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.

Clinical use of cold atmospheric pressure argon plasma in chronic leg ulcers: A pilot study

OBJECTIVE

In the age of multiresistant microbes and the increasing lack of efficient antibiotics, conventional antiseptics play a critical role in the prevention and therapy of wound infections. Recent studies have demonstrated the antiseptic effects of cold atmospheric pressure plasma (APP). In this pilot, study we investigate the overall suitability of one of the first APP sources for wound treatment focusing on its potential antimicrobial effects.

METHOD

The wound closure rate and the bacterial colonisation of the wounds were investigated. Patients suffering from chronic leg ulcers were treated in a clinical controlled monocentric trial with either APP or octenidine (OCT). In patients who presented with more than one ulceration in different locations, one was treated with APP and the other one with OCT. Each group was treated three times a week over a period of two weeks. The antimicrobial efficacy was evaluated immediately after and following two weeks of treatment.

RESULTS

Wounds treated with OCT showed a significantly higher microbial reduction (64%) compared to wounds treated with APP (47%) immediately after the treatment. Over two weeks of antiseptic treatment the bacterial density was reduced within the OCT group (-35%) compared to a slight increase in bacterial density in the APP-treated group (+12%). Clinically, there were no signs of delayed wound healing observed in either group and both treatments were well tolerated.

CONCLUSION

The immediate antimicrobial effects of the APP prototype source were almost comparable to OCT without any signs of cytotoxicity. This pilot study is limited by current configurations of the plasma source, where the narrow plasma beam made it difficult to cover larger wound surface areas and in order to avoid untreated areas of the wound bed, smaller wounds were assigned to the APP-treatment group. This limits the significance of AAP-related effects on the wound healing dynamics, as smaller wounds tend to heal faster than larger wounds. However, clinical wound healing studies on a larger scale now seem justifiable. A more advanced plasma source prototype allowing the treatment of larger wounds will address APP's influence on healing dynamics, synergetic treatment with current antiseptics and effects on multiresistant bacteria.