An epidemiological study on skin tumors of the elderly in a community in Shanghai, China.

The morbidity of skin tumors (ST) in China is a great concern as the population ages. No epidemiological survey on ST in elderly communities in China has been reported. A questionnaire survey was conducted among the residents over 60 years old in a community in Shanghai, China from May 1, 2011 to November 30, 2011. The prevalence of cutaneous tumors and associated factors were analyzed. Among 2038 valid cases, a total of 78 (3.8%, 95% CI 3.0-4.7) skin cancers (SC) were confirmed. According to the final multivariate regression analysis, age, gender and previous occupation were the significantly influential factors for SC. Actinic keratosis (AK) accounted for the largest proportion (63, 3.1%) in SC. The head and neck was the physiological site with the highest incidence of SC (64, 82.1%), and AK was the most common (55, 87.3%) in head and neck SC. The common concomitant diseases of SC were hypertension (26, 33.3%) and diabetes mellitus (9, 11.5%). Seborrheic keratosis (SK) was the most common benign skin tumor with a prevalence of 100%. Men and women developed SK in significantly different parts of the body (P < 0.0001). The incidence of ST in the elderly population in Shanghai community increased with age. ST preferred to occur in the head and neck, which might be attributed to excessive ultraviolet (UV) exposure in these areas. Therefore, early diagnosis and sun-protection education are essential interventions for ST in the elderly.

Treating cutaneous squamous cell carcinoma using 5-aminolevulinic acid polylactic-co-glycolic acid nanoparticle-mediated photodynamic therapy in a mouse model.

BACKGROUND: Squamous cell carcinoma (SCC) is a common skin cancer, and its treatment is still difficult. The aim of this study was to evaluate the effectiveness of nanoparticle (NP)-assisted 5-aminolevulinic acid (ALA) delivery for topical photodynamic therapy (PDT) of cutaneous SCC. MATERIALS AND METHODS: Ultraviolet-induced cutaneous SCCs were established in hairless mice. ALA-loaded polylactic-co-glycolic acid (PLGA) NPs were prepared and characterized. The kinetics of ALA PLGA NP-induced protoporphyrin IX fluorescence in SCCs, therapeutic efficacy of ALA NP-mediated PDT, and immune responses were examined. RESULTS: PLGA NPs enhanced protoporphyrin IX production in SCC. ALA PLGA NP-mediated topical PDT was more effective than free ALA of the same concentration in treating cutaneous SCC. CONCLUSION: PLGA NPs provide a promising strategy for delivering ALA in topical PDT of cutaneous SCC.

In vitro evaluation of 5-aminolevulinic acid (ALA) loaded PLGA nanoparticles.

BACKGROUND: 5-Aminolevulinic acid (ALA) is a prodrug for topical photodynamic therapy. The effectiveness of topical ALA can be limited by its bioavailability. The aim of this study was to develop a novel ALA delivery approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). METHODS: A modified double emulsion solvent evaporation method was used to prepare ALA loaded PLGA NPs (ALA PLGA NPs). The characteristics, uptake, protoporphyrin IX fluorescence kinetics, and cytotoxicity of ALA PLGA NPs toward a human skin squamous cell carcinoma cell line were examined. RESULTS: The mean particle size of spherical ALA PLGA NPs was 65.6 nm±26 nm with a polydispersity index of 0.62. The encapsulation efficiency was 65.8%±7.2% and ALA loading capacity was 0.62%±0.27%. When ALA was dispersed in PLGA NPs, it turned into an amorphous phase. ALA PLGA NPs could be taken up by squamous cell carcinoma cells and localized in the cytoplasm. The protoporphyrin IX fluorescence kinetics and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that ALA PLGA NPs were more effective than free ALA of the same concentration. CONCLUSION: PLGA NPs provide a promising ALA delivery strategy for topical ALA-photodynamic therapy of skin squamous cell carcinoma.

Therapeutic and immune effects of 5-aminolevulinic acid photodynamic therapy on UVB-induced squamous cell carcinomas in hairless mice.

The therapeutic effects of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) on cutaneous squamous cell carcinoma (SCC) are not fully understood, and the usefulness of topical PDT in the treatment of SCC is still debatable. The most interesting aspect in SCC PDT is perhaps its potential in inducing antitumor immune responses. In this study, cutaneous SCCs were established by UVB irradiation of hairless mice and treated with multiple ALA PDT. Immunohistochemistry assays showed that ALA PDT could induce quick apoptosis, overexpression of TNFα and marked increases in DCs, CD4(+) and CD8(+) cells in tumor interstitium and subcutaneous connective tissues. However, a complete response was only achieved for small SCCs. The clinical value of ALA PDT-induced specific antitumor immune responses in long-term control of SCCs deserves further study.