Merkel-Zell-Karzinom: Ein hochaggressiver Tumor mit möglicher viraler Genese

Tumor vascularization and clinicopathologic parameters as prognostic factors in merkel cell carcinoma

PURPOSE

Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine tumor of the skin with an increasing incidence. The clinical course is variable and reliable prognostic factors are scarce. Tumor angiogenesis has been shown to have prognostic impact in different types of cancer. The aim of our study was to determine potential prognostic factors, including tumor vascularization, for clinical outcome of MCC.

METHODS

The medical records of 46 patients with MCC diagnosed between 1997 and 2010 were analyzed retrospectively. Tissue samples were immune-stained for the lymphatic endothelial vessel marker podoplanin/D2-40 and the panvascular marker CD31. These immunostained sections were analyzed using computer-assisted morphometric image analyses. Aside from the parameters of tumor vascularization, clinicopathologic features were investigated, and progression-free survival (PFS) and tumor-specific survival (TSS) were assessed. Univariate and multivariate analyses were performed to determine prognostic factors.

RESULTS

Male sex of the MCC patients and a high cross-sectional whole vessel area (WVA) in relation to the entire tumor area as determined on CD31-stained tumor sections were found to be negative prognostic factors for PFS in a univariate and multivariate regression analysis. Ulceration of the primary tumor was significantly associated with both impaired PFS and TSS.

CONCLUSIONS

Our results indicate a high prognostic impact of tumor vascularization on the clinical outcome of MCC patients. Male sex and ulceration of the primary MCC were identified as independent unfavorable prognostic markers for the clinical outcome. As an outlook, MCC patients with increased angiogenesis might be identified and subjected to a targeted anti-angiogenic treatment.

PD-1 blockade: a therapeutic option for treatment of metastatic Merkel cell carcinoma

The immune system is extremely important in the development and progression of Merkel cell carcinoma (MCC). Immune checkpoint blockade has recently been shown to enable efficacious treatment of a variety of tumours. We report the use of an anti-programmed death receptor 1 (PD-1) antibody for treatment of a patient with metastatic MCC. An 80-year-old patient with metastatic MCC received off-label treatment with the anti-PD-1 antibody pembrolizumab after the disease had progressed during therapy with oral etoposide. A positron emission tomography (PET) computed tomography scan performed after three cycles of pembrolizumab revealed responses to therapy with reduced size of the adrenal gland metastases and less PET activity in the adrenal gland and lymph node metastases. Treatment was resumed owing to disease progression after a treatment-free interval of > 4 months. During subsequent months of treatment, the size of the metastases stabilized and uptake of nuclide by all tumour sites once again decreased. These results reveal the potential efficacy of an anti-PD-1 antibody for treatment of metastatic MCC. Thus, they contribute to currently limited data on the use of anti-PD-1 antibodies for the treatment of MCC. Moreover, this is the first report of successful resumption of treatment of metastatic MCC with an anti-PD-1 antibody. Results from ongoing trials will contribute to determination of the relevance of PD-1 blockade in metastatic MCC.

Vulvar merkel carcinoma: a case report

This is a new case of Merkel cell carcinoma of the vulva. It is a rare neuroendocrine carcinoma with an aggressive behavior. Because of its rarity in this location, it is not clear whether it behaves differently from the usual neuroendocrine carcinomas of the skin. A case of a 63-year-old patient with vulvar Merkel carcinoma is presented. The clinical presentation, microscopic and immunohistochemical features, and treatment are discussed.