No abstract

Summary Photodynamic therapy (PDT) is a promising technique for the treatment of small tumours in organs where it is essential to minimise damage to immediately adjacent normal tissue as PDT damage to many tissues heals by regeneration rather than scarring. As preservation of function is one of the main aims of treating laryngeal tumours, this project studied the effects of PDT on the normal rabbit larynx with two photosensitisers, endogenous protoporphyrin IX (PPIX) induced by the administration of 5-aminolaevulinic acid (ALA) and disulphonated aluminium phthalocyanine (AlS2Pc). The main aims of the study were to examine the distribution of protoporphyrin IX and AlS2Pc by fluorescence microscopy in the different regions of the larnyx and to assess the nature and subsequent healing of PDT damage. Peak levels of PPIX were found 0.5-4 h after administration of ALA (depending on dose) with highest levels in the epithelium of the mucosa. With 100 mg kg-', PDT necrosis was limited to the mucosa, whereas with 200 mg kg-l necrosis extended to the muscle. With 1 mg kg -AlS2Pc, 1 h after administration, the drug was mainly in the submucosa and muscle, whereas after 24 h, it was predominantly in the mucosa. PDT at 1 h caused deep necrosis whereas at 24 h it was limited to the mucosa. All mucosal necrosis healed by regeneration whereas deeper effects left some fibrosis. No damage to cartilage was seen in any of the animals studied. The results of this study have shown that both photosensitisers are suitable for treating mucosal lesions of the larynx, but that for both it is important to optimise the drug dose and time interval between drug and light to avoid unacceptable changes in normal areas.

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)

44 women with laryngeal cancer were treated between 1961 and 1991 in the ENT clinic of the university of Rostock. 7 patients were found in the phase of fertility, 12 patients within the climacteric and 25 patients in the senium. Half of the patients before menopause and 2/3 of the patients after menopause were smokers. Only one of the women at the fertile age had a laryngological history lasting 1 year before the onset of the cancer illness but half of the patients after menopause revealed such an anamnesis. Laryngological symptoms that existed over a period of one year or more began before the onset of the climacteric phase or clearly in the senium phase. These points in time corresponded to phases of relative or absolute decrease of oestrogens from an endocrinological view. The mean controlled survival time of the patients decreased clearly with increasing age. Furthermore, in the case of the patients with over one year's laryngeal anamnesis the survival time was longer than for patients without anamnesis, at least for patients in the phase of the senium. Several parameters of tumour biology, tumour dynamics and gynaecological history were examined by the authors. A trend indicating an increase of glottic localisation after the onset of the climacteric phase and increase of keratinised carcinomas in the phase of senium was apparent. No other clear differences amongst the patients of various groups could be observed.