Effects of topical 0.8% piroxicam and 50+ sunscreen filters on actinic keratosis in hypertensive patients treated with or without photosensitizing diuretic drugs: an observational cohort study

Background: Photosensitizing diuretics use (especially thiazide compounds) is associated with a significantly higher risk of squamous cell carcinoma (SCC). Actinic keratosis (AK) is a precursor of SCC. Study aim: To evaluate in a prospective cohort study the efficacy of topical piroxicam 0.8% and sunscreen 50+ (ACTX) in the treatment of AK in hypertensive subjects with or without TD treatment. Subjects and methods: A total of 119 hypertensive subjects with multiple AK (39 under chronic TD treatment; and 80 treated with other non-TD, non-photosensitizing antihypertensive drugs) were enrolled after their informed consent in a 6-month observational cohort study. All the subjects were treated with ACTX twice daily. The primary endpoint was the evolution of AK lesions at baseline, after 3 and 6 months. The secondary endpoint was the clearance of AK target lesions and field of cancerization by dermoscopic evaluation using a score evaluating erythema, scaling, pigmentation, and follicular plugs (ESPFP score; ranging from 0 to 20). An investigator, unaware of the type of antihypertensive treatments (TD or non-TD), performed all the clinical and dermoscopy evaluations. Results: At baseline, AK mean (SD) lesion number in TD group was 14.1(4) and 14.6(4) in the non-TD group. ESPFP mean (SD) score at baseline was 5.8(1.2) in both groups. A significant reduction of AK lesions in comparison with baseline was observed in both groups. A statistically significant greater reduction was observed in TD in comparison with the non-TD group (-54% vs -32%). ESPFP score was reduced in a higher proportion in the TD group in comparison with the non-TD group (-60% vs -37%, respectively). ACTX treatment was very well tolerated. Conclusion: In hypertensive subjects with multiple AK, the topical use of ACTX is associated with a significant reduction of lesions count with an improvement in the field cancerization. The clinical efficacy is more pronounced in subjects under thiazide diuretics treatment.