Histological findings after argon plasma coagulation: an ex-vivo study revealing a possible role in superficial ablative treatment of the skin

Argon plasma coagulation (APC) is an electrosurgical technique which can be used to ablate skin lesions with limited invasion depth into dermal tissue. Hence, APC might be well suited for the removal of epithelial tumours. However, there are no data on the effects of APC on human skin tissue. Thus, the aim of this study was to determine the extent of epidermal and dermal damage after APC of human skin. We performed APC ex-vivo on 91 freshly resected human skin samples, which were obtained after reconstructive surgical closures in actinically damaged areas. Tissue effects were evaluated histologically and compared across different power settings. Using 15, 30, and 45 W, median (interquartile range; IQR) coagulation depths were 110.0 µm (91.7-130.0), 113.3 µm (85.8-135.0), and 130.0 µm (100.0-153.3.0), respectively. Median (IQR) thickness of necrosis zone was 30.0 µm (23.3-40.0) at 15 W, 26.7 µm (20.0-41.6) at 30 W, and 43.3 µm (30.8-57.5) at 45 W. The Kruskal-Wallis test showed significant differences between 15 and 30 W versus 45 W for coagulation depth (P = 0.0414), necrosis zone (P = 0.0017), and necrosis according to overlaying epidermal thickness (P = 0.0467). In summary, APC is a simple and controllable electrosurgical technique to remove epidermal tissue with limited penetration to the dermis. Thus, APC is particularly suited for the ablation of epithelial skin lesions and, therefore, may serve as possible treatment approach for intraepithelial neoplasms such as actinic keratosis.

Phase IV head-to-head randomized controlled trial comparing ingenol mebutate 0·015% gel with diclofenac sodium 3% gel for the treatment of actinic keratosis on the face or scalp

BACKGROUND

Ingenol mebutate (IngMeb) and diclofenac sodium (DS) are approved treatments for actinic keratosis (AK).

OBJECTIVES

To compare the efficacy and safety of IngMeb 0·015% gel with DS 3% gel (NCT02406014).

METHODS

Patients with 4-8 visible, discrete AK lesions on the face/scalp in a 25 cm² contiguous area of skin were randomized 1:1 to IngMeb once-daily for three consecutive days or DS twice-daily for 90 days. Patients with AK lesions at Week 8 following IngMeb were offered a second IngMeb course. Primary end point was complete clearance of AK lesions (AKCLEAR 100) at end of first treatment course (Week 8, IngMeb; Week 17, DS). Secondary end points included AKCLEAR 100 at end of last treatment course and Week 17; adverse events (AEs) were assessed at these time points. Patients completed treatment satisfaction questionnaires for medication (TSQM; Week 17).

RESULTS

AKCLEAR 100 at end of first treatment course was higher with IngMeb (34%) vs. DS (23%; P = 0·006). AKCLEAR 100 at end of last IngMeb course (53%) and Week 17 (45%) was higher than DS (both P < 0·001). The most frequent AE was application-site erythema (IngMeb 19%; DS 12%). Treatment-related AE (TRAE) duration was shorter with IngMeb. TRAE withdrawals were lower for IngMeb (2%) vs. DS (6%). TSQM scores for global satisfaction (P < 0·001) and effectiveness (P = 0·002) were higher with IngMeb, as was dosing instruction adherence (≥ 90% vs. 70%).

CONCLUSIONS

AKCLEAR 100, patient treatment satisfaction and effectiveness were significantly higher with IngMeb compared with DS, demonstrating superiority of IngMeb for AK treatment on face/scalp.

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.

BH3-only protein Bim predicts advanced stage of cutaneous melanoma

BACKGROUND

Bim having strong pro-apoptotic effects belongs to the BH3-only proteins of the Bcl-2 protein family and contributes to survival pathways in cancer cells.

OBJECTIVES

We aimed to investigate Bim protein expression in cutaneous melanoma (CM).

METHODS

Bim protein expression was assessed by immunohistochemistry in primary and metastatic melanomas and correlated with clinical and histopathological features.

RESULTS

The Bim immunoreactivity score of the primary melanomas investigated (4.6 ± 1.5) was significantly (P < 0.0001) higher than that observed in metastases (2.8 ± 1.1). Low Bim expression was significantly associated with primary nodular melanoma type (P = 0.005). Moreover, Bim expression was significantly inversely correlated with tumour thickness (r = -0.36; P = 0.0035), advanced stage of disease (stage III and IV; r = -0.60; P < 0.0001), disease relapse (r = -0.18; P = 0.034) and disease-related death (r = -0.19; P = 0.026). Advanced stage of disease was independently predicted by low Bim expression (P = 0.0010, odds ratio: 0.22, 95% CI: 0.10-0.56) on multivariate analysis; however, Bim was not shown to be an independent predictor for disease relapse (P = 0.40) and disease-related death (P = 0.77).

CONCLUSIONS

Our data demonstrate that Bim protein expression is significantly inversely correlated with melanoma features that are associated with worse prognosis. We have shown that Bim protein expression in CM is an independent predictor for advanced disease confirming that this pro-apoptotic BH3-only protein might be a potent biomarker and promising therapeutic target.

Actinic keratosis: correlation between clinical and histological classification systems

BACKGROUND

There are several clinical and histological classification systems for grading actinic keratosis (AK) lesions. The Olsen clinical classification scheme grades AK lesions according to their thickness and degree of hyperkeratosis (grades 1-3). The Roewert-Huber histological classification system grades AK lesions based on the extent of epidermal atypical keratinocytes (AK I-III).

OBJECTIVE

The aim of this study was to determine whether there is a correlation between these clinical and histological AK classification schemes.

METHODS

One AK lesion from patients in three pivotal clinical studies and routine practice was assessed clinically and histologically. A match in grading was defined as Olsen grade 1 being classified histologically as AK I, Olsen grade 2 as AK II and Olsen grade 3 as AK III.

RESULTS

Of the 892 lesions included, 29.0% were classified as Olsen grade 1, 59.6% as Olsen grade 2 and 11.3% as Olsen grade 3; 19.2% were histologically classified as AK I, 69.6% as AK II and 11.2% as AK III. Only 480 lesions (53.8%) had a matching clinical and histological classification. Of these matches, most were 'Olsen grade 2 = AK II' (83.1%). The Spearman's rank correlation coefficient for clinical and histological classification was r = 0.0499 (P = 0.137).

CONCLUSIONS

Clinical classification of AK lesions using the system of Olsen does not accurately match histological classification of the same lesions using the system of Roewert-Huber. Consequently, it is not possible to draw conclusions about the histology of AK lesions from their clinical appearance. This finding reinforces the need to treat all AK lesions as well as field cancerization.

Lack of activity of betulin-based Oleogel-S10 in the treatment of actinic keratoses: a randomized, multicentre, placebo-controlled double-blind phase II trial

BACKGROUND

Betulinic acid and other triterpenes have shown strong antitumour activity in vitro and in vivo. A triterpene extract of birch bark formed the base of Oleogel-S10 and allowed topical application. Two previous trials have shown efficacy and tolerability in the treatment of actinic keratoses (AKs) with betulin-based Oleogel-S10.

OBJECTIVES

To confirm the efficacy and tolerability/safety of Oleogel-S10 in the treatment of AKs in a multicentre placebo-controlled study.

METHODS

Patients (n = 165) were treated topically for 3 months in a four-arm parallel study design, randomly allocated to A (n = 53) Oleogel-S10 once daily, B (n = 51) Oleogel-S10 twice daily, or C (n = 25) or D (n = 28) placebo (petroleum jelly) once or twice daily, respectively. Clinical efficacy in this double-blind study was assessed by the investigators. Final and baseline biopsies were evaluated by central histopathology.

RESULTS

Complete clearance of the target lesions was seen in 4% of patients in group A and 7% in group B, but not in the placebo groups. A clearance rate of > 75% was seen for 15% and 18% of patients in groups A and B, respectively, and for 13% in the placebo groups. These differences were not statistically significant. Histopathologically, 43·9% of patients showed a downgrading or clearance of the marker AK with no significant differences between the groups. Treatment with Oleogel-S10 was well tolerated. The tolerability as assessed by the investigator was mostly 'very good' (78·8%), followed by 'good' (18·2%) and only 1·2% assessed it as 'intolerable'. Patient-assessed tolerability was graded mostly 'very good' (56·4%) or 'good' (34·5%).

CONCLUSIONS

Treatment with Oleogel-S10 was well tolerated during a treatment period of 3 months, yet was no better than placebo in terms of efficacy in the treatment of AKs.