Poor prognosis for malignant melanoma in Northern Ireland: a multivariate analysis.

All cases of cutaneous malignant melanoma, CMM, diagnosed in Northern Ireland between 1974-1978 were reviewed, classified and followed up until the end of 1984. The overall 5 year survival is 54%, among the worst reported in recent literature. Multivariate analysis of these cases confirms some previous findings from other studies, but also reveals features not apparent in univariate analysis. Prognosis worsens with increasing thickness and the presence of ulceration. Likewise histopathological type has an independent effect on survival, ALM having the worst prognosis. Tumour profile emerges as a significant feature affecting prognosis, flat lesions having the poorest outlook, given their thickness. Survival is worse with increasing age. Anatomical site is less important than suggested by previous univariate analysis. Sex has little influence on prognosis when adjusted for the other variables. Cell type and pigmentation are of no prognostic value. Several features including diagnostic delay contribute to the poor overall survival for CMM in Northern Ireland. Educational intervention is essential if this trend is to be reversed.