Second primary tumours in oropharyngeal squamous cell carcinoma.

Improved diagnostic techniques and more effective treatment concepts have resulted in a growing number of patients with oropharyngeal cancer diagnosed with second primary tumours. In order to evaluate the relative number of patients with second primary tumours and to estimate the efficacy of diagnostic procedures, a retrospective evaluation of 981 patients with oropharyngeal cancer, who were treated during 20 years in one single medical centre, was performed. In total, 9.2% of the patients were affected by secondary cancer, 1.5% from tertiary cancer and 0.2% from quartary cancer. Of the multiple cancers, 27.8% occurred synchronously and 72.2% metachronously. If the index tumour was located at the oral floor or the pharynx, the risk of second primary tumours was enhanced; if the index tumour was located at the lips or the tongue, the risk was reduced. The 5-year survival of all examined patients was 34.1%; the survival of patients with multiple cancers was 62.3% at the diagnosis of the index tumour and dropped to 30.5% at the diagnosis of an additional malignancy. Of the second primary tumours, 23.2% were diagnosed by panendoscopy. We conclude that among patients with oropharyngeal cancer, the presence of second primary tumours always has to be considered and that panendoscopy is a valuable tool for their diagnosis.