Immunocytochemical study of epidermal growth factor receptor, transforming growth factor alpha, and "squamous differentiation" in human endometrial carcinoma

Molecular targets in gynaecological cancers

The application of high throughput expression profiling and other advanced molecular biology laboratory techniques has revolutionised the management of cancers and is gaining attention in the field of gynaecological cancers. Such new approaches may help to improve our understanding of carcinogenesis and facilitate screening and early detection of gynaecological cancers and their precursors. Individualised prediction of patients' responses to therapy and design of personalised molecular targeted therapy is also possible. The studies of various molecular targets involved in the various signal pathways related to carcinogenesis are particularly relevant to such applications. At the moment, the application of detection and genotyping of human papillomavirus in management of cervical cancer is one of the most well established appliances of molecular targets in gynaecological cancers. Methylation, telomerase and clonality studies are also potentially useful, especially in assisting diagnosis of difficult clinical scenarios. This post-genomic era of clinical medicine will continue to make a significant impact in routine pathology practice. The contribution of pathologists is indispensable in analysis involving tissue microarray. On the other hand, both pathologists and bedside clinicians should be aware of the limitation of these molecular targets. Interpretation must be integrated with clinical and histopathological context to avoid misleading judgement. The importance of quality assurance of all such molecular techniques and their ethical implications cannot be over-emphasised.

Carcinosarcoma, endometrial intraepithelial carcinoma and endometriosis after tamoxifen therapy in breast cancer

The fourth case of heterologous mesodermal tumour of the uterine corpus, that developed, years following tamoxifen therapy for breast cancer in a postmenopausal woman with no previous pelvic irradiation, is presented with coincidental endometriosis and endometrial intraepithelial carcinoma. This coincidence after tamoxifen treatment appears to be an indication for the possible carcinogenic potency of tamoxifen.

Immunohistochemical expression of thymidine phosphorylase in human endometrial cancer

OBJECTIVE

To investigate correlations between the expression of thymidine phosphorylase (TP) by endometrial cancer cells and the density of microvessels within the tumor, the clinicopathologic features, and the prognosis.

METHODS

We examined tumor specimens obtained from 46 patients with endometrial cancer (9 FIGO stage IA, 16 stage IB, 8 stage IC, 1 stage IIA, 6 stage IIB, and 6 stage IIIC). The cellular expression of TP and the intratumoral density of microvessels were determined by immunohistochemistry using monoclonal antibodies to TP and factor VIII-related antigen, respectively. We investigated the relationship between the cellular expression of TP and the following factors: clinicopathologic features (menopausal status, histologic type, tumor size, histologic grade, myometrial invasion, cervical invasion, and metastasis), the microvessel count, and the disease-free survival period.

RESULTS

Of the 46 tumors, 19 (41%) were TP-positive. The microvessel count was significantly higher in TP-positive tumors than in TP-negative tumors (P = 0.01, Mann-Whitney U test). There was no significant correlation between TP expression and clinicopathologic features, and there was no significant difference in the disease-free survival period between patients with TP-positive tumors and patients with TP-negative tumors.

CONCLUSION

TP expression was not correlated with clinicopathologic features or prognosis, but was associated with an increased density of microvessels in endometrial cancer. These findings suggest that TP may play an important role in angiogenesis and may be involved in the tumorigenesis of endometrial cancer.

Transforming growth factor alpha immunoreactivity in human gallbladder and extrahepatic biliary tract tumours

AIMS

Transforming growth factor alpha (TGF-alpha), a protein structurally similar to epidermal growth factor (EGF), is implicated in the development of many human tumours. This study examines the expression of TGF-alpha in gallbladder and extrahepatic biliary tract tumours in which EGFR expression has been previously shown to be important.

METHODS

A monoclonal antibody to the TGF-alpha protein was used to investigate the immunohistochemical expression of TGF-alpha in carcinoma of the gallbladder (n = 13), common bile duct (CBD) (n = 6) and ampulla of Vater (n = 8). Tissues from cases of chronic cholecystitis (n = 11), gallbladder dysplasia (n = 3) and adenoma (n = 1), and ampullary carcinoma in situ (CIS) (n = 3) were used as non-malignant controls. These cases were previously studied for EGFR expression.

RESULTS

TGF-alpha overexpression, defined as intense immunoreactivity in more than two-thirds of cells immunostained for TGF-alpha, was present in most gallbladder carcinomas (n = 10; 77%) but with no significant differences in expression between different tumour grades. None of the cases of gallbladder dysplasia or chronic cholecystitis had strong TGF-alpha expression and this was significantly different from the carcinomas (P = 0.013 and P = 0.0001, respectively; chi 2 test), although a few cases of chronic cholecystitis showed weak (n = 4), moderate (n = 6) or no (n = 1) immunoreactivity. A few ampullary carcinomas (n = 2; 25%) and CIS (n = 1; 33%), and half of the CBD carcinomas (50%) had strong TGF-alpha immunoreactivity. There was correlation between TGF-alpha and EGFR immunoreactivity in the tumour cases (r = 0.70, r2 = 0.49, P = 0.0001; simple regression analysis), although the rate of EGFR immunoreactivity in CBD and ampullary carcinomas was somewhat higher than that of TGF-alpha. However, no statistically significant correlation between TGF-alpha expression with patient survival or tumour recurrence (r = 0.11, r2 = 0.012, P = 0.65; simple regression analysis) was found.

CONCLUSIONS

Increased TGF-alpha expression occurs more frequently in gallbladder carcinoma than in gallbladder dysplasia, chronic cholecystitis, CBD or ampullary tumour, with no specific relationship to tumour grade, suggesting that TGF-alpha overexpression occurs early in the development of gallbladder cancers, and that biliary tract cancers have a different molecular origin. Correlation was found between TGF-alpha and EFGR expression in gallbladder and biliary tract tumours.

Expression of vascular permeability factor (vascular endothelial growth factor) and its receptors in endometrial carcinoma

BACKGROUND

Solid tumors, including endometrial carcinomas, must induce a vascular stroma to grow beyond a minimal size. The mechanisms responsible for angiogenesis in endometrial carcinoma, however, are not well defined. Vascular permeability factor (VPF), also known as vascular endothelial growth factor (VEGF), is a multifunctional cytokine that is an important regulator of tumor angiogenesis. We evaluated VPF/VEGF mRNA and protein expression, as well as VPF/VEGF receptor mRNA expression, in endometrial carcinoma.

METHODS

Fourteen examples of endometrial carcinoma were evaluated by in situ hybridization; in 7 cases, benign atrophic endometrium from the same patient was also examined. Histologic sections were subjected to in situ hybridization using 35S-labeled riboprobes specific for VPF/VEGF and, in a subset of cases, riboprobes specific for the VPF/VEGF receptors flt-1 and KDR. In addition, ten examples of endometrial carcinoma were evaluated for VPE/VEGF protein expression by immunohistochemistry.

RESULTS

All 14 examples of endometrial carcinoma studied by in situ hybridization exhibited focal strong VPF/VEGF mRNA expression by tumor cells. In addition, the endothelial cells of surrounding microvessels strongly expressed flt-1 and KDR mRNAs in all ten cases examined. In contrast, no strong expression of VPF/VEGF, flt-1, or KDR mRNA was observed in the seven examples of benign atrophic endometrium studied. All ten cases of endometrial carcinoma studied by immunohistochemistry exhibited strong VPF/VEGF protein expression by tumor cells.

CONCLUSIONS

These observations suggest that VPF/VEGF is an important angiogenic factor in endometrial carcinoma.

TGF-alpha immunoreactivity in laryngeal carcinoma: lack of prognostic value and correlation to EGF-receptor expression

BACKGROUND

Transforming growth factor alpha (TGF-alpha) is a polypeptide that is structurally similar to epidermal growth factor (EGF) that binds to the epidermal growth factor receptor (EGFR) and has been implicated in the development of several types of human tumours.

METHODS

The expression of TGF-alpha is examined in laryngeal squamous cell carcinoma (SCC) (n = 24) and non-neoplastic polyps (n = 7) using streptavidin-biotin immunohistochemistry and a monoclonal antibody to the TGF-alpha protein. These cases had been previously characterized for EGFR immunoreactivity. The carcinomas were classified as well differentiated (n = 2), moderately differentiated (n = 16) and poorly differentiated (n = 6). Tissues from metastatic tumour deposits in lymph nodes (n = 5) were also studied.

RESULTS

TGF-alpha overexpression was defined as intense immunoreactivity in more than two-thirds of tumour cells immunostained for TGF-alpha and was present in the majority of the SCC cases (n = 15; 63%) and metastatic tumour deposits (n = 4; 80%). In contrast, although some of the vocal cord polyps showed weak (n = 2) to moderate (n = 5) immunostaining, none had evidence of strong TGF-alpha immunoreactivity. The differences in TGF-alpha immunoreactivity were significant between primary laryngeal SCC and vocal cord polyps (P = 0.013; chi 2 test with continuity correction), and between metastatic laryngeal SCC and vocal cord polyps (P = 0.023; chi 2 test with continuity correction). There was no significant difference in TGF-alpha expression between the different grades of carcinomas (P = 0.92, chi 2 test) or between non-metastatic and metastatic carcinomas (P = 0.82; chi 2 test with continuity correction). No significant correlation was found between TGF-alpha expression and patient survival or tumour recurrence (r = 0.077, r2 = 0.006, P = 0.75; simple regression analysis), or between TGF-alpha expression and EGFR immunoreactivity (r = 0.325, r2 = 0.106, P = 0.0851).

CONCLUSIONS

In conclusion, increased TGF-alpha immunoreactivity is present in most cases of laryngeal SCC with no specific relationship to tumour grade, suggesting that it may be important in the development of laryngeal carcinomas but not in its progression. No significant correlation was found between TGF-alpha and EGFR expression in laryngeal tumours and TGF-alpha immunoreactivity is of no prognostic value.

Assessment of EGFR and TGF-alpha expression in relationship to HPV status and Ki-67 distribution in cervical intraepithelial neoplasms

Expression of epidermal-growth-factor receptor (EGFR), transforming growth factor alpha (TGF-alpha) and Ki-67 proliferation antigen in cervical intra-epithelial neoplasms were analyzed. To examine the interrelationship of TGF-alpha, EGFR, Ki-67 and HPV status in dysplasia and carcinoma in situ, formalin-fixed tissue sections of 92 women were immunostained with monoclonal antibodies to EGFR, TGF-alpha and Ki-67. The presence of HPV was assessed by in situ DNA hybridization. The highest positive TGF-alpha expression was seen in the group of mild dysplasia. The difference was significant between the relatively high expression in mild dysplasia and the low occurrence in severe dysplasia and carcinoma in situ as well. The same relation could be found between TGF-alpha expression in papilloma-virus-negative dysplasia and those with the presence of HPV 16/18. In contrast to these findings, the Ki-67 proliferation marker was intensely detectable in severe dysplasia and carcinoma in situ. Ki-67-stained neoplastic cell nuclei were found in a significantly higher percentage of HPV-positive than in HPV-negative lesions. TGF-alpha over-expression is obviously combined with low proliferating activity and vice versa. Irrespective of the grade of dysplasia or HPV status, EGFR was expressed abnormally as compared with normal squamous epithelium. Over-expression of TGF-alpha in mild dysplasia could be associated with the autocrine pathway of cell-growth regulation. In the presence of HPV 16/18 the EGFR/TGF-alpha pathway for growth stimulation is probably not involved.