Epidermal growth factor receptor expression is associated with poor outcome in cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans after basal cell carcinoma, and its incidence is dramatically rising. CSCC is rarely problematic, but given its high frequency, the absolute number of complicated cases is also high. It is necessary to identify molecular markers in order to recognize those CSCCs with poor prognosis. There is controversy concerning the role of epidermal growth factor receptor (EGFR) as a marker of prognosis in CSCC. In addition, EGFR-targeted therapies have emerged in recent years and a better understanding of the role of EGFR in CSCC may be of help for some patients in predicting prognosis and guiding curative management. OBJECTIVES: To evaluate the role of EGFR as a prognostic factor in CSCC. METHODS: We evaluated clinical and histopathological features, including events of poor clinical evolution, in a series of 94 cases of CSCC. We also analysed EGFR expression by immunohistochemistry, fluorescent in situ hybridization and quantitative polymerase chain reaction. RESULTS: We detected EGFR in 85 cases (90%), with overexpression in 33 cases (35%), and aberrant EGFR expression in the cytoplasm in 50 cases (53%). EGFR overexpression in the primary tumours was associated with lymph node progression, tumour-nodes-metastasis stage progression and proliferation (Ki-67 staining) in CSCC. EGFR overexpression and poor grade of differentiation were the strongest independent variables defining lymph node metastasis and progression in CSCC in a logistic regression model. CONCLUSIONS: We demonstrate that EGFR overexpression has prognostic implications associated with lymph node metastasis and progression in CSCC.

A new role of SNAI2 in postlactational involution of the mammary gland links it to luminal breast cancer development.

Breast cancer is a major cause of mortality in women. The transcription factor SNAI2 has been implicated in the pathogenesis of several types of cancer, including breast cancer of basal origin. Here we show that SNAI2 is also important in the development of breast cancer of luminal origin in MMTV-ErbB2 mice. SNAI2 deficiency leads to longer latency and fewer luminal tumors, both of these being characteristics of pretumoral origin. These effects were associated with reduced proliferation and a decreased ability to generate mammospheres in normal mammary glands. However, the capacity to metastasize was not modified. Under conditions of increased ERBB2 oncogenic activity after pregnancy plus SNAI2 deficiency, both pretumoral defects-latency and tumor load-were compensated. However, the incidence of lung metastases was dramatically reduced. Furthermore, SNAI2 was required for proper postlactational involution of the breast. At 3 days post lactational involution, the mammary glands of Snai2-deficient mice exhibited lower levels of pSTAT3 and higher levels of pAKT1, resulting in decreased apoptosis. Abundant noninvoluted ducts were still present at 30 days post lactation, with a greater number of residual ERBB2+ cells. These results suggest that this defect in involution leads to an increase in the number of susceptible target cells for transformation, to the recovery of the capacity to generate mammospheres and to an increase in the number of tumors. Our work demonstrates the participation of SNAI2 in the pathogenesis of luminal breast cancer, and reveals an unexpected connection between the processes of postlactational involution and breast tumorigenesis in Snai2-null mutant mice.