In our survey, cryotherapy is the most used treatment by dermatologists for AK. Cryotherapy is recommended by guidelines to treat single AK lesion (Eisen et al.2021)(Werner et al., 2015) but sometimes it can be used also to treat multiple AKs, mainly in the elderly with photodamaged skin. PDT, which is preferable as field therapy to treat multiple AKs, is prescribed by 20.9% dermatologists for 50% of AKs and by 10% of them for 75% of AKs. However, in our sample, 17.3% of participants did not prescribed PDT probably because not all medical institutions have facilities to dispense this therapy or because some dermatologists are not confident to use traditional PDT or day light PDT. Another reason could be that PDT is an expensive treatment and, dependently from National Health System, there could be few hospitals that offer it without any payments (Lee et al., 2020).
Surgery, instead, is the less common therapeutic option: 53.7% of dermatologists never prescribed it and 28.2% used it only for 5% of AK cases. In fact, surgery is not recommended by guidelines to treat AK but it is needed in uncertain cases that could progress to an invasive SCC (Chetty et al., 2015; Newlands et al., 2016).
Regarding laser therapy, about 50% of dermatologists never require it and about 35% prescribed it in 5–15% of AKs. A reason to explain this result is that laser therapy is more expensive compared to cryotherapy. Besides, CO2 laser ablation is not superior to cryotherapy for the treatment of isolated AKs of the face and of the scalp, as reported in a randomized clinical trial (Zane et al., 2014).
As regards to topical therapeutic options, the results are variable. DIC was the most prescribed topical product for AK. About 80% of interviewed dermatologists used it for AK and in particular about 25% prescribed it for 50–75% of AK cases. These results can be explained due to the efficacy and safety of DIC. It could be quite well tolerated also by elderly patients because side effects, such as mild erythema or itching, generally are rarer compared to IMQ (Dianzani et al., 2020).
IMQ is present in two different percentage (5% and 3.75%) in Italy. Our survey showed that 3.75% IMQ is more prescribed than 5% IMQ. Specifically, for 50–75% of AKs, 3.75% IMQ is prescribed by about 15% of dermatologists while 5% IMQ is used by about 6% of them. Both topical immunotherapy with IMQ (i.e., 3.75% and 5%) are effective to treat the whole cancerization field but they cannot be used in patients who have received an organ transplant. According to international guidelines regarding AK therapies, IMQ 5% has to be applied 3 days a week for 6 weeks while IMQ 3.75% is used for 14 consecutive days a month for 2 months. The different posology and the lower side effects for IMQ 3.75% could explain the major used of this percentage of IMQ as showed in our data.
Regarding 5-FU, a recent systematic review and network meta- analysis reported that this topical therapy has the best efficacy and safety profile compared with other field-directed therapies for AKs (Ezzedine et al., 2020). 5-FU cream has been approved for the treatment of non-hyperkeratotic, non-hypertrophic AK (Dohil, 2016). Despite this, in our sample only 60% of interviewed dermatologists prescribed 5-FU, and only 9% of them utilized 5-FU for 50–75% of AKs. 40% of participants have never used 5FU. These limited used of this topical therapy could be due to the recent introduction of 5-FU in Italy for the treatment of AK.
Moreover, in our sample about 80% of participants declared not to use Ing Meb. This topical therapy has been approved by FDA for multiple non hypertrophic and non- hyperkeratotic AKs on a field of cancerization in January 2012 (Costa et al., 2015). Despite it could provoke moderate-severe side effects after the treatment, it was acceptable for patients for its efficacious and because it had to be used for only 3 days on the scalp and for 2 days on the trunk (Ricci et al., 2016; Elías et al., 2016). However, in 2020 the market authorization for Ing Meb in the European Union was withdrawn because this drug was proven to be associated to an increase of skin cancer (Tzogani et al., 2014).
As regards piroxicam, about 50% of dermatologists declared not to prescribe it and about 35% used it for 5–10% of AKs. These data can be understandable considering that this product is utilized for the treatment of AK or to prevent the development of new AK on photodamaged area, but it is not recommended by European and Italian Guidelines (Werner et al. 2015; Moscarella et al. 2020). Furthermore, the multivariable model showed that dermatologists who had finished their training more recently were more used to prescribe piroxicam than the older ones.
It is interesting to observe that laser therapy is more utilized for AKs in Northern compared to Central Italy probably due for the major availability in the first region. Otherwise, DIC is more used in Southern Italy while IMQ is prescribed more in Northern Italy. This difference could be due to the fact that dermatologists from Southern Italy prefer to use DIC because it gives less side effects than IMQ.
The results of our study seems in line with a recent Italian consensus (Moscarella et al., 2020) and with European guidelines (Heppt et al., 2020; Werner et al., 2015). Cryotherapy is the most used treatment for patients with few AK (less than 5 scattered AKs or less than 3 AKs in an area of 25 cm2), while, PDT and IMQ cream are preferred for patients with multiple AKs (5 or more AKs or 3 or more AKs in an area of 25 cm2) (Moscarella et al., 2020).
Considering that AK could be a chronic disease, most dermatologists are used to have a combination approach with multiple treatment for AK (Dirschka et al., 2017). Specifically, a field therapy with IMQ 3.75% can be prescribed after cryotherapy to obtain a better clearance of AK, and similarly cryotherapy can follow PDT or other topical treatment.
The results of our survey confirm that the real-world therapeutic approach is variable, and the goal of treatment is AK reduction and long-term disease control to prevent SCC development. The challenge for every dermatologist is to choose the proper treatment for every patient, considering not only the clinical presentation and number of AK, but also patient’s condition such as age, comorbidity, immunosoppression and adherence to treatment (Heppt et al., 2020).
A limitation of our study is the restricted number of the considered dermatologists and the fact that the questionnaire did not distinguished the treatment for singles AKs or for multiple AKs in a field of cancerization.