Liquid nitrogen for the treatment of actinic keratosis: A longitudinal assessment

Skin thermal recovery following cryotherapy: a comparison of liquid nitrogen and liquid nitrous oxide

Cryotherapy is a common technique used in the management of superficial skin lesions, with current advice on the correct timing for freeze-thaw cycles based on nonscientific visual skin appearances. We investigated the effect of cryotherapy on thermal thawing times by creating a porcine skin model in a laboratory setting maintained at normal skin temperature and comparing liquid nitrogen and liquid nitrous oxide. Thermal assessment was performed using a thermal camera attached to an iPhone 11Pro® smartphone. Liquid nitrogen reduced skin temperature to -60 °C after 5 s of application, recovering to 0 °C after 70 s. Liquid nitrous oxide reduced skin temperature to -34.8 °C after 5 s but had a faster recovery to 0 °C after only 20 s. Both cryogens required a thawing period of 5 min to recover to normal skin temperature. We therefore suggest that optimum cellular degradation should allow for 5-min freeze-thaw cryotherapy cycles; a slower thawing period than is in current common practice.

Single-center real-world treatment outcomes of ablative fractional laser-assisted photodynamic therapy for actinic keratosis

BACKGROUND

Among various treatment modalities of actinic keratosis (AK), ablative fractional laser-assisted photodynamic therapy (fractional PDT) has shown higher efficacy despite shorter incubation time. However, there are lack of real-world studies on the therapeutic response of ablative PDT for AK and the factors that can predict the therapeutic response.

PURPOSE

The aim of this study was to analyze the association between clinical characteristics and treatment outcomes of fractional PDT.

METHODS

One hundred fifty-six patients who were histologically diagnosed with AK and treated with fractional PDT were retrospectively reviewed. The Kruskal-Wallis test was used to compare treatment session differences according to grades.

RESULTS

In multivariate analysis, the grade 2 category tended to be more clinically nonresponders than the grade 1 (OR, 5.17; 95% CI, 1.011-26.439; p = .048) and the group treated four or more times with ablative fractional laser-assisted PDT were more likely to show no response compared with the single treatment session group (OR, 8.78; 95% CI, 1.355-56.874; p = .023). Treatment sessions were significantly lower in grade 1 (1.72 ± 0.63, mean ± SD) when compared to grades 2 and 3, respectively (2.17 ± 0.76; 2.60 ± 1.60, mean ± SD). Recurrence was highest in grade 2, and most of them occurred after 1 year.

CONCLUSION

On average, two treatment sessions are sufficient for AK lesions, but the thicker the lesion, the more treatment sessions may be required. Although there are relatively smaller number of grade 3 patients were included, recurrence was more frequent in higher grade of AK category, which needs special attention to thicker lesions.

Safety and efficacy of the combination of cryotherapy and photodynamic modalities with imiquimod in patients with actinic keratosis: a systematic review and meta-analysis

INTRODUCTION

Actinic keratosis (AK) is an intraepithelial tumor that, in most cases, arises in chronically sun-exposed areas. The combination of cryotherapy and photodynamic modalities with imiquimod has been proven to be a potential therapeutic option for AKs. However, there is no comprehensive systematic study that discussed this concept in literature taking into consideration both efficacy and safety.

EVIDENCE ACQUISITION

We performed a comprehensive search of the literature for studies assessing the efficacy and toxicity of the combinatorial tripartite regimen, consisting of cryotherapy and photodynamic modalities with imiquimod in AK. Metanalysis was performed using comprehensive meta-analysis version 3.0.

EVIDENCE SYNTHESIS

After the screening of 1031 studies, five studies were included. Two trials compared the effect of imiquimod/cryotherapy versus cryotherapy alone or versus cryotherapy/vehicle. Our meta-analysis indicated that imiquimod/cryotherapy effectively induces complete clinical clearance in patients with AKs (OR: 6.26; 95%CI: 1.56-24.1; P=0.01). Moreover, another two studies, which were not meta-analyzed, indicated a substantial clinical clearance in the number of AK lesions in the imiquimod plus photodynamic therapy arm as compared to 5% imiquimod or PDT alone. No serious systemic adverse events were reported in all the treatment arms.

CONCLUSIONS

Combined PDT or cryotherapy with imiquimod is more effective in the complete recovery of AK than treatment with imiquimod alone.

Efficacy and safety of a thermal fractional skin rejuvenation system (Tixel) for the treatment of facial and/or scalp actinic keratoses

Actinic keratoses are common cutaneous lesions with a potential to progress to invasive squamous cell carcinoma. Therefore, treatment is crucial. The Tixel® is a noninvasive thermomechanical device designed to transfer heat to the upper dermis in a controlled manner according to a predetermined setting. This study aimed to evaluate the safety and efficacy of a thermomechanical fractional skin resurfacing technology for the treatment of facial and scalp actinic keratoses. A prospective, open-label, before-after study was conducted in a tertiary medical centre from May 2020 to April 2021. Patients presenting with facial/scalp actinic keratoses of mild-to-moderate thickness underwent 2 or 3 Tixel treatments (depending on clinical improvement), 3-4 weeks apart. The reduction in lesion count and overall improvement in appearance were assessed by clinical examination and digital photography. Findings were compared between baseline and follow-up at 3 months after the last treatment session. Patient satisfaction was evaluated by questionnaire, and adverse effects were documented. A total of 20 patients participated in the study. All completed 2-3 treatments and follow-up visits. Assessment of digital photographs was performed by 2 assessors blinded to the timepoint at which each photo was taken (before or after treatment). The average number of lesions at baseline was 9.8 (± 4.8) and the mean reduction in lesion count was 7.9 (± 4.4) (80.6%). Complete clearance was observed in 31.6% of patients. No adverse effects were noted during treatment and follow-up. Most patients reported being "very satisfied" or "satisfied" with the treatment results (85%) and experience (95%). Treating facial and scalp actinic keratoses with the Tixel device was found to be effective and safe.

Cryotherapy for Actinic Keratosis: Basic Principles and Literature Review

Actinic keratoses (AKs) are pre-malignant epithelial lesions induced by chronic cumulative UV exposure. Several guidelines concerning AKs treatment have been published in the past years. Among destructive procedures, cryotherapy is today considered a standard first-line approach in case of single lesions. The aim of the present review article is to analyse the treatment technique, its efficacy and safety.

Dermoscopy and ultrosound monitoring actinic keratosis with cutaneous squamous cell carcinoma: A case report and literature review

Actinic keratosis(AK) is a common premalignant skin lesion that can progress to invasive squamous cell carcinoma(iSCC). Clinically, AK presents as reddish or brownish macules, papules, or hyperkeratotic plaques. AK cannot be reliably predicted whether it will transform into invasive carcinomas, so skin biopsy is currently a gold standard for identifying suspicious malignancy. Currently, there are non-invasive methods to help diagnose and determine the difference between AKs and iSCC. For example, dermoscopy and ultrasound can be very useful in diagnosing and monitoring skin diseases non-invasively. Therefore, we report a case of multiple facial AKs with poorly differentiated skin squamous cell carcinoma, which was diagnosed early through dermoscopy and ultrasound, and confirmed by histopathology.

Guidelines of care for the management of actinic keratosis

BACKGROUND

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma.

OBJECTIVE

This analysis examined the literature related to the management of AK to provide evidence-based recommendations for treatment. Grading, histologic classification, natural history, risk of progression, and dermatologic surveillance of AKs are also discussed.

METHODS

A multidisciplinary Work Group conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

RESULTS

Analysis of the evidence resulted in 18 recommendations.

LIMITATIONS

This analysis is based on the best available evidence at the time it was conducted. The pragmatic decision to limit the literature review to English language randomized trials may have excluded data published in other languages or limited identification of relevant long-term follow-up data.

CONCLUSIONS

Strong recommendations are made for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are made for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

Efficacy and safety of hydrogen peroxide topical solution in treating actinic keratosis: A randomized controlled trial

Actinic keratosis (AK) is a precancerous skin lesion associated with the development of squamous cell carcinoma. Approved topical treatments for AK are unmet needs. To evaluate the safety and efficacy of hydrogen peroxide topical solution 35% (H₂ O₂ ) with cryosurgery for the treatment of AKs. Eligible subjects were randomly assigned to receive H₂ O₂ and cryosurgery on each side of their scalp/face. Patients were assessed at baseline and after 3 months of follow-up. Efficacy was evaluated based on the Actinic Keratosis Area and Severity Index (AKASI) and dermoscopic assessments. Fifteen patients with 98 lesions completed the study. At the follow-up visit, the mean improvement of AKASI from baseline was 1.7 ± 0.9 for H₂ O₂ and 1.7 ± 0.8 for cryosurgery (p < 0.001, both). Both treatments significantly improved dermoscopic features of yellow scale, white scale, linear-wavy vessels, pigmented dots, and rosette at the end of the 3-month follow-up. Complete dermoscopic response occurred in 57.7% and 73.9% of lesions treated with H₂ O₂ and cryosurgery, respectively (p > 0.05). Regarding safety, hypopigmentation occurred more frequently in the cryosurgery group (28.3% vs. 9.6%; p = 0.017). Moreover, patients endured more pain with cryosurgery application than H₂ O₂ (p < 0.001). The effect of H₂ O₂ solution was comparable to cryosurgery. This treatment was well tolerated and had a favorable safety in patients with AKs.

Guidelines of care for the management of actinic keratosis: Executive summary

BACKGROUND

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma. Treatment options for AK include topical medications, photodynamic therapy, cryosurgery, and laser ablation.

OBJECTIVE

This executive summary provides a synopsis of the 18 evidence-based recommendations for the treatment of AK detailed in the Guidelines of Care for the Management of Actinic Keratosis.

METHODS

A multidisciplinary workgroup conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations Assessment, Development and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

RESULTS

Analysis of the evidence resulted in 18 recommendations, suggesting there are several effective treatments available for AK.

LIMITATIONS

The analysis informing the recommendations was based on the best available evidence at the time it was conducted. The results of future studies may necessitate a revision of current recommendations.

CONCLUSIONS

Strong recommendations are presented for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are presented for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

Reflectance confocal microscopy in actinic keratosis-Comparison of efficacy between cryotherapy protocols

BACKGROUND

Actinic keratosis (AK) incidence is increasing. Due to the risk of progression to squamous cell carcinoma, early detection and treatment are essential. The method stated in the European Consensus is cryotherapy, but there is no standard protocol defined for better results.

OBJECTIVES

To compare two different cryotherapy protocols for AK using reflectance confocal microscopy (RCM) as a noninvasive imaging method for evaluation.

METHODS

A self-controlled clinical trial was proposed to compare the efficacy of cryotherapy in two different application protocols. Grade II AKs in the forearms were submitted to freezing and thawing time of 10 seconds for 1 cycle (group A) or 2 cycles (group B). At baseline and 4 weeks after treatment, the same dermatologists assessed RCM evaluation (thickness of horny layer, parakeratosis, dyskeratosis, atypia in spinous layer, fibrosis, and presence of inflammatory cells in epidermis and dermis).

RESULTS

We examined 24 AK lesions in each group. Statistical evaluation of the results evidenced superior response after 2 cycles of cryotherapy in parakeratosis and number of inflammatory cells in epidermis.

CONCLUSION

Both protocols are effective in clearing clinical AK. Two cycles are not generating more side effects (fibrosis) and could reduce the risk of recurrence (better "clearance" of parakeratosis).

Current therapies for actinic keratosis

Actinic keratosis (AK) is a very common skin disease caused by chronic sun damage, which in 75% of cases arises on chronically sun-exposed areas, such as face, scalp, neck, hands, and forearms. AKs must be considered an early squamous cell carcinoma (SCC) for their probable progression into invasive SCC. For this reason, all AK should be treated, and clinical follow-up is recommended. The aims of treatment are: (i) to clinically eradicate evident and subclinical lesions, (ii) to prevent their evolution into SCC, and (iii) to reduce the number of relapses. Among available treatments, it is possible to distinguish lesion-directed therapies and field-directed therapies. Lesion-directed treatments include: (i) cryotherapy; (ii) laser therapy; (iii) surgery; and (iv) curettage. Whereas, field-directed treatments are: (i) 5-fluorouracil (5-FU); (ii) diclofenac 3% gel; (iii) chemical peeling; (iv) imiquimod; and (v) photodynamic therapy (PDT). Prevention plays an important role in the treatment of AKs, and it is based on the continuous use of sunscreen and protective clothing. This review shows different types of available treatments and describes the characteristics and benefits of each medication, underlining the best choice.

Contribution to characterization of skin field cancerization activity: morphometric, chromatin texture, proliferation, and apoptosis aspects

BACKGROUND

A skin field cancerization is a cutaneous area with subclinical changes resultant from chronic sun exposure, with a higher predisposition to development of pre-neoplastic and neoplastic lesions. So far, there are no well-defined objective parameters that can indicate their degree of activity.

OBJECTIVES

To describe and compare morphometric aspects and expression of factors related to apoptosis and cell proliferation in actinic keratosis (AK), in both photoexposed and photoprotected epidermis.

METHODS

A cross-sectional study of patients with actinic keratosis in the forearms, biopsied at two points: the actinic keratosis and the axillary region. The biopsies of the actinic keratosis, perilesional area, and axilla were evaluated through keratinocyte intraepithelial neoplasia (KIN), and immunohistochemistry of p53, survivin, and Ki67. Nuclear morphometry of basal layer cells was performed through digital image analysis: entropy, area, perimeter, Ra, fractal dimension, circularity, color intensity, and largest diameter.

RESULTS

There were 13 patients included and 38 actinic keratosis biopsied. In morphometry, 1039 nuclei were analyzed, of which 228 represented axillary skin, 396 demonstrated actinic keratosis, and 415 represented the perilesional area to the actinic keratosis. There was a significant difference (p<0.05) in all variables tested for the topographies evaluated. A significant correlation was identified between nucellar morphometric elements, KIN, proliferation markers, and apoptosis. Joint patterns of p53, Ki67, and KIN discriminated the topographies sampled.

STUDY LIMITATIONS

This was a cross-sectional study with a small number of patients.

CONCLUSIONS

There are patterns of proliferation, resistance to apoptosis, and different cellular morphometrics between photoprotected skin and photoexposed skin. The joint expression of p53, Ki67, and KIN can characterize skin field cancerization activity.

A randomized, open, controlled trial of tretinoin 0.05% cream vs. low-dose oral isotretinoin for the treatment of field cancerization

BACKGROUND

Sun exposure may lead to actinic keratoses (AKs), field cancerization, and skin cancer. Effective treatment of AKs and field cancerization is important. Oral and topical retinoids can be used for this purpose. To compare clinical, histological, and immunohistochemical effects of oral and topical retinoid for AKs and field cancerization on face and upper limbs of immunocompetent patients, as well as the impact on quality of life, safety, and tolerability.

METHODS

This study compared 10 mg/day oral isotretinoin (ISO) to 0.05% tretinoin cream (TRE) every other night, associated with sunscreen (SPF 60). Patients of both genders, aged 50-75 years, underwent cryotherapy with liquid nitrogen for AKs at baseline and after 120 days when they were randomized into two groups, TRE (n = 31) and ISO (n = 30), for 6 months. Outcome measures were: number of AKs, histological (thickness of stratum corneum and epithelium) and immunohistochemical parameters (p53, Bcl-2 and Bax), dermatology life quality index (DLQI), and adverse events.

RESULTS

Both treatments reduced the number of AKs (around 28%), the thickness of stratum corneum, and expression of p53 and Bax. By contrast, the epithelium thickness and Bcl-2 expression increased. There was no difference in the outcomes between TRE and ISO. Both treatments improved quality of life and were well tolerated with minimal side effects.

CONCLUSIONS

Retinoids are effective and safe for field cancerization. Classical treatments for field cancerization (imiquimod and ingenol mebutate) are used for a short period; retinoids may be a good choice to intercalate with them and can be used continuously.