Immunohistochemically stained markers (p53, PCNA, bcl-2) in dysplastic lesions of the larynx.

The percentage of malignant transformation of laryngeal dysplastic lesions is difficult to estimate. There is a need for new histological markers which could enable more objective assessment of the premalignant stages of the larynx and help in estimation of the potential of future neoplastic progression. We performed a retrospective study to determine whether immunohistochemical staining for the proliferating cell nuclear antigen (PCNA), tumour suppressor gene protein p53 and antiapoptotic protein bcl-2 may be prognostic factors in laryngeal epithelial lesions. Staining was performed on 57 paraffin-embedded biopsies from patients with clinically detected precancerous stages of the larynx. Histopathologic examination revealed normal epithelium in six cases, mild dysplasia in 20 cases, moderate dysplasia in 18 cases, severe dysplasia in seven cases, CA in situ in four cases, papilloma in one case and CA invasivum in one case. The p53 count in mild and moderate dysplasia was 26.8 and 38.6%, respectively. This difference was statistically significant. There was significant correlation between PCNA and p53 scores. There was also a relationship between the scores of these markers and bcl-2 expression. In ten out of 45 cases of dysplastic lesions the invasive cancer developed in 4 years of follow-up. The correlation between PCNA score and malignant progression of the dysplastic lesions was on the statistical borderline. There was significant relationship between malignant transformation and age of the patients.

Epidermal growth factor receptor (EGFR), proliferating cell nuclear antigen (PCNA) and Ki-67 antigen in laryngeal epithelial lesions.

The epidermal growth factor receptor (EGFR), proliferating cell nuclear antigen (PCNA) and Ki-67 immunostaining in paraffin sections from 154 cases of laryngeal squamous cell carcinoma, 25 specimens of normal and hyperplastic laryngeal epithelium, and 21 preneoplastic lesions was examined. The difference of EGFR expression and PCNA score between laryngeal cancer and dysplastic lesions vs normal and hyperplastic epithelium was significant. There was significant difference in Ki-67 score between malignant vs premalignant lesions and normal and hyperplastic epithelium. There was significant correlation between PCNA score and histopathological grading of the tumour. The highest PCNA expression was detected in stage G3. Our findings have shown that PCNA and Ki-67 staining can be used as a marker of cell proliferative activity in laryngeal epithelial lesions. EGFR, PCNA and Ki-67 expression correlate with severity of laryngeal lesions. PCNA immunostaining can aid in estimating the histological grade of malignant lesions.

In vivo tumor necrosis factor-alpha induction following chlorin e6-photodynamic therapy in Buffalo rats.

Photodynamic therapy may induce in the in vivo conditions the cytokine tumor necrosis factor-alpha in Buffalo rats. The sensitizer, i.e. chlorin e6, in the doses 2.5, 5.0 and 7.5 mg/kg of body weight followed by light treatment with total doses 50, 100, 150, 200 and 250 J/cm2 resulted in the increase of serum levels of the cytokine. The levels of tumor necrosis factor-alpha have been determined at different time points using enzyme-linked immunosorbent assay (ELISA). In control animals these levels did not exceed the mean value of 189 pg/ml, whereas in photodynamically treated rats the levels were almost 3-4 times higher. The entire experiment has been carried out on healthy animals; control, tumor-bearing rats have also been included to the present experiment.

Ki-67 immunostaining and prognosis in laryngeal cancer.

The expression of the antigen defined by the Ki-67 antibody in paraffin sections from 154 biopsies of laryngeal squamous cell carcinomas was examined. There was a significant difference in Ki-67 expression between the control group and the patients with cancer (P < 0.001). There was no significant difference in the Ki-67 score between the patients with recurrence and the patients with a satisfactory outcome after treatment. There was no significant correlation between the Ki-67 score and the patient's age and sex, T and N stage and site of the tumour. The survival time of patients with a Ki-67 score > 30 was shorter than patients with a Ki-67 score < or = 30 but the difference did not reach statistical significance (P = 0.055). Multivariate analysis indicated that the only important prognostic factor was the existence of lymph node metastases. We could not confirm the value of Ki-67 as a prognostic factor in laryngeal cancer. Ki-67 score may assist in differentiating malignant from benign laryngeal epithelium.

Expression of type IV collagen and matrix metalloproteinase-2 (type IV collagenase) in relation to nodal status in laryngeal cancer.

Laryngeal carcinoma has a lower incidence of neck metastases than other malignant carcinomas of the head and neck region. However, some cases are very aggressive, showing neck metastases even in the early stages. In this study the expression of collagen IV and type IV collagenase (MMP-2) were examined immunohistologically in 50 patients with laryngeal carcinomas, and the results were compared with the incidence of neck metastases and other clinicopathological factors. The correlation between collagen IV expression and the existence of nodal metastases was statistically significant (P < 0.001). There was also significant correlation between collagen IV expression and the histological grading of the tumour. There was a tendency for samples with continuous collagen IV staining to have no matrix metalloproteinase-2 (MMP-2) immunoreactivity. No significant correlation was seen between MMP-2 protein expression and clinicopathological parameters although the correlation between MMP-2 and existence of nodal metastases was statistically borderline (P = 0.07). Multivariate analysis of the clinicopathological factors that may have an influence on the nodal status in laryngeal cancer revealed that, apart from T stage, collagen IV pattern in the basement membrane surrounding nests of carcinoma is an important prognostic factor.