Second primary malignancies pose a significant clinical challenge to the head and neck oncologist. The prognosis for these patients is poor and therefore early detection of these tumours is essential. There are considerable differences in the reported cohorts of patients and the biological behaviour of these tumours throughout the world literature. This is particularly marked when there is considerable demographic variation present.

The behaviour of second primary malignancies in 425 Irish patients with head and neck cancer was reviewed retrospectively. The overall incidence of second cancers was 8.5 per cent. There were a higher proportion of oral cancer patients 47 per cent, the second cancers overall presented with a more advanced T stage, and the overall five-year survival was much lower than that of the index tumour.