Comparative histological and immunohistochemical changes in recurrent nodular basal cell carcinoma after photodynamic therapy.

Photodynamic therapy (PDT) is an established nonsurgical treatment for nodular basal cell carcinoma (nBCC). This study compares the clinical, histopathological, and immunohistochemical findings in recurrent nBCC after PDT versus pre-treatment (primary) nBCC. This retrospective study analyzed nodular BCCs treated with methyl aminolevulinate (MAL)-PDT at the Department of Dermatology, San Jorge Hospital (Huesca, Spain), between 2006 and 2015. Only cases in which both the primary and the recurring tumor were histologically confirmed were included in the analysis. Data on clinical, histological, and immunohistochemical variables were collected. The analysis included a total of 15 nBCCs resistant to 2 sessions of MAL-PDT: 11 (73.3%) were persistent BCCs (cure not achieved within 3 months of treatment) and 4 (26.7%) recurred in the first 2 years of follow-up. Subsequent biopsies of the 11 persistent nBCCs revealed that 9 (81.8%) retained the same histological type while the other 2 (18.2%) had another histological variant (micronodular and metatypical). Biopsy of the 4 recurring nBCCs revealed a persistent nodular subtype in all cases. MAL-PDT resulted in no changes in p53, survivin or ß-catenin expression, and trend toward increased EGFR immunostaining. Histology revealed a trend toward a dense stroma without ulceration in recurrent nBCC after PDT. Trend toward increased EGFR immunostaining, and no changes in survivin (which remained negative or mildly positive) or ß-catenin, (which remained moderately or our findings indicate that MAL-PDT does not induce histological or immunohistochemical changes that increase tumor aggressiveness.

The role of the aqueous extract Polypodium leucotomos in photoprotection.

Solar radiation in the ultraviolet (UV), visible (VIS), and infrared (IR) ranges produces different biological effects in humans. Most of these, particularly those derived from ultraviolet radiation (UVR) are harmful to the skin, and include cutaneous aging and increased risk of cutaneous diseases, particularly skin cancer. Pharmacological photoprotection is mostly topical, but it can also be systemic. Oral photoprotectives constitute a new generation of drugs to combat the deleterious effects of solar radiation. Among these, an extract of Polypodium leucotomos (PL/Fernblock®, IFC Group, Spain) contains a high content of phenolic compounds that endow it with antioxidant activity. PL can administered orally or topically and is completely safe. PL complements and enhances endogenous antioxidant systems by neutralizing superoxide anions, hydroxyl radicals, and lipoperoxides. In addition to its antioxidant activity, PL also improves DNA repair and modulates immune and inflammatory responses. These activities are likely due to its ability to inhibit the generation and release of reactive oxygen species (ROS) by UVR, VIS, and IR radiation. PL also prevents direct DNA damage by accelerating the removal of induced photoproducts and decreasing UV-induced mutations. Oral PL increases the expression of active p53, decreases cell proliferation, and inhibits UV-induced COX-2 enzyme levels. PL has been used to treat skin diseases such as photodermatoses and pigmentary disorders and recently as a complement of photodynamic phototherapy in actinic keratoses. The photoprotective capability of PL has been proven in a multitude of in vitro and in vivo studies, which include animal models and clinical trials with human subjects. Based on this evidence, PL is a new generation photoprotector with antioxidant and anti-inflammatory properties that also protects DNA integrity and enhances the immune response.