Cytokeratins and Lung Carcinomas

Overview

Background:
Recently, cytokeratins (CK) were studied as tumor markers for many carcinomas. Inlung cancer they appeared to be useful in distinguishing primary from secondary tumors, inhistological typing as well as in evaluating patient’s prognosis. However, the results have yet tobe conclusive. In this study, expression of CK7, CK10/13, CK18, CK19, CK20 was investigated ina group of 72 surgically resected specimens of lung including 31 adenocarcinomas, 30 squamouscell carcinomas and 11 neuroendocrine carcinomas. Cytokeratin immunophenotypes were analy-zed in comparison to histological characteristics of tumors, TNM stages and patients survival.Results: CK7, CK10/13 and CK18 can be used in distinguishing the lung adenocarcinomas from thelung squamous cell carcinomas: CK7(+), CK10/13(-), CK18(+) for adenocarcinomas; CK7(-),CK10/13(+), CK18(-) for squamous cell carcinomas. Relatively higher CK7 and CK18 immunostai-ning rates of the squamous cell carcinomas with high keratinization, with high percentage ofdead cells and with late stages of disease suggested their prognostic significance but is was notconfirmed when comparing different survival groups. Both adenocarcinomas and squamous cellcarcinomas were stained strongly with antibody against CK19 (90.3% and 86.7% respectively) butmuch less with anti-CK20 antibody (9.7% and 3.3% respectively). In general, neuroendocrine tu-mors of the lung were non-reactive for these cytokeratins except CK18, among them all carcinoidtumors expressed CK18 abundantly.

Key words:
Lung carcinomas - immunohistochemistry - cytokeratins - staging - survival.