Sex hormone receptor levels in laryngeal carcinoma: a comparison between protein and RNA evaluations

Abstract

The larynx is a secondary sex organ, and the hormone dependence of laryngeal carcinomas is considered an interesting matter of speculation. However, while tumors of other secondary sex organs, including the prostate, breast, and endometrium, have been recognized as hormone-dependent cancers, the laryngeal carcinomas are still subject to controversy. In this study, samples from 15 laryngeal carcinomas obtained at the time of surgery were assayed for specific estrogen alpha, progesterone, and androgen receptor expression, both at mRNA and protein levels. Detectable levels of specific estrogen and progesterone receptors, 53.3 and 73.3%, respectively, were found in the tumors. This positive detection by immunohistochemical analysis was higher in tumors than in normal mucosa adjacent to the tumor areas and was correlated with the absence of metastatic lymph nodes. No androgen receptor protein was detected in any sample analyzed, even if quantitative RT-PCR revealed high mRNA levels specific for this receptor. A strict correspondence between protein and mRNA hormone receptor levels was not found. This is in agreement with the transcriptional and protein synthesis mechanisms, and it is also compatible with the complex larynx tumorigenesis.