Somatic mutations in kinetochore gene KNSTRN are associated with basal proliferating actinic keratoses and cutaneous squamous cell carcinoma.

BACKGROUND: Mutations in kinetochore gene KNSTRN accelerate the development of cutaneous squamous cell carcinoma (SCC) and may correlate with different histological classifications of actinic keratosis (AKs). OBJECTIVE: To determine KNSTRN gene mutation frequency in healthy skin (HS), actinically damaged skin (ADS), in AKs with different histomorphological gradings and invasive SCCs. METHODS: All samples were histologically evaluated. AK lesions were additionally classified according to their upwards (AK I-III) and downwards (PRO I-III) directed growth pattern. Mutation analyses of all samples were performed using the Sanger method. RESULTS: With one exception, all detected mutations in KNSTRN gene showed an alanine-to-glutamate substitution at codon 40 (p.Ala40Glu). p.Ala40Glu mutation was found in 6.9% (2/29) of HS, in 16.1% (5/31) of ADS, in 18.3% (20/109) of AKs and in 30.0% (9/30) of invasive SCCs. Further stratification of AKs using the common AK classification of Röwert-Huber revealed the p.Ala40Glu mutation in 14.7% (5/43), 13.3% (4/30) and 24.4% (11/45) (AK I, II and III). In contrast, the new PRO classification showed a distribution of 3.6% (1/28) in PRO I, 21.7% (13/60) in PRO II and 28.6% (6/21) in PRO III. Mutation frequency in HS showed significant differences compared to AKs classified as PRO III and invasive SCCs (P < 0.05). In contrast, there were no statistically significant differences between HS and AKs when classified according to Röwert-Huber. CONCLUSIONS: Recurrent somatic mutation p.Ala40Glu in KNSTRN gene is associated with basal proliferating AKs in accordance with invasive SCCs. This supports the impact of basal proliferative pattern in terms of progression.

A randomized split-scalp study comparing calcipotriol-assisted methyl aminolaevulinate photodynamic therapy (MAL-PDT) with conventional MAL-PDT for the treatment of actinic keratosis.

BACKGROUND: Topical photodynamic therapy (PDT) is an approved treatment for actinic keratosis (AK). To enhance the efficacy of PDT for AKs, physical and chemical pretreatments have been suggested. OBJECTIVES: To compare the efficacy and safety of the combination of topical calcipotriol (CAL) before methyl aminolaevulinate (MAL)-PDT for AKs of the scalp vs. conventional MAL-PDT in a randomized controlled clinical trial. METHODS: Twenty patients with multiple AKs on the scalp were randomized to receive conventional MAL-PDT with previous curettage on one side of the scalp and CAL-assisted MAL-PDT once a day for 15 days before illumination on the other side. After 3 months, patients were evaluated for clearance of AKs, side-effects and histopathology before and after the procedure. Protoporphyrin IX (PpIX) fluorescence was measured before and after illumination on both sides. RESULTS: All 20 patients completed the study. Overall AK clearance rates were 92·1% and 82·0% for CAL-PDT and conventional PDT, respectively (P < 0·001). Grade 1 AKs showed similar response rates for both sides (P = 0·055). However, grade II AKs showed more improvement on the CAL-PDT side (90%) than on the MAL-PDT side (63%) (P < 0·001). Before illumination, PpIX fluorescence intensity was higher on the CAL-assisted side (P = 0·048). The treatment was more painful on the CAL-PDT side, although well tolerated. The mean visual analogue scale score was 5·4 ± 1·4 on the CAL-PDT side and 4·0 ± 0·69 on the conventional MAL-PDT side (P = 0·001). Side-effects such as erythema (P = 0·019), oedema (P = 0·002) and crusts (P < 0·001) were more pronounced on the CAL-assisted side. Histopathological analyses were obtained from five patients and both sides showed improved keratinocyte atypia following PDT, with slightly more improvement on the CAL-assisted side. CONCLUSIONS: CAL-assisted PDT proved to be safe and more effective than conventional MAL-PDT for the treatment of AKs on the scalp. CAL pretreatment increased PpIX accumulation within the skin and may have enhanced the efficacy in this first human trial.

Treatment of molluscum contagiosum with potassium hydroxide: a clinical approach in 35 children.

Potassium hydroxide (KOH) is a strong alkali that has long been known to digest proteins, lipids, and most other epithelial debris of skin scrapings to identify fungal infections. To our knowledge, KOH has never been used for the treatment of molluscum contagiosum (MC). We evaluated 35 children with MC for the clinical effectiveness of treatment with topical 10% KOH aqueous solution. The solution was applied by the parents of affected children, twice daily, on each MC lesion. The therapy was continued until all lesions underwent inflammation and superficial ulceration. Thirty-two of 35 patients achieved complete clinical cure after a mean treatment period of 30 days. Three children discontinued treatment: two reported severe stinging of the lesions and refused further applications; the other, with giant MC lesions, developed a secondary infection with prolonged treatment. Therapy with KOH was found to be effective and safe in the treatment of MC in children.