These findings are meaningful for the growing numbers of actinic keratoses patients and the dermatologists who treat them, says one of the study authors, Zoe Apalla, M.D., Ph.D., department of dermatology, Aristotle University of Thessaloniki, Greece.
“Actinic keratosis represents the main precursor of squamous cell carcinoma. It is the most common neoplastic lesion in Caucasians, with an increasing incidence worldwide. Cumulative sun exposure and increasing age are major risk factors for development of actinic keratosis,” she says. “Multiple coalescent lesions in sun-exposed areas — the so-called ‘cancerized field’ — is a quite common scenario. Taking into consideration the latter observation and the high recurrence rates of actinic keratoses, many authors suggest that they should be considered a chronic disease and managed accordingly.”
Goals of actinic keratosis treatment, Dr. Apalla says, are to reduce the extent of field cancerization, by eradicating as many clinical and subclinical actinic keratoses as possible, prolong the time to relapse or disease-free interval and decrease the risk of progression into invasive squamous cell carcinoma.
“Currently, photodynamic therapy is recommended as one of the first-line field treatments for patients with multiple actinic keratoses, according to many expert consensuses. Conventional photodynamic therapy allows treatment of large areas with multiple actinic keratoses, achieving high response rates and excellent cosmesis. Response rates of up to 90 percent have been demonstrated in multiple publications,” she says.
But drawbacks, including pain during irradiation, need for an artificial light source and prolonged stays in physicians’ offices for occlusion and irradiation processes, have restricted wide adoption of conventional photodynamic therapy, according to Dr. Apalla.
“Introduction of daylight photodynamic therapy simplified the procedure, since instead of an artificial light source we use the daylight, without the need of preliminary occlusion. In this context, treatment becomes less expensive, less time-consuming, less painful and better tolerated by the patients,” she says. “Previous studies demonstrated similar to conventional photodynamic therapy response rates, with less pain and discomfort. However, there was a lack of long-term efficacy data. The current study provides data for long-term efficacy, safety and tolerability of daylight photodynamic therapy, and, in this scenario, it may radically change our perception of this therapeutic strategy.”
It turns out photodynamic therapy is highly efficient, easily applied, quick, cheap, safe and a painless treatment, with a very short treatment downtime, according to Dr. Apalla.
“The latter characteristics make it a very attractive option for patients with grade I and II actinic keratoses, involving areas that can be easily exposed to the daylight,” she says.
More long-term follow-up studies are needed to confirm these findings and evaluate long-term efficacy and recurrence rates associated with daylight photodynamic therapy treatment for actinic keratoses, the authors write.
Sotiriou E, Evangelou G, Papadavid E, Apalla Z, Vrani F, Vakirlis E, Panagiotou M, Stefanidou M, Pombou T, Krasagakis K, Rigopoulos D, Ioannides D. Conventional vs. daylight photodynamic therapy for patients with actinic keratosis on face and scalp: 12-month follow-up results of a randomized, intra-individual comparative analysis. J Eur Acad Dermatol Venereol. 2017 Oct 3. DOI: 10.1111/jdv.14613.