A CRITICAL-APPRAISAL OF THE PROGNOSTIC UTILITY OF 4 SEPARATE IMMUNOCYTOCHEMICAL MARKERS (SOMATOSTATIN, GASTRIN-RELEASING PEPTIDE, NEUROPEPTIDE-Y, AND OPIOID-PEPTIDES) IN SPORADIC MEDULLARY-THYROID CARCINOMA

The purpose of the present study was to evaluate the prognostic utilit y of somatostatin, gastrin-releasing peptide, neuropeptide Y, and opio id peptide expression in sporadic medullary thyroid carcinoma. To this end, we submitted to statistical analyses the immunocytochemical data on a consecutive series of 109 such tumors. In univariate analysis, a significantly increased risk of disease progression was present in pa tients with opioid-immunoreactive tumors. An increased, though statist ically insignificant risk of death was also found for patients with ne uropeptide Y- or opioid-immunoreactive tumors. Multivariate analyses w ere performed by adding the four peptide variables to the final (refer ence) models obtained in an earlier work on the same case series in wh ich 18 clinicopathologic variables had been taken into account. This a ddition did not change the prognostic impact of the variables consider ed in the two reference models, nor did it seem to increase the progno stic information, since the adjunctive contribution of each variable ( as assessed by the likelihood ratio test) was not statistically signif icant. It is concluded that expression of somatostatin, gastrin-releas ing peptide, neuropeptide Y, and opioid peptides is of no prognostic v alue in patients with sporadic medullary thyroid carcinoma.