Viscum album Lipophilic Extract in Actinic Keratosis, Cutaneous Squamous Cell Carcinoma and Basal Cell Carcinoma: A Retrospective Case Series.

Introduction Cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC) belong to the group of keratinocyte carcinomas (KC). Actinic keratosis (AK) is a precursor lesion of cSCC. The incidences of cSCC, BCC and AK are currently strongly increasing. Different standard therapies exist for these conditions but are not always applicable or successful. Hydrophilic Viscum album extracts have been used in anthroposophic cancer therapy since 1917. Viscum album Lipophilic Extract (VALE) is prepared by means of supercritical CO2 extraction. This retrospective case series assessed the safe-ty and clinical effects of a topical application of 10% VALE in individual cases of cSCC, BCC and AK. Methods For this retrospective case series, a positive vote was obtained from the ethics committee of the University of Witten/Herdecke (No. 146/2020). Eligible patients signed a declaration of consent prior to inclusion in the study. The main outcome parameters were the clinical response to treat-ment with VALE and adverse drug reactions. Risk factors, concomitant therapies and diseases, fur-ther diagnostic and therapeutic information were documented where available. Data analysis was performed on the level of patients and of individual lesions. Results The study population consisted of 55 patients with 74 skin lesions. Individual case analysis accom-panied by photographic documentation revealed typical and promising treatment courses. Clinical response rates (complete + partial remissions) for individual lesions were 78 % for cSCC, 70 % for BCC, and 71 % for AK. Complete remission rates for individual lesions were 56 % for cSCC, 35 % for BCC, and 15 % for AK. In cSCC and BCC, shorter times to best clinical response were observed. Ad-verse drug reactions were reported in five patients including erythema and inflammatory reactions of mostly moderate severity that resolved completely. In one case, therapy was temporarily paused, in four cases it was continued without interruption. Discussion/ Conclusion The results of this study suggest that VALE is a safe and tolerable extract under whose application complete and partial remissions of KC could be observed. To improve and assess the efficacy of VALE, prospective investigations are necessary.