Spontaneous regression rates of actinic keratosis: a systematic review and pooled analysis of randomized controlled trials

Abstract

Actinic keratosis (AK) are precancerous lesions of the skin which may progress to invasive squamous cell carcinoma. However, single lesions may also persist or even regress and heal spontaneously. Until now, evidence on the natural course of AK including spontaneous regression is limited. We aimed to synthesize regression rates of AK. We performed a systematic literature research in Medline, Embase, and CENTRAL for eligible trials until 3rd March 2020. Spontaneous regression rates were pooled using a random-effects model to calculate pooled proportions of participant-specific and lesion-specific complete clearance rates reported for the placebo arms of randomized controlled trials. Subgroup analyses were performed to dissect differences according to the type of placebo, immunocompetence of the participants, and localization of the lesions. Data from 38 records was included. The pooled participant-specific clearance rate was 8% (95% CI 6–10%, I2 = 71%) while the lesion-specific clearance rate was 23% (95% CI 16–31%, I2 = 97%). The highest participant- and lesion-specific clearance rates were achieved 12 weeks after the end of treatment (12% and 33%, respectively). Subgroup analysis revealed participant- as well as lesion-specific clearance rates of 0% for organ transplant recipients (OTR). We conclude that only a few participants achieve complete regression of their AK without any active treatment. Besides, the results underline that lesion clearance without active treatment is unlikely in OTR. Thus, early and consequent treatment of AK is recommended. Special attention should be paid when treating AK of OTR.

Transcriptomic Study on Human Skin Samples: Identification of Two Subclasses of Actinic Keratoses

“…It can be noticed that the division of the AK class into two subclasses results from the unsupervised classification. Interestingly, this result matches the two clinical classes observed: AKs that evolve into SCC versus AKs that spontaneously regress [ 31 ]. Interestingly, 44% of the nine AK_L were diagnosed as grade I AK (AK I) by histopathology.…”

Natural Compounds in Non-Melanoma Skin Cancer: Prevention and Treatment

“…Metastatic potential Less than 0.1% [5] From 0.3% to 3.7% [5] Pre-malignant lesion [32] Site of development Sun-exposed areas of the body, including the scalp, face, and forehead [6] Sun-exposed areas of the body, de novo or from a predisposing lesion, including AK [11] Sun-exposed areas of the body, including the face, neck, dorsum of the hands, forearms, and lower legs [32] Survival rate About 100% [33] 95% [33] About 100% [34] Mutation statues Hh pathway genes, particularly PTCH and SMO [8] TP53, p16INK4a genes, PTEN [12,13,18] TP53, p16INK4a genes, MYC, EGFR genes [26][27][28] Considering the morbidity and fatality rates associated with NMSCs, emphasis is placed on the development of effective preventive and treatment strategies. Given the involvement of ultraviolet radiation in their pathogenesis, photoprotection is essential for the prevention of non-melanoma skin cancers [35].…”

Evaluating the Efficacy and Safety of 4% 5-Fluorouracil Cream in Patients with Actinic Keratosis: An Expert Opinion

“…As part of the continuum of actinic skin damage, AKs are managed rather than cured (13). Moreover, the natural history of AK is dynamic, and characterized by spontaneous regression and recurrence, even in the absence of active treatment (10,20). The aim of AK treatment is to eradicate as many lesions as possible, including subclinical lesions in the field of cancerization, to maintain the longest possible recurrence-free interval, reduce the need for additional spot treatments and decrease the risk of the patient developing an invasive SCC (21,22).…”