European journal of cancer. Part B, Oral oncology最新文献

Paraffin embedded, formalin fixed tissue sections from patients suffering from a primary oral squamous cell carcinoma were immunohistochemically investigated for the presence of p53 expression using the Bp53-11 antibody. The aim of this study was to determine the predictive value of p53 expression as a biomarker for the development of a second primary tumour (SPT) in the respiratory and upper digestive tract. In a nested case control study, neoplastic and normal tissue sections of 44 patients who had a previous history of cancer were used. 15 of the 44 had developed a SPT, while the other 29 were minimally 7 years free of disease. Additionally, nine SPTs were included in this study to establish whether concordance exists in tumours that develop in the same field. 10 of the 29 patients (34%) free of tumour during follow-up had p53 positive tumours. 8 of 15 patients (53%) who developed a SPT had a p53 positive primary tumour. This difference is not statistically different (χ²-test). Forty per cent of the total group of primary oral cavity tumours showed p53 positivity. When comparing the first and the second tumours, discordance in p53 expression between the first and second tumours was seen in 4 out of 9 cases. None of the cases showed p53 positivity in adjacent normal mucosa. In conclusion, p53 immunoreactivity in neoplasia, dysplasia and normal tissue does not predict the development of a SPT. In addition, multiple primary tumours do not have identical p53 expression.

The expression of oncogenes c-myc, c-jun and c-raf and tumour suppressor gene p53 was assessed by northern blot analysis of 42 tumours and p53 protein expression by immunohistochemistry on paraffin-embedded sections from 36 specimens of squamous cell carcinoma of the head and neck (SCCHN) obtained before therapy. Of the 42 tumours, 89, 100 and 100% expressed c-myc, c-jun and c-raf oncogenes, respectively. These oncogene expressions did not correlate with sex, age or clinical stage of the disease. However, an association was found between low c-myc expression (P = 0.0001) and high c-jun expression (P = 0.0001) and absence of tumoral response to neoadjuvant chemotherapy. On the other hand, c-raf overexpression was observed in patients resistant to radiation therapy (P = 0.0494). Forty-two per cent of the tumours showed p53 protein overexpression, which did not correlate with any clinical parameter. This p53 protein overexpression was associated with high p53 mRNA levels (REL) (P = 0.0223). A correlation was found between increased c-myc RNA expression and lack of p53 protein expression (P = 0.0407). In addition, a lack of p53 protein expression was indicative of tumour relapse (P = 0.05). None of these biological parameters were associated with disease-free survival (Cox-Mantel test). In conclusion, the overexpression of c-myc, c-jun and c-raf may be independently associated to tumoral response to chemotherapy or radiotherapy, or to tumour relapse, but fail to predict long-term survival.

The simple mucin-type T (Thomsen-Friedenreich) antigen is a marker of carcinomas, and has been related to aggressiveness of malignant tumours. We studied the expression of T, sialosyl-T, A and H blood group antigens in salivary gland carcinomas. The aim was to study whether the tumours, based on the expression of these structures, could be divided into new diagnostic groups that may later show prognostic significance.

Formalin fixed paraffin-embedded tissue sections from 77 salivary gland carcinomas of different histological types were studied using immunohistology and monoclonal antibodies (MAbs). Fresh frozen tissue was examined in 30 of the cases. Frozen sections were superior to paraffin sections in demonstrating T and H antigens.

Aberrant glycosylation with accumulation of T (in cytoplasm) and sialosyl-T antigens (in cytoplasm, membrane and mucin) was found in all tumour types except acinic cell carcinomas. In carcinomas in pleomorphic adenomas (CinPA) the effect of fixation was minimal and T antigen location was different. In carcinomas with myoepithelial cell (MEC) participation, the MECs had retained a normal glycosylation pattern. H antigen was expressed in all tumour types, except acinic cell carcinomas and CinPA. A antigen was expressed in all tumour types from blood group A patients, except in CinPA. The expression of T, sialosyl-T, H and A antigens in relation to differentiation grade varied with tumour type in poorly differentiated areas. High and moderate differentiated areas were always stained, whereas poorly differentiated areas in some tumour types expressed T and sialosyl-T antigens and others did not. The accumulation versus lack of expression of the investigated structures in poorly differentiated areas of the tumours may be of prognostic significance.

To explore the involvement of apoptosis in the development of oral and oropharyngeal squamous cell carcinoma (SCC) in vivo, biopsies were taken from patients with macroscopically normal (n = 6), leukoplakic (n= 12) or malignant (n = 8) mucosa. Leukoplakic lesions were divided histologically into dysplasia (n=5) or carcinoma in situ (CIS: n=7). Material was prepared for light and electron microscopy. The apoptotic index (AI), vertical cell position of apoptoses (cp), mitotic index (MI) and AI:MI ratio were calculated for each patient. AI increased from 0.12% ± 0.07 S.E.M. (normal) to 0.58 ± 0.13 (CIS) but fell to 0.14 ± 0.14 in SCC. Apoptoses were suprabasal in normals, but generalised in CIS. MI increased from normal (0.20 ± 0.06) to SCC (0.32 ± 0.09), and AI:MI was at its maximum in CIS (1.57; SCC: 0.44). The results suggest that a change in apoptosis accompanies the onset of invasion in a premalignant lesion of the human oral cavity and oropharynx.