Increased E2F-1 expression via tumour cell proliferation and decreased apoptosis are correlated with adverse prognosis in patients with squamous cell carcinoma of the oesophagus.

BACKGROUND: The retinoblastoma (Rb) pathway, which governs cell cycle progression, is frequently genetically altered in cancer, causing deregulated expression of the E2F-1 transcription factor, which promotes DNA synthesis and cell cycle progression. Recent studies show that E2F-1 also participates in apoptosis induction in a p53 dependent or independent manner. Despite its crucial role and paradoxical effects on cell turnover, the function of E2F-1 in human cancer is unclear. AIMS: To evaluate E2F-1 expression using immunohistochemistry in 43 surgically resected oesophageal squamous cell carcinoma (OSCC) specimens. METHODS: This study analysed the association of E2F-1 with tumour cell proliferation and apoptosis and the upstream regulators modulating these processes, and its impact on patient outcome. Tumour cell proliferation and apoptosis were assessed as percentage of MIB-1 positive or apoptotic cells (MIB-1 labelling index (MI) and apoptotic index (AI)), respectively. RESULTS: Entire specimens showed abnormal expression of one or more upstream regulators of pRb/E2F-1. Although E2F-1 positivity was not associated with the expression of upstream regulators, it showed a linear and positive correlation with MI but not AI. Patients with high MI, low AI, or high E2F-1 positivity had significantly shorter recurrence free survival. By multivariate analysis, high MI and low AI were independently associated with recurrence free survival, but E2F-1 was not. CONCLUSIONS: Increased cell proliferation and decreased apoptosis are associated with adverse prognosis in patients with OSCC. Although E2F-1 remains a controversial prognostic factor, its expression was closely associated with tumour cell proliferation and might influence clinical outcome, mainly via cell cycle progression.

Increased cyclin D1 expression in cancer of the ampulla of Vater: relevance to nuclear beta catenin accumulation and k-ras gene mutation.

AIMS: Several studies have reported that dysregulation of beta catenin or k-ras mutation promotes cyclin D1 expression. This study investigated the relation between cyclin D1 expression and clinicopathological parameters in carcinoma of the ampulla of Vater (CAV), and also assessed the relation between increased cyclin D1 expression and beta catenin/k-ras status in this series. METHODS: Thirty CAVs were evaluated for cyclin D1 expression by immunohistochemistry in relation to patient clinicopathological features. Aberrant beta catenin expression and k-ras mutation were also investigated by immunostaining and direct sequencing, and related to cyclin D1 expression. RESULTS: Increased cyclin D1 expression was seen in 17 of 30 CAVs and was significantly correlated with tumour cell proliferation and disease free survival time (p = 0.018, p = 0.018, respectively). Nuclear accumulation of beta catenin was found in nine of 30 cases, including four cases with missense mutations in exon 3 of CTNNB-1, and was significantly correlated with increased cyclin D1 expression (p = 0.003). k-ras gene mutation was detected in 12 of 30 cases, and was also significantly correlated with increased cyclin D1 expression (p = 0.026). Overall, 14 of 17 CAVs with increased cyclin D1 expression showed nuclear accumulation of beta catenin and/or k-ras mutation. CONCLUSIONS: Increased cyclin D1 expression appears to be associated with tumour proliferation and poorer clinical outcome in CAV. It is also associated with both aberrant beta catenin expression and k-ras mutation. These results are consistent with the in vitro data that cyclin D1 can be transactivated by activated beta catenin-T cell factor/LEF and k-ras pathways.

Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma.

AIMS: We propose the designation 'sialolipoma' to establish and characterize a new category of benign lipomatous tumour occurring in salivary glands. Until now, these tumours have not been regarded as a distinct entity in the salivary glands. METHODS AND RESULTS: We evaluated the clinicopathological and immunohistochemical features of seven sialolipomas among 2051 surgically resected primary salivary gland tumours deposited in our files. The seven patients with sialolipoma were five men and two women, aged 20-75 years (mean: 54.4 years). Five tumours had arisen in the parotid gland, one in the soft palate, and one in the hard palate. The tumours ranged from 10 to 60 mm (mean: 38 mm) in maximum diameter. Histologically, the tumours were characterized by a well circumscribed mass composed of glandular tissue and mature adipose elements. The adipose elements in the tumours arising in the parotid gland were more abundant than those arising in the minor salivary gland. The glandular components consisted of ductal, acinar, basal and myoepithelial cells, and closely resembled the cellular and structural compositions of normal salivary gland tissues. These findings were confirmed by immunohistochemical and ultrastructural studies. These components had no atypia, except for the presence of some minor variations, e.g. ductal ectasia with fibrosis and focal oncocytic metaplasia. In all cases, cell proliferative activity, as assessed by Ki67 (MIB1) immunostaining, was low. From these findings, it is likely that our cases were lipomas with secondary entrapment of the salivary gland elements. No recurrence was seen in all cases after superficial parotidectomy, or after surgical excision in the patients with palatal tumours. CONCLUSIONS: We regard sialolipoma as a distinct variant of salivary gland lipoma that can occur in both the major and minor salivary glands. Superficial parotidectomy, or surgical resection in the case of palatal tumours, is an appropriate treatment for this benign tumour.

Primary large-cell neuroendocrine carcinoma of the parotid gland: immunohistochemical and molecular analysis of two cases.

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a newly proposed clinicopathologic entity; a few cases of LCNEC have been reported in other sites, such as the uterine cervix and the thymus. In the salivary glands, LCNEC is extremely rare and is not recognized as a specific entity in the World Health Organization classification. We retrospectively reviewed from our files 1675 cases of surgically resected primary parotid gland tumors and found 2 cases of LCNEC that fulfilled the criteria of pulmonary LCNEC. These cases occurred in 72- and 73-year-old men who had short histories of enlarging parotid gland tumors. The tumors were composed of large cells that exhibited organoid, solid, trabecular, and rosette-like growth patterns with a high mitotic rate and a conspicuous tendency for necrosis. The tumor cells were polygonal and characterized by a moderate nuclear:cytoplasmic ratio, coarse chromatin, and conspicuous nucleoli. Immunohistochemical examination revealed that the tumor cells were positive for six general neuroendocrine markers, cytokeratin, p53, bcl-2, epidermal growth factor receptor, and cyclin D1. Markedly reduced expressions of p21Waf1 and p27Kip1 were also noticed. The Ki-67 labeling index was more than 50% in both cases. One case showed loss of heterozygosity at TP53 accompanied by a p53 gene point mutation. Loss of heterozygosity at chromosome 9p21 was detected in both cases; one was accompanied by a p16 gene silent point mutation. Both patients died of the disease, with recurrence 5 months and 4 years after surgery, respectively. These findings indicate that LCNEC is a rare but distinct salivary gland tumor with highly aggressive biologic behavior. Multiple alterations of cell cycle regulators and tumor suppressor genes may play an important role in presenting the biologic characteristics of this rare parotid gland tumor.

Expression of E-cadherin, alpha-catenin, beta-catenin, and gamma-catenin in bronchioloalveolar carcinoma and conventional pulmonary adenocarcinoma: an immunohistochemical study.

Bronchioloalveolar carcinoma (BAC) has features distinct from those of conventional pulmonary adenocarcinoma (CPA) in terms of its characteristic growth pattern along alveolar walls and intrapulmonary metastasis via the aerogenous route. We speculated, therefore, that BAC might differ from CPA in its capacity for cell-to-cell or cell-to-basement membrane adhesion. E-cadherin (E-CD), one of the most important elements of epithelial integrity molecules, is related to tumor metastasis in various organs. Differences of E-CD and associated catenin expressions between BAC and CPA, however, have not been elucidated. We examined the expression of E-CD and alpha-, beta- and gamma-catenin immunohistochemically in 18 BACs (9 mucinous, 7 nonmucinous, and 2 sclerosing) in comparison with CPAs, all of which were well-differentiated adenocarcinomas. In addition, we analyzed the correlation between the expression of these cell adhesion molecules and the presence of intrapulmonary metastasis, histologic subtypes, and cell proliferation activity. Clinicopathologically, we observed intrapulmonary metastases in 4 of the 18 BACs and none of the CPAs. In 14 of the 18 BACs, more than one-half of the tumor cells expressed E-CD, and the E-CD expression level was significantly higher in the BACs than in the CPAs. In addition, all of the BACs exhibited preserved membranous staining for E-CD, whereas in 5 of the 14 CPAs, the expression pattern was disorganized cytoplasmic staining; the difference was statistically significant. The Ki-67 labeling index was significantly lower in the BACs than in the CPAs. There were no appreciable differences in E-CD expression among the BAC subtypes. E-CD expression was significantly lower in the BACs with intrapulmonary metastasis than in the BACs without intrapulmonary metastasis. These findings indicated to us that BAC was distinct from CPA in terms of proliferation activity and expression of certain adhesion molecules and that E-CD downregulation was associated with a tendency toward intrapulmonary metastasis.