STAGE OF DISEASE CONFOUNDS APPARENT RELATIONSHIP BETWEEN LEVELS OF N-RAS AND DURATION OF SURVIVAL IN HEAD AND NECK TUMORS

The objective of this study was to determine whether elevated levels o f N-ras correlated with clinicopathological data. Complete clinical da ta were available on 133 of 481 patients surgically treated for squamo us cell carcinoma of the head and neck (SCCHN) who had immunohistochem ical data for N-ras. Advanced stages of disease were strongly related to the staining for N-ras in tumour cells (P=0.0031). The stage of dis ease was inversely related to duration of survival (P=0.0017). Initial statistical evaluation revealed an apparent correlation between survi val and N-ras staining. However, duration was found to be independent of the level of N-ras. The illusory relationship initially was a resul t of the confounding effect of the stage of disease. (C) 1996 Publishe d by Elsevier Science Ltd