Head and neck in situ carcinoma: survival analysis of the Thuringian cancer registration database.

Head and neck in situ carcinoma is seldom diagnosed. Our knowledge about in situ cancer is limited. This study describes the epidemiology and prognosis of head and neck in situ cancer in Thuringia, Germany. We analyzed the cancer data of the Thuringian cancer registry database from 1996 to 2005. The database contained 3821 patients with primary head and neck cancer. Thirty-four patients (0.88%) had an in situ carcinoma. They were evaluated for patient's characteristics, tumor stage, incidence, treatment and trends in overall survival (OS) and recurrence-free survival (RFS). During 1996-2005, the average annual incidence of head and neck in situ carcinoma was 0.14 per 100,000 persons. Half of the cases were localized in the larynx. The patients were treated by local excision. Six patients (18%) developed a local recurrence. Only one recurrent tumor was diagnosed in early stage (rT1), but the other five tumors in advanced stage (rT3/rT4). The median time to recurrence was 27.43 months. For all 34 patients with in situ carcinoma, the 5-year OS was 84% and the 5-year RFS 60.4%. OS was better for laryngeal in situ cancer than for oral cavity or pharyngeal in situ cancer (p=0.031). The surveillance of patients with head and neck in situ carcinoma after treatment should be performed like in patients with invasive cancer, because nearly one fifth of patients developed a recurrence, predominantly in advanced stage.