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World J Dermatol. May 2, 2016; 5(2): 115-124
Published online May 2, 2016. doi: 10.5314/wjd.v5.i2.115
Actinic keratosis and field cancerization
Selma Emre
Selma Emre, Dermatology Clinic, Ataturk Training and Research Hospital, Medical School, Yildirım Beyazit University, Bilkent 06800, Ankara, Turkey
Author contributions: Emre S designed of the paper, performed data acquisiation and writing of the paper.
Conflict-of-interest statement: There is no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Selma Emre, MD, Associated Professor, Dermatology Clinic, Ataturk Training and Research Hospital, Medical School, Yildirım Beyazit University, Çankiri Caddesi Çiçek Sokak No: 3, Bilkent 06800, Ankara, Turkey. dr_semre@yahoo.com
Telephone: +90-312-2912525-3660 Fax: +90-312-2912705
Received: September 27, 2015
Peer-review started: October 3, 2015
First decision: December 28, 2015
Revised: February 25, 2016
Accepted: March 14, 2016
Article in press: March 16, 2016
Published online: May 2, 2016
Abstract

While actinic keratoses (AKs) have been considered precancerous until recently for being able to turn into squamous cell carcinomas (SCCs), it is now agreed that it would be more appropriate to call them cancerous. Although not all AKs turn into SCC and some of them may even have a spontaneous regression, there is an obvious association between SCC and AK. Approximately 90% of SCs have been reported to develop from AKs and AKs are the preinvasive form of SCCs. The presence of two or more AKs on a photodamaged skin is an indicator of field cancerization and represents an increased risk of invasive SCC. All lesions should be treated since it cannot be foreseen which of the lesions will regress and which will progress to SCC. AK can be a single lesion or it can involve multiple lesions in a field of cancerization; thus, AK treatment is grouped under two headings: (1) Lesion-specific treatment; and (2) Field-targeted treatment. Lesion-specific treatments are practicable in patients with a small number of clinically visible and isolated lesions. These treatments including cryotherapy, surgical excision, shave excision, curettage and laser are based on physical destruction of the visible lesions. Field-targeted treatments are effective in the treatment of visible lesions, subclinical lesions and keratinocyte changes in the areas surrounding the visible lesions. Field targeted treatment options are topical imiquimod cream, 5% 5-fluorouracil cream, ingenol mebutate, diclofenac gel, resimiquimod and photodynamic therapy.

Keywords: Actinic keratosis, Squamous cell carcinoma in situ, Field cancerization

Core tip: While actinic keratoses (AKs) have been considered precancerous until recently for being able to turn into squamous cell carcinomas (SCCs), it is now agreed that it would be more appropriate to call them cancerous. The presence of two or more AKs on a photodamaged skin is an indicator of field cancerization and represents an increased risk of invasive SCC. All lesions should be treated since it cannot be foreseen which of the lesions will regress and which will progress to SCC. In this review, epidemiology, ethiopathogenesis, diagnostic approach and treatment options for AK and field cancerization have been evaluated in light of recent literature.