ARGYROPHILIA AND CHROMOGRANIN-A AND CHROMOGRANIN-B IMMUNOSTAINING IN PATIENTS WITH SPORADIC MEDULLARY-THYROID-CARCINOMA - A CRITICAL-APPRAISAL OF THEIR PROGNOSTIC UTILITY

The purpose of the present study was to evaluate the prognostic utilit y of tumour argyrophilia and chromogranin A (CgA) and B (CgB) immunocy tochemical expression in patients with sporadic medullary thyroid carc inoma. To this end, the histo-immunocytochemical data on a consecutive series of 99 such tumours were submitted to statistical analysis. In univariate analysis, a significantly increased risk of disease progres sion and death was present in patients with CgA-poor and CgB-poor tumo urs, respectively. Multivariate analyses were performed by adding the histo-immunocytochemical variables to the final (reference) models obt ained in earlier work on the same case series, in which 18 clinicopath ological variables had been taken into account, This addition did not change the prognostic impact of the variables considered in the two re ference models; it did, however, increase the prognostic information f or overall survival, since the adjunctive contribution of CgB immunocy tochemical expression (as assessed by the likelihood ratio test) was s tatistically significant. It is concluded that the chromogranin B immu nostaining pattern of the primary tumour allows the distinction of pat ients with an increased risk of death. Argyrophilia and expression of chromogranin A seem instead to be of no prognostic value in patients w ith sporadic medullary thyroid carcinoma. (C) 1998 John Wiley & Sons, Ltd.