AC involvement may be more suitable for endoscopic resection; on the contrary, tumors with vertical extension invading both AC and su- praglottis should be evaluated more suspiciously due to high rate of thyroid cartilage invasion, which may still necessitate external laryngectomy techniques.