[Testosterone versus dihydrotestosterone effects on permanent squamous epithelial cancer cell lines of the larynx]

Whereas stimulating effects of androgenic hormones on the laryngeal mucosa and their tumours have been reported in the literature, we are faced with the highest incidence of laryngeal carcinomas in the presence of a reduced androgen signal from the testes associated with aging. The discrepancies between reports in the literature and our own recent experiences with in vitro application of testosterone on permanent laryngeal squamous carcinoma cell lines, initiated this current examination of testosterone, dihydrotestosterone (DHT) and cyproterone acetate effects on two different laryngeal cancer cell lines. No DHT and cyproterone acetate effects on the androgen receptor negative line UM-SCC11B were found. However, growth of the HEp-2 line was significantly inhibited undergoing the cyproterone acetate application and significantly enhanced after DHT application. Both lines underwent a dose-dependent growth inhibition after testosterone application. These effects seem to be cytostatic rather than cytotoxic. The mechanisms leading to these effects can only be discussed hypothetically at present. Furthermore, if one takes into consideration the decrease of serum testosterone levels in aging males and the near normal levels of DHT in serum and tissues, so one may assume an imbalance between testosterone and DHT as an important cofactor in the genesis of laryngeal cancer. Current research knowledge on the basics of benign prostate hyperplasia, several experimental and clinical reports in the ENT literature together with our own experimental results, are leading to a new and hopeful therapeutic opportunity for the future, involving the blocking of 5 alpha reductase as the enzyme which manages the DHT formation from testosterone.(ABSTRACT TRUNCATED AT 250 WORDS)